Workshop on Golden Spike Human Lunar Expeditions (2013) 6008.pdf

MULTI-MISSION VEHICLE (MMSEV): AN EVA AND ROBOTICS WORK- SYSTEM FOR MULTIPLE DESTINATIONS. A. F. J. Abercromby1, S. P. Chappell1, and M. L. Gernhardt2, 1 Wyle Science, Technology, and Engineering, , TX 77058, USA, (andrew.abercromby-1@.gov), 2 National Aeronautics and Space Administration, NASA , Houston, TX 77058, USA. Vision: The Multi-Mission Space Exploration Ve- MMSEV Features: MMSEVs optimize hicle (MMSEV) is an EVA and robotics work system safety and performance during exploration by combin- optimized at the level of astronaut performance and ing a comfortable shirtsleeve environment for habita- safety rather than at the subsystem level with key fea- tion, gross translations, and geological observations, tures including: EVA-equivalent visibility, low- with the ability to rapidly place suited out- overhead EVA, and protection against solar particle side the vehicle to take full advantage of the percep- events. The MMSEV uses a modular approach with a tion, judgment, and dexterity of EVA astronauts. Low- low-volume, high-function core cabin that is kitted with overhead EVA capability is achieved via “step-in” different mobility and work packages making it exten- space suits and suit ports, which allow crewmembers to sible to multiple mission destinations and applications. egress or ingress the vehicle in 15 minutes or less with Originally developed as a small pressurized rover minimal consumables or energy usage [5], improving for human lunar exploration missions, MMSEV proto- productivity and ensuring rapid EVA ingress and types have been developed for multiple destinations egress to and from the shelter of the MMSEV in re- and applications using the same core cabin design out- sponse to solar particle events, suit malfunctions, med- fitted differently for each case. A small multi-center ical emergencies, or cabin depressurization. Compared team rapidly designed, built, and tested two prototype with unpressurized astronaut mobility systems, this planetary MMSEVs from 2007–2010 [1-3]. A third combination of features could more than double the MMSEV prototype incorporates a cabin module modi- productivity of human exploration while requiring less fied from the planetary MMSEVs and a modular reac- than half the suited crew time and eliminating the over- tion control system sled designed for free-flying micro- head of returning to a habitat at the end of each day [1]. gravity missions to ISS, satellite servicing, or near- MMSEVs are envisioned as relatively small, sim- Earth asteroids [4]. A fourth prototype is being devel- ple, and low cost vehicles combining elements of the oped for use as a habitable for an in-space habi- EVA suits’ life support systems, with additional con- tat and a fifth was recently built and evaluated for use sumables tankage, cabin circulation fans, passive radia- as a two-person or four-person lunar lander. tors, and an ice block heat sink for removal of cabin Extensibility & Affordability: Multi-mission ap- avionics and crew metabolic heat loads that also dou- plicability provides flexibility in response to changes in bles as radiation protection. MMSEV cabins (12 m3) programmatic direction as well as potentially signifi- are sized to support 2 astronauts in a shirtsleeve envi- cant cost reductions through utilization of an extensible ronment for up to 14 days of exploration, but provide core design for multiple vehicles rather than develop- contingency support for 4 crewmembers for 24 hours; ing optimal point for every potential destina- testing of prototype MMSEVs in integrated mission tion and mission application. The commercial offshore simulations has demonstrated that the MMSEV cabin remotely operated vehicle (ROV) industry uses a design meets these requirements [2, 3]. common propulsion and telemetry bus outfitted for Exploring Beyond Apollo: A low-cost lunar ex- different work applications as a much more cost effec- ploration architecture could begin with 1–2 day mis- tive approach than developing entirely unique ROVs sions using a simple 2-person MMSEV-lander (esti- for every different work application. NASA Air mated cabin wet mass: 2,207 kg) with EVAs performed Cost Model (NAFCOM) estimates suggest significant on foot. Subsequent delivery of a single MMSEV-rover cost savings are also achievable through the MMSEV (estimated 6,075 kg) would provide long-range explo- project’s lean development approach of iterative design ration and 14-day habitation capability, representing and build of increasingly flight-like prototype vehicles meaningful progression beyond Apollo. combined with frequent and rigorous operational test- References: [1] Abercromby, A.F.J., et al, ing at analog test sites and using high-fidelity integrat- NASA/TP 216136. 2010. [2] Abercromby, ed software simulations. This testing provides high A.F.J., et al. Acta Astro, 2012. [3] Abercromby, A.F.J., confidence in design requirements for flight vehicles et al., NASA/TP 217360. 2012. [4] Abercromby, A.F.J., and enables informed decision making when trading et al., 43rd ICES. RATS. 2013. [5] Abercromby, A.F.J., multi-mission applicability against optimization for et al., 43rd ICES. Exploration Prebreathe. 2013 each destination and application.