When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface elementsuch as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.
Most view the Apollo Program as expensive. It was. But, a human mission to Mars will be orders of magnitude more difficult and costly. Recently, NASA's Evolvable Mars Campaign (EMC) mapped out a step-wise approach for exploring Mars and the Mars-moon system. It is early in the planning process but because approximately 80% of the total life cycle cost is committed during preliminary design, there is an effort to emphasize cost reduction methods up front. Amongst the options, commonality across small habitat elements shows promise for consolidating the high bow-wave costs of Design, Development, Test and Evaluation (DDT&E) while still accommodating each end-item's functionality. In addition to DDT&E, there are other cost and operations benefits to commonality such as reduced logistics, simplified infrastructure integration and with inter-operability, improved safety and simplified training. These benefits are not without a cost. Some habitats are sub-optimized giving up unique attributes for the benefit of the overall architecture and because the first item sets the course for those to follow, rapidly developing technology may be excluded. The small habitats within the EMC include the pressurized crew cabins for the ascent vehicle, rover, Mars-moon taxi and exploration vehicle. In addition, the scope of commonality is broadened to include a precursor cis-lunar Exploration Augmentation Module (EAM) and the logistic elements supporting both the EAM and Mars surface operations. Together, these amount to over 20 flight vehicles. The approach to maximizing commonality combines not only the physical and functional characteristics of the habitats, but also methods of acquisition and management spanning the multi-decade exploration campaign. The paper presents a method of quantifying the cost benefits of developing common habitats. First, based on the campaign schedule, the time for developing individual habitat is identified. Then this is compared to strategy that combines all habitat requirements into a core for a single DDT&E with follow-on delta development for each end item. The savings as a result of overall program schedule compression is measured using analogous DDT&E and recurring costs escalated to a common year dollar. In order to demonstrate a workable common solution, three design/analysis products are shown. These include a commonality analysis tool derived from the master equipment list for each habitat, a cost analysis tool and representative configurations that validate the initial common core tailored to each vehicle. NomenclatureCBM = Common Berthing Mechanism CDR = Critical Design Review CSM = Command Service Module DDT&E = Design Development Test and Evaluation EAM = Exploration Augmentation Module EMC = Evolvable Mars Campaign EMU = Extravehicular Mobility Unit HAT = Human Spaceflight Architecture Team ISS = International Space Station LEM = Lunar Excursion Module LCC = Life Cycle Cost LEO = Low Earth Orbit MACES = Mars Advanced Crew Escape Suit MAV = Mars Ascent Vehicle MEL = Master Equipment List M...
The International Space Exploration Coordination Group (ISECG) formed two Gap Assessment teams to evaluate topic discipline areas that had not been worked at an international level to date. Accordingly, the ISECG Technology Working Group (TWG) recommended two discipline areas based on Global Exploration Roadmap (GER) Critical Technology Needs reflected within the GER Technology Development Map (GTDM): Dust Mitigation and LOX/Methane Propulsion, with this paper addressing the former. The ISECG approved the recommended Gap Assessment teams, and tasked the TWG to formulate the new teams with subject matter experts (SMEs) from the participating agencies. The participating agencies for the Dust Mitigation Gap Assessment Team were ASI, CSA, ESA, JAXA, and NASA. The team was asked to identify and make a presentation on technology gaps related to the GER2 mission scenario (including cislunar and lunar mission themes and long-lead items for human exploration of Mars) at the international level. In addition the team was tasked to produce a gap assessment in the form of a summary report and presentation identifying those GER Critical Technology Needs, including opportunities for international coordination and cooperation in closing the identified gaps. Dust is still a principal limiting factor in returning to the lunar surface for missions of any extended duration. However, viable technology solutions have been identified, but need maturation to be available to support both lunar and Mars missions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.