davispw t1_j1f9zmr wrote
Not decided yet. The leak is in the “outer” coolant loop, so the question is, how hot will the crew cabin get during the return to Earth? The “inner” coolant loop is working, but without the outer loop, it can’t radiate the heat away. They’re analyzing. If it’s safe, then they’ll skip the rescue.
Here’s the press conference: https://youtu.be/CvTN7DH23M4. The crappy Yahoo article left out all the details. The Russian spokesperson is hard to understand, though (bad audio quality).
Vagabond_Grey t1_j1fb2mb wrote
I know these things cost money but it's always better to err on the side of caution.
davispw t1_j1fbneo wrote
Sure, but there are redundancies and NASA has an astronaut on board, too. If NASA agrees with Russia’s technical analysis, I’ll take it.
I’m wondering if they can just plan for a quick decent that maximizes the time in the Earth’s shadow.
Vagabond_Grey t1_j1fgkso wrote
AFAIK, there's nothing available that can maximize the re-entry time. I believe both NASA and CNSA was testing out an inflatable heat shield but we're long ways from that reality. And if it were available, they'd still need to send a new capsule.
Just a quick thought; maybe a foolish idea. Remember that Redbull stunt with the guy parachuting down from Space? Would that work for the ISS? Get SpaceX to send the necessary equipment and have the astronauts parachute down.
Chevron7Nice t1_j1fwkpr wrote
While that would be awesome, it wouldn't work. The red bull guy was stationary. The people on the ISS are traveling incredibly fast to keep their orbit - and that is what causes the heat buildup on reentry. So it won't work sadly.
broberds t1_j1i7ik9 wrote
Well it will work sadly. Problem is there’s no way to make it work happily.
Thighbleman t1_j1ivq8u wrote
The red bull guy was also 10 times lower and still technicly in the atmosphere. Its also all denser there. Even if the astronouts came to a stop at 400km they would have 300km to hit the atmosphere. They would do it at 2.5km/s... and that would not start slowing them down for probably another 50 or sth. Its mach 7... they would burn
Thighbleman t1_j1iwgf5 wrote
I assumed they cant leave landing capsule at some lower hight. No depressurization chamer etc... also having rocket engine brings to much to the equation... it cant have fuel to stop all 2.5km/s of the decend so...
ammonium_bot t1_j1jfdz1 wrote
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Vagabond_Grey t1_j1fyfce wrote
What about taking the damaged capsule to a point where it's safe to parachute down?
davidbenett t1_j1gq62f wrote
It's not about reaching a certain point it's about bleeding off all the excess speed.
Rayden440 t1_j1gvmwr wrote
Redbull guy was relatively stationary in space. The astronauts on the ISS is moving 7.7km per second around the earth. If they attempted to parachute back to earth, the astronauts will burn up. We’ll be lucky to even find a bit of their charred remains if at all.
abstract_concept t1_j1jfhhr wrote
They're in orbit, not just high up. The red bull guy was high up.
These people are much higher up AND going sideways so fast they keep missing the earth even though they're falling towards it.
It's slowing down from going sideways fast that creates a bunch of the heat. Even if they could stop, they also still have a really long way to fall and would still build up a ton of speed as they hit the atmosphere.
Turns out, space is hard.
sctvlxpt t1_j1fiwi7 wrote
If SpaceX is sending something, might as well send a fully working dragon capsule for re-entry, instead of parachutes.
Vagabond_Grey t1_j1fkwyg wrote
I was thinking about the next resupply event. This is assuming the wait time doesn't kill the astronauts.
danielv123 t1_j1hkbto wrote
Resupply with a crew dragon packed with cargo instead of people? It doesn't have that much less cargo capacity, right?
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ProjectDv2 t1_j1ij04z wrote
Why would the wait time kill the cosmonauts?
Vagabond_Grey t1_j1itcrh wrote
Prolonged time in micro-gravity have brought about health problems like that Canadian astronaut who suffered from temporary blindness and one of the Kelly twins had problems to walk again. Although both fully??? recovered from their experience, it wouldn't surprise me that it could be fatal.
ProjectDv2 t1_j1izvw3 wrote
They are nowhere near the maximum amount of time a person has spent in space. They're not in any life-threatening danger at this point.
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Tomon2 t1_j1gd73m wrote
It's a good question. There's a couple of considerations and engineering challenges before you can get to a safe point of parachuting and landing.
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The ISS is orbiting. Just stepping out of it means you're also orbiting. What that means is that it's moving so fast in one direction, it's constantly falling and missing the earth. What you would need to do is slow down the individual's velocity in the direction of orbit - some kind of rocket or jet-pack style tech that blasts them in the opposite direction of the ISS orbit path - that way, when they're falling, they'll actually fall and "hit" earth.
