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Space Robotics

NASA GRC Lunar Dust Adhesion Bell Jar

Current operating status unconfirmed. Every published description of this chamber dates from 2007 to 2011 [1][2][3], and it does not appear in the index NASA Glenn publishes of its laboratories and test facilities [4]. That index omits facilities Glenn is known to operate, so it does not establish that the chamber is gone [4]. Contact Glenn for current availability.

Lunar dust cost Apollo more than any other environmental factor short of the launch window: vision obscuration, false instrument readings, seal failures on every rock box flown, suit-joint abrasion that crews said would have seized the joints on a longer surface stay, and radiator coatings that never recovered brushing they had passed on the ground [5]. The Lunar Dust Adhesion Bell Jar is a small vacuum chamber at NASA GRC built around the mechanism behind that last failure: what a dust mitigation method does once the dust has been made lunar rather than merely dusty. Its distinguishing asset is not the chamber but the activation protocol run inside it. Simulant out of the bottle carries adsorbed water and organics on every grain, which is exactly the monolayer that lowers terrestrial surface energy and that vacuum removes; without it, effective adhesion can rise by up to two orders of magnitude over what a bench test shows, an image-force and van der Waals effect that dominates at different separation ranges for a ten micrometer grain near a conductor [6]. A coating brushed clean in the unactivated state does not predict lunar behavior, so the chamber bakes, thermally cycles and plasma-treats the simulant before a sample ever sees it [1].

It is the documented case where a dust mitigation technique passed in air and failed in the chamber, reproducing at bench scale what Apollo found on the Moon: ground testing at 1e-6 torr showed Lunar Roving Vehicle brush cleaning working well, and it failed on the surface, where dust stayed on the radiators through many brushings and the vehicle overheated [7]. Nylon and PTFE strip brushes that cleared most of the dust from a radiator coupon on the bench recovered only about half of pristine thermal performance under simulated lunar conditions in this chamber, matching what happened to the nylon brushes actually carried on the LRV [3].

It is a small-sample facility. A sample is a 2.54 cm disk, runs are four to seven per material, and the deposition step cannot be commanded [2]. The simulants loaded into it, JSC-1AF and NU-LHT-1D, sit inside the root and derivative simulant framework NASA adopted after Apollo-era stocks of JSC-1 and MLS-1 were found exhausted and never quality-controlled as reference materials [8]; a result measured here is a result for those two batches, not for lunar regolith in general.

Laboratory data

Section titled “Laboratory data”
ParameterValue
OperatorNASA GRC [1]
LocationCleveland, Ohio, United States
CommissionedFacility paper published 2007 [1]
TypeDust adhesion and thermal-optical property chamber
Floor areaNot published
CapabilitiesChamber, dust conditioning
Simulant or terrainJSC-1AF and NU-LHT-1D, activated in situ [1][3]
InstrumentationQuadrupole residual gas analyzer; computer-controlled x-y-theta microscope stage [1][2]
Ground truthDust coverage counted by microscopy after the fact, not commanded [2]
Fidelity limits1e-7 torr against 1e-10 to 1e-14 torr lunar; no reduced gravity; no particle radiation [1]
AccessNot published
Cited bydust testing, thermal vacuum testing

Capabilities

Section titled “Capabilities”

Bell jar chamber

Section titled “Bell jar chamber”
ParameterValue
Working volumeNot published. Samples up to about 7 cm diameter [2]
Test article limitsCoupons on a rotatable sample holder; 2.54 cm disks used in practice [2]
VacuumAbout 1e-7 torr with dust present; 7e-8 torr after bakeout [1]
Temperature77 K liquid nitrogen cold wall; 30 K helium-refrigerated cold box in use [1]
IlluminationXenon arc solar simulator, 200 to 1200 nm [1]
Simulant or terrainLunar simulant loaded into an in-chamber sieve [2]
SlopeNot applicable
Gravity offloadNone [1]
InstrumentationType K thermocouples on sample backs; residual gas analyzer to 1e-11 torr partial pressure [1]

The pump is a liquid-nitrogen-trapped oil diffusion pump, chosen for robustness to dust ingress rather than for ultimate pressure, and the chamber is built around keeping dust out of it: a top-mounted pumping port, five alternating baffles, an offset antechamber, and glass sampling tubes between the baffles so dust transport can be monitored [1]. The residual gas analyzer detects pump oil at 1e-11 torr partial pressure, which is the check that the trap is working.

The cold wall sits centimeters from the xenon-illuminated zone, so a sample can hold an illuminated and a shadowed region a few centimeters apart, reproducing the 200 K contrast that occurs over a few centimeters on the lunar surface [1]. A 40 K cryobox for permanently shadowed crater conditions was planned but not installed at the time the facility was described [1]; the later measurement campaigns used a helium-refrigerated 30 K copper cold box [2].

Dust conditioning and deposition

Section titled “Dust conditioning and deposition”
ParameterValue
Working volumeIn-chamber sieve over the sample holder [2]
Test article limits25 or 32 micron sieve mesh [2]
TemperatureDust baked at 200 C, chamber at 60 C, overnight [2]
InstrumentationSteel comb stirring the dust throughout pumpdown [1]

The activation sequence is the transferable part of this facility. Rough down to 1e-1 torr with the dust stirred continuously by a steel comb, which is a safety requirement rather than a preparation step because trapped gas in a cohesive powder can throw the charge; bake at 200 C at 1e-6 torr until the residual gas spectrum stops changing; three thermal cycles to about -150 C; an RF air plasma at 1e-4 torr for at least an hour to strip organics; then a hydrogen-helium plasma to re-reduce the grain surfaces and stand in for solar wind implantation [1][2]. Chamber pressure after that sequence is about 2e-7 torr [2].

The 200 C bakeout is above the roughly 125 C lunar surface maximum, so the treated simulant has been taken somewhere the destination does not go [1]. The authors state only that they hope the treatment produces the right surface defects and dangling bonds; no published source demonstrates that a plasma-treated simulant grain resembles a regolith grain [1]. The hydrogen-helium plasma is meant to stand in for solar wind proton implantation, but nothing in the chamber reproduces the photoelectric and triboelectric charging that keeps real lunar dust electrostatically active in sunlight and drives the lofting seen from orbit near the terminator [9]; the activated grain in this chamber is a chemically weathered grain, not a charged one.

Thermal property extraction

Section titled “Thermal property extraction”
ParameterValue
Working volumeOne coupon at a time under the in-chamber lamp
Test article limitsAZ-93 paint and silvered or aluminized FEP on aluminum and graphite composite [2]
IlluminationCollimated unfiltered xenon lamp inside the chamber; about 10 suns as used [3]
Instrumentation743-node, 1840-conductor Thermal Desktop and SINDA/Fluint model [2]

Absorptance is fitted from the heating curve and emittance from the cooling curve, by minimizing the weighted average temperature difference against the model to under 1 percent [2]. The pristine values that anchor everything else, each an average of four to seven runs: AZ-93 on aluminum at emittance 0.886 +/- 0.024 and absorptance 0.173 +/- 0.029; AZ-93 on K-1100 graphite composite at 0.833 +/- 0.027 and 0.196 +/- 0.006; AgFEP on aluminum at 0.719 +/- 0.041 and 0.073 +/- 0.006. A broader thermal survey of lunar surface hardware puts these numbers in scale: solar absorptivity can rise by as much as 50 percent at only 12 percent areal dust coverage, so the sub-monolayer sensitivity this chamber measures is the dominant term, not a second-order correction [7].

What it does not reproduce

Section titled “What it does not reproduce”

Deposition is not repeatable. Activated simulant is too cohesive to sieve evenly. A 60 s sieving run sometimes deposited more than a 600 s run, and sinusoidal, jarring and vibrating sieve motions all failed to give consistent coverage [2]. Dust coverage in this facility is measured after the fact, never commanded, and the resulting data set is a scatter of whatever coverage happened to occur. A sample that looked clean to the eye was 5 percent covered under the microscope [2].

Coverage measurement is coarse. Fifty of 641 frames per sample are sampled by a computer-controlled x-y-theta stage at 100x with random frame and angle selection, gray-scale thresholded, with a finite population correction applied [2]. The 95 percent confidence interval on coverage is still 9 to 13 percentage points wide, worst near 50 percent coverage. A conclusion drawn from a coverage difference smaller than that is not supported.

Lamp intensity was never independently calibrated. The detector saturated, so the 29.1 kW/m2 figure, about 21.5 suns, was back-solved by assuming literature absorptance and emittance for the AZ-93 on aluminum baseline [2]. Every subsequent extraction inherits that assumption, and all experimental error is deliberately swept into absorptance and emittance rather than apportioned [2].

