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Space Robotics

Test Facilities

Ground facilities used to qualify robotic hardware for environments that cannot be reproduced in full on Earth. One page per laboratory, test center or field site, each recording the same set of parameters so that a reader choosing where to run a campaign can compare them directly.

A page is an organizational unit with a door, a director and a budget. Everything inside it, chambers, bins, gantries, tanks, towers, yards and benches, is a capability section on that laboratory’s page rather than a page of its own. A reader wants to know what a laboratory can do for them, and that question is answered by one page listing everything under the roof. Where two rigs sit under different institutes or different operators, they get different pages even when they share a site: at ESTEC the Large Space Simulator is run by the Test Center and ORBIT and the Dusty Thermal Vacuum Chamber by the Automation and Robotics Laboratories, and DLR’s landing facility in Bremen and its terramechanics bench at Oberpfaffenhofen sit under two institutes at opposite ends of Germany.

What a facility page records: the physical envelope of each rig, the conditions it can hold and to what tolerance, the material it contains, the instrumentation available to a test article, the throughput and access route, and the stated fidelity limits. A chamber that reaches its rated vacuum but cannot hold it with a rover outgassing inside it has a different useful envelope than its specification sheet claims, and that difference is what belongs here.

Table cells carry a value, its units and a citation, and nothing else. The explanation behind a number belongs in the prose below the table, where it can be read as sentences.

Pages are named for the laboratory and led by the operating institution, and the section sorts alphabetically on that name, so everything an institution runs falls together without an editorial ordering to argue about. Short names the operators and the literature actually use are recorded in each page’s aka list, so SLOPE, GEER, GMRO, ASSIST, ARGO, LAMA, TROLL and Swamp Works all remain findable.

What the facilities cover

Section titled “What the facilities cover”

Facilities fall into families by the quantity they reproduce, and no single rig reproduces more than one or two of them. All of it is ground testing. What has flown is the hardware qualified on these rigs, not the rigs, and where a method has only been shown in a laboratory the family text says so.

Vacuum, dust and regolith conditioning. Ambient-air testing with simulant misleads: clean-surface cohesion appears below a few torr, but surface adhesion needs pressures many orders lower, which is the argument for dedicated dust-in-vacuum rigs [1]. Moist or frozen simulant has to be conditioned before it enters a thermal vacuum chamber, and the bed changes with depth once exposed to vacuum, so a cryogenic dirty chamber test carries a time and procedure cost that a dry test does not [2]. Wear testing with dust on a mechanism rather than a coupon, at a stated areal dust dose, has been demonstrated in a laboratory vacuum chamber at NASA Langley [3]. Simulant is not regolith: the one quantified simulant-to-lunar-grain discrepancy in the corpus is photoelectric yield, measured on individual returned grains [4].

Venus and extreme-temperature chambers. Earlier Venus chambers were limited in volume, pressure, temperature or gas species, and the Glenn Extreme Environments Rig was built to close that gap [5]. Its operational envelope, electrical feedthrough limits and schedule cost decide which electronics tests are feasible there [6]. The first campaign result held for the rig is a 60 Earth-day exposure of a ceramic electronics package, which passed as a material system and degraded as an assembly [7]. A broader materials exposure set, including coated versus uncoated comparisons, was run under Venus lower-atmosphere conditions [8]. Glenn’s own facility index, by contrast, omits the Lunar Dust Adhesion Bell Jar that [1] describes, and lists other rigs such as a 5.18 s zero gravity drop tower and a 40 K lunar night structural rig [14].

Radiation. Single-event-effect and total-dose testing is done at beam and source facilities outside the robotics community. The JPL Cobalt-60 dose rate envelope and Dynamitron chamber, with the off-site facilities JPL uses, are stated in one facility description [9]. A high-energy heavy-ion facility’s beam time cost, annual availability and tuning times are documented separately [10]. Testing complex system-on-chip devices needs board selection, die thinning, in-beam thermal control and beam time budgeting, which a defensible report must record [11]. This family is the most transferable from the wider electronics field, and its numbers apply to any flight computer regardless of mission.

Gravity offload and microgravity. Cable suspension at a single pivot offloads only the body segments inboard of the attachment, cannot follow a moving center of gravity, and has dead zones in the gimbal, so a result must be discounted by the artifact the rig adds [12]. The same literature compares ARGOS against POGO, parabolic flight and the neutral buoyancy lab on degrees of freedom, work volume, task duration and induced artifacts [13]. Short-duration drop towers and free-flying testbeds cover the other end of the range; Astrobee on the International Space Station is the case where ground testing was followed by flight results [27], and a joint review compares it with the CIMON and Int-Ball free flyers [28].

Terramechanics and mobility. The Glenn SLOPE laboratory publishes its full-vehicle drawbar pull procedure, from soil loosening and tamping to cone penetration readings before every run, which is what makes results from different campaigns comparable [15]. A drawbar comparison with a particle-level failure study for the same soil showed that inching raises thrust through a different failure mode, not only lowers resistance [16]. The motion capture array that supplies ground-truth position there has been validated against an independent reference [17]. Modeling approaches span semi-empirical terramechanics to higher-fidelity methods, with the semi-empirical models structurally unable to represent tire compliance and grousers [18]. DLR’s single-wheel bench began as a feasibility study with traceable requirements for test length, sink depth and measurement rate [19], and now automates soil preparation, leveling, compaction and the run itself [20]. Field-measured slip and sinkage have been fed into a real-time photorealistic simulator, a laboratory result with no flight use [21].

Excavation, ISRU and drilling. The IPEx autonomy test site at Kennedy is a light-tight tent with stadium lighting standing in for low-elevation polar sun, and it holds the only quantitative record of how repeated excavation changes worksite soil state [22]. Actuator qualification for the same vehicle ran in a small space environment dynamometer, found a rotor bearing failure under accelerated life, and produced a fitted current-torque model valid only inside narrow bounds [23]. Bucket-drum force scaling was measured empirically because classical blade equations do not apply [24]. A drill intended for a flight rover was exercised in an Antarctic field campaign [25]. None of these is a flight result.

Telerobotics and field analogs. METERON Analog-1 is the field analog in this group: a crew member on orbit driving a surface rover with haptic feedback, tabulated with the experiments that preceded it [26].

Servicing and manipulation. On-orbit servicing manipulators are tested in facilities surveyed alongside arm specifications [30], within a broader survey of manipulation and capture [29]. A NASA catalog of servicing, assembly and manufacturing activity counts developers and capability areas, and notes that areas with no completed demonstration lack documented standards [31]. A planned ISS rendezvous testbed was never flown as described [33], and the independent review that ended OSAM-1 records the programmatic reasons a flagship servicing mission was canceled [32].

Which of these can still be booked

Section titled “Which of these can still be booked”

A measurement does not expire when the machine that made it is scrapped, but a test plan does. Facilities are therefore split below into the ones a reader can approach today and the ones that are a record rather than an option. Every facility page carries a status value in its frontmatter, one of four:

StatusMeaning
activeOperating, under the name the page carries
renamedOperating, under a different name, operator or parent organization
closedNo longer operating
unknownNo published evidence settles it either way

renamed and unknown are separate from closed on purpose. A facility whose status could not be established is not a facility established to be gone, and saying so is cheaper than a reader repeating the search. A renamed or closed facility names its successor, or “None”, in a successor field, and carries the modern name in aka so a search for either finds it. A page whose facility is not active opens by saying what changed and who to approach instead, before any of its numbers.