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Reentry. Before they hit denser air, they're gonna pick up a lot of vertical speed. Considerably more than the red bull stunt guy had. As they hit the atmosphere, they're gonna make a lot of friction and heat up. So they'll need some kind of protective heat-shield until they slow and cool down to the point that a parachute is viable.
It's not impossible - but once you put together a small rocket motor and a heat shield for a couple of people, you start looking like a conventional re-entry vehicle real quick.
ProjectDv2 t1_j1ik7tj wrote
It's not friction that creates the massive heat, it's compression. Entering the atmosphere at the speeds that stellar objects and orbiting vehicles do turns the object into essentially a large diesel piston. The air in front of the object can't move around it fast enough and instead stacks up and compresses, which causes the molecules to gain heat. By the time the object slows enough, the heat is immense.
That being said, I want people to think about what effect compression intense enough to burn up meteorites would have on a squishy human body. The cosmonauts' bodies would be utterly destroyed long before they could burn up, like stepping on a tomato.
Vagabond_Grey t1_j1gewza wrote
What about using the damaged capsule to get the astronauts to the appropriate "bail-out zone" and jump off from that point?
Tomon2 t1_j1gfdun wrote
Once you've made it to the "bail-out zone" - you're basically in the clear anyway. You're moving slow and cool, and you can let the capsule's parachutes do the work.
Getting them to that point is the dangerous and difficult but that we're currently worried about.
If you want to learn and play around with orbital mechanics and structures, I'd recommend playing Kerbal Space Program - or waiting til Feb and catching it's long anticipated sequel.
Lots of YouTube tutorials to help you with the mechanics, but a great way to see and feel and solve the various challenges there are with space travel.
Imadope_1960 t1_j1ftk33 wrote
Dropping down a couple hundred miles from space requires an actual capsule, you can't just float down 250 miles and pull the parachute chord.
Vagabond_Grey t1_j1fxvyp wrote
Yes I know. But take a ride on the damaged capsule to the point where one could jump out from it. IMHO, it's better they send a new capsule to pick them up.
DarthBrooks69420 t1_j1gfhty wrote
The deceleration from entering the atmosphere produces heat. The systems that are damaged is the external cooling that dissipates the heat (I think).
You can't just reenter the atmosphere at that speed without something to absorb and shed that heat. If the astronauts just tried to parachute back to earth they would be vaporized.
Gazza_s_89 t1_j1hdz3y wrote
But its a catch 22, to slow the capsule to a speed where the astronauts wouldn't jump out and become human missiles travelling several km per second, the coolant system will have to do the bulk of the work regardless.
Vagabond_Grey t1_j1ipgi6 wrote
I was under the impression that these capsules had enough propellant onboard to slow itself down without relying on the atmosphere to do it.
EvilNalu t1_j1jidpb wrote
Not even close. They slow down just enough to start reentry. Generally around 1% of their orbital velocity. They lose the other 99% by using the atmosphere.
RhesusFactor t1_j1h845q wrote
Spacecraft like soyuz are not designed or built for you to be able to jump out of them. Cosmonauts are also typically fairly weak after extended stays in microgravity so won't be doing stunts on reentry. There are also no parachutes aboard the ISS.
Vagabond_Grey t1_j1iodz2 wrote
Yes I know there are no parachutes on the ISS. My initial idea was to have the astronauts wait for the next resupply with them along with any required equipment. This is assuming the next resupply isn't too far off away before any permanent health damage sets in.
davispw t1_j1fgyyv wrote
Minimize, not maximize. I believe they can choose shorter or longer options for the descent, which I imagine depends on how perfectly the ISS’s orbit is aligned with the desired recovery zone, which would determine how many orbits the Soyuz needs to do on its own before deorbiting.
Edit: to clarify—minimize time to deorbit, while maximizing time in the Earth’s shadow since the Sun’s heat is the main thing the coolant loop needs to deal with.
Vanimo t1_j1h3gr6 wrote
Minimising means that you need to deal with all the energy of re-entry (heat) in a short time. So you need a high dissipation rate, which is exactly the problem here.
Rough_Idle t1_j1gnfpv wrote
It's a fun thought, but Baumgartner was practically stationary compared to the ground beneath him during his jump. By comparison, astronauts on the ISS are moving over 17,000 miles per hour relative to the ground below with no way of slowing down enough to land safely other than atmospheric braking.
saltywalrusprkl t1_j1h7ksg wrote
The redbull guy wasn’t moving at thousands of metres per second horizontally like the ISS is in orbit. The hard part about getting to (or back from) space isn’t getting to a high enough altitude, it’s accelerating sideways fast enough to reach the correct orbital velocity.
phryan t1_j1h7jln wrote
The astronaut would never get to the parachute step, they'd burn up during entry.
andthatswhyIdidit t1_j1ho495 wrote
> Remember that Redbull stunt with the guy parachuting down from Space? Would that work for the ISS?
