SpaceDev Tests Rocket Motor for Powered Spaceshipone Flight

quicken.com ^ | 11 Dec 03 | staff

[RightWhale]

SpaceDev Tests Rocket Motor for Powered Spaceshipone Flight

POWAY, Calif.--(BUSINESS WIRE)--Dec. 11, 2003--SpaceDev has successfully tested a hybrid rocket motor designed for the first powered flight of SpaceShipOne, built by Scaled Composites.

SpaceDev successfully test fired a motor with its proprietary propellant equal to about one-half the total capacity of the motor. The purpose of the test was to qualify the exact configuration of the motor to be used for SpaceShipOne's first powered test flight.

SpaceDev also performed a full flow oxidizer test through its proprietary main valve, during a recent glide test of SpaceShipOne, in further preparation of the first powered flight. The test was successful.

"This project gets more exciting every day," said SpaceDev founder and chief executive Jim Benson. "SpaceDev and Scaled engineers are working well together on a very tight schedule, and you can feel the excitement and tension as this historic project continues to charge forward."

[RightWhale]

Sure is a slow trip towards asteroid mining

[r9etb]

SpaceDev successfully test fired a motor with its proprietary propellant equal to about one-half the total capacity of the motor.

Proprietary.... Bah. If it's a hybrid, they're using LOX and (probably) paraffin. NASA, Stanford, and LockMart have been working hard on this for a while now.

[farmfriend]

Interesting.

[<1/1,000,000th%]

Bring back Kiwi B. It produced more thrust with less fuel than any conventional engine.

[boris]

"Spaceshipone", n, 1. a telephone used to connect a space ship to the ground via a very long wire.

2. A space ship constructed of corn pone.

--Boris

[boris]

"Bring back Kiwi B. It produced more thrust with less fuel than any conventional engine."

Yes but.

You are speaking of "specific impulse", i.e., thrust per pound per second of mass ejected. NERVA/KIWI were capable of about 800-900 "seconds" (actually lbf-second/lbm) of specific impulse. Conventional rocket engines (chemical) cannot go much over 500 seconds.

BUT.

Solid-core nuclear engines have a very bad thrust-to-weight ratio. I believe NERVA was something like 8:1 or 10:1, certainly not as much as 20:1.

Thus nuclear engines are not a good fit for a booster; they are much too heavy and the launcher pays a heavy (sorry) price in payload. They are by nature space engines which must be launched on a high thrust and high-thrust-to-weight vehicle. By way of comparison, the Space Shuttle Main Engine (SSME) has a thrust-to-weight of about 60-70. Some of the small engines currently in use for missile defense have thrust-to-weights of hundreds or even a thousand.

--Boris

[anymouse]

Actually SpaceDev bought the patents on this hybrid engine from Ameroc, who developed and tested full up engines back in the 1980s before the untimely death of it's founder in a auto wreck driving back from an engine test at their central California test facility. I interviewed with Ameroc at their Camarillo, CA facility back in 1987 when they were going strong. Some smart people working there.

NASA, Stanford and LockMart weren't interested in hybrid technology back then, until Ameroc showed how cheap, powerful and safe it was in comparison to solid or liquid rocket engines. I'm glad that SpaceDev is resurecting this technology, especially in Scaled Composites effort to win the X-Prize and reroute manned spaceflight development around NASA and its bloated contractors like LockMart.

[RightWhale]

SPDV ping

[r9etb]

Actually SpaceDev bought the patents on this hybrid engine from Ameroc, who developed and tested full up engines back in the 1980s

In which case they might be using rubber, as opposed to paraffin.

I was merely chuckling at the "proprietary" part of the claim -- their choices are pretty limited. BTW, performance is somewhat better than existing solid rockets.

Solids generate an Isp of ~290-300 sec. Hybrids are somewhere over 320 sec, probably because you've got pure oxygen in contact with the fuel, instead of an oxygenating compound.

AvWeek did an interesting article on hybrids last year. Paraffin has tremendous advantages over rubber, having mostly to do with burn rates (and therefore thrust-generating ability).