[amsat-bb] Re: Model Rocket Booster Engine for Picosatellite
rhyolite at nettally.com
Tue Jan 17 15:33:12 PST 2012
I have developed the perfect solution;
A gatling gun type canister for the rocket motors would solve all of
your objections per below:
On 1/17/2012 4:22 PM, Ken Ernandes wrote:
> How would attitude be controlled so the thrust is in the correct direction? Spin stabilization about the maximum moment off inertia axis is probably the best choice. This would require a magnetic torquing system.
Yes just like other missions.
> Another issue is the thrust needs to be directed through the spacecraft's center-of-mass or there will be stability problems. How would a cluster be fired individually with each, in turn, directed through the center of mass? That's a complex design problem.
A motorized canister with 6 to 8 motors aligned such that the active
motor is aligned through the COM. Picture a revolver or gatling gun.
> One more issue is that when you carry multiple motors, the first must accelerate the mass of the unfired motors, so the early firing will be less effective. The mass of the spent casings will need to be accelerated buy the subsequent motor firings.
Spent casings would be ejected using the ejection charge normally used
for deploying a parachute. Just as with any fuel, the mass of the
unfired fuel will create mass for the initial firings.
> You do have some work to do before you have a practical solution.
Work is done. Took about 4 minutes. Coffee break now!
> 73, Ken N2WWD
> Sent from my iPad
> On Jan 17, 2012, at 3:44 PM, Joe Leikhim<rhyolite at nettally.com> wrote:
>> There are some much bigger motors! Ask the Level-3 rocketry folks! Anyway a cluster of medium sized motors could be fired individually as required to raise altitude. I would think that SRB's would be more reliable and safer than hypergolic used on previous Oscars. There would of course be a lot of heat in the rocket casings that would need to be dissipated.
>> Joe Leikhim
>> Leikhim and Associates
>> Communications Consultants
>> Oviedo, Florida
>> JLeikhim at Leikhim.com
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