Shooting for the lowest $/lb leads one to think about larger and
larger
vehicles. But when I think minimum cost, I think small. After all, a
Big
Dumb Booster that lifts 100,000 lbs to LEO is still going to cost a lot
of money, even if it is super cheap per pound of payload. Given the
rapid
advances in microelectronics technology, I think it makes more sense to
build the smallest possible vehicle. If my cost cap for a launcher is
$1M,
then maybe I can only figure out how to lift 10kg to LEO using minimum
cost design principles and off the shelf technology. Fine. My laptop
weighs
less than 10kg and does a lot more than the average satellite.
- Joshua Cohen
- New Space
I plan to describe a minimum cost SLV in a later Column. If
advantage
is taken of the attributes of a rugged design in simplifying structure
and in reducing weight, the SLV is not much larger than one designed
for
minimum weight. Today’s method of estimating costs is to use CERs, or
cost
estimating relationships. These relationships essentially assign fixed
costs that are multiplied by vehicle component weights. If you assume
this
approach to be valid, then smaller vehicles will cost less. These
relationships
are valid only when one designs essentially the same subsystems to the
minimum weight criteria. Electronic components are the only hardware
elements
that get smaller, weigh less, and increase in reliabiliy with time.
These
characteristics do not apply to other hardware elements. Hence, a
laptop
computer cannot be compared with the major components of a payload.
- Arthur Schnitt
- Consultant
Excellent. BDB is one system. I would be rather keen on the good
ole'
SASSTO, with a potentially low structural cost and partial to complete
re-usability. Read Niven Pournelle & Flynn's 'Fallen Angels',
and/or
Gatland and Bono's 1974 book 'Frontiers of Space'. Almost anything is
better
than flying a bathroom to orbit, wasting fuel on a lot of wings. Maybe
fine for military missions, but not to get the ordinary bloke into
orbit.
I bags the janitorial franchise on the first decent space-station.
- Richard Edkins
- Richard
Wordsmith