I've ready maybe 6 articles on the issue, all of them just copy the ORNL release. A few actually talked about missions, but in general when describing the production milestones it seems all they can do is copy the press release word to word
Meanwhile, outer planets mission proposals consists of 'a tennis field of solar panels with two tiny instruments attached to it' as some people on twitter quipped.
I understand that the first method is to irradiate Neptunium-237. The other is to irradiate Americium, right? In both cases then you have to chemically separate the Pu.
“What we’re shooting for is to get to an interim production level of around 400 to 500 grams [14 to 18 ounces] per year in 2019, and then full-scale, a kilogram and a half [3.3 lbs.] — if everything goes right — in 2023,” Bob Wham, the Pu-238 project lead in the Nuclear Security and Isotope Technology division at Oak Ridge, said last month during a presentation with NASA’s Future In-Space Operations (FISO) working group.
...{snip}In a few months I'll be working with Ralph McNutt again and Ralph probably knows more about the overall history and the infrastructure issues than anybody. So I'll have to get some perspective from him on this.
The article also confirms that they have baselined the solvent separation method. If I understood you right the last time, this was something that even back then they wanted to do and they appear to have decided to do this time. It would make sense that if you are going to have to design, validate and certify the process again, to start with the cheap and easy one, since you don't have the nuclear weapon subsidy now.
Which effort? If they build an ASRG and have confidence in it, that will use less Pu-238, meaning that more is available for other missions--with a caveat: some missions require the MMRTG because they need the excess heat that an ASRG does not produce. Also, there may be missions that people don't want to use the ASRG on.
Quote from: savuporo on 10/01/2015 06:39 PMMeanwhile, outer planets mission proposals consists of 'a tennis field of solar panels with two tiny instruments attached to it' as some people on twitter quipped.And this would be *perfectly fine*, except we resolutely refuse to prioritize the production of tennis courts worth of solar panels, a product that is useful in the inner system, the Earth orbit, and the outer system (as a first choice out to maybe Saturn, and a backup option farther out). Lots of powerpoints, very few, very small grants.Why is the 300kw Government Reference Array (3kw at Saturn, 300W at Neptune) still posed as being years off? Why aren't we building and testing them by the dozen?
I'm sorry for jumping back to relatively old posts. I don't have time to keep up with interesting topics like this regularly.Quote from: Blackstar on 10/01/2015 08:07 PMWhich effort? If they build an ASRG and have confidence in it, that will use less Pu-238, meaning that more is available for other missions--with a caveat: some missions require the MMRTG because they need the excess heat that an ASRG does not produce. Also, there may be missions that people don't want to use the ASRG on. Are you aware off the top of your head of specific mission studies where the lower heat output of an ASRG would have been a problem. It may only 1/4 as much waste heat as an MMRTG, but 400-500W still seems like a decent amount for keeping electronics boxes and bearings warm.
While NASA and the Department of Energy (DOE) have restarted production of a plutonium isotope used to power some space missions, a new report warns of challenges that could threaten its long-term supply.The Oct. 4 report by the Government Accountability Office, tied to a House space subcommittee hearing on the subject, said that while there is sufficient plutonium-238 in stockpiles now for missions planned through the mid-2020s, scaling up production of the isotope faces a number of technical issues.“DOE is making progress towards producing new plutonium-238,” said Shelby Oakley, director of acquisition and sourcing management at the GAO, in testimony at the hearing. “However, DOE faces challenges in hiring and training the necessary workforce, perfecting and scaling up chemical processing, and ensuring the availability of reactors that must be addressed or its ability to meet NASA’s needs could be jeopardized.”