Space shuttle for space tourism and first stage of a TSTO.

This article describes the plan to sell the orbiters minus engines
for $42 million:

For sale: Used space shuttles. Asking price: $42 million apiece
By John Matson
Dec 18, 2008 04:00 PM in Space
http://www.scientificamerican.com/bl...ing-2008-12-18

It is currently intended only to be sold to educational institutions,
or governmental agencies.
The Air Force is looking for designs for reusable first stage
boosters for two-stage-to-orbit (TSTO) systems. Then it might be able
to be used for this purpose. Most likely you would use kerosene fuel
for this since dense fuels are more suitable for first stages.
The payload bay would be converted to a fuel tank, and the second
stage of the TSTO would be carried on top or below the orbiter. High
performance kerosene engines such as the Russian NK-33, with a near
legendary thrust/weight ratio of 136.66 to 1 at a weight of 1,222 kg,
could be used for propulsion:

NK-33.
http://www.astronautix.com/engines/nk33.htm

The orbiter without the SSME engines masses around 68,600 kg:

Atlantis.
http://www.astronautix.com/craft/atlantis.htm

Its payload bay is around 300 cubic meters that could be used for
propellant. Using the densities of kerosene and lox given he

Lox/Kerosene.
http://www.astronautix.com/props/loxosene.htm

and the oxidizer to fuel ratio of the NK-33 of 2.8 to 1 we can
calculate the propellant load that can be carried as about 300,000 kg.
You would need at least 3 of the NK-33's to lift this fuel load,
orbiter and second stage.
The tank weight of kerosene/lox is typically around 1/100th of the
propellant weight so around, 3,000 kg. Then the empty weight of the
reconfigured orbiter would be 68,600kg + 3*1,222kg + 3,000kg =
75,266kg. And the fully fueled weight of this stage would be
375,266kg.
For this first stage alone without a second stage, this would be a
mass ratio of about 5. Using an average Isp of the NK-33 of 315 you
could get a delta-V of 315*9.8*ln(5) = 4,970 m/s, about Mach 15.
A total delta-V this high raises the possibility it could be used for
suborbital space tourism or point-to-point hypersonic transport, if
sale to commercial organizations were to be allowed.


Bob Clark