Re: SPACE: Roton in New Scientist

mark@unicorn.com
Fri, 7 Aug 1998 06:44:44 -0700 (PDT)

Michelle Jones [spike66@ibm.net] wrote:
>mark the reason i am having such difficulty with this concept is that the
>roton is a re-entry system. you still have to lift the thing into orbit
>somehow to reenter the atmosphere.

Uh, Roton is a supposedly low-maintenance SSTO; using rotors significantly reduces the mass because you don't have to carry a lot of fuel to use for the landing. A very large part of the cost of government launchers is the cost of assembling the numerous stages, testing them, building parts with extremely low probability of failure and then throwing them all away.

An SSTO can in principle be much cheaper because it's not thrown away, it can land if there's an in-flight failure, and all you need to do to fly it again is tow it to the launch pad, run the pre-flight checks and hook up the fuel lines. Obviously with a first-generation it's not going to be as simple as flying a modern jet, but it should be much simpler than any expendable launch vehicle in operation today.

So the rotors are a minor point except to the extent that they make it a workable SSTO.

> the reentry system of modern
>government launchers is neither the cost driver nor the weight driver.
> spike

As far as I'm aware the shuttle's wings add a large amount to the cost and weight.

Mark