Interesting news for space geeks.

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partlyscot
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Interesting news for space geeks.

Post by partlyscot »

On December 6, The Japanese space agency JAXA returned samples collected from asteroid Ryugu.
On on around the 16th, China is expected to recover samples from the Chang'e 5 mission to the moon. Both of these missions while probably providing interesting information, are also examples of building space capabilities for nation states.

Meanwhile, in the world of private space ventures, on the 9th, SpaceX launched Starship SN8 (literally serial number 8 ) for their first ever attempt at getting Starship to high altitude (not orbital, just 12.5 km or about 41,000 feet) with the intention of demonstrating the "belly flop" manoeuvre, which is the attitude it is expected to begin re-entry to Earth or Mars. Then it was to demonstrate the flip back to vertical, and land. Well it succeeded, mostly. There was a problem with fuel pressure in the header tanks that provided fuel for the landing, so thrust was reduced and the touchdown was a little fast, and SN8 had what they call an RUD, or rapid unscheduled disassembly. (big bang in other words) Elon Musk and SpaceX were still delighted, as they got the needed data to confirm the practicality of their intended re-entry method. Not all the data, the speeds were not as fast as they will be when dealing with orbital re-entry, but the stability and controllability in the belly flop configuration has been demonstrated. I was struck how closely the test resembled the CGI simulations they had shown prior to this test.

If you want to watch the whole thing, here. https://www.youtube.com/watch?v=ap-BkkrRg-o skip forward to just before 1:48, for the flight, the rest is just waiting.

For a privately shot video from about 5 km away, see this. https://www.youtube.com/watch?v=amFK58SSphY After the initial launch, I suggest you skip forward to either 4: 35 for the descent, or 6:00 for the "flip" manoeuvre, as the distance gives a better idea of what is happening.

The best shot is this one from a camera very close the landing pad. https://www.youtube.com/watch?v=zKtDV_tHykw This one looks like a CGI simulation.

Going forwards, they intended to have SN9 on the pad for Monday the 14th, but it had a fall in the assembly 'tent" it seems it either fell off the support, or the support failed, so there will be a delay. SN10 and SN11 are not far from being finished, so the delay should be only a week or two. When you consider this version of Starship (in stainless steel!) started development just over two years ago, the rate of progress is phenomenal. That it's being done in the open, verges on the ridiculous.
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crfriend
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Re: Interesting news for space geeks.

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partlyscot wrote:
Sun Dec 13, 2020 10:56 pm
On December 6, The Japanese space agency JAXA returned samples collected from asteroid Ryugu.
On on around the 16th, China is expected to recover samples from the Chang'e 5 mission to the moon. Both of these missions while probably providing interesting information, are also examples of building space capabilities for nation states.
Good stuff.
Meanwhile, in the world of private space ventures, on the 9th, SpaceX launched Starship SN8 (literally serial number 8 ) for their first ever attempt at getting Starship to high altitude (not orbital, just 12.5 km or about 41,000 feet) with the intention of demonstrating the "belly flop" manoeuvre, which is the attitude it is expected to begin re-entry to Earth or Mars. Then it was to demonstrate the flip back to vertical, and land. Well it succeeded, mostly.
It looks like this was plagued by engine instability. First, one main engine cut off early -- and apparently uncontrolled -- then a second one did. That'd doom any mission because the vehicle could not likely make it to a useful orbit.

The subsequent manoeuvre to "flight" worked well enough, but was handled by an entirely different propulsion system. That part of the flight regime went well enough until the main engines had to re-ignite, and which it only looked like two did. This would be useful as the first stage would have been largely empty by that time. Note that all three main engined gimballed separately, which is useful in this regard.
There was a problem with fuel pressure in the header tanks that provided fuel for the landing, so thrust was reduced and the touchdown was a little fast, and SN8 had what they call an RUD, or rapid unscheduled disassembly. (big bang in other words)
The resulting fireball on the ground was spectacular, but did not cost life, and was useful in proving that the tactic might work. In that case, kudos to Space-X. They need to fix the fuel system to the main engines.

But it's better than NA$A has been able to do thus far.

I'd like to see what those intrepid Germans from Peenemunde would be able to do with today's control technology.
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partlyscot
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Re: Interesting news for space geeks.

Post by partlyscot »

The 3 engine, 2 engine, 1 engine ascent was deliberate, as was the relatively slow climb out. Didn't look like it, I agree. Starship on it's own can't get anything like a useful payload to orbit, for that it needs the super heavy booster, with 28 raptor engines. Can you imagine? :shock: I also think there were only supposed to be 2 engines for landing. From reports, the only issue was low pressure in the header tanks used for the landing. Note the colour of the exhaust, apparently the green tint meant that a poor fuel/oxygen ratio leads to parts of the engine burning up. Thus the low thrust and hard landing. I have not seen any reason given for the low pressure, but presumably they know what the reason was and can correct it in future flights. Slightly disappointed SNM9 had the little incident in the high bay, it would have been fantastic to see SN9 having another attempt within the week. As it is, at the least it will need a new flap. SN10 is almost complete, so at worst, I expect the next flight no later than the first week of 2021. They are not wasting any time.
partlyscot
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Re: Interesting news for space geeks.

Post by partlyscot »

Here's a nice little "documentary" talking to some locals about their attitude to Starship, and examining the various groups and people who were there to record the event. The launch and landing is captured from several cameras and viewpoints, as is the reactions from those watching. Nice bit of editing.

https://www.youtube.com/watch?v=xrVqLhh ... e=youtu.be
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