Was it possible for the ISS to...?

[bigdad84]

Have 2 Space Shuttles simultaneously docked?

[astropapi1]

I think so, but don't quote me on that.

[Scotius]

Theoretically? Why not? ISS does have more than one NASA compatible docking ring. Shuttles had their own life support and power systems. And since ISS does not rotate, there should be no problems with center of mass shifting.

[brooklyn666]

Possible in what sense? The station has 2 unused PMAs that the shuttle used to dock, but I imagine the logistics would have been difficult at best.

[bigdad84]

Would there have been enough room? With all the modules and trusses?

[TheShadow1138]

I believe the only available ports were PMA-1 and PMA-3. PMA-1 is the one the Shuttle used and, though I can't get a good look at it in the short time I've looked, I believe PMA-3 may be too close to the radiators on the truss to allow the Shuttle space to dock there.

[brooklyn666]

I believe the only available ports were PMA-1 and PMA-3. PMA-1 is the one the Shuttle used and, though I can't get a good look at it in the short time I've looked, I believe PMA-3 may be too close to the radiators on the truss to allow the Shuttle space to dock there.

That's what I'm thinking. Even though the PMAs are movable, I don't think there was clearance anywhere except PMA-1.

[Themohawkninja]

Maybe if you undocked the Soyuz escape pod, and used its docking ring for the shuttle.

[Kryten]

Maybe if you undocked the Soyuz escape pod, and used its docking ring for the shuttle.

They use/d completely different, incompatible systems.

[Tiberion]

Yeah the shuttles docked in a few positions over the years, but it was because the PMAs were moved around to different modules as things were delivered and attached.

[Warhorse]

They use/d completely different, incompatible systems.

*shrug*

Put an adapter in the shuttle's cargo bay. No big deal, as long as there's room for the shuttle at that port ...

[AlamoVampire]

*shrug*

Put an adapter in the shuttle's cargo bay. No big deal, as long as there's room for the shuttle at that port ...

Except how much does the adapter weigh? How much cargo volume would it take? All major considerations, thus a very BIG deal. Especially when it's like $10,000+- per POUND to get an item into orbit

[Warhorse]

Hey, I'm just talking possibilities. Considerations of why you'd want to do it or what it would cost are not relevant in this case. :-)

ETA: Since the shuttle used an adapter in the cargo bay to dock to the ISS in any case, the weight and volume lost are unlikely to be an issue at all, although development cost might be if NASA did it.

Edited January 6, 2014 by Warhorse

[TheShadow1138]

I'm not 100% certain, but I believe that the docking hardware on the Shuttle was permanently installed in the orbiters in preparation for ISS construction. This would mean that a probe-and-drogue type docking adapter would have to be attached to the permanent docking hardware to allow docking with the Russian Orbital Segment of the station. It would probably have been possible to carry it up in the cargo bay, attach it to the docking hardware, or station, and then dock. This seems to me like an awful lot of work just to allow multiple orbiters to dock to the ISS at once. I can't really think of a situation where you would need, or want more than one shuttle to dock to the station, but with an adaptor it would be possible.

[bigdad84]

This seems to me like an awful lot of work just to allow multiple orbiters to dock to the ISS at once. I can't really think of a situation where you would need, or want more than one shuttle to dock to the station..

Well i was just thinking, if there happened to be another Challenger type hole in the wing, they would have to bring up another shuttle to possibly repair, or bring the crew back.

[NovaSilisko]

Well i was just thinking, if there happened to be another Challenger type hole in the wing, they would have to bring up another shuttle to possibly repair, or bring the crew back.

1. Columbia had a hole in the wing, not Challenger

2. The plan was to keep the crew on the station and bring them home with normal Soyuz flights (I believe they would have been launched with one or two crew absent, to provide a free seat on return), then remotely undock and deorbit the shuttle. The payload bay doors would've been kept open to make sure the shuttle disintegrated completely on entry, so it didn't threaten anything on the ground.

