So Thorium RTGs almost impossible or not worth (costs)?
It would be nice for someone to get Americium-241 working.. ok its 25% power, and needs approx 2cm lead for enclosure
It's not really an issue of cost or difficulty, but that they'd be completely useless; the heat produced from thorium decay is negligible.
Quote from: Kryten on 01/07/2014 03:23 am It's not really an issue of cost or difficulty, but that they'd be completely useless; the heat produced from thorium decay is negligible.Thanks for responding. You're correct on the heat factor; it's just a few ideas on my mind about Thorium. Say, for Power generation for various applications.
I mentioned awhile back that there was news on the Pu-238 front.This afternoon at the SBAG meeting in Washington, it was revealed that there are 35 kg of plutonium available for NASA missions. About 17 kg of this is suitable for the General Purpose Heat Source pellets (meaning high enough energy density). The remainder is lower quality, meaning that it would have to be reprocessed to get its energy density up.
Quote from: Blackstar on 01/09/2014 01:56 amI mentioned awhile back that there was news on the Pu-238 front.This afternoon at the SBAG meeting in Washington, it was revealed that there are 35 kg of plutonium available for NASA missions. About 17 kg of this is suitable for the General Purpose Heat Source pellets (meaning high enough energy density). The remainder is lower quality, meaning that it would have to be reprocessed to get its energy density up.Thanks for passing that along.So from the charts we have, and assuming that the remaining mass after MSL is the 35 kg, without an ASRG develoment that likely puts any hope of a Europa mission clearly on the back-burner for some time, well beyond 2030 (not that there was much chance due to cost)
Quote from: robertross on 01/09/2014 02:07 amQuote from: Blackstar on 01/09/2014 01:56 amI mentioned awhile back that there was news on the Pu-238 front.This afternoon at the SBAG meeting in Washington, it was revealed that there are 35 kg of plutonium available for NASA missions. About 17 kg of this is suitable for the General Purpose Heat Source pellets (meaning high enough energy density). The remainder is lower quality, meaning that it would have to be reprocessed to get its energy density up.Thanks for passing that along.So from the charts we have, and assuming that the remaining mass after MSL is the 35 kg, without an ASRG develoment that likely puts any hope of a Europa mission clearly on the back-burner for some time, well beyond 2030 (not that there was much chance due to cost)Huh? You're misreading this. There's more Pu-238 than previously acknowledged.
Other than NRO stuff, what else uses that much Pu-238?
MT @Shamrocketeer: #NASA's latest Discovery mission AO just came out: no radioisotope power; bad news outer planets https://prod.nais.nasa.gov/cgibin/eps/synopsis.cgi?acqid=159660
Btw.Emily Lakdawalla just tweeted:QuoteMT @Shamrocketeer: #NASA's latest Discovery mission AO just came out: no radioisotope power; bad news outer planets https://prod.nais.nasa.gov/cgibin/eps/synopsis.cgi?Not RTG's for You!
MT @Shamrocketeer: #NASA's latest Discovery mission AO just came out: no radioisotope power; bad news outer planets https://prod.nais.nasa.gov/cgibin/eps/synopsis.cgi?
Quote from: kevin-rf on 02/20/2014 12:16 pmBtw.Emily Lakdawalla just tweeted:QuoteMT @Shamrocketeer: #NASA's latest Discovery mission AO just came out: no radioisotope power; bad news outer planets https://prod.nais.nasa.gov/cgibin/eps/synopsis.cgi?Not RTG's for You!Get a flagged security warning on that link?
The schedule for fueling of radioisotope power systems (RPSs) cannot be met in time for the expected launch window of Discovery 2014 investigations. Therefore, Discovery Program investigations may not propose the use of RPSs. Proposed investigations may include the use of radioactive sources for science instruments and the use of radioisotope heater units (RHUs).
