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NASA Cancels RTG Research Program


Magicide

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I just came across this on Reddit and didn't see it posted here yet:

http://www.planetary.org/blogs/casey-dreier/2013/20131115-nasa-just-cancelled-its-asrg-program.html

I didn't realize the RTG was such an inefficient power source or that the deep space missions required that much Pu 238. It seems foolish to cancel a nearly complete program that promised a 400% efficiency increase. It appears they not only killed the more efficient RTG but also cut the Plutonium 238 production that all deep space missions require.

In this PDF http://science.nasa.gov/media/medialibrary/2013/07/15/Green_PPSubcommittee.pdf it talks about scaling production from 1.0-1.5 to 1.5-2.0 kg/year of Pu 238. The first article states that a deep space probe requires 10 kg or more which means at current production rates that is only one mission beyond Saturn every 7-8 years. With this new decision, further Pu 238 production has now been halted as the administration feels there is sufficient supply on hand for expected future needs.

I'm guessing future needs implies outer planet exploration is not in the cards for any time soon. Hopefully we can rely on the Russians, Chinese and Indians to go push the boundaries...

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We should just close down NASA while it still has its legacy to be proud of. Go China.

As usual, Congress is basically drawing all funds towards the SLS to keep contractors happy. There is little respect for research which is basically an investment towards our development and even the economy.

Edited by deadshot462
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Not like NASA's really needed anymore anyway. There's private companies that fill pretty much every niche NASA did. Sure, they were good in the 50's when there wasn't the commercial motivation to develop space technologies but now there is, and without all the bloated bureaucracy behind them.

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Not like NASA's really needed anymore anyway. There's private companies that fill pretty much every niche NASA did. Sure, they were good in the 50's when there wasn't the commercial motivation to develop space technologies but now there is, and without all the bloated bureaucracy behind them.

Really? When was the last time a private company funded a space exploration mission out of their pocket?

There is actually zero incentive right now for a private company to explore space, either manned or unmanned. The only viable business models right now are GEO comsats and government launches, either military or government-sponsored science. That government-sponsored science is the only way of finding out if any real business models actually exist for the private sector.

Without government paying for a manned program, nobody is going to send people into space anytime soon, because there simply is no viable reason to do so.

Edited by Nibb31
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That's pretty much how it works already. Most spacecraft are designed by NASA employees collaborating with folks from Boeing, Lockheed Martin and other suppliers. It's the same for ESA and EADS or other countries...

Outsourcing hardly ever saves money in the long term. It just replaces public "bloated bureacracy" with private bloat. The bloat is still funded by the government, but the corporation takes a large share of it to pay shareholders instead of paying more workers or increasing the value of the project. It doesn't make much of a difference for the taxpayer, but I guess if you own Boeing stock, it's a great deal.

Edited by Nibb31
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I think that this is a setback, but not a deathnail. The main reason for the production of the sterling rtg was to help extend the life of current pu238 stockpiles. The DOE recently signed a deal with NASA to restart production at the Oak Ridge national laboratory. It is true that with current funding projections there will only be enough for a major mission every decade, but it is important to note that there is no money being allocated for these missions. I believe (hope) with the next election cycle we may be able to increase planetary science funding by a reasonable amount, 25-50%+, and will be able to step up pu production with accordance to the missions proposed. The sterling rtg was only a postponement for the actions that have just been taking, rendering it nolonger (completely) necessary

Just my 2 cents

Hal9000

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This is Stirling RTG's not Thermocouple RTG's. Stirling rtg's have never flown, it was considered for Curiosity but research was not complete by the deadline so curiosity has a Thermocouple rtg. All other rtg's in space use are of the thermocouple design.

The Stirling version uses an oscillating free-floating piston in He gas, so has moving parts, making it more susceptible to failure than the thermocouple design. Even though it is vastly more efficient I suspect the wear issue is what has caused the cancellation of research for deep space use.

You should also note that there are other heat sources available beside the standard GPHS (Pu pellets)...