Vacuum, by three to seven orders of magnitude. About 1e-7 torr against a lunar surface value of 1e-10 to 1e-14 torr [1]. The facility paper argues the gap rather than closing it: clean-body cohesive behavior appears below a few torr, an inference drawn from the 1971 MSFC Apollo LRV wheel dust test program, where LSS-4 simulant clumped and held together until impact below about 5 torr in a full-scale wheel-and-fender test flown at one-sixth g [10], while surface adhesion work needs 1e-7 torr or better [1].

Gravity, and particle radiation. Reduced gravity was explicitly ruled out as not a prudent use of resources, which the facility paper itself notes could invalidate any mitigation strategy that relies on dust falling off [1]. X-rays, gamma rays and energetic particles are not simulated; the hydrogen-helium plasma stands in for a solar wind ion flux of about 3e8 ions/cm2/s rather than reproducing it [1].

Campaigns run there

Section titled “Campaigns run there”

Thermal control surface degradation, reported 2010. A full monolayer of activated lunar simulant raises the ratio of solar absorptance to infrared emittance of a thermal control surface by about a factor of three, and that holds across AZ-93 paint and silvered FEP on both aluminum and graphite composite substrates [2]. The consequence is that a radiator expected to be dusted must be sized about three times larger. The figure is an extrapolation from sub-monolayer points with R squared 0.72 and one excluded outlier, not a measurement at monolayer coverage [2].

The same campaign overturned the common assumption that dust changes absorptance and not emittance. At sub-monolayer coverage AZ-93 emittance degraded to a projected 80 percent of clean at a monolayer, while AgFEP emittance was enhanced by about 20 percent [2]. That matters most where a radiator views shade rather than sun.

Brushing as a mitigation strategy, reported 2011. Ten brushes spanning nylon, PTFE, Thunderon, carbon and fiberglass bristles in strip, fan and round geometries, first on the bench in air and then in the chamber with plasma-cleaned, vacuum-baked, hydrogen-helium reduced JSC-1AF [3]. Strip brushes that cleared over 90 percent of the dust from AZ-93 in ambient bench tests restored only about half of pristine absorptance-to-emittance in the chamber, matching the Apollo LRV experience [7]. Longer, more pliable fan and round brushes did work: the Escoda nylon fan and the Zephyr fiberglass round brush both restored over 80 percent of pristine performance in 20 strokes and over 90 percent in 200 [3].

In absolute terms, AZ-93 went 0.22 pristine, 0.65 dusted, 0.30 after 20 strokes and 0.26 after 200; AgFEP went 0.12, 0.40, 0.21 and 0.15 [3]. Brushed AgFEP therefore beats brushed AZ-93 by 1.6 to 1.9 times despite retaining more dust: residual coverage after 200 strokes was 3 percent on AZ-93 with the Zephyr brush and 10 percent with the Escoda, against 29 to 31 percent on AgFEP for both. Brushing speed made no difference over a factor of ten in stroke rate.

Three qualifications the campaign states about itself. The bench stages used NU-LHT-1D highland simulant and the chamber stages JSC-1AF, because funding ended the plan to run both, and the assumption that brush ranking is simulant-independent is not shown [3]. Only four AZ-93 coupons were available for the in-chamber stage, and in-situ dust removal efficiency spreads by about a factor of two, so the difference between the two winning brushes is inside the error on most surfaces. Brushing visibly scratched both AZ-93 and FEP, and no cumulative damage or life assessment was made.

Where it sits among dust mitigation testing

Section titled “Where it sits among dust mitigation testing”

The chamber tests one family of mitigation, mechanical removal, against one degradation mode, optical property loss. Other facilities and campaigns test adjacent parts of the same problem and reach comparable or contradictory conclusions by a different route.

The reason mechanical removal is the method tested here, rather than a surface coating alone, follows from the force budget: below about 10 nanometers separation van der Waals force dominates and no practical coating removes it, while beyond about 10 to 100 nanometers the image force from localized surface charge dominates and is the term a surface treatment can actually change [5]. Brushing is a direct answer to the first regime and a poor one to the second, which is consistent with strip brushes clearing bulk dust while leaving the fraction held by charge behind. Apollo’s own record set the bar this chamber’s campaigns are measured against: radiator absorptance doubled at eleven percent areal coverage on flown hardware, a nonlinearity close to what the chamber later measured in the laboratory [6]. The simulants activated inside it, JSC-1AF and NU-LHT-1D, are two batches out of a root and derivative family adopted specifically because earlier reference stocks were exhausted and never quality-controlled [8], so a result here carries the same batch caveat as any other simulant-based measurement.

Passive surface treatment is the alternative to brushing rather than a complement to it: an ion-beam-modified black Kapton, silicon and quartz set tested by centrifugal detachment in vacuum against JSC-1 found reductions in adhesive force of 24 to 87 percent depending on substrate and measurement method, driven by lower contact charging on the treated Kapton rather than by a change in van der Waals force [11]. That result depends on ultraviolet exposure in the wrong direction: two hours of xenon-mercury illumination increased adhesion on virgin and treated quartz substantially, while it left treated Kapton shedding more easily, an interaction the bell jar’s own campaigns do not test because its xenon lamp is there to heat the sample, not to age the coating before dust is applied.

Active removal is the other branch. Electrodynamic dust shields recovered solar panels dusted with 50 to 75 micrometer JSC-1A to at least 90 percent of output within two minutes, including a parabolic-flight demonstration at lunar gravity against real Apollo 16 dust [12], and a carbon-nanotube-yarn EDS woven into spacesuit orthofabric removed 80 to 95 percent of JSC-1A in ambient bench testing [13]. Both results are for freshly deposited, unactivated simulant at 1 atmosphere; neither has been run against the chemically weathered dust this bell jar produces, so whether an EDS clears activated dust as readily as it clears dust straight from the sieve is untested.

A companion chamber approach to hardware survival, rather than optical recovery, screened seven ceramic and cermet coatings for lander-leg service using a sonic wand that separates cohesion from adhesion, and found alumina, Cr3C2-NiCr and Tribaloy T-800 shed simulant best while surviving a liquid-nitrogen thermal shock with no cracking or delamination [14]. A separate Taber abrasion study found that the abrasive medium itself changes the ranking: a wheel bound with LMS-1 mare simulant produced a higher wear index and a rougher scar than the standard silicon carbide wheel it is meant to stand in for [15]. Between them, the two studies make the same point the bell jar’s brushing campaign makes about deposition, that the specific simulant batch and the specific test apparatus are part of the result, not incidental to it.

Deposition is the step other Glenn work set out to fix. The Uniform Dust Deposition System lays sieved JSC-1A on articles up to 60 cm diameter in a dry-air glovebox; one run misses a prescribed mass with a standard deviation of 18 to 24 mg, but stacking short runs toward a target brings it to 0.2 to 0.6 mg, and a machine-learning particle counter predicts deposited mass with R squared of 0.93 [17]. It was validated only in dry air on a flat tray, so it does not replace the in-chamber sieve for activated simulant under vacuum [17].

Charging is the property this chamber leaves out, and it has been measured separately. Single returned grains from Apollo 17 and Luna 24, levitated in an electrodynamic balance at 1e-4 to 1e-5 torr, gave nearly identical photoelectric yields, and JSC-1 simulant underpredicted the lunar yield by a factor of about 4 at 120 nm [16]. A simulant-based charging test therefore biases charge low [16]. A Kennedy Space Center electrometer showed that triboelectric charge sign and magnitude depend on the insulator and the mineral together, but it used JSC Mars-1 in 10 mbar carbon dioxide, so it supports no lunar conclusion [24].

Abrasion and sealing address wear rather than optical loss. A pilot three-body test (dry ASTM B611 variant, 55 N, 450 revolutions) found alumina removed the most material from every specimen, simulants matched silica sand only on soft aluminum and PMMA, and unsieved JSC-1A-F outwore its sub-25 micron fraction [22]. A proposed abrasion index combining mission risk, mineral hardness, wear mode and interaction frequency is defined only functionally, with no scales [21]. Spring-energized PTFE seals of the MER type kept simulant from passing the seal-shaft interface in 17 screening tests, but only to 10000 cycles at ambient temperature [19]. The VIPER mobility system layered a 42-layer outer barrier over labyrinth, felt and PTFE seals and ran 57.5 hours in a dust box with no measurable simulant inside, at ambient pressure and without a combined dust, vacuum and thermal test [20].

A layered taxonomy of mitigation (avoid, prevent, remove, tolerate) ranks candidates by weighted subjective scores, with no measured removal efficiency, so it orders approaches without rating them [18]. In low Earth orbit, an electrodynamic dust shield flown on MISSE-11 matched its ground vacuum current behavior on a glass panel, while the Kapton panel showed unexplained current spikes, and no dust removal was measured because the wake position carries no dust [23].

