Posted on 11/25/2003 7:00:20 PM PST by KevinDavis
Canadian rocketeers competing in the X-Prize contest to send passengers on suborbital space hops have test fired their rocket engine, a major milestone in the team's plans to launch sometime next year.
The engine test was a crucial step for the Ontario, Canada-based Canadian Arrow team, one of 25 efforts to send loft a three-person vehicle up 62 miles (100 kilometers) up, return it safely and reuse the spacecraft within two weeks. The X Prize for the first team to do so includes a trophy and $10 million.
"Our team has spent five years researching, designing and building toward the test we performed tonight," said Canadian Arrow leader Geoff Sheerin of the Nov. 21 test. "We had a perfect ignition and a good clean burn. There were a lot of smiles here, that's for sure."
During the late-night test, Canadian Arrow's rocket engine produced 57,000 pounds of thrust using a fuel mixture of liquid oxygen and ethyl alcohol. Project engineers believe their engine, which is modeled after the German V-2 rocket and consumes about 250 pounds (113 kilograms) of propellant per second, is the largest liquid propellant engine in Canada.
Canadian Arrow engineers will continue testing the engine to prepare it for its first flight expected to take place in upcoming months.
In other X Prize-related news, the contest's newest competitor High Altitude Research Corp. (HARC), of Huntsville, Alabama, unveiled its Liberator space capsule during a Nov. 22 presentation and engine test. HARC's flight plan calls for an ocean rocket launch to a maximum altitude of 70 miles (112 kilometers) before reentering the Earth's atmosphere, deploying parachutes and splashing down.
X Prize officials anticipate that their contest will be won within seven to 10 months.
How is that supposed to work (balloon and rocket)?
Amateurs! NASA would have spent ten years and $2 billion!
Wait...I thought that the plan was to inflate a giant balloon under the rocket on the launch pad, and then someone pricks it with a pin to initiate the launch.
At 62 miles, there's enough friction from the tenuous atmosphere at 17.5KMpH (as B-Chan has mentioned) that I believe any type vehicle will decay within one orbit, so it has to start above that.
I have heard of spy satellites tasked down to 67 miles. However, they could stay that low only a short time before having to use their onboard motor to kick them back up to a sustainable orbit--probably at least 250 miles.
Why is it easy to go 62 miles (which sure sounds damn high to me) but hard to go higher?
It ain't easy to get to any significant altitude. The higher you plan to go, the more fuel and engine you have to have, which makes everything bigger, requiring still more fuel and engine, etc. Oh--you want a payload too? Sheesh! Order up still more engine, fuel, etc.!
62 miles was chosen, I'm sure, because it's a nice round 100 kilometers. I think that the old X-15 rocket plane pilots got their astronaut wings on those flights that went over 50 miles high.
It is speed, or velocity, that determines being in orbit, not height. The suborbital will be moving 4000 mph at maximum.
Orbital speed would be 17,500 or so. That is over 4 times faster, which means several obvious things. The orbital version would be much bigger because it needs to carry much more fuel. The greater weight means the motor needs to be much bigger. The manned capsule would be very different because it has to re-enter the atmosphere at the higher speed. If the capsule is not properly designed or if there is a serious problem on re-entry, the capsule will burn up as we all know by now. The sub-orbital capsule could also be destroyed on re-entry, but the much lower speed means that it would break up in flight rather than burn up.
The difference between an orbital and a sub-orbital launch is also that the rocket would be ten times the size. If a sub-orbital launch is barely do-able at this time, the orbital launch is far from being do-able. For cost, the orbital launch would also be ten times more expensive, and these sub-orbital launches aren't cheap.
That is quite true. Robert M. White, Joseph A. Walker, Robert A. Rushworth, Joseph H. Engle, John B. McKay, William H. Dana, William J. Knight, and Michael J. Adams all got their astronaut wings this way.
"My name, Jose Jimenez."
+<]B^)
(Actually, that was said by a different Bill Dana.)
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