Operating

Section titled “Operating”

Several of these have changed names, owners or hardware without changing what they are. NASA Langley’s gantry was the Lunar Landing Research Facility, then the Impact Dynamics Research Facility, and is now the Landing and Impact Research Facility; the structure is the same steel and the facility takes work today, so it is active under its present name and the old names are recorded alongside it rather than in a historical section. The same rule puts the UCF Exolith Lab under Florida Space Institute rather than its original CLASS home, and ZARM’s tower under a GraviTower that did not exist when the tower was built.

NASA Kennedy’s Swamp Works is the one organizational unit deliberately left without a page: it is a lean development environment spanning granular mechanics and regolith operations, applied chemistry, electrostatics and surface physics, advanced materials and systems, applied physics and corrosion technology, and it is context on the pages of the laboratories it owns rather than a laboratory itself. Its stated method also bears on how its results should be read: testing is performed at early stages to drive design improvements, with stretch goals and accepted technical risk, so a result from one of its laboratories is a prototype-generation datum rather than a qualification result.

Retired facilities are recorded on separate historical pages.

What is not established

Section titled “What is not established”

Fidelity limits are stated by the operators for some rigs and measured independently for few: the position instrumentation at SLOPE is one of the rare validated cases [17], and the cable-offload artifacts are quantified for one rig geometry [12]. Venus and radiation results rest on small numbers of articles, such as two packages in one 60-day campaign [7], and the cited facility descriptions date from 2004 and 2013 [10][9], so beam availability and dose rates stated there are not confirmed as current. Simulant fidelity against real regolith is quantified for photoelectric yield only [4]. Several actuator and drum results were taken at 1 g with dust from a cup rather than a real excavation environment [23]. Status values record published evidence of operation, not booking availability.

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. Kleinhenz, J. (2014). Lunar Polar Environmental Testing: Regolith Simulant Conditioning . Symposium on Space Resource Utilization, 20140012567. Source
    BibTeX
    @inproceedings{kleinhenz2014lunar,
  title = {Lunar Polar Environmental Testing: Regolith Simulant Conditioning},
  author = {Kleinhenz, Julie},
  booktitle = {Symposium on Space Resource Utilization},
  number = {20140012567},
  institution = {NASA},
  year = {2014},
  doi = {10.2514/6.2014-0689},
  abstract = {As ISRU system development approaches flight fidelity, there is a need to test hardware in relevant environments. Extensive laboratory and field testing have involved relevant soil (lunar regolith simulants), but the current design iterations necessitate relevant pressure and temperature conditions. Including significant quantities of lunar regolith simulant in a thermal vacuum chamber poses unique challenges. These include facility operational challenges (dust tolerant hardware) and difficulty maintaining a pre-prepared soil state during pump down (consolidation state, moisture retention).For ISRU purposes, the regolith at the lunar poles will be of most interest due to the elevated water content. To test at polar conditions, the regolith simulant must be doped with water to an appropriate percentage and then chilled to cryogenic temperatures while exposed to vacuum conditions. A 1m tall, 28cm diameter bin of simulant was developed for testing these simulant preparation and drilling operations. The bin itself was wrapped with liquid nitrogen cooling loops (100K) so that the simulant bed reached an average temperature of 140K at vacuum. Post-test sampling was used to determine desiccation of the bed due to vacuum exposure. Depth dependent moisture data is presented from frozen and thawed soil samples.Following simulant only evacuation tests, drill hardware was incorporated into the vacuum chamber to test auguring techniques in the frozen soil at thermal vacuum conditions. The focus of this testing was to produce cuttings piles for a newly developed spectrometer to evaluate. This instrument, which is part of the RESOLVE program science hardware, detects water signatures from surface regolith. The drill performance, behavior of simulant during drilling, and characteristics of the cuttings piles will be offered.}
}
  3. Wiesner, V. L., King, G. C., Domack, C. S., Widener, B. M., Gordon, K. L. and Wohl, C. J. (2024). Testbed for Lunar Extreme Environment Wear Tolerant Applications . Aerospace Mechanisms Symposium. Source
    BibTeX
    @inproceedings{wiesner2024testbed,
  title = {Testbed for Lunar Extreme Environment Wear Tolerant Applications},
  author = {Wiesner, Valerie L. and King, Glen C. and Domack, Christopher S. and Widener, Brandon M. and Gordon, Keith L. and Wohl, Christopher J.},
  booktitle = {Aerospace Mechanisms Symposium},
  address = {Hampton, Virginia},
  year = {2024},
  url = {https://ntrs.nasa.gov/citations/20240003704},
  abstract = {The abrasive dust from lunar regolith poses significant long-term durability and performance challenges to materials, vehicles, mechanisms and structures that will be used for the next generation of lunar exploration. The development of advanced materials, coatings and device technologies that can withstand these abrasive particles and extreme environmental conditions is critical. However, the lack of standardized and accessible methods for evaluating such materials and devices in a facsimile of the harsh lunar environment hinders progress in dust-tolerant technologies. To address this challenge, NASA Langley Research Center is creating an extreme environment testbed. This reconfigurable testbed will allow rapid, repeatable wear testing of material and candidate mechanisms under vacuum conditions, facilitating the development of critical materials technologies for lunar exploration. Preliminary results from exposing an actuating mechanism similar to a pin joint to lunar regolith simulant under high vacuum are reported.}
}
  4. 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.}
}
  5. Kremic, T., Vento, D., Lalli, N. and Palinski, T. (2014). Extreme Environment Simulation - Current and New Capabilities to Simulate Venus and Other Planetary Bodies . IEEE Aerospace Conference, 20140013390. Source
    BibTeX
    @inproceedings{kremic2014extreme,
  title = {Extreme Environment Simulation - Current and New Capabilities to Simulate Venus and Other Planetary Bodies},
  author = {Kremic, Tibor and Vento, Dan and Lalli, Nick and Palinski, Timothy},
  booktitle = {IEEE Aerospace Conference},
  number = {20140013390},
  pages = {1-9},
  institution = {NASA},
  year = {2014},
  doi = {10.1109/aero.2014.6836350},
  abstract = {Science, technology, and planetary mission communities have a growing interest in components and systems that are capable of working in extreme (high) temperature and pressure conditions. Terrestrial applications range from scientific research, aerospace, defense, automotive systems, energy storage and power distribution, deep mining and others. As the target environments get increasingly extreme, capabilities to develop and test the sensors and systems designed to operate in such environments will be required. An application of particular importance to the planetary science community is the ability for a robotic lander to survive on the Venus surface where pressures are nearly 100 times that of Earth and temperatures approach 500C. The scientific importance and relevance of Venus missions are stated in the current Planetary Decadal Survey. Further, several missions to Venus were proposed in the most recent Discovery call. Despite this interest, the ability to accurately simulate Venus conditions at a scale that can test and validate instruments and spacecraft systems and accurately simulate the Venus atmosphere has been lacking. This paper discusses and compares the capabilities that are known to exist within and outside the United States to simulate the extreme environmental conditions found in terrestrial or planetary surfaces including the Venus atmosphere and surface. The paper then focuses on discussing the recent additional capability found in the NASA Glenn Extreme Environment Rig (GEER). The GEER, located at the NASA Glenn Research Center in Cleveland, Ohio, is designed to simulate not only the temperature and pressure extremes described, but can also accurately reproduce the atmospheric compositions of bodies in the solar system including those with acidic and hazardous elements. GEER capabilities and characteristics are described along with operational considerations relevant to potential users. The paper presents initial operating results and concludes with a sampling of investigations or tests that have been requested or expected.}
}
  6. Beckley, B. W., Motil, C. A., Henry, I. M., Chi, I. S. and Sprouse, M. D. (2024). Glenn Extreme Environments Rig (GEER) Facility Users Guide . Planetary Science Technology Symposium, 20240012869. Source
    BibTeX
    @inproceedings{beckley2024glenn,
  title = {Glenn Extreme Environments Rig (GEER) Facility Users Guide},
  author = {Beckley, Blake W. and Motil, Craig A. and Henry, Ian M. and Chi, Ike S. and Sprouse, Mark D.},
  booktitle = {Planetary Science Technology Symposium},
  number = {20240012869},
  institution = {NASA},
  address = {Cleveland, OH},
  year = {2024},
  url = {https://ntrs.nasa.gov/citations/20240012869},
  abstract = {The Glenn Extreme Environment Rig (GEER) is a large capacity pressure vessel capable of simulating high pressure and temperature conditions with a specified, custom mixture of gas. The chamber is certified for operation in physical and chemical conditions representative of the surface conditions of Venus. It can accommodate large scientific or engineering test articles while maintaining the specified conditions indefinitely. The user-configurable gas supply is capable of handling a mixture of up to nine independent streams for injection directly into the vessel. GEER is supported in part by NASA’s Planetary Science Division under the Science Mission Directorate and is available for use by the commercial, academic, and research communities.

