Astra
A lunar terrain vehicle seating system
Industry
Aerospace
Systems
▸ HFE & HCD
▸ 3D Modeling & VR Simulation
▸ Rapid Prototyping
▸ User testing
Credits
▸ Lead designer & researcher: Jessica Paola Sanchez Russi
▸ Advisory board: Associate Prof. Jeff F. Feng, Elham Morshedzadeh, Ph.D., Gordon A. Vos, Ph.D., and Associate Prof. Larry Toups
▸ Simulation and testing support: Vittorio Netti, Paolo Mangili, and the Sasakawa International Center for Space Architecture (SICSA)
NASA's Artemis program relies on the Lunar Terrain Vehicle (LTV) as an unpressurized mobility platform to expand astronaut exploration ranges. The core conflict is that astronauts operating in the lunar environment must wear bulky, 50-pound Exploration Extravehicular Mobility Units (xEMU) that severely restrict mobility, dexterity, and visibility. Traditional seating designs force suited astronauts into restrictive postures, leading to fatigue, reduced operational effectiveness, and physical strain. If the LTV seating system fails to accommodate both the rigid constraints of the xEMU suit and the diverse anthropometry of the crew, it introduces a critical risk of user error, injury during ingress/egress, and compromised mission safety during terrain navigation and sample collection.
A detailed task analysis of Apollo EVAs and experiential benchmarking across terrestrial vehicles revealed that conventional seated postures require excessive leg room and hip flexion, while standing postures induce rapid fatigue over long durations. During initial VR testing, data showed that traditional static seating forced astronauts to hunch forward, as the suit's Portable Life Support System (PLSS) lacked dedicated rear support, causing immediate lower back pressure and discomfort. The solution demanded a humans-first approach: the seating could not be a static fixture the human had to conform to. It required radical adaptive functionality, a dynamic, dual-position system allowing astronauts to fluidly transition between a high-visibility leaning posture and a stable seated posture, directly mitigating the physical limitations of the xEMU suit.
The development utilized a rigorous Human-Centered Design methodology, moving from contextual task analysis to tangible validation. We built a low-to-mid-fidelity physical LTV structure using MDF and aluminum, covered in a green screen, and paired it with a high-fidelity Unreal Engine VR simulation to conduct Human-in-the-Loop (HIL) testing.
Early pilot testing with a padded suit proxy revealed that front-mounted control boxes obstructed movement. We pivoted the restraint system design, adapting an amusement-park-style lap bar mounted on a telescopic rod that rotates at its base, simultaneously serving as a secure handhold during the difficult ingress phase.
To ensure adaptive functionality without compromising rover resources, the seat required manual mechanical systems, a screw jack for height and a counterbalance mechanism for unfolding, because electrical or hydraulic systems present unacceptable maintenance liabilities in the lunar vacuum. We utilized coated aluminum for the frame and hyper elastic polymers for the cushioning because these materials dampen vehicle vibration, endure the -173°C to 127°C lunar temperature extremes, and conform to the astronaut's movements. A flexible Kevlar mesh was engineered into the rear of the seat to securely suspend the PLSS backpack, allowing astronauts to recline without overextending.