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This is Stirling RTG's not Thermocouple RTG's. Stirling rtg's have never flown, it was considered for Curiosity but research was not complete by the deadline so curiosity has a Thermocouple rtg. All other rtg's in space use are of the thermocouple design.

The Stirling version uses an oscillating free-floating piston in He gas, so has moving parts, making it more susceptible to failure than the thermocouple design. Even though it is vastly more efficient I suspect the wear issue is what has caused the cancellation of research for deep space use.

The amount of testing suggested that probability of failure is far beyond the 14 year warranty required. It may have been worthwhile despite having "moving parts" more importantly with current budgets it would have been the cheaper option. Now we might not even have enough Pu238 for deep space mission for decades. ASTG would have allowed the same amount of power for 1/4 the amount of Pu238.

You should also note that there are other heat sources available beside the standard GPHS (Pu pellets)...

Like what?

Edited by RuBisCO
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We should find whoever is opposing the Space Agency in Congress, then proceed to remove them from their office and fire them without another word said. Then maybe we'll get some funds back for the new Striling RTGs. Heard about a well-supported bill by influential members of Congress (Both Parties this time...I'm finally happy) that would give NASA the same capabilites and power as the US DOD and the US Military...maybe Congress still has some sense.

Otherwise, I'm quite saddened at the loss of such a program. The Stirlings where so promising to me.

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We should find whoever is opposing the Space Agency in Congress, then proceed to remove them from their office and fire them without another word said. Then maybe we'll get some funds back for the new Striling RTGs. Heard about a well-supported bill by influential members of Congress (Both Parties this time...I'm finally happy) that would give NASA the same capabilites and power as the US DOD and the US Military...maybe Congress still has some sense.

Otherwise, I'm quite saddened at the loss of such a program. The Stirlings where so promising to me.

It more complex than that, the problem is austerity: until goverment income increases, things are going to need to be cut, but that are far as I'm going to say on this forum because it would violate forum rules on talking about politics.

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:sigh:

That's how dreams die. Slowly and unnoticed. I won't be surprised if 3-5 years from now we read some article like "NASA Resignes From Outer Planets Exploration". With little plutonium and no alternative missions beyond Mars are endangered. And there is so much to learn! Titan, Europa, Callisto, Uranus, Neptune...

Luckily there are other space agencies with big plans like ESA, CNSA or Roskomos. It's just a shame to see NASA in such sad state.

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We should find whoever is opposing the Space Agency in Congress, then proceed to remove them from their office and fire them without another word said. Then maybe we'll get some funds back for the new Striling RTGs. Heard about a well-supported bill by influential members of Congress (Both Parties this time...I'm finally happy) that would give NASA the same capabilites and power as the US DOD and the US Military...maybe Congress still has some sense.

Otherwise, I'm quite saddened at the loss of such a program. The Stirlings where so promising to me.

Is the bill available online somewhere for public perusal? Or is there a news article on the subject? I would very much like to see a source on this - might be a good advancement for NASA and US space policy in general after decades of political crap.

The reason NASA has so many white elephants and so much bloat, by the way, is because that's the only way to prevent their funding from being cut FURTHER. Allow me to explain:

Let's say the Federal Department of Government is budgeted $2,000,000 for this fiscal year. The Department's entire expenses, up to about a month before the end of the FY, amount to $1,000,000. Now, we could say it's laudable that they're cutting costs, right? Only problem is, that means that the Powers That Be will slash their budget next year to $1,000,000, because that's "all they need". So, how to defeat this (and avoid risking running out of money next year)? Simple: spend, spend, spend. Spend every penny of that money, so your budget doesn't get slashed further.

Welcome to bureaucracy.

Edited by NGTOne
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It seems foolish to cancel a nearly complete program that promised a 400% efficiency increase.

On the face of it yes, but the article doesn't actually mention how well development was progressing. Stirling engines aren't new, it strikes me that if they required many years of development then there must have been some major technical challenges that were preventing their use in this application.

Stirlings seem to be one of those technologies that pop up every few years in another new context and show lots of promise, but never really come to anything.

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