GEER was operationally commissioned in November of 2014. At that time, it successfully maintained the temperature, pressure, and chemistry of the Venus surface atmosphere. In the spring of 2015, GEER began operations for engineering and scientific research. Since then, over 20 tests have been successfully conducted in the chamber with a variety of atmospheric test conditions.}
}
  7. Chen, L.-Y., Neudeck, P. G., Meredith, R. D., Lukco, D., Spry, D. J., Nakley, L. M., Phillips, K. G., Beheim, G. M. and Hunter, G. W. (2018). Sixty Earth-Days Test of a Prototype Pt/HTCC Alumina Package in Simulated Venus Environment . Additional Conferences, 20180006758. Source
    BibTeX
    @inproceedings{chen2018sixty,
  title = {Sixty Earth-Days Test of a Prototype Pt/HTCC Alumina Package in Simulated Venus Environment},
  author = {Chen, Liang-Yu and Neudeck, Philip G. and Meredith, Roger D. and Lukco, Dorothy and Spry, David J. and Nakley, Leah M. and Phillips, Kyle G. and Beheim, Glenn M. and Hunter, Gary W.},
  booktitle = {Additional Conferences},
  volume = {2018},
  number = {20180006758},
  pages = {000015-000021},
  institution = {NASA},
  address = {Albuquerque, New Mexico},
  year = {2018},
  doi = {10.4071/2380-4491-2018-hiten-0000015},
  abstract = {Abstract This paper presents experimental results of a prototype high temperature co-fired ceramic (HTCC) package with Au/Pt metallization in a three-phase harsh environment test that culminated with 60-day demonstration in simulated Venus surface environment of 465 °C with corrosive atmosphere at 90 bar pressure. The prototype package is based on previously developed and reported HTCC package successfully tested with multiple analog and digital silicon carbide (SiC) high temperatures semiconductor integrated circuits (ICs) at NASA Glenn Research Center in 500 °C Earth air ambient for over ten thousands hours, and short-term tested at temperatures above 800 °C. The three-phase harsh environment test started with 48 hours in 465 °C Earth air, followed by 48 hours in 465 °C nitrogen at 90 bar pressure and 1400 hours in simulated Venus surface environment of 465 °C with corrosive atmosphere at 90 bar. Initial analytical results of the package materials and surfaces after exposure to Venus environment are discussed to assess the stability of the packaging materials in the tested environments. The test in simulated Venus environment was implemented in the NASA Glenn Extreme Environment Rig (GEER). The results of this study suggest that an effective encapsulation of areas of surface metallization and vicinities may help to improve electrical performance of a HTCC alumina packaging system in Venus environment.}
}
  8. Costa, G. C. C., Jacobson, N. S., Lukco, D., Hunter, G. W., Nakley, L., Radoman-Shaw, B. G. and Harvey, R. P. (2017). Chemical and Microstructural Changes in Metallic and Ceramic Materials Exposed to Venusian Surface Conditions . NASA, NASA/TM-2017-219437. Source
    BibTeX
    @techreport{costa2017chemical,
  title = {Chemical and Microstructural Changes in Metallic and Ceramic Materials Exposed to Venusian Surface Conditions},
  author = {Costa, Gustavo C. C. and Jacobson, Nathan S. and Lukco, Dorothy and Hunter, Gary W. and Nakley, Leah and Radoman-Shaw, Brandon G. and Harvey, Ralph P.},
  number = {NASA/TM-2017-219437},
  institution = {NASA},
  year = {2017},
  url = {https://ntrs.nasa.gov/citations/20170006025},
  abstract = {The chemical and microstructural behavior of steels (304, 310, 316, and 1018), nickel-based alloys (beta-NiAl, G30, and 625), gold, coatings (4YSZ, SilcoNert(TradeMark) 1040 (SilcoTek Co.), Dursan(TradeMark) (SilcoTek Co.), and porcelain), and bulk ceramics (alpha-Al2O3, fused quartz, beta-SiC, and alpha-Si3N4) were probed after exposure to supercritical fluid with temperature, pressure, and composition mimicking the Venus lower atmosphere. Exposures were carried out in the Glenn Extreme Environments Rig (GEER) chamber with the Venusian gas mixture (96.5% CO2, 3.5% N2, 30 ppm H2O, 150 ppm SO2, 28 ppm CO, 15 ppm OCS, 3 ppm H2S, 0.5 ppm HCl, and 5 ppb HF) at 92 bar (1330 psi) and 467 C (873 F) for durations of 10 and 42 days. An additional 21-day exposure was done to stainless steel uncoated and coated with SilcoNert(TradeMark) and Dursan(TradeMark). Samples were characterized before and after the experiment by gravimetric analysis, X-ray diffraction, X-ray photoelectron and Auger electron spectroscopies, and cross section electron microscopy analysis. All steels exposed for 10 and 42 days formed double-layered scales consisting mainly of metal (Cr, Fe, Ni) oxides and sulfides showing different chemistry, microstructure, and crystalline phases. The alloys G30 and 625 formed double-layered scales consisting mainly of nickel sulfides. After 10 days, the beta-NiAl exhibited no detectable scale, suggesting only a very thin film was formed. The 304 and 316 stainless steels coated with 4YSZ that were exposed for 10 and 42 days exhibited no significant oxidation. Steel 1018 coated with 4YSZ exhibited a corrosion scale of iron and/or chromium oxide formed at the base of the alloy. The 304 steel coated with porcelain did not exhibit corrosion, although the coating exhibited recession. SilcoNert(TradeMark) exposed for 10 and 42 days exhibited recession, although no oxidation was found to occur at the base of the alloy. Stainless steel 316 coated with Dursan(TradeMark)  exhibited corrosion at the base of the alloy. All ceramics tested showed no clear evidence of reaction. The weight-gain-per-area performance of the materials exposed in the GEER for 10 and 42 days are reported from the lowest to the highest weight gain per area as follows: gold did not exhibit any weight change; nickel-based alloys: beta- NiAl < G30 < 625; steels: 304 < 310 < 316 < 1018; ceramics: considering the experimental uncertainties, no weight change was observed for all ceramics of this work (alpha-Al2O3, Si3N4, SiC, and amorphous SiO2).}
}
  9. 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}
}
  10. Ladbury, R., Reed, R. A., Marshall, P. W., LaBel, K. A., Anantaraman, R., Fox, R., Sanderson, D. P., Stolz, A., Yurkon, J., Zeller, A. F. and Stetson, J. W. (2004). Performance of the High-Energy Single-Event Effects Test Facility (SEETF) at Michigan State University's National Superconducting Cyclotron Laboratory (NSCL) . IEEE Transactions on Nuclear Science, 20040171458. Source
    BibTeX
    @article{ladbury2004performance,
  title = {Performance of the High-Energy Single-Event Effects Test Facility (SEETF) at Michigan State University's National Superconducting Cyclotron Laboratory (NSCL)},
  author = {Ladbury, R. and Reed, R. A. and Marshall, Paul W. and LaBel, Kenneth A. and Anantaraman, R. and Fox, R. and Sanderson, D. P. and Stolz, A. and Yurkon, J. and Zeller, A. F. and Stetson, J. W.},
  journal = {IEEE Transactions on Nuclear Science},
  volume = {51},
  number = {20040171458},
  pages = {3664-3668},
  institution = {NASA},
  address = {Atlanta, Georgia},
  year = {2004},
  doi = {10.1109/tns.2004.839300},
  abstract = {The performance of Michigan State University's Single-Event Effects Test Facility (SEETF) during its inaugural runs is evaluated. Beam profiles and other diagnostics are presented, and prospects for future development and testing are discussed.}
}
  11. Guertin, S. M. (2018). Guideline for Single-Event Effect (SEE) Testing of System on a Chip (SOC) Devices . NASA, 20190002148. Source
    BibTeX
    @techreport{guertin2018guideline,
  title = {Guideline for Single-Event Effect (SEE) Testing of System on a Chip (SOC) Devices},
  author = {Guertin, Steven M.},
  number = {20190002148},
  institution = {NASA},
  year = {2018},
  url = {https://ntrs.nasa.gov/citations/20190002148},
  abstract = {The use of complex single and multicore processors with significant cache memory, on-chip peripherals, memory controllers, and high speed input/output (IO) that integrate many of the parts of a traditional computer system is becoming more common in space applications. Such devices are often referred to as system on a chip devices (SOCs), even though the term is used somewhat inaccurately due to the lack of analog and mixed signal subcircuits. These devices are complex combinations of single- or multi-core processors with memory controllers, high-speed input/output (IO), and other peripheral structures that formerly would have been handled by off-chip resources. In the past the processors were tested for single event effects (SEE) separately, and the peripherals were often put into custom application-specific integrated circuits (ASICs) along with other resources required by the user. Performance and cost pressures have pushed commercial devices to incorporate many of the functional blocks into a single chip, an SOC. The NASA Electronic Parts and Packaging Program (NEPP) has been examining ways to perform SEE radiation hardness assurance (RHA) testing of these processor-centric SOCs to achieve reasonable understanding of their performance in space missions.}
}
  12. 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.}
}