Simulant choice limits transfer beyond this chamber. Standardized ASTM testing of six lunar simulants found that matching the lunar average particle size distribution within one standard deviation does not make shear strength or compressibility match, so a result in one simulant cannot be assumed for another [25]. Those tests were run at 1 g in air at one density state, so they characterize the simulant, not its behavior on the Moon [25]. NASA’s consolidation of mobility test practice states the same constraint from the other side: there is no NASA standard simulant for the south pole, and simulant selection extrapolates from Apollo equatorial data [26]. That document is a first-release review without new measurements, and its authors say it is not a standard [26].

The two environmental factors the chamber omits have been characterized elsewhere. Reduced gravity was ruled out here, and parabolic-flight wheel tests on a Falcon 20 show what that omission can hide for soil behavior: equal-weight testing in 1 g overstated mobility, with drawbar pull to weight 20 percent or more lower and sinkage up to 40 percent higher at lunar gravity, while 1 g soil prepared to match the lunar-gravity cone index gradient overestimated drawbar pull to weight by 44 percent mean squared percentage error [27]. Those data are 20 to 30 second parabolas on a wheel testbed, not dust adhesion, so they bound the size of the gravity effect on soil and do not transfer to adhesion of single grains [27]. Cable offload, the other ground route to reduced gravity, carries its own artifacts: in suited testing at ARGOS, only body segments inboard of the attachment are offloaded, and a pivot point set at the modeled center of gravity left 14 xEMU subjects unmanageably unstable [30]. Particle radiation is likewise handled by dedicated irradiation facilities: the JPL Radiation Effects Group runs Cobalt-60 sources spanning 0.001 to 500 rad(Si)/s for total ionizing dose work [28], a capability statement without measurements, and not coupled to dust or vacuum conditioning. Loads on a sampling drill are another place where a single simulant at one compaction state, here 98 percent relative density at 1 g and ambient pressure, sets the scope of the result [29].

Two recent ground rigs measure regolith strength at lunar gravity, which this chamber cannot. A magnetic levitation rig counteracting five sixths of Earth gravity ran static cone penetration in a magnetite-bearing simulant: penetration resistance averaged over the top 150 mm at 1/6 g was 29.1 percent below 1 g at 40 percent relative density and 8.8 percent below at 76 percent, so the gravity effect shrinks as the soil densifies [31]. The simulant is about 40 percent magnetite by mass and the field adds an apparent cohesion between grains, so the result is for that rig and soil, and the 95 mm working volume admits no wheel or dust adhesion test [31]. A drop tower Shear and Compression Cell is built to measure angle of internal friction, bulk cohesion and tensile strength at lunar or Titan acceleration, with a 1.8 m tower for reduced gravity and a 0.6 to 0.9 m tower that fits inside a vacuum chamber [32]. It is an instrument paper: the only curves shown are at ambient pressure and 1 g, and vacuum throughput is about four measurements per day [32].

What is not established

Section titled “What is not established”

No published source demonstrates that plasma-activated simulant reproduces the surface chemistry of a real lunar grain; the bakeout, thermal cycling and plasma steps are the facility’s best guess at replicating weathering, not a validated equivalence [1]. No test run in this chamber, or in any of the mitigation campaigns it can be compared against, combines vacuum, lunar gravity, lunar thermal range and lunar electrostatic charging at once [9]; each fidelity gap is closed one at a time, if at all. The coverage measurement method caps how fine a distinction the chamber can support, so mitigation methods separated by less than about ten percentage points of residual coverage cannot be ranked against each other on this facility’s own data [2]. Whether activated dust behaves differently under active removal methods such as electrodynamic shields, tested elsewhere only against unweathered simulant, has not been tested at all [12][13]. And because the facility itself does not appear in NASA Glenn’s current laboratory index, whether any of this apparatus still exists in operable form is unconfirmed [4].

