Thursday, 13 October 2011

America's space strategy

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.

Author, 2077 AD