  13. Bekdash, O. S., Valle, P. S., Kim, K. J., Jarvis, S. L., Dunn, J. T., Norcross, J. R. and Abercromby, A. F. J. (2020). Development and Evaluation of the Active Response Gravity Offload System as a Lunar and Martian EVA Simulation Environment . International Conference on Environmental Systems, 20205003610. Source
    BibTeX
    @inproceedings{bekdash2020development,
  title = {Development and Evaluation of the Active Response Gravity Offload System as a Lunar and Martian EVA Simulation Environment},
  author = {Bekdash, Omar S. and Valle, Paul S. and Kim, Kyoung Jae and Jarvis, Sarah L. and Dunn, Jocelyn T. and Norcross, Jason R. and Abercromby, Andrew F. J.},
  booktitle = {International Conference on Environmental Systems},
  number = {20205003610},
  institution = {NASA},
  year = {2020},
  url = {https://ntrs.nasa.gov/citations/20205003610},
  abstract = {In preparation for future exploration missions, NASA seeks the ability to simulate partial-gravity operations  for  use  in  ground-based  research,  crew  training,  and  engineering  design  evaluations.  The  Active  Response  Gravity  Offload  System  (ARGOS)  at  the  Johnson  Space  Center (JSC) is designed to simulate reduced gravity environments, such as lunar, Martian, or  microgravity,  using  a  robotic  system  similar  to  an  overhead  bridge  crane.  ARGOS  continuously offloads a portion of a suited human’s weight during all dynamic motions within the test facility, which can include basic functional movements such as walking, running, and jumping, as well as a wide range of planetary surface activities. This system will be used as part of a metabolic-rate task characterization study to determine the workload associated with partial-gravity  extravehicular  activity  (EVA).  Pilot  testing  was  conducted  using  the  MKIII  prototype planetary space suit and two gimbal designs to determine the ability of the ARGOS test environment to simulate planetary EVA operations. This paper will describe the lessons learned from the feasibility testing,  simulation-environment  mockup  design,  and  the results from  the  pilot  tests  and  their  influence  into  the  final  study  design.  Being  able  to  effectively  simulate partial-gravity environments and characterize the performance of crewmembers will have an impact on multiple domains including suit design, task design, thermal models, and life-support-system capacity verification plans, among others.}
}
  14. 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/}
}
  15. Creager, C., Asnani, V., Oravec, H. and Woodward, A. (2017). Drawbar Pull (DP) Procedures for Off-Road Vehicle Testing . NASA Glenn Research Center, NASA/TP-2017-219384. Source
    BibTeX
    @techreport{creager2017drawbar,
  title = {Drawbar Pull (DP) Procedures for Off-Road Vehicle Testing},
  author = {Creager, Colin and Asnani, Vivake and Oravec, Heather and Woodward, Adam},
  number = {NASA/TP-2017-219384},
  institution = {NASA Glenn Research Center},
  year = {2017},
  url = {https://ntrs.nasa.gov/citations/20170010706},
  abstract = {As NASA strives to explore the surface of the Moon and Mars, there is a continued need for improved tire and vehicle development. When tires or vehicles are being designed for off-road conditions where significant thrust generation is required, such as climbing out of craters on the Moon, it is important to use a standard test method for evaluating their tractive performance. The drawbar pull (DP) test is a way of measuring the net thrust generated by tires or a vehicle with respect to performance metrics such as travel reduction, sinkage, or power efficiency. DP testing may be done using a single tire on a traction rig, or with a set of tires on a vehicle; this report focuses on vehicle DP tests. Though vehicle DP tests have been used for decades, there are no standard procedures that apply to exploration vehicles. This report summarizes previous methods employed, shows the sensitivity of certain test parameters, and provides a body of knowledge for developing standard testing procedures. The focus of this work is on lunar applications, but these test methods can be applied to terrestrial and planetary conditions as well. Section 1.0 of this report discusses the utility of DP testing for off-road vehicle evaluation and the metrics used. Section 2.0 focuses on test-terrain preparation, using the example case of lunar terrain. There is a review of lunar terrain analogs implemented in the past and a discussion on the lunar terrain conditions created at the NASA Glenn Research Center, including methods of evaluating the terrain strength variation and consistency from test to test. Section 3.0 provides details of the vehicle test procedures. These consist of a review of past methods, a comprehensive study on the sensitivity of test parameters, and a summary of the procedures used for DP testing at Glenn.}
}
  16. Creager, C., Moreland, S., Skonieczny, K., Johnson, K., Asnani, V. and Gilligan, R. (2012). Benefit of Push-pull Locomotion for Planetary Rover Mobility . ASCE Earth and Space Conference. Source
    BibTeX
    @inproceedings{creager2012benefit,
  title = {Benefit of Push-pull Locomotion for Planetary Rover Mobility},
  author = {Creager, Colin and Moreland, Scott and Skonieczny, Krzysztof and Johnson, Kyle and Asnani, Vivake and Gilligan, Ryan},
  booktitle = {ASCE Earth and Space Conference},
  pages = {11-20},
  publisher = {American Society of Civil Engineers},
  year = {2012},
  doi = {10.1061/9780784412190.002},
  abstract = {As NASA's exploration missions on planetary terrains become more aggressive, a focus on alternative modes of locomotion for rovers is necessary. In addition to climbing steep slopes, the terrain in these extreme environments is often unknown and can be extremely hard to traverse, increasing the likelihood of a vehicle or robot becoming damaged or immobilized. The conventional driving mode in which all wheels are either driven or free-rolling is very efficient on flat hard ground, but does not always provide enough traction to propel the vehicle through soft or steep terrain. This paper presents an alternative mode of travel and investigates the fundamental differences between these locomotion modes. The methods of "push-pull" locomotion discussed can be used with articulated wheeled vehicles and are identified as "walking" or "inching/inch-worming". In both cases, the braked non-rolling wheels provide increased thrust. An in-depth study of how soil reacts under a rolling wheel vs. a braked wheel was performed by visually observing the motion of particles beneath the surface. This novel technique consists of driving or dragging a wheel in a soil bin against a transparent wall while high resolution, high-rate photographs are taken. Optical flow software was then used to determine shearing patterns in the soil. Different failure modes were observed for the rolling and braked wheel cases. A quantitative comparison of inching vs. conventional driving was also performed on a full-scale vehicle through a series of drawbar pull tests in the Lunar terrain strength simulant, GRC-1. The effect of tire stiffness was also compared; typically compliant tires provide better traction when driving in soft soil, however it's been observed that rigid wheels may provide better thrust when non-rolling. Initial tests indicate up to a possible 40% increase in pull force capability at high slip when inching vs. rolling.}
}
  17. Schepelmann, A. and Gerdts, S. (2022). Characterization of Infrared Optical Motion Tracking System in NASA's Simulated Lunar Operations (SLOPE) Laboratory . NASA, NASA/TM-20220005304. Source
    BibTeX
    @techreport{schepelmann2022characterization,
  title = {Characterization of Infrared Optical Motion Tracking System in NASA's Simulated Lunar Operations (SLOPE) Laboratory},
  author = {Schepelmann, Alexander and Gerdts, Stephen},
  number = {NASA/TM-20220005304},
  institution = {NASA},
  year = {2022},
  url = {https://ntrs.nasa.gov/citations/20220005304},
  abstract = {This work characterizes the accuracy of a 16 camera OptiTrack motion tracking system installed in NASA Glenn Research Center's Simulated Lunar Operations (SLOPE) laboratory.  The position of a rigid body mounted on a motorized linear stage is compared to its position reported by the motion tracking system as it travels through the facility's 777m$^3$ capture volume of interest.  Experiments show that the mean error reported by the motion tracking system for the aggregate capture volume is in-line with independent measurements collected using the motion stage.  Error within regions of the capture volume exceed the mean error reported by the motion tracking system, likely due to occlusion, and suggests that additional cameras should be used to increase measurement accuracy in these regions.  Overall, results show that error values reported by the motion tracking system are representative of the measurement error in a collected data set and validates the system's use for characterizing the mobility and tractive performance of robots, rovers, and other vehicles for planetary exploration.}