References

  1. Gaier, J. R. and Sechkar, E. A. (2007). Lunar Simulation in the Lunar Dust Adhesion Bell Jar . AIAA Aerospace Sciences Meeting, NASA/TM-2007-214704. Source
    BibTeX
    @inproceedings{gaier2007lunar,
  title = {Lunar Simulation in the Lunar Dust Adhesion Bell Jar},
  author = {Gaier, James R. and Sechkar, Edward A.},
  booktitle = {AIAA Aerospace Sciences Meeting},
  number = {NASA/TM-2007-214704},
  institution = {NASA},
  year = {2007},
  doi = {10.2514/6.2007-963},
  abstract = {The Lunar Dust Adhesion Bell Jar has been assembled at the NASA Glenn Research Center to provide a high fidelity lunar simulation facility to test the interactions of lunar dust and lunar dust simulant with candidate aerospace materials and coatings. It has a sophisticated design which enables it to treat dust in a way that will remove adsorbed gases and create a chemically reactive surface. It can simulate the vacuum, thermal, and radiation environments of the Moon, including proximate areas of illuminated heat and extremely cold shadow. It is expected to be a valuable tool in the development of dust repellant and cleaning technologies for lunar surface systems.}
}
  2. Gaier, J. R., Siamidis, J. and Larkin, E. M. G. (2010). Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar . Space Simulation Conference, NASA/TM-2010-216828. Source
    BibTeX
    @inproceedings{gaier2010extraction,
  title = {Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar},
  author = {Gaier, James R. and Siamidis, John and Larkin, Elizabeth M. G.},
  booktitle = {Space Simulation Conference},
  number = {NASA/TM-2010-216828},
  institution = {NASA},
  address = {Annapolis, MD},
  year = {2010},
  url = {https://ntrs.nasa.gov/citations/20100039312},
  abstract = {A simulation chamber has been developed to test the performance of thermal control surfaces under dusty lunar conditions. The lunar dust adhesion bell jar (LDAB) is a diffusion pumped vacuum chamber (10(exp -8) Torr) built to test material samples less than about 7 cm in diameter. The LDAB has the following lunar dust simulant processing capabilities: heating and cooling while stirring in order to degas and remove adsorbed water; RF air-plasma for activating the dust and for organic contaminant removal; RF H/He-plasma to simulate solar wind; dust sieving system for controlling particle sizes; and a controlled means of introducing the activated dust to the samples under study. The LDAB is also fitted with an in situ Xe arc lamp solar simulator, and a cold box that can reach 30 K. Samples of thermal control surfaces (2.5 cm diameter) are introduced into the chamber for calorimetric evaluation using thermocouple instrumentation. The object of this paper is to present a thermal model of the samples under test conditions and to outline the procedure to extract the absorptance, emittance, and thermal efficiency from the pristine and sub-monolayer dust covered samples.}
}
  3. Gaier, J. R., Journey, K., Christopher, S. and Davis, S. (2011). Evaluation of Brushing as a Lunar Dust Mitigation Strategy for Thermal Control Surfaces . International Conference on Environmental Systems, NASA/TM-2011-217231. Source
    BibTeX
    @inproceedings{gaier2011evaluation,
  title = {Evaluation of Brushing as a Lunar Dust Mitigation Strategy for Thermal Control Surfaces},
  author = {Gaier, James R. and Journey, Khrissaundra and Christopher, Steven and Davis, Shanon},
  booktitle = {International Conference on Environmental Systems},
  number = {NASA/TM-2011-217231},
  institution = {NASA},
  address = {Portland, OR},
  year = {2011},
  url = {https://ntrs.nasa.gov/citations/20120000070},
  abstract = {Evaluation of brushing to remove lunar simulant dust from thermal control surfaces is described. First, strip brushes made with nylon, PTFE, or Thunderon (Nihon Sanmo Dyeing Company Ltd.) bristles were used to remove JSC-1AF dust from AZ93 thermal control paint or aluminized FEP (AlFEP) thermal control surface under ambient laboratory conditions. Nylon and PTFE bristles removed a promising amount of dust from AZ93, and nylon and Thunderon bristles from AlFEP. But when these were tested under simulated lunar conditions in the lunar dust adhesion bell jar (LDAB), they were not effective. In a third effort, seven brushes made up of three different materials, two different geometries, and different bristle lengths and thicknesses were tested under laboratory conditions against AZ93 and AlFEP. Two of these brushes, the Zephyr fiberglass fingerprint brush and the Escoda nylon fan brush, removed over 90 percent of the dust, and so were tested in the fourth effort in the LDAB. They also performed well under these conditions recovering 80 percent or more of the original thermal performance (solar absorptance/thermal emittance) of both AZ93 and AgFEP after 20 strokes, and 90 or more percent after 200 strokes}
}
  4. NASA Glenn Research Center. (2026). Glenn Labs and Test Facilities. nasa.gov/glenn-labs-and-test-facilities
    BibTeX
    @misc{grc2026labs,
  title = {Glenn Labs and Test Facilities},
  author = {{NASA Glenn Research Center}},
  organization = {nasa.gov},
  year = {2026},
  url = {https://www.nasa.gov/glenn-labs-and-test-facilities/}
}
  5. Walton, O. R. (2007). Adhesion of Lunar Dust . NASA Glenn Research Center, NASA/TM-2007-214430, 20070020448. Source
    BibTeX
    @techreport{walton2007adhesion,
  title = {Adhesion of Lunar Dust},
  author = {Walton, Otis R.},
  number = {NASA/TM-2007-214430, 20070020448},
  institution = {NASA Glenn Research Center},
  year = {2007},
  url = {https://ntrs.nasa.gov/citations/20070020448},
  abstract = {This paper reviews the physical characteristics of lunar dust and the effects of various fundamental forces acting on dust particles on surfaces in a lunar environment. There are transport forces and adhesion forces after contact. Mechanical forces (i.e., from rover wheels, astronaut boots and rocket engine blast) and static electric effects (from UV photo-ionization and/or tribo-electric charging) are likely to be the major contributors to the transport of dust particles. If fine regolith particles are deposited on a surface, then surface energy-related (e.g., van der Walls) adhesion forces and static-electric-image forces are likely to be the strongest contributors to adhesion. Some measurement techniques are offered to quantify the strength of adhesion forces. And finally some dust removal techniques are discussed.}
}
  6. Gaier, J. R. (2007). The Effects of Lunar Dust on EVA Systems During the Apollo Missions . NASA, NASA/TM-2005-213610/REV1. Source
    BibTeX
    @techreport{gaier2007effects,
  title = {The Effects of Lunar Dust on EVA Systems During the Apollo Missions},
  author = {Gaier, James R.},
  number = {NASA/TM-2005-213610/REV1},
  institution = {NASA},
  year = {2007},
  url = {https://ntrs.nasa.gov/citations/20070021819},
  abstract = {Mission documents from the six Apollo missions that landed on the lunar surface have been studied in order to catalog the effects of lunar dust on Extra-Vehicular Activity (EVA) systems, primarily the Apollo surface space suit. It was found that the effects could be sorted into nine categories: vision obscuration, false instrument readings, dust coating and contamination, loss of traction, clogging of mechanisms, abrasion, thermal control problems, seal failures, and inhalation and irritation. Although simple dust mitigation measures were sufficient to mitigate some of the problems (i.e., loss of traction) it was found that these measures were ineffective to mitigate many of the more serious problems (i.e., clogging, abrasion, diminished heat rejection). The severity of the dust problems were consistently underestimated by ground tests, indicating a need to develop better simulation facilities and procedures.}
}
  7. Sibille, L., Carpenter, P., Schlagheck, R. and French, R. A. (2006). Lunar Regolith Simulant Materials: Recommendations for Standardization, Production, and Usage . NASA Marshall Space Flight Center, NASA/TP-2006-214605. Source
    BibTeX
    @techreport{sibille2006development,
  title = {Lunar Regolith Simulant Materials: Recommendations for Standardization, Production, and Usage},
  author = {Sibille, Laurent and Carpenter, Paul and Schlagheck, R. and French, R. A.},
  number = {NASA/TP-2006-214605},
  institution = {NASA Marshall Space Flight Center},
  type = {NASA Technical Publication},
  year = {2006},
  url = {https://ntrs.nasa.gov/citations/20060051776},
  abstract = {Experience gained during the Apollo program demonstrated the need for extensive testing of surface systems in relevant environments, including regolith materials similar to those encountered on the lunar surface. As NASA embarks on a return to the Moon, it is clear that the current lunar sample inventory is not only insufficient to support lunar surface technology and system development, but its scientific value is too great to be consumed by destructive studies. Every effort must be made to utilize standard simulant materials, which will allow developers to reduce the cost, development, and operational risks to surface systems. The Lunar Regolith Simulant Materials Workshop held in Huntsville, AL, on January 24 26, 2005, identified the need for widely accepted standard reference lunar simulant materials to perform research and development of technologies required for lunar operations. The workshop also established a need for a common, traceable, and repeatable process regarding the standardization, characterization, and distribution of lunar simulants. This document presents recommendations for the standardization, production and usage of lunar regolith simulant materials.}
}
  8. Howard, A. Z. and Stewart, S. (2024). Thermal Impact of Lunar Dust on Rovers . Thermal and Fluids Analysis Workshop, 20240009829. Source
    BibTeX
    @inproceedings{howard2024thermal,
  title = {Thermal Impact of Lunar Dust on Rovers},
  author = {Howard, Abby Zinecker and Stewart, Sarah},
  booktitle = {Thermal and Fluids Analysis Workshop},
  number = {20240009829},
  institution = {NASA},
  address = {Cleveland, Ohio},
  year = {2024},
  url = {https://ntrs.nasa.gov/citations/20240009829},
  abstract = {Experience and ground tests have shown that lunar dust coverage can severely degrade thermal system performance, and with the push to go back to the Moon for longer than a few days, lunar dust is being recognized as a significant technical challenge. The Lunar Terrain Vehicle (LTV) and Pressurized Rover (PR) will be operating on the lunar surface for long durations and roving at high speeds with interaction with astronauts and other robotics, which will cause dust to transfer to the vehicle, potentially to critical thermal surfaces. Dust coverage results in a change of overall optical properties, increased resistance to heat rejection due to the insulating effect of a dust layer, and even abrasion to thermal surfaces and soft goods. This paper provides an overview of what is currently known and unknown about what will happen to thermal surfaces exposed to dust on the Lunar South Pole, some dust mitigation options and testing guidance, and what resources can be used to help overcome this problem. }