NASA DISCOVERY PROGRAM DRAFT ANNOUNCEMENT OF OPPORTUNITYSynopsis - Feb 19, 2014General InformationSolicitation Number: NNH14ZDA004JPosted Date: Feb 19, 2014FedBizOpps Posted Date: Feb 19, 2014Recovery and Reinvestment Act Action: NoOriginal Response Date: N/ACurrent Response Date: N/AClassification Code: A -- Research and DevelopmentNAICS Code: 541712Contracting Office Address NASA/Goddard Space Flight Center, NASA Headquarters Acquisition Branch, Code 210.H, Greenbelt, MD 20771Description NASA’s Science Mission Directorate (SMD) is releasing this Community Announcement for a Draft Announcement of Opportunity (AO) for Discovery Program missions by May 2014. The Discovery Program conducts Principal Investigator (PI)-led space science investigations in SMD’s planetary programs under a not-to-exceed cost cap. It is anticipated that approximately two to three Discovery investigations will be selected for nine-month, $3M (RY) Phase A concept studies through this AO. At the conclusion of these concept studies, it is planned that one Discovery investigation will be selected to continue into Phase B and subsequent mission phases. There will be no Missions of Opportunity (MO) solicited as part of this AO. All MOs are now solicited through the Stand Alone Mission of Opportunity Notice (SALMON) AO.Discovery Program investigations must address NASA’s planetary science objectives as described in 2014 NASA Strategic Plan and the 2014 NASA Science Plan. Both of these documents will be publicly released following the submission of the FY 2015 budget to Congress.Investigations may focus on any body in the Solar System, excluding the Earth and the Sun. Investigations may not focus on the identification or characterization of extra-solar planetary systems.Discovery Program investigations may propose activities that have the potential to broaden the scientific impact of investigations as optional Science Enhancement Options (SEOs). SEOs include, but are not limited to, guest investigator programs, general observer programs, participating scientist programs, interdisciplinary scientist programs, and archival data analysis programs. Discovery Program investigations may also propose Technology Demonstration Opportunities (TDOs) to demonstrate new capabilities. TDO proposals, like Science Enhancement Opportunities (SEOs), are funded outside of the cost cap and may possibly not be selected even if the parent mission is selected for flight.Discovery Program investigations involving entry, descent, and landing (EDL) into the atmosphere of a Solar System object (including the Earth) shall include an Engineering Science Activity, to be funded outside of the cost cap, to obtain diagnostic and technical data about vehicle performance and entry environments. Details of the goals and objectives of this activity will be posted on the Discovery Program Acquisition Website (discovery.larc.nasa.gov) in the Program Library.The schedule for fueling of radioisotope power systems (RPSs) cannot be met in time for the expected launch window of Discovery 2014 investigations. Therefore, Discovery Program investigations may not propose the use of RPSs. Proposed investigations may include the use of radioactive sources for science instruments and the use of radioisotope heater units (RHUs).NASA is considering providing additional technologies as Government-Furnished Equipment (GFE). Currently under consideration is a commercially produced version of the NASA Evolutionary Xenon Thruster (NEXT) ion propulsion system (two flight model power processing units and two thrusters). Also under consideration is the Heat Shield for Extreme Entry Environment Technology (HEEET) — a woven Thermal Protection System.NASA is also considering requiring all investigations to carry a Deep Space Laser Communications (DSLO) package, to be provided as GFE. Given the success of the Lunar Laser Communication Demonstration (LLCD) on the Lunar Atmosphere and Dust Environment Explorer mission, a demonstration of laser communications from deep space is a high priority for NASA.Decisions on the three technologies described above, or any other technologies (e.g., Deep Space Atomic Clock, Advanced Solar Arrays), will be made before the release of a draft AO.Launch Vehicle costs and procurement will be the responsibility of NASA. Launch vehicle standard services will be provided as GFE and the cost will not be included in the cost cap. The cost of mission specific and special launch services, including the use of radioisotope heating units (RHUs), is the responsibility of the PI and must be included within the cost cap. NASA is reviewing the possibility of offering options for different launch vehicle capabilities and their impact on the cost cap.The constraint that the value of foreign contributions must not exceed one-third of the PI-Managed Mission Cost has been modified: the total value of foreign contributions may still not exceed one-third of the PI-Managed Mission Cost and the value of foreign contributions to the science payload may not exceed one-third of the total payload cost.Investigations are capped at a Phase A-D cost of $450M (FY 2015), excluding standard launch services. The now-standard 25% minimum reserve on Phases A-D will be required within the cost cap. Operations costs (Phase E) are not included in the cost cap, but will be evaluated for reasonableness. Lower-cost investigations and cost-efficient operations are encouraged.The time frame for the solicitation is intended to be:Release of draft AO May 2014 (target) Release of final AO September 2014 (target) Preproposal conference ~3 weeks after final AO release Proposals due 90 days after AO release Selection for competitive Phase A studies May 2015 (target) Concept study reports due April 2016 (target) Down-selection October 2016 (target) Launch readiness date NLT December 31, 2021The Draft Discovery AO will be based on the Standard PI-led Mission AO Template available at http://soma.larc.nasa.gov/standardao/sao_templates.html . Proposers should read the Draft Discovery AO carefully when it is released.NASA has not approved the issuance of the Discovery AO and this notification does not obligate NASA to issue the AO and solicit proposals. Any costs incurred by prospective investigators in preparing submissions in response to this notification or the planned Draft Discovery AO are incurred completely at the submitter's own risk.Further information will be posted on the Discovery Program Acquisition Page at http://discovery.larc.nasa.gov/as it becomes available. Questions may be addressed to Dr. Michael New, Discovery Program Lead Scientist, Planetary Science Division, Science Mission Directorate, NASA, Washington, DC 20546; Tel.: (202) 358-1766; Email: [email protected].Point of ContactName: Dr Michael NewTitle: Planetary Science DivisionPhone: 202-358-1766Fax: 202-358-3097Email: [email protected]
Space Politics has an article on this:http://www.spacepolitics.com/2014/02/20/next-nasa-discovery-solicitation-will-miss-congressional-deadline/