}
  18. Schepelmann, A., Creager, C. M., Proctor, M. P., Johnson, K. A., Breckenridge, J. R., Elmland, A., Naghipour Ghezeljeh, P. and Oravec, H. A. (2025). An Overview of Tire-Ground Contact Modeling Approaches for Surface Mobility Applications . NASA Glenn Research Center, NASA/TM-20250006958. Source
    BibTeX
    @techreport{schepelmann2025overview,
  title = {An Overview of Tire-Ground Contact Modeling Approaches for Surface Mobility Applications},
  author = {Schepelmann, Alexander and Creager, Colin M. and Proctor, Margaret P. and Johnson, Kyle A. and Breckenridge, John R. and Elmland, Asher and Naghipour Ghezeljeh, Paria and Oravec, Heather A.},
  number = {NASA/TM-20250006958},
  institution = {NASA Glenn Research Center},
  year = {2025},
  url = {https://ntrs.nasa.gov/citations/20250006958},
  abstract = {Wheels and tires serve as the critical interface between vehicles and the ground, enabling traction, force transmission, and ultimately mobility. As planetary exploration systems adopt increasingly complex wheel and tire designs, look to explore increasingly extreme terrains, and adopt increasingly aggressive performance requirements, physics-based modeling has become essential for both designing these mechanisms and predicting performance under conditions that are difficult or impractical to replicate experimentally, such as reduced gravity. This paper provides a high-level overview of commonly used modeling approaches for simulating tireground interaction, including those currently employed or under development at NASA Glenn Research Center, NASA Johnson Space Center, and the Jet Propulsion Laboratory. The paper first categorizes modeling techniques based on their fidelity and underlying assumptions. It then discusses the applications, benefits, and limitations of each approach, highlighting current knowledge gaps and modeling challenges. Finally, the paper outlines ongoing and future work aimed at addressing these limitations, including initial results from automated soil preparation experiments that support the generation of consistent physical test data and the development of terramechanics simulations for evaluating and comparing model fidelity.}
}
  19. Buse, F. (2015). Machbarkeitsstudie für einen roboterbasierten Radprüfstand zur Entwicklung von Mars- und Mondrovern. Source
    BibTeX
    @mastersthesis{buse2015machbarkeitsstudie,
  title = {Machbarkeitsstudie für einen roboterbasierten Radprüfstand zur Entwicklung von Mars- und Mondrovern},
  author = {Buse, Fabian},
  school = {Rheinisch-Westfälische Technische Hochschule Aachen},
  type = {Master's thesis},
  year = {2015},
  url = {https://elib.dlr.de/97400/}
}
  20. Buse, F. (2019). Fully Automated Single Wheel Testing with the DLR Terramechanics Robotics Locomotion Lab (TROLL) . Symposium on Advanced Space Technologies in Robotics and Automation. Source
    BibTeX
    @inproceedings{buse2019fully,
  title = {Fully Automated Single Wheel Testing with the {DLR} Terramechanics Robotics Locomotion Lab ({TROLL})},
  author = {Buse, Fabian},
  booktitle = {Symposium on Advanced Space Technologies in Robotics and Automation},
  organization = {European Space Agency},
  address = {Noordwijk, The Netherlands},
  year = {2019},
  url = {https://elib.dlr.de/128404/}
}
  21. Kern, J. M., Hurrell, J. M., Santra, S., Takehana, K., Uno, K. and Yoshida, K. (2025). Data-Driven Terramechanics Approach Towards a Realistic Real-Time Simulator for Lunar Rovers . arXiv preprint. Source
    BibTeX
    @article{kern2026data,
  title = {Data-Driven Terramechanics Approach Towards a Realistic Real-Time Simulator for Lunar Rovers},
  author = {Kern, Jakob M. and Hurrell, James M. and Santra, Shreya and Takehana, Keisuke and Uno, Kentaro and Yoshida, Kazuya},
  journal = {arXiv preprint},
  pages = {662-668},
  year = {2025},
  doi = {10.1109/isparo66239.2025.11436587},
  abstract = {High-fidelity simulators for the lunar surface provide a digital environment for extensive testing of rover operations and mission planning. However, current simulators focus on either visual realism or physical accuracy, which limits their capability to replicate lunar conditions comprehensively. This work addresses that gap by combining high visual fidelity with realistic terrain interaction for a realistic representation of rovers on the lunar surface. Because direct simulation of wheel-soil interactions is computationally expensive, a data-driven approach was adopted, using regression models for slip and sinkage from data collected in both full-rover and single-wheel experiments and simulations. The resulting regression-based terramechanics model accurately reproduced steady-state and dynamic slip, as well as sinkage behavior, on flat terrain and slopes up to 20°, with validation against field test results. Additionally, improvements were made to enhance the realism of terrain deformation and wheel trace visualization. This method supports real-time applications that require physically plausible terrain response alongside high visual fidelity.}
}
  22. Cloud, J. M., Nick, A. J., Buckles, B. C., Dixon, K. L., Muller, T. J., Ortega, V. V., Smith, J. D., Clark, C. J., Dyas, J. E., Zhang, E. L., Leucht, K. W., Mueller, R. P. and Schuler, J. M. (2025). The IPEx Autonomy Test-Site: Terrestrial Testing of Autonomous Excavation in Lunar South Pole Conditions . ASCE Earth and Space Conference, 20250000128. Source
    BibTeX
    @inproceedings{cloud2025ipex,
  title = {The IPEx Autonomy Test-Site: Terrestrial Testing of Autonomous Excavation in Lunar South Pole Conditions},
  author = {Cloud, Joseph M. and Nick, Andrew J. and Buckles, Bradley C. and Dixon, Kyle L. and Muller, Thomas J. and Ortega, Victoria V. and Smith, Jonathan D. and Clark, Casey J. and Dyas, Jeffrey E. and Zhang, Elizabeth L. and Leucht, Kurt W. and Mueller, Robert P. and Schuler, Jason M.},
  booktitle = {ASCE Earth and Space Conference},
  number = {20250000128},
  pages = {1-14},
  institution = {NASA},
  year = {2025},
  doi = {10.1109/aero63441.2025.11068688},
  abstract = {NASA's Artemis program aims to send humans to the lunar south pole (LSP), requiring in-situ resource utilization (ISRU) technologies like the ISRU Pilot Excavator (IPEx) to perform site preparation and resource extraction. The LSP is a uniquely challenging environment, characterized by low solar angles and long shadows that disrupt vision-based autonomy. To approximate these conditions, we developed the IPEx autonomy test-site, a 21.3×33.5 m enclosed area for testing excavation technologies under simulated LSP conditions. The test-site is equipped with granular material, scattered rocks, and a full-scale lander model. Strategically placed high-power lights replicate the low solar angles, while a motion capture system offers ground truth robot poses. Additional site awareness cameras provide complete coverage of the test area for monitoring. The test-site has been utilized to evaluate performance of both autonomous navigation and excavation tasks. Finally, we discuss initial results obtained from test runs, calculations compared against a digital simulation, features of the terrain that mimic the visual properties of lunar regolith, and challenges observed.}
}
  23. Clark, C. J., Smith, J. D., Nick, A. J., Ortega, V. V., Schuler, J. M., Dyas, J. E. and Lahl, J. (2025). Design and Testing of TRL5 IPEx Actuators . IEEE Aerospace Conference, 20250000003. Source
    BibTeX
    @inproceedings{clark2025design,
  title = {Design and Testing of TRL5 IPEx Actuators},
  author = {Clark, Casey J. and Smith, Jonathan Drew and Nick, Andrew J. and Ortega, Victoria V. and Schuler, Jason M. and Dyas, Jeffrey E. and Lahl, John},
  booktitle = {IEEE Aerospace Conference},
  number = {20250000003},
  institution = {NASA},
  address = {Big Sky, MT},
  year = {2025},
  url = {https://ntrs.nasa.gov/citations/20250000003},
  abstract = {NASA is advancing In-Situ Resource Utilization (ISRU) by focusing on missions aimed at establishing sustainable infrastructure on the Moon and Mars. On the Moon, regolith serves as the most abundant resource. To support ISRU objectives, a 30-kg-class robot called ISRU Pilot Excavator (IPEx) is being developed to excavate 10,000 kg of lunar regolith during a future technology demonstration mission. IPEx uses novel excavation tools, called bucket drums, which are hollow cylinders with scoops staggered around the outside. Regolith is collected with the scoops and flows into the drum where it is captured by an internal baffle system. The excavator can then transport the regolith in the drum and reverse the direction of the drum rotation to dispense the regolith out. IPEx uses two sets of bucket drums that dig simultaneously in opposing directions and results in counteracting excavation forces. This combination of bucket drum excavation tools and counteracting excavation forces enables low mass robotic excavators to effectively dig in reduced gravity environments. This is a significant departure from terrestrial excavators that rely on high mass to produce tractive forces to counteract the forces of excavation.

