Letting the ISS burn up......Why?

[fredinno]

12 minutes ago, sevenperforce said:

Any sort of ablative or single-use or otherwise expendable re-entry system can benefit from the data that would be gleaned when the ISS burns up.

Yeah, but a tank would shed debris onto the payload, and is not designed for that kind of use anyways. Ballutes are also expendable.

[Nibb31]

49 minutes ago, sevenperforce said:

Are you really suggesting that there's absolutely no way we could glean useful data from a better understanding of how modules intended for on-orbit endurance handle unprotected re-entry? After all, it's not like space flight ever involves unplanned emergencies.

What sort of emergency would see an unshielded vehicle doing an uncontrolled reentry where it made any difference if it disintegrates at Mach 20 or Mach 18 ?

49 minutes ago, sevenperforce said:

Bare minimum, using a video feed from the deorbit of the ISS would provide useful data for determining how aggressively we could aerobrake an unprotected orbital module in an emergency situation.

There is no way you would aerobrake an unprotected orbital module in any kind of survivable manner. Seriously, what type of crazy scenario would this be useful ?

For the same reason, Boeing or Airbus don't do simulations or train airliner crew to recover from stall situations, because they assume that an airliner should never get that far into a failure, and that if it does, everything has failed so terribly that it won't be recoverable anyway.

49 minutes ago, sevenperforce said:

But it's bigger than that. We can model a lot of stuff, but we also need to be able to test our simulations. Having real data from the breakup of multiple ISS modules would provide a huge resource for testing our modeling software.

What software ? Nobody does simulations about the reentry disposal. The crude data is more than enough to know that everything is pretty much destroyed. Even large parts that aren't vaporized will never be reusable. It's typically a chaotic situation that doesn't require modelling.

 

 

[fredinno]

16 minutes ago, Nibb31 said:

There is no way you would aerobrake an unprotected orbital module in any kind of survivable manner. Seriously, what type of crazy scenario would this be useful ?

You can still aerobrake Mars manned landers in the atmosphere before reentry slowly. Understanding how it impacts equipment would allow it to go deeper.

[sevenperforce]

22 minutes ago, Nibb31 said:

What sort of emergency would see an unshielded vehicle doing an uncontrolled reentry where it made any difference if it disintegrates at Mach 20 or Mach 18 ?

It would be a very bad day to be sure, but it could happen. If you were inside an orbital module and suffered damage from a micrometeoroid strike which punctured the module and damaged your re-entry capsule's heat shield, then it would be worth knowing whether de-orbiting with your capsule inside the shell of the dead orbital module would give you a better chance of survival or a worse chance of survival. Or, what if your RCS system was completely destroyed and you had no way of decoupling from the module in-flight? Would it be safe to let the module push you onto the right trajectory and then just allow re-entry to burn it off?

Obviously that is an extreme case and we may already have the answer in that particular situation. But space is a dangerous place and a lot of stuff can happen. I wouldn't ever want to give up the opportunity for more data.

22 minutes ago, Nibb31 said:

There is no way you would aerobrake an unprotected orbital module in any kind of survivable manner. Seriously, what type of crazy scenario would this be useful ?

I don't mean re-entry aerobraking; I mean skip aerobraking. If a flight anomaly or other emergency on an interplanetary flight (to or from Mars, for example) left you with excess velocity and not enough dV for a complete orbital insertion, how far into the atmosphere would it be safe to dip in an attempt to bleed off that excess velocity?

22 minutes ago, Nibb31 said:

What software ? Nobody does simulations about the reentry disposal. The crude data is more than enough to know that everything is pretty much destroyed. Even large parts that aren't vaporized will never be reusable. It's typically a chaotic situation that doesn't require modelling.

We don't model re-entry disposal so much, but we definitely model re-entry in general. And being able to extend the modeling software's accuracy range to include extreme scenarios is a good test of your assumptions.

EDIT: Sniped by fred; he said exactly what I was thinking.

