Mars Solar Array Technology (MSAT) Innovations

Subtopic Problem Statement/Description: This subtopic seeks innovations for lightweight deployable solar arrays for Mars surface power ranging from 3 to 20 kW at beginning-of-life. Proposals are requested in at least one of these two areas: 1) Structural Design and Analysis: Conceive and validate novel minimum-mass and -launch volume mechanical designs and their deployment and/or assembly methods through design and analysis in Phase I, and test scaled prototype hardware in Phase II. Solar arrays can be envisioned to remain on landers for early missions or be offloaded and moved on later missions. 2) Survivability, Especially from Dust: Develop design solutions for surviving the Mars environment, including performance- and mission-threatening accumulation of dust particles on solar cells, mechanisms, and radiators; dust storms and dust devils with winds to 25 m/s requiring adequate strength and anchoring; persistent sub-0 C temperatures with seasonal changes (darker, colder winters); and slow, one-way communication (3-22 min) if required from Earth. While nuclear fission is the primary option for initial crewed missions [Reference 1], a diverse suite of power generation options will provide mission flexibility and power for a variety of other missions of various power scales [References 2-3]. These MSAT arrays might be built on technologies to be used on the lunar surface by multiple companies that originated out of NASA's Vertical Solar Array Technology (VSAT) project [Reference 4] and related SBIR contracts, in the multi-Center Mars Surface Solar Arrays with Storage (SAWS) study [Reference 5], or on other successful space missions such as the International Space Station (ISS). Solar arrays are lightweight, reliable, and generally long-lasting, and they have been selected for most space missions. Their consistent durability has often led to mission extensions for numerous space missions throughout the Space Age, allowing for prolonged exploration and data collection. For example, the Mars Exploration Opportunity rover successfully operated over 14 years much longer than its planned lifetime of 90 Mars days (sols)--but eventually succumbed to a major dust storm that disabled the solar panels, which did not have active dust-control technology [Reference 6]. NASA estimates solar arrays for Mars with state-of-the-art space solar cells will require about 150 m2 per 10 kW of deployed area (4x lunar) with clear skies and solar cells, and the mass of solar cell blankets will be about 1 kg/m2. And, of course, power generation (W/m2) decreases with higher atmosphere haziness (optical depth) and dust coverage. Achieving the overall total power using modules of about 50-150 m2 is permitted and is, in fact, likely constructive. Firms are encouraged to propose adaptable designs for the entire 3 to 20 kW power range (approx. 45 to 300 m2 area) assuming landing sites in the northern lowlands at 30 to 60 N latitude like Arcadia Planitia, or at other latitudes if missions and solar array requirements are discussed [Reference 7]. Better environment-resistant solar arrays have the potential to be a lower cost, flexible alternative to mission operations that do not require extensive lifetime capabilities or rapid deployments. Furthermore, mobility and operability innovations can allow maximum flexibility in site selection, dust storm survival, and repurposing. Much preliminary design and analysis of potential Mars solar power systems have been accomplished for decades [e.g., Reference 8]. Proposals should address one or both areas mentioned at the beginning of the solicitation and should primarily include structural and mechanical innovations, not photovoltaics, electrical, or energy storage innovations, although a complete solar array systems analysis is encouraged. If solar concentrators are proposed, strong arguments must be developed to justify why they are better than planar solar arrays. These arguments should include analysis with a dusty atmosphere. Of special interest are novel modular concepts, improved deployment/assembly and anchoring methods, and innovations for keeping solar cells and radiators at least 90% free of dust most of the time. Using futuristic construction assistants such as intelligent robots will be considered [e.g., Reference 9]. Requirements for lander payload mass and volume capacity and other infrastructure should be well defined. Solar array concepts should be compatible with state-of-the-art solar cell products with documented environmental degradation properties. Design, build, and test of scaled flight hardware or functioning lab models to validate proposed innovations is of high interest. Improved dust-resistant coatings are also of interest.