IPEx is made up of several custom actuators that all need to be verified for their intended application. This paper focuses on the initial design, testing and modifications of three actuators: the mobility actuator, the shoulder actuator, and the excavation actuator.

Each actuator was tested under four separate test profiles: ambient motor characterization, hot and cold motor characterization, accelerated life test (ALT), and concept of operations (ConOps) test. The motor characterization tests enabled derivation of torque equations for each actuator to estimate output torque without implementing sensors. The accelerated life tests were successful for each actuator and verified the motors’ ability to survive the mission. For the ConOps test, only the bucket drum actuator performed a complete ConOps without the need to restart the test. Overall, the first series of testing resulted in various failure modes and minor design alterations for each actuator. The test results, failure modes, and design alterations are highlighted within this paper. This paper focuses on discussing the mobility, excavation, and shoulder actuator design, testing principles, and results that qualified it as a TRL 5 system.}
}
  24. Schuler, J., Nick, A., Leucht, K., Langton, A. and Smith, D. (2022). ISRU Pilot Excavator: Bucket Drum Scaling Experimental Results . ASCE Earth and Space Conference, 20210025846. Source
    BibTeX
    @inproceedings{schuler2022isru,
  title = {ISRU Pilot Excavator: Bucket Drum Scaling Experimental Results},
  author = {Schuler, Jason and Nick, Andrew and Leucht, Kurt and Langton, Austin and Smith, Drew},
  booktitle = {ASCE Earth and Space Conference},
  number = {20210025846},
  pages = {394-407},
  institution = {NASA},
  year = {2022},
  doi = {10.1061/9780784484470.037},
  abstract = {NASA’s Space Technology Mission Directorate (STMD) is funding the development of a robotic excavator called the “ISRU Pilot Excavator” (IPEx) which will be a technology demonstration of excavating and transporting 10 metric tons of lunar regolith on the surface of the Moon with a 30 kg-class robotic excavator. IPEx will be the next generation of robotic excavators to use bucket drums as excavation tools. This is an evolution of the regolith advanced surface systems operations robot (RASSOR) developed at NASA’s Kennedy Space Center (KSC). Bucket drums are hollow cylinders with regularly spaced scoops around the perimeter. The drums rotate in one direction to collect regolith with the scoops. The regolith slides down an internal baffling system inside the drum which prevents the regolith from falling back out of the scoops. The captured regolith can then be transported while held in the drum and then deposited by rotating the drum in the opposite direction allowing the regolith to slide back down the baffling and out of the excavation scoops. Bucket drums were developed by Lockheed Martin in 2008 and used on multiple robotic excavator prototypes ever since. However, the forces on a bucket drum and considerations for scaling have not been measured in detail. Bucket drums are challenging to model using classical blade\bucket equations because of their unique geometry. Therefore, this experiment was performed to measure the forces on three bucket drums of the same geometry at different scales. Small: 9.4” (239 mm) dia. × 8.1” (206 mm) width, medium: 11.6” (294 mm) dia. × 10” (254 mm) width, and large: 17” (432 mm) dia. × 14.1” (358 mm) width. The test stand consisted of an actuated gantry with controlled motion in the vertical (Z) and horizontal (X) axes and a single rotation axis (R). The bucket drums were individually mounted to the rotary axis of the test stand and translated across a prepared bed of Black Point 1 (BP-1) lunar regolith simulant at a specified linear speed and cutting depth. The test stand was outfitted with a torque sensor in line with the rotation of the drum (R) and a 3 axis (X, Y, and Z) load cell. In addition to the three sizes of bucket drums the linear excavation speed and cutting depth were test variables. The results of these experiments show the relationship between the three scales of bucket drums for factors such as: excavation force, torque due to regolith rotation inside the drum, excavation energy, time to fill, etc. and will be discussed in detail in this paper. This fundamental data will be used in the design of IPEx and can inform the design of future bucket drum excavators.}
}
  25. Boelter, S., Brown, G., Stucky, T., Temesgen, E., Mai, R., Weber, L., Gini, M., Bergman, D., Fortuin, C., Glass, B. and Wilhelm, M. (2026). TRIDENT Drill Performance and Subsurface Fault and Anomaly Detection in Antarctic Environments . Annals of Glaciology. Source
    BibTeX
    @article{boelter2026trident,
  title = {TRIDENT Drill Performance and Subsurface Fault and Anomaly Detection in Antarctic Environments},
  author = {Boelter, Sarah and Brown, Greta and Stucky, Thomas and Temesgen, Ebasa and Mai, Rene and Weber, Lucas and Gini, Maria and Bergman, Dean and Fortuin, Carter and Glass, Brian and Wilhelm, Marybeth},
  journal = {Annals of Glaciology},
  year = {2026},
  url = {https://ntrs.nasa.gov/citations/20260007172},
  abstract = {The Regolith and Ice Drill for Exploring New Terrain (TRIDENT), a 1-meter rotary percussive drill developed by Honeybee Robotics, is designed for extraterrestrial subsurface exploration. Because extraterrestrial drilling cannot rely on prior subsurface characterization or direct human operation, adaptive state estimation and anomaly detection are necessary for reliable autonomous drilling. We evaluate TRIDENT’s drilling performance in planetary analog environments during fieldwork in Schirmacher Oasis and Lake Untersee, Antarctica, including cold-desert permafrost terrain, glacially smoothed rock, ice-covered surfaces, subsurface frozen boundary layers, and ice-rock transitions representative of planetary subsurfaces. This paper investigates subsurface fault and anomaly detection methods for planetary drilling with minimal prior training data while further characterizing TRIDENT’s operational performance across representative analog terrains.}
}
  26. Carey, W., Krueger, T., Wormnes, K., Grenouilleau, J., Ferreira, E., Nergaard, K., van der Hulst, F., den Exter, E. and Gerdes, L. (2022). METERON Analog-1: A Touch Remote . International Astronautical Congress, IAC-22-A3.2B.4. Source
    BibTeX
    @inproceedings{carey2022meteron,
  title = {METERON Analog-1: A Touch Remote},
  author = {Carey, William and Krueger, Thomas and Wormnes, Kjetil and Grenouilleau, Jessica and Ferreira, Edmundo and Nergaard, Kim and van der Hulst, Frank and den Exter, Emiel and Gerdes, Levin},
  booktitle = {International Astronautical Congress},
  number = {IAC-22-A3.2B.4},
  year = {2022},
  url = {https://elib.dlr.de/190115/}
}
  27. Alexandrov, O., Barlow, J., Benavides, J., Bualat, M., Carlino, R., Coltin, B., Cortez, J., Daley, E., Feller, J., Flückiger, L., Fong, T., Fusco, J., Garcia Ruiz, R., Hamilton, K., Kanis, S., Katterhagen, A., Kim, Y., Love, J. F., McIntyre, M., McLachlan, B., Mora Vargas, A., Moratto, Z., Moreira, M., Morse, T., Orosco, H., Park, I.-W., Provencher, C., Sanchez, H., Sharif, K., Smith, E., Smith, T., Soussan, R., Symington, A., Talavera, R. O., To, V., Wheeler, D. and Yoo, J. (2026). Astrobee: Free-Flying Robots for the International Space Station . IEEE Transactions on Field Robotics. Source
    BibTeX
    @article{alexandrov2026astrobee,
