** The Official Space Flight Thread - The Space Station and Beyond **

PlacidCasual said:
Apparently the RTG from Appolo 13 re-entered the atmosphere and as far as NASA can tell the container survived intact and hasn't leaked any radiation.
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Learnt something new today - I didn't know the Apollo missions carried an RTG!

Chuk_Chuk said:
I never claimed it was easy cheap or quick to get fuel for RTG. Not sure where you got that idea from.

But since you’ve brought it up why don’t you go into more details about how RTG fuel is acquired?

Is immense todays word of the day?
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RTGs, or ones that make usuable power, use Plutonium 238, of which there is only one place in the US currently making it and produces the immense volume of 400g per year, having recently restarted production. It's something you can simply buy off a shelf, and the cost is immense.
 
Yeah plutonium just isn't made that much today. Back in the cold war it obviously was for the weapons program, the US apparently has 88 tonnes of plutonium but they won't be giving any of that to a private company. SpaceX won't be shipping dozens of RTGs to Mars.
 
PlacidCasual said:
Apparently the RTG from Appolo 13 re-entered the atmosphere and as far as NASA can tell the container survived intact and hasn't leaked any radiation.
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I believe the NASA RTGs launched into space are designed to stand a catastrophic rocket failure and/or reentry. The Russian's cosmos 954 was not as robust.

The Voyagers RTGs are still doing well despite their forty five years years in space.
 
Colonel_Klinck said:
Yeah plutonium just isn't made that much today. Back in the cold war it obviously was for the weapons program, the US apparently has 88 tonnes of plutonium but they won't be giving any of that to a private company. SpaceX won't be shipping dozens of RTGs to Mars.
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I couldn't easily find a breakdown of which isotopes they keep, but I would imagine most of it is in the higher isotope ranges for use in nuclear weapons, rather than 238 which just sits there being hot as balls for decades.
 
Penfold101 said:
I couldn't easily find a breakdown of which isotopes they keep, but I would imagine most of it is in the higher isotope ranges for use in nuclear weapons, rather than 238 which just sits there being hot as balls for decades.
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Yeah you are right. Those stockpiles would likely be no use for RTGs
 
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Colonel_Klinck said:
You think RTGs are 2 a penny? NASA only put them on their last 2 rovers, there is a reason for that. Before that it was solar but solar is a major problem on Mars and the dust storms killed the rovers. RTGs are rare and expensive. They aren't going to be made for a private space company when NASA have their own missions requiring them? The current RTG design makes 110w, there is the GPHS-RTG which makes 300w but that needs 7.8kg of Plutonium 238, not exactly a common element. You'd need dozens of those to generator the power required to make the fuel for a Starship and they cost between $65-90m each.
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So you're not talking about an engineering issue you are talking about a costing issue. Yeah I don't care about costing issues but we'll get to that.

I'm assuming you mean P238 is rare not RTGs themselves, since the Soviets considered RTGs to be so precious that they used them in light houses, the americans stuck 10 of them in a single arctic base and Nasa has launched multiple Satellite with between 1 and 4 of them.

Colonel_Klinck said:
Nothing is impossible. With enough money just about anything can be done but where is the commercial revenue coming from to justify the investment in Mars? The Moon has elements we could use like Helium-3 and is only 3 days away, what does Mars have? No investors are going to give $b to satisfy Elon's dream if there is no pay day at the end of it.
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You do realise that investement happens in stages.
You have an idea, you pitch it to people in hopes that someone believe in that idea and gives you some pocket money. You devlop it, get a working prototype, people have more confidence and you get a bigger cheque. You develop it more and the idea you first had becomes a reality and now even more people want in.

It is hard to get funding for an idea (why do you think starlink became a thing) but if/when a craft from SpaceX lands on Mars, a lot of wallets are going to open. Private and public. All hoping to find the next gold rush or bubble. Maybe if it was my money, I was investing I would care more about the cost, but I ain't investing it, so I don't. I'm only here because i'm fascinated by the engineering of all of this and I like talking about engineering, something you seem to not understand when discussing this with me because you keep bringing up that Musk wants solar panels like I'm supposed to give a **** or as if that's going to affect my opinion.

Penfold101 said:
Learnt something new today - I didn't know the Apollo missions carried an RTG!



RTGs, or ones that make usuable power, use Plutonium 238, of which there is only one place in the US currently making it and produces the immense volume of 400g per year, having recently restarted production. It's something you can simply buy off a shelf, and the cost is immense.
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You clearly had to look that answer up so why not post a link.
BTW did the site you read not mention that they have been steadly increasing production since 2015 and are looking to increase it up to 1.5Kg per year by 2026? Though depending on sources they appear to be a bit late on the NASA target.

ORNL-produced plutonium-238 to help power Perseverance on Mars | ORNL

www.ornl.gov www.ornl.gov
 
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Of course I did - I want to make sure what I’m saying is true before posting it. If you don’t believe it, feel free to google it yourself.

What I’ve also googled is the fact that the Perseverance rover used a plutonium RTG with 5kg of the stuff and the New Horizons probe used almost 10kg of it, so at even future possible production rates no-one is powering anything on Mars with them beyond a very small and slow kettle.
 
Chuk_Chuk said:
So you're not talking about an engineering issue you are talking about a costing issue. Yeah I don't care about costing issues but we'll get to that.

I'm assuming you mean P238 is rare not RTGs themselves, since the Soviets considered RTGs to be so precious that they used them in light houses, the americans stuck 10 of them in a single arctic base and Nasa has launched multiple Satellite with between 1 and 4 of them.
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Imagine that when Russia was producing lots of plutonium for their weapons program and the USSR had lots of nuclear reactors. Does the US have lots of nuclear reactors producing plutonium? You think Elon is going to build a nuclear reactor?

Chuk_Chuk said:
You do realise that investement happens in stages.
You have an idea, you pitch it to people in hopes that someone believe in that idea and gives you some pocket money. You devlop it, get a working prototype, people have more confidence and you get a bigger cheque. You develop it more and the idea you first had becomes a reality and now even more people want in.

It is hard to get funding for an idea (why do you think starlink became a thing) but if/when a craft from SpaceX lands on Mars, a lot of wallets are going to open. Private and public. All hoping to find the next gold rush or bubble. Maybe if it was my money, I was investing I would care more about the cost, but I ain't investing it, so I don't. I'm only here because i'm fascinated by the engineering of all of this and I like talking about engineering, something you seem to not understand when discussing this with me because you keep bringing up that Musk wants solar panels like I'm supposed to give a **** or as if that's going to affect my opinion.
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Why are the wallets going to open? What is there on Mars that we don't have here? What is the business plan? Are people going to spend $b to go and live on Mars, somewhere totally hostile to life? Starlink obviously has a commercial market, we've been able to buy satellite internet for decades, he's just jumped into an existing market and had the hardware to launch the satellites cheaply.
 
Did anyone watch the HAKUTO-R stream? This was the first attempt from a private company to send a lunar lander and rover to the moon but it doesn't look like it worked.
 
www.youtube.com

SpaceX Stage 0 plans changed after huge damage from testing...

SpaceX Stage 0 plans changed after huge damage from testing...1) ABOUT ALL TRACK IN MY VIDEO Building Up Your Future by soundrollThe Doctor by Infract...
www.youtube.com www.youtube.com

This was quite an interesting video about the launch pad being damaged. It seems they went ahead knowing it would get damaged, just not to the degree that it did. Big rockets have crazy destructive power, who knew?
 
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