On Sun, 07 Dec 2008 22:00:43 -0500, John Doe wrote:

Does it really reduce flight software complexity ?

Yes, but not very much.

Seems to me that you
still need precise guidance, ability to stop and station keep (more so
with HTV since it will need to station keep very close to the station.

Where would HTV berth ?

Probably Node 1 nadir now that Node 3 won't be there (Node 3 is now
baselined for Node 1 port, opposite Quest).

And how far from its berthing point will it
need to station keep for the arm to go and grapple it ? couple of metres
? 10 metres ?

10 meters is a good guess. Has anyone seen any hard data on HTV
approach and grapple?

ATV/Soyuz/Progress use "targets" on the station to get Kurs to guide
their approach. Does the USA side have ay such targets to allow HTV to
guide itself to proper location an orientation to be grappled ?

ATV's approach can be aborted by a crew member on ISS, and ATV has an
auto-retreat system to get out of Dodge if the approach is botched.
Almost certainly, HTV will have the same setup, and can be aborted by
the crew member in the Cupola waiting to grapple it.

Brian