So its all gone a bit...
Predictions are firming up for when China's Tiangong-1 spacecraft will make its final re-entry-crash-and-burn. The Chinese space station was launched in 2011 and had a two-year operational lifetime. Originally slated to make its return to Earth in 2013, its lifetime was extended to 2016. Loss of telemetry effectively ended …
> Though even SpaceX are expecting this one to URD*. Butt hey will learn a lot from it either way.
What?! You seriously think SpaceX are expecting this to fail? They have lower confidence than usual, and a failure (RUD, Rapid Unscheduled Disassembly, is the usual acronym) is possible, but saying they expect it is a stretch.
Also, But. Nobody likes finding random butts on their screen.
"But they expect" Sorry, quite a lot of typos today. :D Thanks for the "RUD" correction.
It was mainly Elon saying he expects it to explode on the pad. But his job is mainly expectation management for investors etc. So aiming high internally, but not getting people too invested on unproven designs just yet.
I am awaiting the big 3 triple landing scene that may come some time this or next year!
That's a trifle unfair. Whilst there are undoubtedly parts of Swindon that would be significantly improved by a direct strike from a falling space station (the Brunel Shopping Centre being one such place) there are some lovely places, one of which possibly could be the Intel offices which will be needed intact to deal with the impacts of Meltdown and Spectre with UK punters.
> "Oh come on - there are not enough drugs in all the world to power an imagination that would come up with Swindon!"
As an ignorant Yank I was curious about all the hubbub over Swindon, so I skimmed the Wikipedia entry and remain mystified. Just what is it about that place that generates so much Sturm und Drang among the El Reg readers? I must know!
Not just the register, (also includes obligatory Slough references)
Only Redeeming feature, (I say redeeming, I probably should say this is the only interesting thing in Swindon and it's a roundabout)
No, Big John, Console yourself. it's not because you are ignorant, it's just because you are, shall we say, Left Pondian.
There are some things about English, and being English, that are beyond the understanding of lesser minds.
Certain places have, shall we say, special significance for us. Like Neasden, or Mornington Crescent.
Just accept it. we have.
Sheer jealousy mainly because they don't live there but of course there is Swindon's epic Magic Roundabout (oh just Google it!) which is nearly unique in the UK (and would absolutely terrify most American drivers who freak at the prospect of a normal roundabout).
Disclaimer, in don't live in Swindon but live sufficiently close to appreciate it from a suitable distance.
I'm pretty sure it will all make it to Earth, one way or another. Where else can it go?
Since you asked...
1) Tiaingong-1 is made of a variety of materials, including polymers. The material that's vaporized will generally be converted to oxides. In the case of polymers, that's mostly carbon dioxide and the horribly dangerous dihydrogen monoxide. Those oxides will disperse into Earth's atmosphere, while other oxides (like aluminum oxide) and debris will continue to Earth's surface. And,
2) Earth's escape velocity is sufficiently high to retain most of its atmosphere over geological timescales, unlike Mars, but there is ongoing loss of light elements, particularly hydrogen. (Earth is currently losing about 3kg of hydrogen per second from its atmosphere.) And,
3) Water is mildly susceptible to photolysis (sp?) from high energy UV above the ozone layer, freeing hydrogen to the exosphere, then
...some of Tiaingong-1 will escape into space after vaporization. A quick back-of-the-envelop calculation making unsubstantiated estimates of Tiaingong-1's polymeric mass fraction concludes several bajillionths** of a gram will escape Earth into space.
**My 5-year old niece assures me this is a valid measurement for small quantities.
+1 for noting the extreme toxicity of dihydrogen monoxide.
I notice however that your detailed calculation suggests that you would expect that 33.33333333 percent approximately of all expotential letters would escape the earth's atmosphere.
Shirly that exceeds a mere several bajillionths** of a gram?
** perhaps you were meaning to use elReg units rather than deprecated obsolete ones?
"The Chinese have the ability to get people into orbit something America and the other WASP remnant nations can no longer manage."
It turns out that getting people into orbit wasn't really all that useful. It hasn't proven to be a good first step on the way to somewhere else, the research that could be done was rather limited, and far too many hard to replace people died in the process. The Chinese are simply repeating the learning process of the West and the Soviet Union.
For vaguely related reasons we are no longer developing quadruple compound steam engines (and gasoline and Diesel engine development is, I think, already winding down).
Meanwhile the US has robots on Mars, which if you stop to think about it is a truly amazing achievement.
"You have a rather naive idea of why military powers might want people in orbit."
Really? When the world's military is trying to get people out of military aircraft for numerous reasons?
A space station is incredibly fragile for human life. If you could detonate even something like a BUK warhead reasonably close, you could kill everybody not in a pressure suit and some of the ones who were, and using pressure suits is really difficult. You really don't need to get very much payload up there to take out a human occupied space station.
"Really? When the world's military is trying to get people out of military aircraft for numerous reasons?"
Military aircraft spend most of their time on the ground, where they are serviced by people.
Satellites don't come down when they need fixed, they have to be repaired in orbit.
Next Amazon delivery setup, orbital warehouses dropping capsules with whatever you ordered.
The step after that, they drop meals which cook using the heat of re-entry.
The step after that, deliver is slowed down to add recipies which are simmered for a long time to the menu
Finally, install titanium rods in the warehouses, hold the world to ransom.
" Next Amazon delivery setup, orbital warehouses dropping capsules with whatever you ordered.
The step after that, they drop meals which cook using the heat of re-entry."
(Start at 3042 for the back story. Or better still, start at 1 for the full experience.)
What salvage rights exist here? If you lose control of a spacecraft and someone else flies up and fixes it, who can claim ownership?
To the best of my knowledge international law on space says satellites are always the property of the country that launched them (as in the sense of paying for the launch, not whose rocket it was), even if they've lost control. The owners are also responsible for any damage caused when/if it re-enters.
That's theoretical of course, it's not like there's a lot of case law on satellite theft.
The usual pattern is for later entrants to learn from the failures of earlier ones. Of course the hype for Skylab was...hype, but it still looks really bad that this is an uncontrolled reentry. Yes, hauling fuel up there just to bring it back down would be expensive, but this could (and therefore should) have been a triump.
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