SpaceBanter.com - View Single Post - MSNBC (JimO) on value of 'big door' on ISS

**Brian Thorn**

On Sat, 8 Jul 2006 06:10:29 GMT, (Henry Spencer)
wrote:

Or unless either the CEV or one of the COTS commercial vehicles berths to
a CBM instead of docking. Which several of the COTS designs do; I'm not
sure about the Continued Employment Vehicle. (For a while it was going to
use a new lightweight docking interface, if I recall correctly, but that
has since been canceled.)

Isn't the lightweight docking system planned for the "Block II' (or
whatever the lunar version is called) to save weight? Block I is
supposed to be as much off-the-shelf as NASA can get, to reduce
development time and cost.

That's what the shuttle *should* have done,
instead of using the CBM interface only for the separate MPLMs.

Why? There doesn't seem to be much room in the Shuttle's crew cabin
for Station racks, which means they'd still have to use the MPLMs to
haul them back and forth. In that case, why bother with the expense of
a new Shuttle airlock, new shuttle docking tunnels, etc., when you can
just berth the MPLM and move cargo directly? The only thing Shuttle
docking at a CBM would help would be with the Spacehab used as a cargo
hauler (i.e., STS-116) but that's always been secondary to MPLM
anyway.

Brian