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Alan Eustace had a much higher jump 2 years later (just not as commercialized)
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The problem with anything orbiting at ISS level (400km [250m]) is NOT the height it has above ground, but the SPEED(28 000 km/h [17 500 mph]) it has relatively to the ground.
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Even if you stood still at ISS levels, you would need at least an outer ablative shield to not destroy your spacesuit through reentry heat.
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Having said all that, there were tons of personal escape concepts looked into since the 1960ies - but none ever got implemented.
alexw888 t1_j1hrc8m wrote
Another issue with parachuting which I haven’t seen mentioned yet is the skill needed to pull it off at that height. If I recall correctly, due to the thin atmosphere, it’s really easy to enter an uncontrolled spin from which you can’t recover. The guy who jumped for Redbull had amazing technical abilities to be able to do so
supersonicpotat0 t1_j1i69fk wrote
There WERE actually studies about basically having a big puck of fireproof foam with a seat on the back. You sit in the chair, and then backflip into the atmosphere. It works because you are going so damn fast the plasma kicked up from reentry can't catch up to the back of the heat shield to roast you. The biggest problem is the infrared air-frying (vacuum frying?) you, but a space suit should be able to handle that much.
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dr_patso t1_j1h5k8n wrote
Red Bull guy wasn’t traveling 17,000 mph.
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Capricore58 t1_j1j5qtc wrote
The parachuting man from space was no where close to the height/orbit of the ISS
jawshoeaw t1_j1l9ost wrote
The red bull guy wasn’t in orbit. He did the equivalent of climbing a tall ladder. Shedding orbital velocity is the problem.
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davispw t1_j1ghz6h wrote
The ISS has American and Russian segments—it’s literally designed so that both countries must continue to cooperate. Designed in the 90s by ex-Soviet engineers who were plenty competent (and who the US wanted to keep employed so they didn’t go off and work for the highest bidder building guided missiles or whatever). Please, go back to the 80s and tell them how you feel!
RhesusFactor t1_j1hbo2n wrote
Uncomfortable as it might make you feel, The soyuz has been the most flown and reliable human rated spacecraft ever.
Also consider the cause of this problem is soyuz MS22 has been whacked by some debris. It could have whacked the Crew Dragon instead. Would you still go off then?
Enzown t1_j1j2pjd wrote
What if I told you that between the retirement of the space shuttle and the rise of Spacex the ISS was fully reliant on Russian rockets.
quirkycurlygirly t1_j1ipmr3 wrote
I agree. It's not worth the risk. If a capsule carrying three lives burns up on reentry it will cost a whole lot more money in lost public support.
RenaissanceBear t1_j1hs4rn wrote
That doesn’t sound like a very Russian thing to do to me…
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Xaxxon t1_j1kqmet wrote
It’ll be interesting if nasa disagrees with it being safe.
gixxerboyson t1_j1i1b9m wrote
That’s not how Radiant Heat works buddy. They putting those men’s lives in danger. The better just call SpaceX and be done with
davispw t1_j1iqnw0 wrote
What’s not?
lanc3rz3r0 t1_j1iqcxn wrote
RU doesn't have the greatest track record in retrieval of its cosmonauts...
davispw t1_j1iqy31 wrote
Explain? NASA has killed many more astronauts, and more recently, than Russia. I’m not defending the state of Russia’s space program at all—there have been several recent, very bad quality issues—but please inform yourself.
lanc3rz3r0 t1_j1ixi2v wrote
Russia also used to not build reentry vehicles, and then they used to try to retrieve over land (to disastrous results).
davispw t1_j1ixtgk wrote
I really have no idea what you’re talking about. Of course they built reentry vehicles—kind of hard to get back from orbit without one.
Xaxxon t1_j1kz483 wrote
I asked him for a source and he got really upset, too. Apparently asking for links is "toxic"
Xaxxon t1_j1kqoul wrote
Please provide links to what you’re referring to.
lanc3rz3r0 t1_j1kyi88 wrote
Honestly, this is the most toxic kind of request on reddit. You have the same internet I do. I don't wish to engage in conversation with you.
Xaxxon t1_j1kz23u wrote
You make claims, you provide sources. You didn't even give any names to base a search off of.
> I don't wish to engage in conversation with you.
Great, but then don't even waste my time telling me you don't want to.
Talk about toxic.
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davispw t1_j1fgati wrote
There’s a NASA astronaut on board this Soyuz, so NASA will be reviewing the analysis.
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gerkletoss t1_j1fkvst wrote
They care about saving face, which means not making this a big deal
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