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Domain: californiaspaceauthority.org

Stories and comments across the archive that link to californiaspaceauthority.org.

Comments · 9

  1. Re:Coriolis Effect in Vortex Combustion by DynaSoar · · Score: 1 · on Mysterious Sound Waves Can Destroy Rockets

    This racetrack instability is actually a well known problem with annular combustion chambers such as those used with the toroidal aerospike engine. One of the main virtues of vortex engines, like Orbital Technologies or the ultracentrifugal one invented by Roger Gregory and myself, is that the coriolis effect distorts the wave front sending it into the wall of the combustion chamber. In theory, at least, this should disrupt the resonance enough to prevent destructive standing waves.

    Experiments have not been conducted to test this theory yet to the best of my knowledge. Pretty much any adaptation which broke the circularity of any of the problem designs would work, no? Graphite vanes, a la V2 steering, only farther up the bell. Grooves down the length of an aerospike. Injectors in the bell which shoot the fuel/oxidizer at alternating angles with pseudo-randomly (slightly) different pressures. Or even building in just enough pogo oscillation to disrupt it. Of course these are just hacks on the present designs, not new designs which address the problem. The hybrids I've seen have all had a pogo effect of sorts, farting their way up. Any idea if they suffer from this problem at all?
  2. Coriolis Effect in Vortex Combustion by Baldrson · · Score: 4, Interesting · on Mysterious Sound Waves Can Destroy Rockets

    This racetrack instability is actually a well known problem with annular combustion chambers such as those used with the toroidal aerospike engine. One of the main virtues of vortex engines, like Orbital Technologies or the ultracentrifugal one invented by Roger Gregory and myself, is that the coriolis effect distorts the wave front sending it into the wall of the combustion chamber. In theory, at least, this should disrupt the resonance enough to prevent destructive standing waves. Experiments have not been conducted to test this theory yet to the best of my knowledge.

  3. Re:Better Link by Anonymous Coward · · Score: 4, Informative · on No Winner In NASA's Moon-Dirt Digging Competition

    It was 30Kw IIRC
    According to the competition page, it is 30 Watts, not 30 Kilowatts:

    • Each team's excavation system must be fully autonomous
    • Systems will perform in a square sandbox filled with compressed lunar regolith simulant.
    • Mass of the system cannot exceed 40 kilograms.
    • 30 Watts of DC power will be provided to the system.
    • Each system will have 30 minutes to excavate as much regolith as possible and deliver it to a fixed collector adjacent to the sandbox.
    • The total purse of $250,000 will go to the winning teams excavating the most regolith above 150 kilograms.
  4. Rules by Anonymous Coward · · Score: 0 · on NASA Gears Up for the Regolith Rumble

    It's 30 Watts, not 30 kilowatts. That is max. power consumption and it will be monitored.
    5 Volts DC at 6 Amps, applied for 30 minutes, that comes to 15 Watt-Hours so you are moving 150kg or more using less than 0.1WH/kg.

    http://www.californiaspaceauthority.org/regolith/i mages/Regolith-Rule-Book-1_01.pdf

  5. Re:Some info missing - how far must rock be moved? by SirBruce · · Score: 2, Informative · on NASA Gears Up for the Regolith Rumble

    Click on registration and you will find several links, including one to the rule book which contains the information you seek. Specifically, there's a "sandbox" 4m x 4m x 0.5m of regolith, which the robot most sit on top of place into the "collector" area which is adjacent to the sandbox. How far you have to go depends upon how much regolith your robot can "reach" and collect in the time allotted; at most you might have to travel 5m to get to the regolith you need. It's really not so much distance moved as it is speed of collection and total quantity collected.

  6. Re:Some info missing - how far must rock be moved? by SirBruce · · Score: 2, Informative · on NASA Gears Up for the Regolith Rumble

    Click on registration and you will find several links, including one to the rule book which contains the information you seek. Specifically, there's a "sandbox" 4m x 4m x 0.5m of regolith, which the robot most sit on top of place into the "collector" area which is adjacent to the sandbox. How far you have to go depends upon how much regolith your robot can "reach" and collect in the time allotted; at most you might have to travel 5m to get to the regolith you need. It's really not so much distance moved as it is speed of collection and total quantity collected.

  7. Well, which is it? lb of kg? W or kW? by Eric+Smith · · Score: 1, Informative · on NASA Gears Up for the Regolith Rumble
    330 pounds (weight) is much different than 150 kilograms (mass). There is no purely numeric conversion factor between the two, as anyone with even the slightest knowledge of physics knows. The imperial unit of mass is the slug, and is approximately 14.59 kilograms.

    30 kilowatts is one heck of a LOT of power to be used by something that is only supposed to mass 40 kilograms. I was unable to find the official rules, because the link on the NASA site was broken, but the challenge page gives the power limit as 30 watts, not 30 kilowatts.

    Can we switch to SI now, please, and try to keep the prefixes straight?

  8. thanks! did you see the foot? by twitter · · Score: 2, Informative · on Successful First Launch of Aerospike Engine
    Wow, a thing about half the size of a man's foot generates 1/20 the thrust of a space shuttle engine. In English units, 1/2 foot is kicking ass.

    If you are not a rocket scientist, that translates to much zoom per pound mass.

    Does the "California Space Authority" bother anyone else besides me? What's next, Arnold calling himself "big chief" of independent California and wearing feathers on his head?

  9. Re:What did they do different? by Anonymous Coward · · Score: 0 · on Successful First Launch of Aerospike Engine

    I don't know, but I'm pretty sure it has something to do with that creepy kid in the jams.