}
  9. Dove, A., Devaud, G., Wang, X., Crowder, M. S., Lawitzke, A. and Haley, C. (2010). Mitigation of lunar dust adhesion by surface modification . Planetary and Space Science. Source
    BibTeX
    @article{dove2010mitigation,
  title = {Mitigation of lunar dust adhesion by surface modification},
  author = {Dove, Adrienne and Devaud, Genevieve and Wang, Xu and Crowder, Mark S. and Lawitzke, Anna and Haley, Christina},
  journal = {Planetary and Space Science},
  volume = {59},
  pages = {1784-1790},
  year = {2010},
  doi = {10.1016/j.pss.2010.12.001}
}
  10. Johansen, M. R., Mackey, P. J., Hogue, M. D., Cox, R. E., Phillips, J. R. I. and Calle, C. I. (2015). History and Flight Development of the Electrodynamic Dust Shield . AIAA SPACE Conference, 20170002286. Source
    BibTeX
    @inproceedings{johansen2015history,
  title = {History and Flight Development of the Electrodynamic Dust Shield},
  author = {Johansen, Michael R. and Mackey, Paul J. and Hogue, Michael D. and Cox, Rachel E. and Phillips, James R., III and Calle, Carlos I.},
  booktitle = {AIAA SPACE Conference},
  number = {20170002286},
  institution = {NASA},
  year = {2015},
  doi = {10.2514/6.2015-4446},
  abstract = {Past and current development of the Electrodynamic Dust Shield - a dust mitigation system for future planetary destinations.}
}
  11. Manyapu, K. K., De Leon, P., Peltz, L., Gaier, J. R. and Waters, D. (2017). Proof of concept demonstration of novel technologies for lunar spacesuit dust mitigation . Acta Astronautica. Source
    BibTeX
    @article{manyapu2017proof,
  title = {Proof of concept demonstration of novel technologies for lunar spacesuit dust mitigation},
  author = {Manyapu, Kavya K. and De Leon, Pablo and Peltz, Leora and Gaier, James R. and Waters, Deborah},
  journal = {Acta Astronautica},
  volume = {137},
  pages = {472-481},
  year = {2017},
  doi = {10.1016/j.actaastro.2017.05.005}
}
  12. Wiesner, V. L., Wohl, C. J., King, G. C., Gordon, K. L., Das, L. and Hernandez, J. J. (2023). Protective Coatings for Lunar Dust Tolerance . NASA, NASA/TM-20230003195. Source
    BibTeX
    @techreport{wiesner2023protective,
  title = {Protective Coatings for Lunar Dust Tolerance},
  author = {Wiesner, Valerie L. and Wohl, Christopher J. and King, Glen C. and Gordon, Keith L. and Das, Lopamudra and Hernandez, Jonathan J.},
  number = {NASA/TM-20230003195},
  institution = {NASA},
  year = {2023},
  url = {https://ntrs.nasa.gov/citations/20230003195},
  abstract = {Materials capable of withstanding the harsh lunar environment are critically needed to
support long duration, sustainable missions on the Moon’s surface. Lunar dust significantly
threatens the durability and reusability of components and vehicles due to possessing a fine, jagged morphology and highly abrasive nature. These characteristics result in the particles eroding, adhering and/or embedding onto component surfaces and into device confined geometries (e.g., gear housing, interlocking systems, etc.) potentially leading to premature failure. The aim of this study is to identify and characterize wear-resistant commercial-off-the-shelf (COTS) materials, including advanced ceramics, for use as protective coatings to minimize abrasion and adhesion caused by lunar dust. Preliminary testing that mimics various aspects of lunar dust degradation, such as abrasive wear and adhesion, suggests that COTS ceramic coatings can improve lunar dust tolerance and protect underlying metallic substrates.}
}
  13. Stein, Z., Tirado-Pujols, A., Wohl, C., Wiesner, V. and Raghavan, S. (2024). Wear-Resistance Investigations on Ceramic Coatings for Lunar Dust Mitigation . 75thInternational Astronautical Congress, 20240012146. Source
    BibTeX
    @inproceedings{stein2024wear,
  title = {Wear-Resistance Investigations on Ceramic Coatings for Lunar Dust Mitigation},
  author = {Stein, Zachary and Tirado-Pujols, Ashley and Wohl, Christopher and Wiesner, Valerie and Raghavan, Seetha},
  booktitle = {75thInternational Astronautical Congress},
  number = {20240012146},
  institution = {NASA},
  address = {Milan},
  year = {2024},
  url = {https://ntrs.nasa.gov/citations/20240012146},
  abstract = {Lunar dust has posed a major challenge to exploration efforts due to abrasion and impact. This work focuses on fundamental studies on ceramic coatings as candidates for enhanced resistance to impact and wear. As a first step, standard and modified approaches to the method of abrasion testing were explored for options to incorporate lunar regolith as wear media, the effects of which were presented for AL6061-T6 control samples. Following this, wear results for air plasma-sprayed (APS) alumina coatings were investigated due to their superior strength and surface hardness. In addition, APS 8 wt % yttria-stabilized zirconia (8YSZ) coatings were studied for their strength and martensitic transformation toughness. Measurements were made by assessing the mass loss, with a standard scale at various intervals. In addition, surface roughness was measured with a profilometer and features identified with a high-resolution microscope. The findings demonstrated that wear media has a distinct effect on the abrasion. The alumina coatings demonstrated improved wear over 8YSZ. However, the tailorability of 8YSZ makes it an attractive option to continue to modify as a wear-resistant coating to protect against lunar dust abrasion. The results of these measurements provide insight into the wear behavior of future directions in candidate ceramic coatings for the harsh lunar environment.}
}
  14. Popel, S. I., Zelenyi, L. M., Golub', A. P. and Dubinskii, A. Y. (2018). Lunar dust and dusty plasmas: Recent developments, advances, and unsolved problems . Planetary and Space Science. Source
    BibTeX
    @article{popel2018lunar,
  title = {Lunar dust and dusty plasmas: Recent developments, advances, and unsolved problems},
  author = {Popel, S. I. and Zelenyi, L. M. and Golub', A. P. and Dubinskii, A. Yu.},
  journal = {Planetary and Space Science},
  volume = {156},
  pages = {71-84},
  year = {2018},
  doi = {10.1016/j.pss.2018.02.010}
}
  15. Mullis, C. H. (1971). A Study and Analysis of the MSFC Lunar Roving Vehicle Dust Profile Test Program . Northrop Services, Inc., for NASA Marshall Space Flight Center, Contract NAS8-26175. Source
    BibTeX
    @techreport{mullis1971study,
  title = {A Study and Analysis of the {MSFC} Lunar Roving Vehicle Dust Profile Test Program},
  author = {Mullis, C. H.},
  number = {Contract NAS8-26175},
  institution = {Northrop Services, Inc., for NASA Marshall Space Flight Center},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19720007590},
  abstract = {The dust problem and fender design for the LRV were studied under reduced gravity with a lunar soil simulant. The test equipment, soil characteristics of the lunar soil simulant, and the test procedures are described.  It is concluded: (1) The fender plus flap design is adequate. (2) Vacuum conditions tend to eliminate or reduce suspended dust clouds. (3) Reduced gravity conditions tend to increase the dust problems. (4) Slow starting speeds are necessary to minimize slip and reduce initial dust generation.}
}
  16. Abbas, M. M., Tankosic, D., Craven, P. D., Spann, J. F., LeClair, A. and West, E. A. (2007). Lunar Dust Charging by Photoelectric Emissions . Planetary and Space Science, 20070014798. Source
    BibTeX
    @article{abbas2007lunar,
  title = {Lunar Dust Charging by Photoelectric Emissions},
  author = {Abbas, M. M. and Tankosic, D. and Craven, Paul D. and Spann, J. F. and LeClair, A. and West, E. A.},
  journal = {Planetary and Space Science},
  volume = {55},
  number = {20070014798},
  pages = {953-965},
  institution = {NASA},
  year = {2007},
  doi = {10.1016/j.pss.2006.12.007},
  abstract = {The lunar surface is covered with a thick layer of sub-micron/micron size dust grains formed by meteoritic impact over billions of years. The fine dust grains are levitated and transported on the lunar surface, as indicated by the transient dust clouds observed over the lunar horizon during the Apollo 17 mission. Theoretical models suggest that the dust grains on the lunar surface are charged by the solar UV radiation as well as the solar wind. Even without any physical activity, the dust grains are levitated by electrostatic fields and transported away from the surface in the near vacuum environment of the Moon. The current dust charging and levitation models, however, do not fully explain the observed phenomena. Since the abundance of dust on the Moon s surface with its observed adhesive characteristics has the potential of severe impact on human habitat and operations and lifetime of a variety of equipment, it is necessary to investigate the charging properties and the lunar dust phenomena in order to develop appropriate mitigating strategies. Photoelectric emission induced by the solar UV radiation with photon energies higher than the work function of the grain materials is recognized to be the dominant process for charging of the lunar dust, and requires measurements of the photoelectric yields to determine the charging and equilibrium potentials of individual dust grains. In this paper, we present the first laboratory measurements of the photoelectric efficiencies and yields of individual sub-micron/micron size dust grains selected from sample returns of Apollo 17, and Luna 24 missions, as well as similar size dust grains from the JSC-1 simulants. The measurements were made on a laboratory facility based on an electrodynamic balance that permits a variety of experiments to be conducted on individual sub-micron/micron size dust grains in simulated space environments. The photoelectric emission measurements indicate grain size dependence with the yield increasing by an order of magnitude for grains of sub-micron to several micron size radii, at which it reaches asymptotic values. The yield for large size grains is found to be more than an order of magnitude higher than the bulk measurements on lunar fines reported in the literature.}
}
  17. Gerdts, S., Jimenez, N. and Dunlap, P. H. J. (2021). Lunar Simulant Deposition Technique for Dust Tolerance Studies . NASA, 20210024128. Source
    BibTeX
    @techreport{gerdts2021lunar,
