In news:44d58be8$0$12884$dbd41001@news.wanadoo.nl,
dre <v> typed:

project) or use an airship or balloons to lift it aloft.

how big is this balloon?
thie size of texas?

I was thinking of something about the size of the Hindenburg.
Airships can
carry quite a high payload and hybrid craft even more. The shuttle
is of
course already transported around on the back of a specially
converted 747.

what is the payload of an airship compared to a 747?
do you have any idea?!

What matters is whether something like the Hindenburg could lift a fully
laden Space Shuttle. The Hindenburg had a useful lifting capacity of 112
metric tons. The space shuttle's fully laden gross lift off weight is
240,000 lbs = 108 metric tons. So obviosly it would have been capable of
lifting a Space Shuttle with lift and power to spare. However obviosly one
could improve on that in a purpose build craft since unlike the Hinenburg
you wouldn't need 50 passanger cabins, an observation deck, dining hall and
a specially constucted aluminium grand piano unless one wanted to launch a
grand piano into space, actually the thick astronaut gloves make playing
difficult LOL

  Using a high altitude release would

enable the shuttle to dive a couple of thousand feet before firing
rockets once at an upward trajectory this would give enourmous
added momentum and totally  dispense with the need to tie it to a
bomb full

of highly explosive

fuel

your rockets don't need fuel?

Yes but you would need less fuel than for a ground launch

look below.
IOW...CRAP
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During development, it was found that the comparatively heavy
rear-mounted engine moved the center of mass of the vehicle
rearwards. This meant that the vehicle had to be designed to push
the center of drag as far rearward as possible to ensure stability
over the entire flight regime. Redesign of the vehicle to do this
cost a significant proportion of the payload, and made the economics
unclear.

In 1988 the Conservative government withdrew further funding, the
project was approaching the end of its design phase but the plans
were still speculative and dogged with aerodynamic problems and
operational disadvantages.

A cheaper redesign, Interim HOTOL or HOTOL 2, to be launched from
the back of an Antonov An-225 transport aircraft, was offered by BAE
in 1991 but that too was rejected.

Alan Bond has formed Reaction Engines Limited where they have since
been working on the Skylon vehicle which seems to avoid many of the
problems of HOTOL.

Yes I read that, but it's not relevant to the amount of fuel needed for a
high altitude launch as opposed to a ground launch.

Canada has a Space Plane project called Da Vinci which I understand uses a
balloon to lift the craft to high altitude and it's a serious contender for
the X-prize. So whilst rockets look impressive they are not necessarily the
only way of doing it and are probably not the most cost effective or
efficient way of doing things either, and in fact that method has cost
lives.

You now have private companies putting craft at least into sub-orbital
space, and obviously private money tends to favour safer and more cost
effective methods.

The shuttle program whilst it has been undoubtedly successful is nearing the
end of it's life and obviously the future may see more efficient safer and
cost effective methods. The problem with ground launch rockets is they are
never going to provide cost effective sustainable space travel and if
something isn't sustainable then it can't develop, and with lack of funding
you end up with a Space program going in reverse.
-- 
Amanda