🚀 go-pugleaf

In article <1993Jan1.165738.24729@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>>... you can put the spare satellite in the same
>>orbital slot as the operational one...  Result, no repointing.  Only
>>the control room needs to even *know* which bird is live.
>
>Redundancy is always desirable if it's affordable, but there is a practical
>difficulty with having *cold* spares in orbit. Will they work when we need
>them? They have to be cold spares if they share the same orbital slot and
>frequencies. That's why spare capacity is not operated cold. It's located
>in another spot where it can be kept as a *hot* spare that can be tested...

Testing co-located spares is trivial.  Once a week at midnight (or
whenever is convenient), switch to one of the spares for ten minutes.
Remember, switching among co-located birds does *not* disrupt service
for more than the time taken to turn one off and the other on (or,
worst case, the time taken to do that once, realize that the spare
is not working, and do it again).

>>The big expense
>>of doing most anything in space is getting into LEO; cutting that cost
>>massively makes *everything* more feasible.  It becomes much more
>>attractive to develop a tug capable of bringing things back down from
>>GEO, or a reentry capsule capable of landing a payload too big for a
>>DC cargo bay.  Neither of these devices is technologically difficult...
>
>Well if they're too big for DC, then they can't *get* into LEO in 
>the first place by that "cheap" launch method...

I note we have changed the subject; thank you for conceding my point.

As for getting them up there, sure they can:  assemble them in orbit.
On-site assembly is normal practice when device X has to be set up at
location Y but is too big for economical transport there when fully
assembled.  (Of course, in principle you could then disassemble them to
bring them back, but it's not really needed.  Coming down is the easy
part.)

>It's not impossible to deploy mulitple special purpose vehicles in
>space, of course, but cheap as an airliner ticket they ain't.

Cheap as an airliner ticket, no, but much cheaper than even a small
"feeder airline" airliner.  If you can get them into orbit cheaply, it
will be worthwhile to build and operate them.  The vehicles themselves
are not that expensive, especially if you can recover them afterward
for re-use (of subassemblies, at least).
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry