NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Stirling to Flight InitiativeNASA has a consistent need for radioisotope power systems (RPS) to enable robotic scientific missions for planetary exploration that has been present for over four decades and will continue into the foreseeable future, as documented in the most recent Planetary Science Decadal Study Report. As RPS have evolved throughout the years, there has also grown a desire for more efficient power systems, allowing NASA to serve as good stewards of the limited plutonium-238 (238Pu), while also supporting the ever-present need to minimize mass and potential impacts to the desired science measurements. In fact, the recent Nuclear Power Assessment Study (NPAS) released in April 2015 resulted in several key conclusion regarding RPS, including affirmation that RPS will be necessary well into the 2030s (at least) and that 238Pu is indeed a precious resource requiring efficient utilization and preservation. Stirling Radioisotope Generators (SRGs) combine a Stirling cycle engine powered by a radioisotope heater unit into a single generator system. Stirling engine technology has been under development at NASA Glenn Research Center (GRC) in partnership with the Department of Energy (DOE) since the 1970's. The most recent design, the 238Pu-fueled Advanced Stirling Radioisotope Generator (ASRG), was offered as part of the NASA Discovery 2010 Announcement of Opportunity (AO). The Step-2 selections for this AO included two ASRG-enabled concepts, the Titan Mare Explorer (TiME) and the Comet Hopper (CHopper), although the only non-nuclear concept, InSight, was ultimately chosen. The DOE's ASRG contract was terminated in 2013. Given that SRGs utilize significantly less 238Pu than traditional Radioisotope Thermoelectric Generators (RTGs) - approximately one quarter of the nuclear fuel, to produce similar electrical power output - they provide a technology worthy of consideration for meeting the aforementioned NASA objectives. NASA's RPS Program Office has recently investigated a new Stirling to Flight (S2F) initiative with the objective of developing a 100-500 We Stirling generator system. Additionally, a different approach is being devised for this initiative to avoid pitfalls of the past, and apply lessons learned from the recent ASRG experience. Two key aspects of this initiative are a Stirling System Technology Maturation Effort, and a Surrogate Mission Team (SMT) intended to provide clear mission pull and requirements context. The S2F project seeks to lead directly into a DOE flight system development of a new SRG. This paper will detail the proposed S2F initiative, and provide specifics on the key efforts designed to pave a forward path for bringing Stirling technology to flight.
Document ID
20160005320
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Hibbard, Kenneth E.
(Johns Hopkins Univ. Laurel, MD, United States)
Mason, Lee S.
(NASA Glenn Research Center Cleveland, OH United States)
Ndu, Obi
(Johns Hopkins Univ. Laurel, MD, United States)
Smith, Clayton
(Johns Hopkins Univ. Laurel, MD, United States)
Withrow, James P.
(NASA Glenn Research Center Cleveland, OH United States)
Date Acquired
April 26, 2016
Publication Date
March 5, 2016
Subject Category
Energy Production And Conversion
Report/Patent Number
GRC-E-DAA-TN27498
Meeting Information
Meeting: IEEE Aerospace Conference 2016
Location: Big Sky, MT
Country: United States
Start Date: March 5, 2016
End Date: March 12, 2016
Sponsors: American Inst. of Aeronautics and Astronautics, Institute of Electrical and Electronics Engineers, PHM Society
Funding Number(s)
WBS: WBS 138494.04.18.01.01.01
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
Robotics
Plutonium
Stirling Cycle
No Preview Available