NASA JSC Planetary Analog Test Site

Joseph Bibby. Public domain (NASA / US government work).

The Planetary Analog Test Site at NASA JSC, universally called the Rock Yard, is an outdoor multi-acre terrain field in five named areas, built for integrated tests that put crew, suits, rovers and robots on the same terrain at the same time [1]. The five areas are the Mars Yard, the Mt Kosmo hill, the Lunar Yard with its three craters, the Sand Pit and the Cat Box, and each is a capability section below.

Three of the five sit on a sprayed concrete underlay, so most of the site is a made surface rather than a deformable soil bed. Nothing on it is a lunar or Martian simulant, and there is no vacuum, no thermal control and no gravity offload outdoors. The indoor JSC facilities that cover those cases sit in other buildings under other organizations [1].

Laboratory data

Parameter	Value
Operator	NASA JSC [1]
Location	Houston, Texas, United States
Commissioned	Not published. In documented rover use by at least 2015
Type	Outdoor analogue terrain field in five named areas
Floor area	Multi-acre; the five areas total roughly 6,000 m2 as dimensioned
Capabilities	Mars Yard, Mt Kosmo, Lunar Yard, Sand Pit, Cat Box
Simulant or terrain	Crushed limestone, decomposed granite, Blackstar granite, basalt, sand, gravel
Instrumentation	None installed. Slope maps and Gazebo world models available for some areas
Ground truth	Not published. No independent position measurement described
Fidelity limits	No simulant, no vacuum, no thermal control; three areas on sprayed concrete
Access	Test planning, consultation and integration offered as a service; no lead time published
Cited by	Robonaut 2 on Centaur 2, Resource Prospector [3]

Capabilities

Mars Yard

Parameter	Value
Working volume	Approximately 40 x 45 m [1]
Test article limits	Suited subjects, Centaur 2 and the RP15 rover run to date [1][3]
Vacuum	Not applicable. Outdoors at ambient pressure
Temperature	Not controlled. Houston outdoor conditions [1]
Illumination	Not applicable. Terrestrial sky; low-light work is done at night
Simulant or terrain	Stabilized crushed limestone and decomposed granite, strewn basaltic rock
Slope	Level. Graded slopes are at Mt Kosmo
Gravity offload	Not available outdoors. Full Earth weight
Instrumentation	None installed. Slope map and Gazebo world model available

The Mars Yard is the reference surface for the site: a stabilized crushed limestone and decomposed granite base covered with strewn basaltic rocks, over an underlay of sprayed concrete [1]. The Resource Prospector team, describing the same yard from a user’s side, gives its rocks as 0.05 m to 1.0 m in height [3].

Mt Kosmo

Parameter	Value
Working volume	Approximately 30 x 43 m, summit about 7 m above the Mars Yard
Temperature	Not controlled. Houston outdoor conditions
Simulant or terrain	Same as the Mars Yard, over sprayed concrete stabilizing the slopes
Slope	Approaches from 15 to over 30 degrees, fixed by construction
Gravity offload	Not available. A rover climbs at full Earth weight
Instrumentation	None installed

Source: [1].

Mt Kosmo is the only graded terrain on the site, and its slopes are set by construction rather than adjustable. The sprayed concrete underlay is there to hold the slopes in place, which also means a climb on it is a climb on a made road [1]. The Resource Prospector description of the site gives a 5 m tall hill and slopes from flat to 20 degrees [3], both lower than the operator’s own figures; neither document reconciles the two.

Lunar Yard

Parameter	Value
Working volume	Approximately 40 x 40 m, with three representative lunar craters
Temperature	Not controlled. Houston outdoor conditions
Simulant or terrain	Stabilized crushed limestone covered with Blackstar granite, over sprayed concrete
Slope	Crater walls only; angles and crater dimensions not published
Gravity offload	Not available. Full Earth weight
Instrumentation	None installed

Source: [1].

The Lunar Yard swaps the Mars Yard’s basaltic surface cover for Blackstar granite and adds the three craters. Crater diameters and depths are not published [1], and the granite is a terrestrial aggregate rather than a lunar simulant.

Sand Pit

Parameter	Value
Working volume	Approximately 15 x 30 m; depth not published
Simulant or terrain	Masonry sand over local soil, mostly unconsolidated clay
Gravity offload	Not available. Full Earth weight
Instrumentation	None installed

Source: [1].

One of the two deformable areas on the site, and the only one described purely as sand. No depth, relative density target or preparation procedure between tests is published [1].

Cat Box

Parameter	Value
Working volume	Approximately 14 x 50 m; depth not published
Simulant or terrain	Coarse gravel with masonry sand at one end, over local soil
Slope	Set by sculpting; range not published
Gravity offload	Not available. Full Earth weight
Instrumentation	None installed

Source: [1].

The Cat Box is the reconfigurable area: the only one the operator describes as supporting limited sculpting into various terrain, which makes it the place where a specific crater, berm or trench geometry can be built for a campaign [1].

Instrumentation

The published facility description lists terrain data as an available product rather than instrumentation as an installed capability: slope maps and Gazebo world models exist for some areas [1]. No permanent motion capture, total station or load instrumentation is described for any of the five areas, unlike the Glenn and Kennedy soil bins, so a slip or sinkage measurement made here rests on the article’s own sensing.