  title = {Lunar Simulant Deposition Technique for Dust Tolerance Studies},
  author = {Gerdts, Stephen and Jimenez, Nathan and Dunlap, Patrick H., Jr.},
  number = {20210024128},
  institution = {NASA},
  year = {2021},
  url = {https://ntrs.nasa.gov/citations/20210024128},
  abstract = {A renewed interest in lunar exploration has spawned an array of development efforts for lunar surface assets. These systems depend on the reliable operation of mechanisms and components that may be susceptible to performance degradations or failure due to dust. The Uniform Dust Deposition System was developed at the NASA Glenn Research Center to provide repeatable, uniform, and automated deposition of simulants on surfaces of interest for dust mitigation testing. The system is capable of depositing simulants on test articles up to 60 cm in diameter and 15 cm high in a dry air environment with less than 1 percent relative humidity while keeping users safe from aerosolized dust. The automation of the system allows for
high testing throughput while not sacrificing test quality and allows the user to reduce data in parallel. The additional development of a simulant preparation technique complements the repeatability of the deposition physics during testing. The system includes an imaging subsystem that leverages the power of machine learning to count simulant particles and measure their size, thereby allowing for accurate predictions of
surface deposition densities (coefficient of determination R^(2) = 0.93) from images alone. The coverage of dust on a surface was shown to be uniform (coefficient of variation CV < 0.11), allowing developers to accurately evaluate the performance of their technology with a prescribed amount of lunar simulant, information that can be used to develop and refine models. The accuracy of the system is currently less than desired for a single deposition run, with a standard deviation (SD) ranging from 18 to 24 mg, or 0.839 to 1.184 mg/sq. cm , for a 5-cm-diameter area. However, the accuracy can be improved by performing multiple deposition runs to build dust to a desired level. Testing has shown that a SD of 0.2 to 0.6 mg, or 0.076 to 0.227 mg/sq. cm, can be achieved for a 5-cm-diameter area using this technique. }
}
  18. Cannon, K. M., Dreyer, C. B., Sowers, G. F., Schmit, J., Nguyen, T., Sanny, K. and Schertz, J. (2022). Working with lunar surface materials: Review and analysis of dust mitigation and regolith conveyance technologies . Acta Astronautica. Source
    BibTeX
    @article{cannon2022working,
  title = {Working with lunar surface materials: Review and analysis of dust mitigation and regolith conveyance technologies},
  author = {Cannon, Kevin M. and Dreyer, Christopher B. and Sowers, George F. and Schmit, John and Nguyen, Thao and Sanny, Keoni and Schertz, Joshua},
  journal = {Acta Astronautica},
  volume = {196},
  pages = {259--274},
  year = {2022},
  doi = {10.1016/j.actaastro.2022.04.037},
  abstract = {The Moon's dusty surface environment threatens any equipment that operates there, especially for long-duration infrastructure needed for a sustained lunar presence. This is doubly true for systems that convey regolith, which by agitating the soil are certain to generate dust. Here, we provide a comprehensive review of technologies that have been proposed to convey regolith on the lunar surface, and to mitigate against dust hazards that are generated by such transport systems. We define functional taxonomies for both regolith conveyance and dust mitigation, then carry out quantitative trade studies in several categories for each. Examples include passive and active dust mitigation, and horizontal and near vertical conveyance. Conveyance technologies that scored particularly high include wheeled haulers, conveyor belts, and auger/hopper transfer points. High scoring dust mitigation technologies include the lotus leaf passive coating, Electrodynamic Dust Shield, and boots or bellow made of fiberglass fabric. We also explore novel or unconventional concepts and describe how dust mitigation and regolith conveyance can be combined using a systems approach with multiple technologies layered together. The results from the trade studies and the subsequent recommendations constitute a practical guide that can be used for designing and developing systems that must perform efficiently and reliably to carry out useful tasks on the Moon or Mars, such as resource extraction, construction, and additive manufacturing.}
}
  19. Delgado, I. R. and Handschuh, M. J. (2010). Preliminary Assessment of Seals for Dust Mitigation of Mechanical Components for Lunar Surface Systems . NASA, NASA/TM-2010-216343. Source
    BibTeX
    @techreport{delgado2010preliminary,
  title = {Preliminary Assessment of Seals for Dust Mitigation of Mechanical Components for Lunar Surface Systems},
  author = {Delgado, Irebert R. and Handschuh, Michael J.},
  number = {NASA/TM-2010-216343},
  institution = {NASA},
  year = {2010},
  url = {https://ntrs.nasa.gov/citations/20100025844},
  abstract = {Component tests were conducted on spring-loaded Teflon seals to determine their performance in keeping lunar simulant out of mechanical component gearbox, motor, and bearing housings. Baseline tests were run in a dry-room without simulant for 10,000 cycles to determine wear effects of the seal against either anodized aluminum or stainless steel shafts. Repeat tests were conducted using lunar simulants JSC-1A and LHT-2M. Finally, tests were conducted with and without simulant in vacuum at ambient temperature. Preliminary results indicate minimal seal and shaft wear through 10,000 cycles, and more importantly, no simulant was observed to pass through the seal-shaft interface. Future endurance tests are planned at relevant NASA Lunar Surface System architecture shaft sizes and operating conditions.}
}
  20. McBryan, E., Francis, P. and Sobey, A. (2025). Dust Mitigation for the VIPER Mobility System . International Conference on Environmental Systems, 20250005201. Source
    BibTeX
    @inproceedings{mcbryan2025dust,
  title = {Dust Mitigation for the VIPER Mobility System},
  author = {McBryan, Emily and Francis, Parker and Sobey, Alexander},
  booktitle = {International Conference on Environmental Systems},
  number = {20250005201},
  institution = {NASA},
  year = {2025},
  doi = {10.32865/2346/108814},
  abstract = {NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) is built to prospect, provide ground truth measurements, and build regional maps of the volatiles at the lunar South Pole that were previously detected by Lunar Reconnaissance Orbiter (LRO), Lunar Crater Observation and Sensing Satellite (LCROSS), and Chandrayaan-1. The rover’s mobility system, responsible for navigating the moon’s partially defined terrain, is the part of VIPER that is most exposed to the lunar surface environment. To ensure it can survive the thermal extremes and lunar regolith, the VIPER project utilized resources across NASA centers to create and evaluate a multi-functional environmental protection strategy. The project’s approach combined thermal insulation with dust protection in a flexible barrier across dynamic actuated joints to serve as the first defense between the hardware and the environment. Additionally, the VIPER project integrated a selection of seals (labyrinth, Nomex felt, and spring-energized PTFE) with individual mechanisms to further mitigate dust infiltration and abrasion risk to the bearings, motors, and sensors. In stages, the project performed extensive testing through a matrix of simulated environmental parameters to evaluate performance margins from the component level to the integrated mobility system. This paper addresses the project’s lessons learned, with an emphasis on systems integration and how this work can affect future long-duration lunar surface systems, such as crewed unpressurized rovers and in-situ resource utilization robotics.}
}
  21. Kobrick, R. L., Klaus, D. M. and Street, K. W. (2010). Defining an Abrasion Index for Lunar Surface Systems as a Function of Dust Interaction Modes and Variable Concentration Zones . NASA, NASA/TM-2010-216792. Source
    BibTeX
    @techreport{kobrick2010defining,
  title = {Defining an Abrasion Index for Lunar Surface Systems as a Function of Dust Interaction Modes and Variable Concentration Zones},
  author = {Kobrick, Ryan L. and Klaus, David M. and Street, Kenneth W.},
  volume = {59},
  number = {NASA/TM-2010-216792},
  pages = {1749-1757},
  institution = {NASA},
  year = {2010},
  doi = {10.1016/j.pss.2010.10.010},
  abstract = {Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and subcategorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a single particle or asperity slides across a given surface removing or displacing material. Three-body abrasion occurs when multiple particles interact with a solid surface, or in between two surfaces, allowing the abrasives to freely rotate and interact with the material(s), leading to removal or displacement of mass. Different modes of interaction are described in this paper along with corresponding types of tests that can be utilized to evaluate each configuration. In addition to differential modes of abrasion, variable concentrations of dust in different zones can also be considered for a given system design and operational protocol. These zones include: (1) outside the habitat where extensive dust exposure occurs, (2) in a transitional zone such as an airlock or suitport, and (3) inside the habitat or spacesuit with a low particle count. These zones can be used to help define dust interaction frequencies, and corresponding risks to the systems and/or crew can be addressed by appropriate mitigation strategies. An abrasion index is introduced that includes the level of risk, R, the hardness of the mineralogy, H, the severity of the abrasion mode, S, and the frequency of particle interactions, F.}
}
  22. Kobrick, R. L., Budinski, K. G., Street, K. W. J. and Klaus, D. M. (2010). Three-Body Abrasion Testing Using Lunar Dust Simulants to Evaluate Surface System Materials . International Conference on Environmental Systems, NASA/TM-2010-216781. Source
    BibTeX
    @inproceedings{kobrick2010three,
  title = {Three-Body Abrasion Testing Using Lunar Dust Simulants to Evaluate Surface System Materials},
  author = {Kobrick, Ryan L. and Budinski, Kenneth G. and Street, Kenneth W., Jr. and Klaus, David M.},
  booktitle = {International Conference on Environmental Systems},
  number = {NASA/TM-2010-216781},
  institution = {NASA},
  year = {2010},
  doi = {10.2514/6.2010-6077},