  title = {Astrobee: Free-Flying Robots for the International Space Station},
  author = {Alexandrov, Oleg and Barlow, Jonathan and Benavides, Jose and Bualat, Maria and Carlino, Roberto and Coltin, Brian and Cortez, Jose and Daley, Earl and Feller, Jeffrey and Flückiger, Lorenzo and Fong, Terrence and Fusco, Jesse and Garcia Ruiz, Ruben and Hamilton, Kathryn and Kanis, Simeon and Katterhagen, Aric and Kim, Yunkyung and Love, John F. and McIntyre, Michael and McLachlan, Blair and Mora Vargas, Andres and Moratto, Zack and Moreira, Marina and Morse, Theodore and Orosco, Henry and Park, In-Won and Provencher, Christopher and Sanchez, Hugo and Sharif, Khaled and Smith, Ernest and Smith, Trey and Soussan, Ryan and Symington, Andrew and Talavera, Rafael Omar and To, Vinh and Wheeler, DW and Yoo, Jongwoon},
  journal = {IEEE Transactions on Field Robotics},
  year = {2026},
  url = {https://ntrs.nasa.gov/citations/20260001396},
  abstract = {The Astrobees are free-flying robots that operate inside the International Space Station (ISS) and were launched to the ISS
in 2019. Since then they have successfully performed hundreds of activities in space supporting almost two dozen separate
research projects. The robots were designed to overcome multiple challenges unique to the ISS environment, including safety,
upgradeability and maintainability, limited mass and computation, and unique localization challenges from lack of gravity and a
constantly changing environment. This article provides an overview of Astrobee, from hardware and software design to deployment
results and activities.}
}
  28. Yamaguchi, S. P., Mora Vargas, A., Eisenberg, T., Rogon, C., Yamamoto, T., Inoue, S., Kössl, C., Coltin, B., Smith, T. and Benavides, J. V. (2025). Free-Flying Crew Cooperative Robots on the ISS: A Joint Review of Astrobee, CIMON, and Int-Ball Operations . International Conference on Space Robotics. Source
    BibTeX
    @inproceedings{yamaguchi2026free,
  title = {Free-Flying Crew Cooperative Robots on the ISS: A Joint Review of Astrobee, CIMON, and Int-Ball Operations},
  author = {Yamaguchi, Seiko Piotr and Mora Vargas, Andres and Eisenberg, Till and Rogon, Christian and Yamamoto, Tatsuya and Inoue, Shona and Kössl, Christoph and Coltin, Brian and Smith, Trey and Benavides, Jose V.},
  booktitle = {International Conference on Space Robotics},
  pages = {402-409},
  year = {2025},
  doi = {10.1109/isparo66239.2025.11436992},
  abstract = {Intra-vehicular free-flying robots are anticipated to support various work in human spaceflight while working side-by-side with astronauts. Such example of robots includes NASA’s Astrobee, DLR’s CIMON, and JAXA’s Int-Ball, which are deployed on the International Space Station. This paper presents the first joint analyses of these robot’s shared experiences, co-authored by their development and operation team members. Despite the different origins and design philosophies, the development and operations of these platforms encountered various convergences. Hence, this paper presents a detailed overview of these robots, presenting their objectives, design, and onboard operations. Hence, joint lessons learned across the lifecycle are presented, from design to on-orbit operations. These lessons learned are anticipated to serve for future development and research as design recommendations.}
}
  29. Papadopoulos, E., Aghili, F., Ma, O. and Lampariello, R. (2021). Robotic Manipulation and Capture in Space: A Survey . Frontiers in Robotics and AI. Source
    BibTeX
    @article{papadopoulos2021robotic,
  title = {Robotic Manipulation and Capture in Space: A Survey},
  author = {Papadopoulos, Evangelos and Aghili, Farhad and Ma, Ou and Lampariello, Roberto},
  journal = {Frontiers in Robotics and AI},
  volume = {8},
  pages = {686723},
  year = {2021},
  doi = {10.3389/frobt.2021.686723},
  abstract = {Space exploration and exploitation depend on the development of on-orbit robotic capabilities for tasks such as servicing of satellites, removing of orbital debris, or construction and maintenance of orbital assets. Manipulation and capture of objects on-orbit are key enablers for these capabilities. This survey addresses fundamental aspects of manipulation and capture, such as the dynamics of space manipulator systems (SMS), i.e., satellites equipped with manipulators, the contact dynamics between manipulator grippers/payloads and targets, and the methods for identifying properties of SMSs and their targets. Also, it presents recent work of sensing pose and system states, of motion planning for capturing a target, and of feedback control methods for SMS during motion or interaction tasks. Finally, the paper reviews major ground testing testbeds for capture operations, and several notable missions and technologies developed for capture of targets on-orbit.}
}
  30. Alizadeh, A. and Zhu, Z. H. (2024). A comprehensive survey of space robotic manipulators for on-orbit servicing . Frontiers in Robotics and AI. Source
    BibTeX
    @article{alizadeh2024comprehensive,
  title = {A comprehensive survey of space robotic manipulators for on-orbit servicing},
  author = {Alizadeh, Ali and Zhu, Zheng H.},
  journal = {Frontiers in Robotics and AI},
  volume = {11},
  pages = {1470950},
  year = {2024},
  doi = {10.3389/frobt.2024.1470950},
  abstract = {On-Orbit Servicing (OOS) robots are transforming space exploration by enabling vital maintenance and repair of spacecraft directly in space. However, achieving precise and safe manipulation in microgravity necessitates overcoming significant challenges. This survey delves into four crucial areas essential for successful OOS manipulation: object state estimation, motion planning, and feedback control. Techniques from traditional vision to advanced X-ray and neural network methods are explored for object state estimation. Strategies for fuel-optimized trajectories, docking maneuvers, and collision avoidance are examined in motion planning. The survey also explores control methods for various scenarios, including cooperative manipulation and handling uncertainties, in feedback control. Additionally, this survey examines how Machine learning techniques can further propel OOS robots towards more complex and delicate tasks in space.}
}
  31. Mulvaney, J., Arney, D., Williams, C., Morel, J., Stockdale, C., Whitlock, C. and Balaji, V. (2025). In-Space Servicing, Assembly, and Manufacturing (ISAM) State of Play, 2025 Edition . NASA, 20250008988. Source
    BibTeX
    @techreport{nasa2025space,
  title = {In-Space Servicing, Assembly, and Manufacturing (ISAM) State of Play, 2025 Edition},
  author = {Mulvaney, John and Arney, Dale and Williams, Christina and Morel, Jose and Stockdale, Christopher and Whitlock, Christopher and Balaji, Vishruth},
  number = {20250008988},
  institution = {NASA},
  year = {2025},
  url = {https://ntrs.nasa.gov/citations/20250008988},
  abstract = {The future of spaceflight will yield increasingly more ambitious missions to support civil, national security, 
and commercial space sectors. Achieving some of these missions will not be feasible by launching an 
integrated, fully functioning system on a single launch vehicle. Future science and human exploration 
missions will require payloads that are larger than any foreseeable launch vehicle fairing, national security 
missions will require persistent assets that are mobile and resilient, and commercial space missions will 
require cost-effective ways to update to the latest technology on orbit.

