[amsat-bb] Ongoing Spacecraft Systems R&D @ BU

[Alex, N3SQ]

Andrew Glasbrenner wrote:

> Date: Sat, 16 Jan 2010 20:11:46 -0500
> From: Andrew Glasbrenner <glasbrenner at mindspring.com>
> Subject: [amsat-bb] Re: AO-7 feat!
> To: "Vince Fiscus, KB7ADL" <vlfiscus at mcn.net>
> Cc: amsat-bb at amsat.org
>
> Vince Fiscus, KB7ADL wrote:
>   
>> Well, it certainly wasn't on FM.  Why couldn't the next LEO be like a new 
>> AO-7 with modern technology?  Why does the Board insist on cramming another 
>> single channel bird down our throats?
>>   
>>     
> We also have a university in the Northeast working on a 3U cubesat that 
> will support a transponder powerwise. This was all laid out in the 
> donation letter, as well as Barry's Apogee View in the Journal.
>
>   
As Andrew mentioned, here at the State University of New York @ 
Binghamton we've been working along on our goals as outlined at the 
Symposium and in the latest edition of the Journal:

(a) We have revised the ARISSat Power Supply Unit, Backplane and Solar 
Panel Charge Controller designs to use Pseudocapacitors instead of 
traditional batteries.
      Based on a worse-case, 600km orbit, we can produce a whole-orbit 
power budget of 7.5 watts using a 3U CubeSat design.
      If a spacecraft is launched into a more optimal orbit, like a 
sun-synchronous orbit, one of the two Pseudocapacitor banks can be removed.
      The design can be scaled to be used with other classes of 
spacecraft - 2U/1U CubeSat, Microsats, etc.
      The design has gone through two reviews with AMSAT Engineering. 
(Thanks Lou, Barry & Tony!)

(b) We have a light-weight deployable solar panel design with integral 
magnetorquer coils for attitude control.
      The design contains original research and integrates CubeSat 
research from:
            * University of Delft (hinge concepts & use of Dyneema wire)
            * University of Illinois at Urbana-Champaign (flex-circuit 
magnetorquers & carbon-fiber substrate)
            * the Aerospace Corporation (thin-film attachment of solar 
cells)
       The design will produce about 12-15 watts per minute in any 
orientation (worse-case) for 3U, less with 2U or 1U
       If a spacecraft is launched into a more optimal orbit the number 
of solar cells can be reduced while maintaining the power budget

(c) We have analyzed the existing AMSAT spacecraft modules (from ARISSat 
& P3D) and determined that:
          * We can fit the SDX and U/V Linear Transponder systems from 
ARISSat into a 2U or 3U CubeSat Chassis without significant re-design
          * The IHU is going to be slightly redesigned to incorporate 
the Command Decoder board functions
          * We can reuse the base concepts from P3D for the Sun & Earth 
Sensor Systems
          * We can reuse a 3-axis Magnetometer design (Honeywell)
          * If the ARISSat boards were redesigned/repackaged they could 
fit within a 1U Chassis.

(d) Things to do between now and Dayton:
          * Complete thermal analysis of a baseline 3U spacecraft
          * Antenna design (based on U of Delft's spring steel U/V 
antenna deployment system)
          * Complete Attitude Determination & Control (ADAC) integration 
(magnetorquers, sun/earth sensors & magnetometer)
          * Finish building engineering model
      
This R&D, being performed by Engineering Students for their Senior 
Design projects (8 ME's/EE's + 26 SE's), is being sponsored by AMSAT.

So I encourage everyone to contribute what you can to AMSAT to help fund 
spacecraft systems development and launch opportunities.
If we have reliable, lower-cost, modular systems, then AMSAT can be more 
responsive to any launch opportunity.

We'll have more info on the research we're doing in the next issue of 
the Journal and look for us at the AMSAT table in Dayton!

Alex Harvilchuck, N3NP
NextGen CubeSat Program Manager