  abstract = {Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement techniques for quantifying controlled volumetric wear. Subsequent efforts described in the paper involved three-body abrasion testing designed to be more representative of actual lunar interactions. For these tests, a new tribotester was developed to expose samples to a variety of industrial abrasives and lunar simulants. The work discussed in this paper describes the three-body hardware setup consisting of a rotating rubber wheel that applies a load on a specimen as a loose abrasive is fed into the system. The test methodology is based on ASTM International (ASTM) B611, except it does not mix water with the abrasive. All tests were run under identical conditions. Abraded material specimens included poly(methyl methacrylate) (PMMA), hardened 1045 steel, 6061-T6 aluminum (Al) and 1018 steel. Abrasives included lunar mare simulant JSC-1A-F (nominal size distribution), sieved JSC-1A-F (μm particle diameter), lunar highland simulant NU-LHT-2M, alumina (average diameter of 50 μm used per ASTM G76), and silica (50/70 mesh used per ASTM G65). The measured mass loss from each specimen was converted using standard densities to determine total wear volume in cm3. Abrasion was dominated by the alumina and the simulants were only similar to the silica (i.e., sand) on the softer materials of aluminum and PMMA. The nominal JSC-1A-F consistently showed more abrasion wear than the sieved version of the simulant. The lunar dust displayed abrasivity to all of the test materials, which are likely to be used in lunar landing equipment. Based on this test experience and pilot results obtained, recommendations are made for systematic abrasion testing of candidate materials intended for use in lunar exploration systems and in other environments with similar dust challenges.}
}
  23. Johansen, M. R., Dupuis, M. A., Phillips III, J. R., Malissa, J. D., Wang, J. J., Hogue, M. D. and Calle, C. I. (2019). Electrodynamic Dust Shield Testing on the Materials on International Space Station Experiment 11 . International Astronautical Congress, IAC-19-C2.6.2. Source
    BibTeX
    @inproceedings{johansen2019electrodynamic,
  title = {Electrodynamic Dust Shield Testing on the Materials on International Space Station Experiment 11},
  author = {Johansen, Michael R. and Dupuis, Michael A. and Phillips III, James R. and Malissa, Joel D. and Wang, Jerry J. and Hogue, Michael D. and Calle, Carlos I.},
  booktitle = {International Astronautical Congress},
  number = {IAC-19-C2.6.2},
  address = {Washington, Washington},
  year = {2019},
  url = {https://ntrs.nasa.gov/citations/20205006073},
  abstract = {Dust is a major concern for lunar exploration.  To combat the effects of dust, NASA, academia, and industry are developing solutions to the dust problem.  One potential technology solution for this problem is the Electrodynamic Dust Shield (EDS).  Many years of research and development have gone into this technology.  The Materials on International Space Station Experiment – 11 (MISSE-11) provides a long term space exposure platform for this technology to verify compatibility of materials and manufacturing processes to the space environment.  The MISSE-11 EDS experiment consists of 12 EDS panels.  These panels are made of glass, polyimide, or prototype spacesuit fabric.  Some panels are covered with a lotus leaf coating while others are covered with thermal paint.  They are flown in the wake position of the ISS to simulate the lunar environment.  Two panels are in an active configuration and are energized with a high voltage power supply, which generates high-voltage pulses to activate the dust shields.  Current and voltage data are recovered from each of these trials to compare to baseline data.  Also, each of the EDS panels are imaged on a monthly basis to track any changes with time that may occur with the EDS variants.  In this paper, we report preliminary data and analysis from this spaceflight experiment.}
}
  24. Mantovani, J. G. (2001). A Study of the Electrostatic Interaction Between Insulators and Martian/Lunar Soil Simulants . NASA Kennedy Space Center, 20020050541. Source
    BibTeX
    @techreport{mantovani2001study,
  title = {A Study of the Electrostatic Interaction Between Insulators and Martian/Lunar Soil Simulants},
  author = {Mantovani, James G.},
  number = {20020050541},
  institution = {NASA Kennedy Space Center},
  year = {2001},
  url = {https://ntrs.nasa.gov/citations/20020050541},
  abstract = {Using our previous experience with the Mars Environmental Compatibility Assessment (MECA) electrometer, we have designed a new type of aerodynamic electrometer. The goal of the research was to measure the buildup of electrostatic surface charge on a stationary cylindrical insulator after windborne granular particles have collided with the insulator surface in a simulated dust storm. The experiments are performed inside a vacuum chamber. This allows the atmospheric composition and pressure to be controlled in order to simulate the atmospheric conditions near the equator on the Martian surface. An impeller fan was used to propel the dust particles at a cylindrically shaped insulator under low vacuum conditions. We tested the new electrometer in a 10 mbar CO2 atmosphere by exposing two types of cylindrical insulators, Teflon (1.9 cm diameter) and Fiberglass (2.5 cm diameter), to a variety of windborne granular particulate materials. The granular materials tested were JSC Mars-1 simulant, which is a mixture of coarse and fine (<5microns diameter) particle sizes, and some of the major mineral constituents of the Martian soil. The minerals included Ottawa sand (SiO2), iron oxide (Fe2O3), aluminum oxide (Al2O3) and magnesium oxide (MgO). We also constructed a MECA-like electrometer that contained an insulator capped planar electrode for measuring the amount of electrostatic charge produced by rubbing an insulator surface over Martian and lunar soil simulants. The results of this study indicate that it is possible to detect triboelectric charging of insulator surfaces by windborne Martian soil simulant, and by individual mineral constituents of the soil simulant. We have also found that Teflon and Fiberglass insulator surfaces respond in different ways by developing opposite polarity surface charge, which decays at different rates after the particle impacts cease.}
}
  25. Jehn, M., Just, G. H., Sargeant, H. M., Long-Fox, J. and Britt, D. T. (2025). Implications of Lunar Simulant Geotechnical Properties on Testbed Experimentation and Engineering Analysis . Space and Planetary Resources. Source
    BibTeX
    @article{jehn2025implications,
  title = {Implications of Lunar Simulant Geotechnical Properties on Testbed Experimentation and Engineering Analysis},
  author = {Jehn, Marcus and Just, Gabriele H. and Sargeant, Hannah M. and Long-Fox, Jared and Britt, Daniel T.},
  journal = {Space and Planetary Resources},
  volume = {1},
  pages = {5},
  year = {2025},
  doi = {10.1007/s44461-025-00002-7},
  abstract = {Understanding the mechanical behavior of lunar regolith simulants is crucial for progressing engineering analysis in surface infrastructure design and testbed evaluation. This study provides a detailed geotechnical characterization of the Colorado School of Mines Lunar Highlands Type-Testbed simulants, including a new highland-type lunar simulant integrated into the Mines Lunar Surface Simulator testbed. It includes the determination of key geotechnical properties such as particle size distribution, density, compressibility, cohesion, friction angle, and particle shape, using standardized ASTM testing procedures. Key findings show that while particle size distribution similarities exist among the simulants and actual lunar regolith, there are significant differences in density-dependent mechanical behaviors such as shear strength, compressibility, and deformation responses. These results emphasize the complexity of simulant fidelity and its impact on testbed experiments when simulating mid-Technology Readiness Level environments. Additionally, we emphasize the importance of density-specific testing for evaluating both geotechnical properties and simulant performance. This work presents the first comprehensive publication of the full geotechnical profile of Colorado School of Mines highland simulants and highlights the importance of using multiple parameters beyond just particle size distribution to evaluate simulant fidelity. Future research will concentrate on characterizing testbed variability and assessing properties across different density states to improve the application of lunar simulants in engineering analysis and testbed experimentation.}
}
  26. Creager, C., Breckenridge, J., Johnson, K., Oravec, H., Moreland, S., Sobey, A. and McBryan, E. (2025). Best Practices for the Testing of Planetary Roving Vehicle Mobility Systems and Tires . NASA, 20250003470. Source
    BibTeX
    @techreport{creager2025best,
  title = {Best Practices for the Testing of Planetary Roving Vehicle Mobility Systems and Tires},
  author = {Creager, Colin and Breckenridge, John and Johnson, Kyle and Oravec, Heather and Moreland, Scott and Sobey, Alexander and McBryan, Emily},
  number = {20250003470},
  institution = {NASA},
  year = {2025},
  url = {https://ntrs.nasa.gov/citations/20250003470},
  abstract = {NASA has an extensive history of conducting mobility testing on planetary tires, rovers, and mobility subsystems.  This paper contains a summary of the best practices and lessons learned from past test approaches, as well as from relevant test methodologies external to NASA, with a focus on tires and mobility systems.  It is intended to be a resource for future planetary rover developments. This document, which will be released in two phases, serves two objectives:  1) compile the existing knowledge of mobility related testing within NASA; and 2) identify major gaps in mobility related test needs and suggest potential paths forward.  This first release of the document (early 2025) captures information based on the authors’ existing knowledge and an abbreviated literature review.  A more thorough version will be released in late 2025 and will include more information on test methods external to NASA, as well as additional lessons learned through further investigations.  The Lunar Terrain Vehicle (LTV) is used as case study to help identify major test needs; however, this document is intended to be applicable to a wide range of potential missions.  Though no current mobility standards exist for the testing of planetary tires and mobility subsystems, future motive is to utilize the information from this whitepaper to guide the development of NASA mobility test standards.}
}
  27. Daca, A. (2023). Predicting Planetary Rover Mobility in Reduced Gravity Using 1-g Experiments . Unpublished. Source
    BibTeX
    @phdthesis{daca2023predicting,
