In article ,
Jorge R. Frank wrote:
On 03/07/2011 09:23 AM, Jordan wrote:
During one media interview with the joint ISS & STS-133 crews, it
was mentioned that after Discovery leaves, they plan to move the
Japanese HTV vehicle from Node 2's zenith port (where it had been
relocated to avoid blocking the shtutle cargo bay) back to its
usual Node 2 nadir berthing position, and that this procedure would
take about six hours. It was also said that HTV is due to leave
the station for reentry within a few weeks.

I was just wondering why they'd bother to take so much time moving
HTV back, and put extra wear on the Node 2 CBM mechanisms in light
of its imminent departure. I understand these vehicles must first
approach from the nadir side because of where the alignment sensors
are on Kibo, but does the same contraint apply for unberthing?

Yes.

Why couldn't the station arm just move HTV down to to the nadir
side of the station at that time (without reberthing it),
release it close to the usual spot, and let its internal
guidance take over from there?

Less reach, HTV would be too close at release.

Ah... makes sense now. Thanks!
--
Jordan.