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

[Gary "Joe" Mayfield]

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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