MMM Classics Year 10: MMM #s 91-100 - Moon Society

horizontally. While this was probably not the deciding factor in
its choice, NASA’s cozy familiarity and complacency with the
Shuttle may have added the appeal of psychological frosting to
Lockheed’s design.
Will passenger cabins on vertical take off horizontal
land craft be fixed, so that passengers are pushed into their
seats through their backs during takeoff, effectively lying on
their backs with legs up, but sitting on their buttocks during
landing, seats and postures remaining the same?
How comfortable this take off posture will be for the
general public is debatable. Given a choice for the same
money, we think the above arrangement will prove disastrously
unpopular.
Another possibility is a seat that unfolds into a berth
for takeoff, and back into seat position for landing. This may
work well enough.
Clusters of Seats could be in Gimbaled pods free to
rotate so that gravity or powered acceleration is towards and
through the pod floor, not the cabin floor in general. Force will
at all times be felt, through the buttocks and feet. A model for
this system are the little passenger pods that take tourists to the
top of the St. Louis Gateway Arch.
As flights are short, the reconfiguration of seat backs
and postures or the closing off of clumsy cramped crawl-space
passageways and gimballing of pods are bound to be distrac-
ting, cumbersome, and annoying. Mere annoyance could
change to trouble fraught with danger if a seat resists reconfiguration
or a pod decides not to gimbal. It is curious that
NASA which shrinks from tests of artificial gravity because of
the engineering challenges, embraces a configuration which
almost mandates one contrived Rube Goldberg accommodation
or another. But there is a history of this, witness the Shuttle tile
thermal protection system which is just as unnecessarily
contrived (and expensive), mandated by an unnecessary choice
of reentry attitude and angle.
In contrast, the VTOL, vertical take off and land, and
HOTOL, horizontal take off and land, offer one simple
unchanging configuration throughout both legs of the flight.
“KISS”, i.e. “keep it simple, stupid!” Fans of VTOL, the Delta
Clipper’s way of doing things, point out that a Clipper-configured
craft could land on the Moon and take off again whereas
a VentureStar-patterned craft could not.
VTOL would give us CATS and CATL (Cheap
Access To Luna) in one craft. That is tempting. But is it the
best route. Could their be cheaper craft specialized for LEO
(Low Earth Orbit) to Luna runs just as VentureStar is best
specialized for ground based shuttle operations to space on a
thick atmosphere world? We must explore and test all the
options. Only then can we have confidence in our choices.
“God and Heinlein decreed that rockets should take off and
land on their tails!” Maybe. Maybe not. I see problems with
VentureStar’s mixed mode operation. But it may just work.
by Peter Kokh
Presently, rockets must carry along all the fuel, and
any extra stages, needed to get a payload in its intended final
orbit. A payload brought up by the Shuttle destined for a higher
orbit than the Shuttle can reach, must carry along a throwaway
pre-fueled kick motor to do the trick. Imagine how expensive it
would be to fly to another city if we had to pay the freight for
bringing along our own taxi (and its fuel) to get us from the
arrival airport to our hotel or other destination! Carrying that
fuel to orbit means either less allowable payload or a bigger
and more expensive booster than would be needed if (a) the
vehicle could be refueled upon reaching low Earth orbit, or (b)
it was possible to “hire” a kick motor once in low Earth orbit to
do the job.
Refueling in low Earth Orbit
Given enough traffic following a given route into
space, it should be feasible to orbit automated or remote
control “tankers” that they could tap robotically or by teleoperation.
Such a tanker could be sent up full, to be replaced and
deorbit when empty. In time, permanent refueling stations
parked in handy orbits, could “purchase” unneeded residual
fuels and oxidizers from some vehicles to “sell” to others
needing to refill or top off their tanks.
A 1988/’89 Space Studies Institute study outlined how
Moon Miners’ Manifesto Classics - Year 10 - Republished January 2006 - Page 85