Soyuz relocation -- why, exactly?

Most stories quote the NASA assertion, "The Soyuz relocation cleared the
Pirs Docking Compartment, which doubles as an airlock, for spacewalks now
scheduled for January and March."

But haven't they already done an EVA from Pirs with the Soyuz in place on
Pirs, like, on the last Expedition?

Was this a requirement, or a desirement? And was it really connected with
the EVAs, or with the next Soyuz docking?

"Jim Oberg" wrote in message
...


Most stories quote the NASA assertion, "The Soyuz relocation cleared the
Pirs Docking Compartment, which doubles as an airlock, for spacewalks now
scheduled for January and March."

But haven't they already done an EVA from Pirs with the Soyuz in place on
Pirs, like, on the last Expedition?

Was this a requirement, or a desirement? And was it really connected with
the EVAs, or with the next Soyuz docking?

I was wondering about this myself, since the drawings I've seen make it look
like there is a large hatch on the side of Pirs, which should make EVA's
possible even with a Soyuz attached to its docking port:

http://www.aerospace-technology.com/.../iss/iss5.html

Perhaps this has to do with contingencies like not being able to close the
hatch on Pirs. If your one and only Soyuz is attached to Pirs when this
happens, would it be possible to enter the Soyuz orbital module while still
wearing Russian EVA suits?

Jeff
--
Remove icky phrase from email address to get a valid address.

Jim Oberg wrote:
Most stories quote the NASA assertion, "The Soyuz relocation cleared the
Pirs Docking Compartment, which doubles as an airlock, for spacewalks now
scheduled for January and March."

But haven't they already done an EVA from Pirs with the Soyuz in place on
Pirs, like, on the last Expedition?

Was this a requirement, or a desirement? And was it really connected with
the EVAs, or with the next Soyuz docking?

On reflection, it does seem unnecessary for a two man crew. For a three
man crew, it's clearly necessary: it allows the non-EVA crewmember to
work in the station, operate the SSRMS, etc, while having a clear route
to the Soyuz in an emergency. Leaving the Soyuz at Pirs would confine
them to the Soyuz.

But that isn't a constraint with a two-man crew, so it does appear
unnecessary.

--Chris

Chris Bennetts wrote:
But that isn't a constraint with a two-man crew, so it does appear
unnecessary.

If the plans were developped at a time when shuttle was expected back at
station in March with crew augment back to 3 in march, then it was wise to
move the soyuz now while they are less busy.

One also has to take a long term look. There may be clearance issues further
on down the line with regards to shuttle and soyuz schedules where it would be
preferable for the zarya/Pirs cycle to have rotated to have a soyus at Pirs
during a certain Shuttle flight.