[amsat-bb] Re: Model Rocket Booster Engine for Picosatellite

[Joe Leikhim]

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!
>
> 73,
> 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:
>>
>>> David;
>>> 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
>>>
>>> www.Leikhim.com
>>>
>>> JLeikhim at Leikhim.com
>>>
>>> 407-982-0446
>>>
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-- 
Joe Leikhim

Leikhim and Associates
Communications Consultants
Oviedo, Florida

www.Leikhim.com

JLeikhim at Leikhim.com

407-982-0446

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