[amsat-bb] Re: Model Rocket Booster Engine for Picosatellite
rhyolite at nettally.com
Tue Jan 17 21:16:38 PST 2012
Like any design a cost-benefit analysis would be required to determine
if the Gatling arrangement is even necessary. I am sure there are about
a dozen ways to "skin the cat". (My apologies to my pet cat Mac)
On 1/17/2012 11:04 PM, Gary "Joe" Mayfield wrote:
> This is a fun thought exercise. The gatling gun is one option. I prefer
> something with no moving parts. It should be possible (not easy) to center
> one engine on each side. That would be six engines. Once in orbit take the
> time to stabilize the satellite along the first axis before firing the first
> engine to boost the orbit. Repeat the process up to 5 times. Wow - This is
> rocket science!
> Joe kk0sd
> -----Original Message-----
> From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
> Behalf Of Joe Leikhim
> Sent: Tuesday, January 17, 2012 5:33 PM
> To: Ken Ernandes
> Cc: amsat-bb at amsat.org
> Subject: [amsat-bb] Re: Model Rocket Booster Engine for Picosatellite
> 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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