NASA has now committed itself to the development of a heavy-lifting
rocket system able to deliver a hundred tons or so into orbit, using a rocket
more powerful than the Saturn V which sent astronauts to the Moon in 1969 and
the ear;y 1970s. The new system will allow heavy structures to be built in orbit and enable
manned expeditions to asteroids to be launched. Later, interplanetary missions
to Mars and other planets could be mounted from bases in orbit around the Earth.
Initially I was disappointed by this approach to space exploration.
It seemed rather unimaginative, a mere upgrade the long abandoned ballistic-missile-type
Apollo programme. In the long term what we need is a low-cost spaceplane able
to take men into orbit and able to both take off from and land on an ordinary
runway. See the post on the Skylon, a revolutionary concept being developed in
the UK.
However, an article in Spaceflight (Nov 2011), a monthly
journal of the British Interplanetary Society (which I belong to) has
given me pause for thought.
One aspect of the low cost spaceplane approach is the
frequency of flights, since this determines the cost per mission of launching one ton into orbit, and the flight frequency depends on the demand, which depends on the
quantity and size of structures in orbit which need servicing. The heavy lifting
ballistic rocket approach will allow a rapid growth in such orbital hardware
and this will create a market for independently operated earth-to-orbit
vehicles like the Skylon.
As the author, Mike Armitage, points out, transport on the
surface of our planet is not restricted to just one type – it ranges from bicycles
to jumbo jets. So it would seem likely that space exploration will become
similarly diverse.
Nevertheless I am perplexed as to why the Skylon project is
not getting much media attention. Maybe if Richard Branson’s Virgin Galactic took
an interest the journalists would flock to it.
John
Author, 2077 AD
cosmik.jo@gmail.com
.
