STS-114: The Rescue That Never Was

[ZeeWulf]

I just read an article that made me rather sad, though I couldn't help but think of some of it in Kerbal terms...

To summarize: When the Columbia was lost, Atlantis was already under prep for STS-114, a trip to the ISS. The linked article discusses the mission NASA would have had to pull off to use her to save the Columbia's crew.

It's a tough read, was audacious and the stuff of legends, and think would have made a fine movie if done. Of course, now I want to try to enact something like it in this, if the parts were in place to do so.

Just because...it's tough to look back and not do anything.

[Accelerando]

Calls out to a hope that the mission controllers could have done more, that somebody could have done something... and maybe you could at least understand better if you tried it out yourself in-game - aye.

I cried at the last page.

[duncan1297]

Wow

(Tenchar)

[FanaticalFighter]

That was a brilliant article. Thank you, OP.

[Kilmeister]

Good article. Always thought that a rescue would've been impossible anyways. This article really lays it out in detail.

[K^2]

Is there a reason why STS-107 could not rendezvous with ISS? Seems like it would have had sufficient fuel, propellant, and time to do any necessary orbit adjustments. They would not have any way to actually dock with the station, but surely, it would have been easier to EVA everyone between the two stations, perhaps, carrying some suits back and forward between Columbia and ISS, then it would have been to organize a shuttle-to-shuttle transfer in such short time.

[mythbusters844]

Thanks for the article! It was an interesting read

Is there a reason why STS-107 could not rendezvous with ISS? Seems like it would have had sufficient fuel, propellant, and time to do any necessary orbit adjustments. They would not have any way to actually dock with the station, but surely, it would have been easier to EVA everyone between the two stations, perhaps, carrying some suits back and forward between Columbia and ISS, then it would have been to organize a shuttle-to-shuttle transfer in such short time.

Good point. Maybe, the rendezvous computers needed to be set on ground? Just a wild speculation.

[Rakaydos]

Is there a reason why STS-107 could not rendezvous with ISS? Seems like it would have had sufficient fuel, propellant, and time to do any necessary orbit adjustments. They would not have any way to actually dock with the station, but surely, it would have been easier to EVA everyone between the two stations, perhaps, carrying some suits back and forward between Columbia and ISS, then it would have been to organize a shuttle-to-shuttle transfer in such short time.

The problem was, the ISS was/is in an orbit inclined enough to be accessable to russian launch sites- not quite a polr orbit, but far beyond the shuttle's ability to alter it's plane.

Try taking a normal orbital booster in Kerbal, nothing interplanetary, from an equatorial orbit into a 45 degree inclination, without refueling. THAT is why they couldnt dock with the ISS.

[maccollo]

Is there a reason why STS-107 could not rendezvous with ISS? Seems like it would have had sufficient fuel, propellant, and time to do any necessary orbit adjustments.

Absolutely no way that would have been possible.

The ISS orbits at a 51.65 inclination and the orbit of STS 107 had a 39 degree inclination. That means that this inclination change would have required 1.7 km/s of delta V. So this is already impossible, and that's for the best possible scenario where the inclination nodes between the orbits would have aligned with the equatorial plane, which they didn't.

Although I couldn't find anything more specific details about the orbit the article does specify the amount of delta V that would have been required for the plane change: 3,84 km/s.

That means that the actual inclination between the ISS and the orbiter was something like 28 degrees instead of 12.

Edited March 3, 2014 by maccollo
Typos and stuff

[Spenzor]

Is there a reason why STS-107 could not rendezvous with ISS? Seems like it would have had sufficient fuel, propellant, and time to do any necessary orbit adjustments. They would not have any way to actually dock with the station, but surely, it would have been easier to EVA everyone between the two stations, perhaps, carrying some suits back and forward between Columbia and ISS, then it would have been to organize a shuttle-to-shuttle transfer in such short time.

From page two of the article:

Columbia's 39 degree orbital inclination could not have been altered to the ISS 51.6 degree inclination without approximately 12,600 ft/sec of translational capability. Columbia had 448 ft/sec of propellant available.

Nowhere near enough dV.

I did a little looking - according to NASA, the OMS provided the shuttle with about 1000 f/s dV when full - so Columbia couldn't have performed a plane change even with a full supply of OMS propellant.

[Camacha]

To me this is a lot of could haves and should haves. It is nice to dream something could have been done, but the reality is that it is unlikely and, of course, that NASA did not even properly recognize the problem. There had been plenty of foam strikes - it was pretty much business as usual. The moment the foam hit the wing the flight and crew were doomed.

