You should start by reading the material at https://www.cubesat.org/
IMO one of the largest difficulties for Cubesat creators is that passive spring deployment of antennas and other facilities is not allowed, because of the difficulty of inserting them correctly in the P-pod and the potential for them to jam the P-pod, and prevent the satellites behind them in the P-pod from deployment. Your antenna can't just pop out as your satellite exits the P-pod, it has to be actively released afterward. So, for release of these things a contrivance of nichrome wire and monofilament fishing line is mainly used - the line is melted and this releases whatever spring device there is.
And surprise, a lot of satellites don't have their antennas deployed, perhaps because this fails. And thus they have weak-signal issues, etc. This also gets in the way of solar panel release, etc.
Second IMO is the use of standard AX.25 packet at 1200 or 9600 Baud as a communications protocol. Karn has said why this is inappropriate, and contributed a satellite modem that can stand fades an appreciable fraction of a minute long. A lot of satellites are never contacted after launch, IMO because the radio is inadequate.
And then we get to components and designs being inadequate for space, between vacuum, temperature extremes, the loss of convective cooling resulting in components overheating once in vacuum, mechanical stress during launch, etc.
And finally, it's too expensive to test adequately.
On Sun, Jan 31, 2021 at 7:43 AM Ray Soifer via AMSAT-BB amsat-bb@amsat.org wrote:
The intent of this email is to begin a serious techncal discussion. I do not know where it will lead.
- My question is: is there something wrong with the Cubesat
platform? Its failure rate is pretty high. If you include the university-built Cubesats which IARU has coordinated over the years, perhaps as many as half have failed upon reaching orbit. AMSAT-NA has orbited quite a few successful communications satellites, all of which are or were larger than Cubesats. I have been a member of AMSAT since 1969 and am not questioning its ability. Rather, my question concerns the Cubesat platform.
The AMSAT-BB reflector includes people with successful as well as unsuccessful Cubesats. Can we learn anything from their experience?
73 Ray W2RS
Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program!
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