The numbers that I came up with also suggest that the Pirs compartment has too large a diameter to fit in the payload bay.
If it's too large to fit in the payload bay, does it matter which missions have empty bays on the way home?
I don't see how. Aside from the Strela and a couple other removable appendages it's only slightly fatter than a Soyuz and Progress (<3 meter diameter) See http://spaceflight.nasa.gov/gallery/images/station/pirs/hires/jsc2001e26682.jpg
1. And why would it take 3 years to return Pirs?2. Let's say that the current manifest is extended out until 2012 or so. Aren't there missions at the tail end of the manifest that will return with at least partially empty payload bays?
If we think that the return flight would be the last flight for that orbiter, then why not using some cargo bands to tie up the Pirs to the cargo bay?
Pirs is tiny compared to, say, an MPLM. For a good comparison, look at the similarly sized Shuttle Mir Docking Module in the Shuttle payload bay (only the orange structure was the module, the rest of the stuff was additional cargo or trusses):
Quote from: Danderman on 09/29/2009 05:17 amPirs is tiny compared to, say, an MPLM. For a good comparison, look at the similarly sized Shuttle Mir Docking Module in the Shuttle payload bay (only the orange structure was the module, the rest of the stuff was additional cargo or trusses):Here is a hint, what else was in the payload bay with it
Quote from: Jim on 09/29/2009 11:05 amHere is a hint, what else was in the payload bay with it A SpaceLAB module, along with the External Airlock/ODS. And let's not forget that Atlantis still had her original internal airlock as well at the time of the Shuttle/Mir missions. The first OV-104 mission to fly without the internal airlock was STS-101 in May 2000.
Here is a hint, what else was in the payload bay with it
Quote from: Zipi on 09/29/2009 10:50 amIf we think that the return flight would be the last flight for that orbiter, then why not using some cargo bands to tie up the Pirs to the cargo bay? The payload bay is not a container (it does not have rigid surfaces) , it is an enclosed mounting frame, and hence cargo can not rest on the bottom and be tied down
If we think that the return flight would be the last flight for that orbiter, then why not using some cargo bands to tie up the Pirs to the cargo bay? Of course it would move and shake more or (hopefully) less during the landing, but by this way it won't require that much upmass penalties... And of course this would be pretty ugly way to treat space hardware, but might do the trick.
The Mir docking module was equipped for a mounting in the Shuttle cargo bay, Pirs is not - i.e. Pirs can not be put into an empty space, because it can not be fixated in the cargo bay.It would require a mounting cradle, which would occupy space and mass on the way up, so it would be a very bad deal to sacrifice upmass to bring back an old module.
Quote from: Skyrocket on 09/29/2009 09:41 amThe Mir docking module was equipped for a mounting in the Shuttle cargo bay, Pirs is not - i.e. Pirs can not be put into an empty space, because it can not be fixated in the cargo bay.It would require a mounting cradle, which would occupy space and mass on the way up, so it would be a very bad deal to sacrifice upmass to bring back an old module.The alternative would be to affix trunnion pins and a keel to Pirs.
What else was in the payload bay with Shuttle Mir Docking Module?