Brent Salmi KB1LQD offers his thoughts on some of the challenges involved in putting a CubeSat or any other spacecraft into High Earth Orbit (HEO). This was originally posted on the AMSAT-BB and is reproduced here with Brent’s permission.
I think this 2-part 4 minute video is very relevant here:
http://www.youtube.com/watch?v=51fKeeHSxTg (Preview)
*Building a SpaceCraft*
Although less bureaucratic companies/organizations will widdle down this process considerably it still holds true. Once that rocket launches there is no turning back, Year’s of peoples lives goes into making the several minutes of reaching orbit actually work and not kill your spacecraft. Each part on a spacecraft needs to be designed correctly, tested to operate correctly, tested to operate in all expected conditions (vibrations, temperature, radiation, etc…) without any physical maintenance.
FUNcube vibration testing: http://vimeo.com/26954073
Getting to orbit is a very difficult process, in-fact the first seconds of the launch is very very violent and has a high potential to destroy
satellites on-board. Vibrations due to the ground reflections will potentially rip components right off the PCB, unscrew bolts/connectors… I’ve seen this happen in testing and when it does it’s time to go back to the drawing board and re-layout your board or parts to dampen/strengthen it. All electronics need to survive the lack of air convection taking heat away from hot things (think amplifiers…) as well as survive incredibly cold temperatures, temperatures in space do not change slowly, they will crack PCB’s, components, etc… All spacecraft need to be qualified for flight to ensure the $100,000’s (if not hundreds of millions) of dollars and years of people’s efforts are not doomed from the beginning, many launch providers require these specifications to be met even to fly on-board their rockets.
*Getting to Orbit – And Surviving*
Getting to HEO is also another challenge since we must travel through the van-allen belts, and survive the long-term exposure of higher radiation. That nice micro-controller that works well on earth or in LEO now has bit’s flip, gates short, and other analog components dies a slow but steady death as well in this radiation environment. All of this needs to be ensured to work.
For the launch itself, there are many more players in the market and many (schools…) that are willing to shell out several million easy. If you’re on-board a HEO launch your likely going to be going under very strict guidelines and you must prove that you won’t hurt the main satellite through rigorous documentation and testing. I’m not say that this is unfeasible as we’ve done this in the past but getting a LEO bird up is considerably easier and cheaper as compared to a HEO.
I also want to say that the cubesat standard is a wonderful thing, cubesat electronics are getting better, more reliable, and are increasing their functional density which means we can do more with less space/weight! The modular systems of cubesats also pave the way for *faster builds and cheaper R&D in the long run!* Standardizing radio/power/control systems into modular boards means we can optimize, upgrade, and reused designs quickly and focus on the bigger better things in years to come. Building a solid LEO cubesat base is very important for this very reason as we can learn to use the platform and avoid re-designing the wheel in years to come. Fox-1 is that stepping stone for us and Fox-2 will provide the continuing efforts to make larger, better, and more capable spacecraft! Each Fox satellite specifically improves on the previous design and when we get a solid and reliable system that can scale to large cubesats (6U) we will have a reliable bird in the sky with incredible functionality.
*Utilizing Our SAT’s – SDR’s*
I think it’s also a good time to think about utilizing our LEO birds for not just voice communications but for data (both communication and sensors/cameras) which current technology makes much easier. With additional help to the effort I don’t see why a simple and cheap ground station set-up can’t be developed and sold that directly increases the ability for people to use our satellites. Think FUNcube( http://www.funcubedongle.com/ ), what better way to increase access and abilities than a cheap and somewhat dedicated ground system? If we’re always limited to 1200 baud through an HT or multi-band radio we’ll never explore other technologies. SDR’s are cheap nowadays and offer the ability to directly downlink voice and data flexibly.
Anyways, that’s my 2 cents! I welcome all of you to help volunteer even if you’ve never been involved in the aerospace industry! From managing, to public appearance, to engineering AMSAT is always looking for help and it’s a great way to give back to the hobby that all of us love. This hobby was a large factor in my career choice and AMSAT satellites were a big draw for me. *Most of my other college peers and even young co-workers love what AMSAT stands for* and how we do it! The more excited and cooperative everyone is the more people will get on-board. I know ton’s of people (technical and not) that are incredibly interested in what AMSAT is doing and just need a push to jump in.
Thanks,
Brent, KB1LQD
AMSAT-UK 
You must be logged in to post a comment.