One of the comments stood out to me:

I worked on the planning for the STS-125 rescue mission, STS-400. It took 18 months of planning to develop the procedures, modify the tools, test and simulate the GN&C, EVA, and robotics choreography, and prepare all the paperwork to satisfy everyone that it was a safe plan for both orbiters and the crew. The proposed plan in this article would have been even more difficult because there was no opportunity to use the RMS (robotic arm) to grapple Columbia. Columbia wasn't carrying an arm, and Columbia itself did not have a grapple fixture that Atlantis's arm could use. I am extremely dubious that the manual station keeping would be doable even just from a propellant standpoint: STS-400 had the crew transfer requiring two days. (The STS-400 timeline is available online) For Columbia, that would mean manually station-keeping for an entire EVA (6.5 hours), then separating until the next EVA is ready, and performing another rendezvous and station keeping for > 6.5 hours. I don't think there is anywhere near enough RCS fuel to do that.

The only hope that this plan would have ever had would have been if the plan had already been in place prior to Columbia's launch, as there is no way on this Earth that NASA would have approved a flight with untested procedures that could destroy both orbiters. As I said above, the very similar STS-400 flight planning took 18 months; even if the entire NASA work force worked around the clock, that amount of work wasn't going to happen in just a few weeks. Sadly, I can't see a path where this would have actually been feasible.

I guess this would be one of the advantages of the SpaceX approach, if it ever happens as projected - if we ever manage to launch a vehicle multiple times a week, rescuing stuck crews will become a more trivial affair.

[K^2]

Although I couldn't find anything more specific details about the orbit the article does specify the amount of delta V that would have been required for the plane change: 3,84 km/s.

That means that the actual inclination between the ISS and the orbiter was something like 28 degrees instead of 12.

If the difference in inclination of orbits is 12.6°, then the maximum angle between the two orbits is 25.2°. The rest of that figure is probably required for altitude adjustments.

I did a little looking - according to NASA, the OMS provided the shuttle with about 1000 f/s dV when full - so Columbia couldn't have performed a plane change even with a full supply of OMS propellant.

That isn't right. Orbiter's mass is 68,585kg. With 65,000lb payload at 1000ft/s delta-V and the 316s I_SP of its engines, it would have only 10,000kg of OMS propellant on board. In contrast, de-orbit burn can last up to 1,250s at 26.7kN, which would require over 20,000kg of fuel. And the figure I found actually quoted for this is 21,660kg of fuel in two pods.

I suppose, they might have been going for something like 1,000ft/s each, but in either case, Orbiter is capable of significantly higher delta-V.

Unfortunately, even taking empty weight and full OMS fuel, I still come up with only 850m/s of delta-V, which would be easily enough sufficient to move to necessary altitude and match orbits if it weren't for inclination change. Even if ascending nodes of the two orbits were drifting fast enough to have them match before life support runs out, that's still almost 1.7km/s burn, as maccollo points out. And inclination change isn't large enough to save any fuel with a bi-elliptic transfer, or any other trick for reducing delta-V required for inclination change. At least, not by any amount that's going to matter.

Thanks to everyone who helped clear this up for me.

[Nibb31]

As mentioned by the article, this proposal was published as an appendix of the CAIB report. It took them several months to come up with this plan, which means that they simply couldn't have evaluated it in the required timeframe. It also assumes that the rescue shuttle processing is strictly nominal, even though it was streamlined with much less testing and checking, which was pretty much unrealistic.

But most of all, I don't think they would even have signed off to risk another shuttle and crew on such a rescue mission. They had no time to properly investigate the problem, so for all they knew, the same defect in the foam could have also stranded the second shuttle, with no hope of rescue this time. Even though they had very little chance of working, they would probably have attempted some of the "fixes" that didn't require a rescue launch, i.e.: Patching the wing with waste bags and freeze sealing with water, jettisonning any superfluous mass (includind the skyhab).

I guess this would be one of the advantages of the SpaceX approach, if it ever happens as projected - if we ever manage to launch a vehicle multiple times a week, rescuing stuck crews will become a more trivial affair.

I don't think that anyone at SpaceX has ever seriously envisioned launching a vehicle multiple times a week. Where would the payloads come from for that sort of launch rate?

[Rakaydos]

I don't think that anyone at SpaceX has ever seriously envisioned launching a vehicle multiple times a week. Where would the payloads come from for that sort of launch rate?

The rich and famous heading to the first Space Casino in human history.

[K^2]

The rich and famous heading to the first Space Casino in human history.

Hm. That's not so crazy. If they get cost of launch down with Falcon 9R as much as they are planning to, cost of launch per seat could be as low as quarter of a million USD. I don't think that's going to account for multiple launches every week, but this is affordable enough for the rich and famous to make some sort of an orbital establishment a viable venture.

[maccollo]

If the difference in inclination of orbits is 12.6°, then the maximum angle between the two orbits is 25.2°. The rest of that figure is probably required for altitude adjustments.

I'm not that well versed in orbital mathematics, so in this case I decided to use my 3d program to set up these two relative orbits to see if that amount of relative inclination was possible, which resulted in this. The only limiting factor I used was the inclination to the equatorial plane.

The highest inclination difference I managed to get was around 85 91 degrees.

Edited March 3, 2014 by maccollo