Hubble's failure was strictly because management decided final quality control checks were expensive, time consuming and unnecessary.  Delivery on schedule was far more important than insuring the product worked correctly.

I can understand both sides of the argument. cost or endurance, cost or capability. Cubesats are a wonderful project - but if they fail once deployed, what has been learned? How NOT to build a satellite? 

Doug -- K0DXV

On 2/1/2021 6:08 AM, Dimitrios Simitas wrote:
Daniel, 

If AMSAT were to build another AO-40, it would take 9 years of current budget to finance it ($4-$4.5 million). And it's life of 4 years, would mean years between satellite activity. Cubesats are a compromise that allows them to launch one every year based on their budget. And during the last 5 years, this has given amateurs near continuous use of the Fox series.

If the goal is to keep satellites in space at all times, CubeSats are the only feasible option under AMSAT's budget constraints. If the membership desires better, then collectively more donations need to be made. Can't ask for a Rolls Royce to drive you around then expect to pay Yellow Cab rates. 

As for criticisms from NASA, they hold the record for the most costly satellite blunder, failing to properly verify the $4 billion Hubble before launch. 

Dimitrios
VA3DSZ

On Sun., Jan. 31, 2021, 22:03 Daniel Schultz, <[email protected]> wrote:
I thought that the Cubesat community had annual conferences to exchange ideas
on what works, but they still keep making the same mistakes over and over
again. Part of training engineers is to teach them to look around and learn
from other people's mistakes.

>"So the Fox line has met industry standards (3 of 5 deployed successfully)."

3 out of 5 deployed successfully is a pretty dismal industry standard. The
"industry" still considers Cubesats to be throw-away disposable space junk
whose main function is to train students. (Train them for what is still a good
question) They are considered to be successful if the students graduate from
their school, they don't need to actually work for any length of time on
orbit, or even to work at all after deployment.

When Mike Griffith was running NASA, he even advised students to forget about
building Cubesats and instead seek internship opportunities in the aerospace
industry where they might be exposed to real world spacecraft engineering.

A school in my local area recently built and launched a Cubesat under
sponsorship of a local aerospace company. The satellite was deployed from the
ISS and was never heard from. This local company has extensive test
facilities, they could have invited the students to bring their Cubesat over
to run a thermal vacuum test for one day at minimal cost, but no one ever
thought of doing that. It could have been a highly educational opportunity for
the students but reliability has never been part of the Cubesat curriculum.

And it is not just student built Cubesats that have reliability problems, I
have heard complaints from both Goddard and APL about the poor quality of
commercially manufactured Cubesats. Even a NASA-built Cubesat suffered from a
failed antenna deployment a few years ago.

How long was RadFXsat in the p-pod before launch? Long storage times without
battery maintenance could also be a risk factor. There is a reason why larger
space missions have access hatches built into their launch vehicle shrouds for
last minute inspections and maintenance.

I am reaching a conclusion that Cubesats are too small to support the HEO
communications mission that AMSAT members desire. Not only are they too
limited in power generation and antenna size but they are also lacking in
thermal control which is the key to a long lived satellite. If AMSAT were able
to raise a couple million dollars we could buy a commercial launch for a
larger satellite that would not require so many compromises in its design. We
did raise that amount of cash for Phase 3D in the 1990's, albeit in the
pre-ITAR days when international projects were still possible. Up until a
couple decades ago AMSAT was the only small satellite builder in the world,
now we live in a different world than the one we grew up in and we are just
one of many such organizations. We have not yet adjusted to our brave new
world.

Dan Schultz N8FGV




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