Site support is 110 V and 220 V AC electrical power, the latter on an SS2-50R outlet, a climate-controlled work and mission support area with 110 V power, limited non-climate-controlled storage during testing, pop-up shade canopies, and space suit hardware and test subject support on an as-required cost basis [1].

What it does not reproduce

Deformable terrain, over most of the site. Three of the five areas sit on a sprayed concrete underlay beneath a stabilized aggregate base [1]. Sinkage, slip and drawbar pull on those surfaces are properties of a made road, not of regolith. The Sand Pit and Cat Box are the exceptions, and the Cat Box is the only area described as reconfigurable.

Regolith of any kind. The listed materials are crushed limestone, decomposed granite, Blackstar granite, basalt, masonry sand, coarse gravel and local clay [1]. No lunar or Martian simulant appears in the facility description, and no preparation or density control procedure is published, which is the structural difference between this site and the GMRO bins or the Glenn SLOPE lanes.

Lighting. The site is outdoors under Earth’s sky and atmosphere. Low solar elevation and the hard shadow of the lunar south pole are not producible; night operations are the substitute [1], and the lunar lighting problem is addressed instead in the rendered visual model driving the B16 motion table described below [2].

Gravity. Nothing outdoors offloads. A rover driving the Mars Yard or climbing Mt Kosmo does so at full Earth weight [1].

Weather. Houston conditions apply. The published service list offers pop-up shade canopies and a climate-controlled support area, which locates the problem [1].

Campaigns run there

Resource Prospector RP15 distributed operations, 2015. RP15 was a Phase A engineering test unit taken from concept to a rover driving in the lunar analogue Rock Yard within a single year [3]. The point of running it there was to validate fully distributed operations: the driver and co-driver worked from Ames, rover systems from Johnson and payload operations from Kennedy, with command allocations refined through fortnightly procedural simulations that began on paper and voice calls and then added data from a processor-in-the-loop rig. The rover was driven by waypoints, sized against an expected round trip command and control time of six to over 25 seconds for the flight mission [3]. Its flight software was built on NASA’s Core Flight Software, and the 2015 build 1 provided hardware interfaces, basic mobility, waypoint driving, odometry and inertial measurement unit localization, basic error checking and camera services. The team records that the rover was capable of operating in the yard by day and by night [3].

Robonaut 2 on Centaur 2, February 2011. The Centaur 2 wheeled base, derived from lessons learned on the Space Exploration Vehicle, was integrated with Robonaut 2 and run at the Planetary Analog Test Site [1].

Other NASA JSC facilities named in the same catalog

The NASA JSC analogs and mockups catalog that describes the Rock Yard also lists several indoor facilities [1], and a 2024 full paper describes a further one [2]. They sit in different buildings under different organizations, they are not part of this test site, and none of them has a published description detailed enough to carry a laboratory page of its own yet, so their figures are recorded here in prose.

NASA. Public domain (NASA / US government work).

Chamber B is the human-rated thermal vacuum capability: an internal volume 7.6 m (25 ft) in diameter by 7.9 m (26 ft), a pressure range from 1 x 10^-6 torr to 760 torr and a low temperature range of -300 F, with a traversing monorail that provides weight relief to one suited crew member at a time and dual crew airlocks for access and for moving test crew in and out during a test [1].

ARGOS, the Active Response Gravity Offload System, has its own page: NASA JSC Active Response Gravity Offload System. It is an overhead bridge crane arrangement 41 x 24 x 25 ft overall giving a 13 x 30 x 15 ft workspace at 750 lb offload capability, with gimbal payload interfaces for suited, unsuited and unmanned articles, pressurized breathing air, suit cooling water and AIBEL motion tracking [1].

The Partial Gravity Simulator is servos, air bearings and gimbals providing reduced gravity simulation for astronaut training, task evaluation and EVA equipment development [1]. The Precision Air Bearing Floor is a flat, smooth surface giving two-dimensional frictionless motion to large articles floated on perforated pads over a cushion of compressed air, for rendezvous and contact testing and low or zero g mass handling. The Building 360 Lunar Development and Dust Containment Room covers dust work [1].

The B16 six degree of freedom motion table is the newest addition. Installed in the B16 Mini Dome at the Systems Engineering Simulator and commissioned by Mikrolar in January 2023, it carries 2,500 lb on a 69.25 in platform with plus or minus 25 in of horizontal travel, plus or minus 12 in vertical, plus or minus 28 degrees of roll, pitch and yaw, and 1 mm repeatability and accuracy across all six axes, with mechanical brakes on every axis [2]. It drives a lunar south pole visual model built on the Trick simulation framework with a multibody dynamic model of the Lunar Terrain Vehicle front-entry reference design, NASA JSC Engineering Orbital Dynamics model, a nodal electrical power system model in GUNNS, and a contact model, so that a shirt-sleeve subject on the platform feels the physical consequence of driving the simulated rover [2].

It was used in 2022 and 2023 for a preliminary handling qualities study of the LTV front-entry reference design, with a shirt-sleeve subject on the platform driving through a virtual reality view of the lunar south pole [2]. Drivers reported that braking stopped the vehicle quickly, with some describing it as abrupt, twitchy and harsh, and some observed that the one-sixth g environment affected stopping distance. The stated rationale for building it is that the only other lunar rover motion simulator was a modified US Air Force SMK23 flight simulator built at Marshall in the late 1960s, which ran a moving map of a smooth Maria area under a television camera, and that no other lunar surface simulator with these capabilities exists [2].