*shrug*

Put an adapter in the shuttle's cargo bay. No big deal, as long as there's room for the shuttle at that port ...

There's really no such thing as "no big deal" in spaceflight.

[SFJackBauer]

The orbiter docking location and attitude related to the station was chosen to keep the thermal and electricity constraints on both the station and orbiter manageable - namely their positioning relative to the sun.

Also the rendezvous and docking maneuver was designed to prevent the shuttle RCS from blowing over certain external surfaces of ISS. And to allow the ISS crew to photograph the orbiter underside.

Adding another orbit would add several complications. If needed, this would have to be planned during the ISS design phase.

[DerekL1963]

Have 2 Space Shuttles simultaneously docked?

No. The ISS has to keep the Shuttle in a particular orientation for thermal control.

[Skyrunner27]

1. Columbia had a hole in the wing, not Challenger

2. The plan was to keep the crew on the station and bring them home with normal Soyuz flights (I believe they would have been launched with one or two crew absent, to provide a free seat on return), then remotely undock and deorbit the shuttle. The payload bay doors would've been kept open to make sure the shuttle disintegrated completely on entry, so it didn't threaten anything on the ground.

There's really no such thing as "no big deal" in spaceflight.

Actually the plan usally involved a shuttle http://en.wikipedia.org/wiki/STS-3xx only in the case of the last flight of Atlantis was there no rescue option besides the Soyuz. This is one of the reasons Atlantis flew because it was originally going to be the rescue mission for Endeavor.

[Nibb31]

Hey, I'm just talking possibilities. Considerations of why you'd want to do it or what it would cost are not relevant in this case. :-)

ETA: Since the shuttle used an adapter in the cargo bay to dock to the ISS in any case, the weight and volume lost are unlikely to be an issue at all, although development cost might be if NASA did it.

There was no adapter. The Shuttle was equipped with an APAS docking port in the cargo bay. These were fitted during the Shuttle-Mir program and required a protruding APAS port on the station side (which is why the Shuttle Docking Module was added to Mir). The result was that the Shuttle could only dock to the two PMA adapters on the ISS.

Ironically, Columbia was the only Orbiter that didn't have an APAS because she was overweight compared to the other Orbiters. Due to being the first orbiter, Columbia had a heavier structure with reinforcements for ejection seats and extra sensors and flight recorders. The result was that Columbia was only ever used for freeflying Spacelab missions and couldn't be used for ISS operations.

In the end, there would not have been enough clearance to dock two shuttles to the ISS. You need to take into account physical clearance, obviously, but also thruster plume clearance so as not to damage the other spacecraft during docking manoeuvers. I also don't think that Houston MCC could support flying two Shuttle missions simultaneously other than in the contingency STS-400 situation.

It would be a big no-go for shuttle operations.

Edited January 6, 2014 by Nibb31

[AviatOrme]

...thruster plume clearance so as not to damage the other spacecraft during docking manoeuvers.

IIRC, all docked spacecraft were 'grounded' while the shuttle was docked for this very reason. There was too much fear of damaging the shuttle's systems and tiles.

In an emergency, I'm sure a way would have been found. For normal operations, I doubt they'd do it.

[DerekL1963]

Ironically, Columbia was the only Orbiter that didn't have an APAS because she was overweight compared to the other Orbiters. Due to being the first orbiter, Columbia had a heavier structure with reinforcements for ejection seats and extra sensors and flight recorders. The result was that Columbia was only ever used for freeflying Spacelab missions and couldn't be used for ISS operations.

On the contrary, if fitted for the docking adapter, she could easily reach the ISS - she just couldn't carry much there.

In fact, during her last OMDP she was modified (cabling and structural mounts installed) to accept the docking adapter. Had she returned successfully from STS-107, she would have been fitted with a docking adapter and flown to ISS as STS-118.

[TechnicalK3rbal]

Possible, yes. Ever done, no.

[Javster]

Would it have been cramped with the 6 normal crew, plus 2 full Shuttle crews of 7 each?