Edited April 4, 2016 by sevenperforce
sniped

[Hasegawa]

51 minutes ago, Nibb31 said:

What software ? Nobody does simulations about the reentry disposal. The crude data is more than enough to know that everything is pretty much destroyed. Even large parts that aren't vaporized will never be reusable. It's typically a chaotic situation that doesn't require modelling.

Considering that NASA's studied reentry and breakup with REBR (news, experiment pages), JAXA has done so with i-ball (and one of NASAs REBR's) on Kounotori 3, and ESA has tried with their own recorder (and it would have had a REBR too) on ATV 5 (Spaceflight Now)? There may just be a reason to do so...

Like working out how to reduce the 10-40% fraction of the mass of a re-entering vehicle that survives to hit the ground

Edited April 4, 2016 by Hasegawa

[John JACK]

6 hours ago, Nibb31 said:

Astronauts have better things to do.

If an only station is going down, astronauts will have no things to do at all. Spending several days installing cameras is better than spending several days more retired groundside without even cool videos to watch at old age.

And yes that should be not only cameras but any others sensors and means of telemetry. Deorbiting such big object will produce unique experimental data, and even computer modelling is impossible without knowledge how exactly things behave in reality.

6 hours ago, Nibb31 said:

When you exceed those requirements, bad stuff happens (see Challenger, or closer to us, CRS-7).

Was it really from old age and neglect? Accidents and catastrophes in space happen mostly with new hardware. Stuff that worked once and again is statistically more reliable. Mir was scrapped by a political/economical decision, not because of old age or even frequent failures. There were projects to conservate it, but to no avail.

Look at planes. Airframes commonly fly for several decades. Some bombers serving in Middle East are older than their pilots parents. Electronics and machinery are not that old, but it can be repaired, refurbished, replaced or upgraded.

4 hours ago, fredinno said:

Hmm

More literally a family member. Just some guy known as "Grandpa Lenin"

[John JACK]

3 hours ago, Nibb31 said:

Boeing or Airbus don't do simulations or train airliner crew to recover from stall situations, because they assume that an airliner should never get that far into a failure

Yep, and they did not do simulations to fly an airliner without working engines. Until someone mistook kilos for pounds and a passenger plane just ran out of gas.

Spaceflight is less about profit and cutting costs, and more about scientific curiosity and military preparedness to anything at all, including sudden green aliens in saucers. Reentry is even not scientifically or logically impossible, so it must be studied.

[StrandedonEarth]

2 hours ago, John JACK said:

Until someone mistook kilos for pounds and a passenger plane just ran out of gas.

Or how about losing both engines to a flock of geese? Amazingly, neither situation ended with loss of life.

I myself would love to see footage from inside and outside a re-entering vehicle. Stick a cam or five in every module and the recorder(s) in a heatproof "black box" with a floatation bag and locator beacon. How much could it really cost, for never-before-seen footage?

 

Edited April 5, 2016 by StrandedonEarth

[Matuchkin]

On 4/5/2016 at 8:52 PM, StrandedonEarth said:

I myself would love to see footage from inside and outside a re-entering vehicle. Stick a cam or five in every module and the recorder(s) in a heatproof "black box" with a floatation bag and locator beacon. How much could it really cost, for never-before-seen footage?

 

There is footage. A Soyuz astronaut took it while his vehicle was reentering.

Personally, I even saw color-footage from Stalingrad.

[sevenperforce]

9 minutes ago, Matuchkin said:

There is footage. A Soyuz astronaut took it while his vehicle was reentering.

Personally, I even saw color-footage from Stalingrad.

Footage from Shuttle re-entries as well...even one from Columbia's last mission, though it ended well before the breakup.

But no footage from something not intended to survive re-entry.

 

[Matuchkin]

2 hours ago, sevenperforce said:

Footage from Shuttle re-entries as well...even one from Columbia's last mission, though it ended well before the breakup.

Actually:

This video ends right at the breakup.

 

[Temeter]

It's questioned in the comments if the video is actually from the accident, tho.

[Vanamonde]

This thread is wandering from its topic. The subject is the advisability of destroying the ISS. 

[fredinno]

5 hours ago, Temeter said:

It's questioned in the comments if the video is actually from the accident, tho.

lolwut? why?