  title = {Predicting Planetary Rover Mobility in Reduced Gravity Using 1-g Experiments},
  author = {Daca, Adriana},
  journal = {Unpublished},
  school = {Concordia University},
  address = {Montreal, Quebec, Canada},
  type = {PhD thesis},
  month = {February},
  year = {2023},
  doi = {10.13140/rg.2.2.12718.28485},
  abstract = {Traversing granular regolith, especially in reduced gravity environments, remains a potential challenge for wheeled rovers. Mitigating hazards for planetary rovers requires testing in representative environments, but direct Earth-based testing fails to account for the effect of reduced gravity on the soil itself. Here, experimental apparatus and techniques for reduced-gravity flight testing are used to systematically evaluate three existing Earth-based testing methods and develop guidelines for their use and interpretation: (i) reduced-weight testing, (ii) matching soil testing instrument response through soil simulant design, and (iii) granular scaling laws (GSL). \nExperimentation campaigns flying reduced-gravity parabolas, with soil and wheel both in lunar-g, have shown reductions in net traction of 20% or more and increases in sinkage of up to 40% compared to Earth-based testing methods (i) and (ii). Scaled-wheel testing, according to GSL (method iii) has shown better agreement with reduced-g tests (less than 10% error) and also tends to err on the side of conservative predictions. \nLimitations of GSL are investigated including a recently proposed cohesion constraint (that the wheel radius ratio must be the inverse of the gravity ratio) and the effects of wheel size and aspect ratio on GSL’s accuracy. It was found that the cohesion constraint can most likely be ignored for mildly cohesive soils such as lunar regolith. Limits on wheel sizes and aspect ratio variation are also proposed. \nThe application of GSL to planetary rover testing is demonstrated through two studies undertaken in collaboration with NASA’s Jet Propulsion Laboratory. One study compares wheel designs for a skid-steer lunar rover in single-wheel tests scaled by GSL, demonstrating that diagonal grousers improve turning performance without requiring larger wheels. The second study involves application of GSL to the design of two reconfigurable test platforms for evaluating steep-terrain mobility performance. \nAnother aspect of rover mobility testing—normal force control in single-wheel testbeds—is also investigated. An improved method for single-wheel testing, using a 4-bar mechanism, essentially eliminates normal force oscillations from frictional vertical sliders. \nFinally, guidelines for conducting and interpreting 1-g mobility tests for lunar rovers are presented, and potential avenues for future research are outlined.}
}
  28. Thorbourn, D. (2013). JPL Radiation Effects Facilities . JPL Open Repository. Source
    BibTeX
    @inproceedings{thorbourn2013jpl,
  title = {JPL Radiation Effects Facilities},
  author = {Thorbourn, Dennis},
  booktitle = {JPL Open Repository},
  year = {2013},
  url = {https://dataverse.jpl.nasa.gov/dataset.xhtml?persistentId=hdl:2014/42836}
}
  29. Quan, Q.-Q., Chen, C.-B., Deng, Z.-Q., Tang, J.-Y. and Tang, D.-W. (2018). On Modeling Drilling Load in Lunar Regolith Simulant . Chinese Journal of Mechanical Engineering. Source
    BibTeX
    @article{quan2018modeling,
  title = {On Modeling Drilling Load in Lunar Regolith Simulant},
  author = {Quan, Qi-Quan and Chen, Chong-Bin and Deng, Zong-Quan and Tang, Jun-Yue and Tang, De-Wei},
  journal = {Chinese Journal of Mechanical Engineering},
  volume = {31},
  pages = {20},
  year = {2018},
  doi = {10.1186/s10033-018-0207-8},
  abstract = {Drilling and coring, as effective ways to obtain lunar regolith along the longitudinal direction, are widely applied in the lunar sampling field. Conventionally, modeling of drill-soil interaction was divided into soil cutting and screw conveyance processes, ignoring the differences in soil mechanical properties between them. To improve the modeling accuracy, a hypothesis that divides the drill-soil interaction into four parts: cuttings screw conveyance, cuttings extruding, cuttings bulldozing, and in situ simulant cutting, is proposed to establish a novel model based on the passive earth pressure theory. An iterative numerical calculation method is developed to predict the drilling loads. A drilling and coring testbed is developed to conduct experimental tests. Drilling experiments indicate that the drilling loads calculated by the proposed model match well the experimental results. The proposed research provides the instructions to adopt a suitable drilling strategy to match the rotary and penetrating motions, to increase the safety and reliability of drilling control in lunar sampling missions.}
}
  30. Jarvis, S. L., Vu, L. Q., Gupta, G., Benson, E., Kim, K. H., Rhodes, R. and Rajulu, S. L. (2023). Development of ARGOS (Active Response Gravity Offload System) Offloading Assessments and Methodology for Lunar EVA Simulations . International Conference on Environmental Systems, 20230002430. Source
    BibTeX
    @inproceedings{jarvis2023development,
  title = {Development of ARGOS (Active Response Gravity Offload System) Offloading Assessments and Methodology for Lunar EVA Simulations},
  author = {Jarvis, Sarah L. and Vu, Linh Q. and Gupta, Garima and Benson, Elizabeth and Kim, K. Han and Rhodes, Richard and Rajulu, Sudhakar L.},
  booktitle = {International Conference on Environmental Systems},
  number = {20230002430},
  institution = {NASA},
  address = {Calgary},
  year = {2023},
  url = {https://ntrs.nasa.gov/citations/20230002430},
  abstract = {The Active Response Gravity Offload System (ARGOS) at NASA Johnson Space Center (JSC) is an analog environment that can offload pressurized suited subjects for various reduced gravity simulations. The suit is suspended from a robotic overhead crane by a cable connected to the suit via a gimbal with an adjustable pivot point (i.e. offload attachment). There has been increased interest in providing planetary pressurized suited training at ARGOS in preparation for lunar missions. Determination of the appropriate gimbal pivot point location for a given subject is vital for a high-fidelity functional lunar simulation. Interactions between the pivot point location and human-spacesuit center of gravity (CG) can result in righting moments that may lead to artificially stable or unrealistically challenging
configurations. Changing the pivot point location is time consuming and repeated adjustment can result in loss of valuable pressurized suited time. This paper aims to share knowledge obtained from the offloading characterization efforts during pressurized suited testing at ARGOS and document the ongoing process to define an appropriate pivot point location through iterative quantitative and qualitative assessments. Human-spacesuit CG locations for the ARGOS lunar simulation were estimated using a 3D body scan and density model combined with spacesuit hardware CAD and specifications. Early pilot testing of the gimbal revealed that setting the pivot point coincident with the modeled CG location was not always possible due to the current gimbal design, and small pivot point shifts had noticeable effects on subject stability. Fourteen subjects performed a series of CG-related tasks in the
Exploration Extravehicular Mobility Unit (xEMU) to assess simulation characteristics. Through iterative testing, this task list evolved to streamline the process needed to efficiently identify a suitable pivot point for a given subject. The developed methodology will be critical for pivot point selection during astronaut training in the ARGOS environment.}
}
  31. Chen, J., Li, R. and Fu, S. (2026). Influence of Low Gravity on the Penetration Resistance of Lunar Regolith . npj Microgravity. Source
    BibTeX
    @article{chen2026influence,
  title = {Influence of Low Gravity on the Penetration Resistance of Lunar Regolith},
  author = {Chen, Jun and Li, Ruilin and Fu, Shigen},
  journal = {npj Microgravity},
  volume = {12},
  pages = {7},
  year = {2026},
  doi = {10.1038/s41526-026-00562-8},
  abstract = {Abstract Lunar surface operations conducted by the United States and the Soviet Union confirmed that penetration resistance is a key indicator for evaluating the engineering properties of lunar regolith. To quantitatively assess the influence of reduced gravity on penetration resistance, this study employed a newly developed Geotechnical Magnetic-gravity Modeling Test (GMMT) system to perform cone penetration tests under controlled gravitational acceleration levels of 1/6 g, 1 g, and 2 g. The results indicated that the normalized penetration resistance increased as gravity decreased, and this effect was amplified at higher relative densities. To investigate the underlying mechanisms, discrete element method (DEM) simulations were conducted. The findings revealed that, in addition to gravity, in situ factors such as high relative density and irregular particle morphology also significantly enhanced penetration resistance by strengthening interparticle contact and friction. These non-gravitational effects partially offset the expected reduction in resistance under lower gravity, leading to a smaller-than-anticipated decline. This study provides new insights into the gravity-dependent penetration behavior of lunar regolith.}
}
  32. Duffey, C., Lea, M. and Brisset, J. (2025). Measuring regolith strength in reduced gravity environments in the laboratory . Review of Scientific Instruments. Source
    BibTeX
    @article{duffey2025measuring,
  title = {Measuring regolith strength in reduced gravity environments in the laboratory},
  author = {Duffey, C. and Lea, M. and Brisset, Julie},
  journal = {Review of Scientific Instruments},
  volume = {96},
  year = {2025},
  doi = {10.1063/5.0249495},
  abstract = {This paper presents the design and development of a Shear and Compression Cell (SCC) for measuring the mechanical properties of granular materials in low-gravity environments. This research is motivated by the increasing interest in planetary exploration missions that involve surface interactions, such as those to asteroids and moons. The SCC is designed to measure key mechanical properties, including Young’s modulus, angle of internal friction, bulk cohesion, and tensile strength, under both reduced gravity and microgravity conditions. Using a drop tower with interchangeable configurations, we can simulate the gravitational environments of celestial bodies such as the Moon and Titan. The SCC, coupled with the drop tower, provides a valuable tool for understanding the behavior of regolith materials and their implications for future space exploration missions.}
}