14 April 2010
Column - Vehicles (Good)
The Cancellation of Constellation
And why it's good news
by David Ashford
Although it seems counter-intuitive, President Obama’s cancellation of Constellation will most likely speed up the return to the Moon.

Constellation, NASA’s human spaceflight program, would have involved years of fraught development of expendable launch vehicles, which are now an obsolete concept.

Now there is a good chance of getting back to the moon far more efficiently.
The key to success for this project is an orbital spaceplane. Two-stage-to-orbit spaceplanes were widely considered feasible some forty years ago. They have never been built, because space history had by then created institutions and ways of thinking that repeatedly reinforced the expendability habit.

The cancellation of Constellation signals the end of ‘old space’ and removes this mind-set, which has been the major obstacle to spaceplane development.

As soon as the first successful design enters service, it will be able to undercut any expendable launcher of comparable payload. It will provide the safety needed for public access to space on a large scale. (Aeroplanes are inherently far safer for passengers than ballistic missiles and the same goes for spacefaring developments.) The marginal cost per flight with a reusable vehicle, which is mainly crew, fuel, and maintenance, will be far lower compared with a new vehicle, which is needed for every flight of an expendable launcher.

Low costs and improved safety will increase traffic levels, which in turn will release funding to enlarge and mature the design. This will further reduce costs and increase traffic levels, thereby releasing even more funding.

The result will be a virtuous downwards cost spiral until the lower limit of spaceplanes using mature developments of more or less existing technology is approached. This works out at about twenty thousand dollars per person for a few days in a space station or space hotel. It is only the high cost of launch and subsequent access that makes present space missions so expensive. I have estimated that the cost of the first lunar base will be ten times less using the aviation approach than it would have been with Constellation.

With priority, this limit could be approached in about fifteen years. We are talking about revolution rather than evolution. (See my paper The Aviation Approach to Space Transportation.)

Returning humans to the Moon is not the only benefit of reusable launch vehicles. Low cost access to orbit will also transform the design of satellites, space stations, lunar transfer vehicles, and even lunar landers and bases. These will all then be built to aviation standards, which results in far lower costs than present space standards. Back-up vehicles will be on stand-by to rescue astronauts or to replace vehicles that fail. Prototypes will be built in experimental workshops, and all vehicles will be reusable or refurbishable. Testing will be combined with early operations.

The key questions are who is going to build the first orbital spaceplane and when will it be built? My own company’s Spacecab has been designed specifically to be a competitive candidate for first. It is designed for ‘safety soon,’ with low development cost and risk. It could be flying in about six years. All we need is the money. At present it is the only published two-stage spaceplane design, but others will no doubt follow soon.

It can only be a matter of a few years before the private sector proposes an orbital spaceplane suitable for a public-private partnership with NASA or another space agency. Several private companies are known to be studying orbital spaceplanes, including X-Corp and Virgin Galactic. Currently, the only published designs are Skylon and my own Spacecab.

David Ashford is the managing director of Bristol Spaceplanes Limited
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Carol Pinchefsky 14 April 2010
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