In-space Servicing, Assembly, and Manufacturing (ISAM) can vastly expand the performance, availability, 
and lifetime of space systems compared to the traditional paradigm of launching an asset with no intent 
to ever interact with it again. ISAM capabilities foster an ecosystem that changes the space operations 
paradigm, creating the foundation for sustainable exploration and serving as a multiplier for other 
capabilities like space logistics, power generation, and reusability.

Previous achievements in ISAM have enabled ambitious human and robotic space missions. The 
assembly, operation, and maintenance of NASA’s International Space Station (ISS); servicing missions to
the Hubble Space Telescope (HST); and Northrop Grumman’s Mission Extension Vehicle (MEV) 
demonstrate the dramatic operational missions that can be achieved using ISAM capabilities. Many 
current and upcoming flight demonstrations are advancing areas that will enable the next generation of 
civil, national security, and commercial space missions.

This document describes the current state of ISAM missions, activities, and technologiesto the best ability 
of the authors. Compiling and organizing the available ISAM capabilities will help mission designers 
incorporate ISAM technologies into their concepts, create the starting point for technology development 
plans and roadmaps, and provide technologists a survey of the field they are developing. This document 
divides the ISAM capabilities into 11 functional capability areas that describe the functions or activities 
that can be performed in space using ISAM.}
}
  32. OSAM-1 Independent Review Board. (2024). Final Report of the OSAM-1 Independent Review Board . NASA. Source
    BibTeX
    @techreport{osam2024final,
  title = {Final Report of the OSAM-1 Independent Review Board},
  author = {{OSAM-1 Independent Review Board}},
  institution = {NASA},
  year = {2024},
  url = {https://www.nasa.gov/wp-content/uploads/2023/02/osam-1-irb-final-report-022729-cleared-redacted-20mar2024.pdf}
}
  33. Naasz, B. J., Strube, M., Van Eepoel, J., Barbee, B. W. and Getzandanner, K. M. (2011). Satellite Servicing's Autonomous Rendezvous and Docking Testbed on the International Space Station . Annual AAS Rocky Mountain Section Guidance and Control Conference, 20180000044. Source
    BibTeX
    @inproceedings{naasz2011satellite,
  title = {Satellite Servicing's Autonomous Rendezvous and Docking Testbed on the International Space Station},
  author = {Naasz, Bo J. and Strube, Matthew and Van Eepoel, John and Barbee, Brent W. and Getzandanner, Kenneth M.},
  booktitle = {Annual AAS Rocky Mountain Section Guidance and Control Conference},
  number = {20180000044},
  institution = {NASA},
  address = {Breckenridge, CO},
  year = {2011},
  url = {https://ntrs.nasa.gov/citations/20180000044},
  abstract = {The Space Servicing Capabilities Project (SSCP) at NASA's Goddard Space Flight Center (GSFC) has been tasked with developing systems for servicing space assets. Starting in 2009, the SSCP completed a study documenting potential customers and the business case for servicing, as well as defining several notional missions and required technologies. In 2010, SSCP moved to the implementation stage by completing several ground demonstrations and commencing development of two International Space Station (ISS) payloads-the Robotic Refueling Mission (RRM) and the Dextre Pointing Package (DPP)--to mitigate new technology risks for a robotic mission to service existing assets in geosynchronous orbit. This paper introduces the DPP, scheduled to fly in July of 2012 on the third operational SpaceX Dragon mission, and its Autonomous Rendezvous and Docking (AR&D) instruments. The combination of sensors and advanced avionics provide valuable on-orbit demonstrations of essential technologies for servicing existing vehicles, both cooperative and non-cooperative.}
}