cheap space flight
Lyle Burkhead (LYBRHED@delphi.com)
Sat, 16 Nov 1996 02:36:09 -0500 (EST)
> Cut-price space flight crept closer last week, following tests of a
> lightweight liquid-fuelled rocket engine in New Mexico. Its makers,
> the Californian company Microcosm, claim that the Scorpius rocket
> will be significantly cheaper than its competitors.
>
> The company plans to develop Scorpius rockets that can put larger
> payloads into orbit for under $1000 per pound. This compares with
> roughly $10,000 for the shuttle. Microcosm's president, James
> Wertz, claims that the new rockets will be more reliable than
> competing engines.
>
> Since some of the engineering in the Scorpius rocket is not yet
> patented, Microcosm will not reveal all its tricks, but Wertz says the
> company has taken advantage of new materials and eliminated the
> most expensive parts of traditional designs. "This engine is not a
> breakthrough in performance for liquid propulsion systems, but
> rather a major breakthrough in cost," he says.
>
> The Scorpius does not have turboprops to deliver fuel to the
> combustion chamber and the engine is not mounted on gimbals to
> direct its thrust. This eliminates some of the most expensive
> components needed for conventional liquid fuel engines. Scorpius
> runs on Kerosene and liquid oxygen, which are both relatively cheap.
> Microcosm estimates that its new rocket delivers thrust at $2.80 per
> pound. In comparison, a Rocketdyne engine of a similar size
> costs $60 per pound and an Aerojet engine costs $260 per pound.
>
> The latest test burn for the 5000 pound thrust (20,000 newton)
> prototype engine took place at New Mexico Institute of Mining and
> Technology in Socorro. The prototype has 31 parts but no precision
> or high-tolerance components, says Wertz. He claims it was
> assembled in less than 40 hours and cost less than $5000 to build.
> Yet this simple engine has already been fired for 200 seconds --
> about 10 percent longer than the time needed to put a vehicle into
> low Earth orbit.
>
> The basic design includes graphite-epoxy fuel tanks, a pressurized
> delivery system, rather than fuel pumps, and a simple combustion
> chamber which is also made of composite materials. Microcosm
> intends to extend the design to create increasingly powerful rockets.
> With funding from the Department of Defense and NASA, it plans to
> build launchers powered by several engines, each rated at 5000
> pounds thrust, then scale these up to 20.000 pounds thrust per engine.
>
> "Our eventual goal is to be able to put 170 pounds into low Earth
> orbit for $750,000, and 2200 pounds for under $2 million," says
> Wertz. Providing funding continues, Microcosm hopes to launch the
> first single stage rockets next year and launch to orbit within three
> years.
>
> "We have sought not to invent anything new where possible, instead
> preferring to adapt existing ideas, such as thrust-vectoring based on
> injecting fluid into the combustion chamber to divert the thrust,
> rather than mount the engine on expensive gimbals," says Wertz.
New Scientist, 2 November 1996, page 21