Ways to sidestep gravity?

A few years ago I saw a talk about a working laser powered vehicle. The
vehicle was about the size of a cigarette pack and was accelerated
straight up, very rapidly, to an altitude of perhaps a few hundred
meters (I don't really remember exactly). The speaker showed a video of
the real McCoy (not a simulation). Obviously, an orbital vehicle for
humans is some ways off, but at least the concept has been physically
demonstrated on a small scale.

On Monday, April 29, 2002, at 05:25 PM, Ian Woollard wrote:

> Lucio de Souza Coelho wrote:
>
>> I have already converted myself to the Space Elevator Cult. It will
>> come and
>> free us all! ;-)
>
> It might. It might not though. Until we have the material AND
> the manufacturing process AND the money we ain't gonna get
> there.
>
> Still, I went to a talk yesterday about laser powered launch
> systems. The guy described a system of using a 100 Mw laser
> (cost: around $1 billion, dropping at 30% per year in price
> currently) used to point at hydrogen monopropellent vehicle
> the vehicle uses a heat exchanger to boil the LH upto a
> relatively low temperature 1000C and then chucks it out through
> a conventional or aerospike nozzle.
>
> The ISP turns out to be 600, c.f. the space shuttle SSME ISP
> of ~450 (the reason is that the space shuttle uses LOX/LH but
> this system would use just LH, so the average exhaust velocity
> goes up- Ox is heavy and reduces the ISP.)
>
> This makes the vehicle much simpler, cheaper and more powerful.
> He was talking a few tens of k per vehicle, either expendable
> or reusable I guess. Noteably, turbopumps are not required.
>
> He was talking of a 500kg vehicle delivering 140kg to LEO,
> although it wasn't SSTO. He thinks the price ends up south
> of $100/kg... It's not clear whether 140kg is enough to launch
> a person, but even if it doesn't the system is very scalable.
>
> The system seems about 5 years off right now; including R&D.
>
> Oh yeah, this guy Jordin Kare who did the talk isn't an
> amateur- he's worked on many different projects for the
> government; including some classified projects.
>
> The cost of the laser isn't as big a problem as you might
> think. If it enabled space tourism (and it easily could in
> my opinion), the cost would be amortised over upto 35000
> launches in the first year alone.
>
> --
> - Ian Woollard (ian.woollard@...)
>
> "Is a planetary surface the right place for an expanding
> technological civilization?"
> - Gerard O'Neill
>

Space tourism could be our ticket to the stars. Save your pennies,
suborbital flights for $100,000 may start in 2005! See
http://www.spaceadventures.com/suborbital/index.html for details.

Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html