[todofwar]

11 hours ago, Vanamonde said:

This thread is wandering from its topic. The subject is the advisability of destroying the ISS. 

On that note, has there been any though given to what the impact of that would be? We've never had anything that big come back from orbit, it could be dangerous for a number of reasons (I guess you would aim for a pacific "landing" and hope nothing goes wrong). I wonder if from a safety stand point it makes more sense to boost it to a more stable orbit and leave it as a museum piece. 

[Nibb31]

54 minutes ago, todofwar said:

On that note, has there been any though given to what the impact of that would be? We've never had anything that big come back from orbit, it could be dangerous for a number of reasons (I guess you would aim for a pacific "landing" and hope nothing goes wrong).

It will be a scheduled deorbit with a series of burns from a visiting vehicle, most likely a Progress. They will make sure it comes down in a remote area.

Quote

I wonder if from a safety stand point it makes more sense to boost it to a more stable orbit and leave it as a museum piece. 

Seriously? Have you even read the thread before posting in it?

Edited April 8, 2016 by Nibb31

[todofwar]

5 minutes ago, Nibb31 said:

Seriously? Have you even read the thread before posting in it?

7 page long thread so no, and I assume with a three option topic like this everything is going to be repeated. I know others have mentioned the idea of putting it into a stable orbit and leaving it there, I was saying it might be the safest option not necessarily the cheapest or most useful option. 

[fredinno]

 

1 hour ago, todofwar said:

7 page long thread so no, and I assume with a three option topic like this everything is going to be repeated. I know others have mentioned the idea of putting it into a stable orbit and leaving it there, I was saying it might be the safest option not necessarily the cheapest or most useful option. 

RECAP: It would eventually break up in a stable orbit, and become a space junk hazard. It's safer to bring it down, even Skylab never killed anyone when she came down uncontrolled.

[todofwar]

1 hour ago, fredinno said:

 

RECAP: It would eventually break up in a stable orbit, and become a space junk hazard. It's safer to bring it down, even Skylab never killed anyone when she came down uncontrolled.

Well if it will require constant maintenance runs no matter where you put it in orbit than I say crash it or repurpose it, but I'm getting convinced that the best option is to deorbit it carefully so it hits an unpopulated area. XKCD What If? did a nice break down of the environmental effects of things burning up in orbit, granted he did the calcs for a volkswagon not the ISS, but overall probably not the worst thing we've done to the environment. 

[RainDreamer]

I wonder, when the ISS lands on a country, who should they fine for littering?

[Perry Apsis]

An abandoned ISS would be what is legally known as an "attractive nuisance." Kids would start having parties there, someone would suffer from alcohol poisoning or explosive decompression, and you've got a liability nightmare. Let's keep the museums here on the ground, where if you fall out a window you've got at least a small chance of surviving.

[Rath]

Seveneves (Great book) sort of talks about this happening, but with it being one of the reasons that the human race survived, its treated with a lot more respect than it does now.  Living in orbit tends to do that.

SPOILER ALERT: 

Spoiler

The ISS ends up getting converted into an mobile orbital ship, and in order to escape the bombardment of chunks of the moon, is transferred onto an massive chunk of the destroyed moon, in order to protect it, and is eventually turned into almost a religious piece, because mankind would be extinct without it.

 

[sevenperforce]

19 hours ago, Perry Apsis said:

An abandoned ISS would be what is legally known as an "attractive nuisance." Kids would start having parties there, someone would suffer from alcohol poisoning or explosive decompression, and you've got a liability nightmare. Let's keep the museums here on the ground, where if you fall out a window you've got at least a small chance of surviving.

My ability to like posts was utterly trashed by the landing yesterday.

[Kryten]

20 hours ago, RainDreamer said:

I wonder, when the ISS lands on a country, who should they fine for littering?

The various modules are legally owned by and registered to their countries of origin, so if it's the whole thing it'd be joint between Roscosmos, NASA, JAXA, ESA and the CSA. One more reason to dump it in the ocean.

[max_creative]

I've changed my mind. Two words: Kessler Syndrome.