May 13th, 2018


OreSat presentation at O4SR annual meeting

I attended the May 12 meeting not really expecting much, but the program was excellent, both informative and amusing.  The speaker was Andrew Greenberg, and the subject was the Oregon Satellite Project and STEM Education.  Specifically he taught us a thing of two about space, orbits and nanosatellites.  I wanted to share just a few factoids that I got from him with you.

Andrew is adjunct faculty at PSU and helps students build rockets and satellites, in addition to his day job  He had recently done an OMSI science pub about the same subject, so he was well prepared and practiced. The OreSat mission is to use an actual satellite project to bring STEM (Science, Tech, Engineering and Math) to all Oregon high schools and to study cirrus clouds.

The Von Karman line is an arbitrary line dividing outer space from not space.  It is 100km above the surface of the earth.  Some balloons fly at 30km above the earth.  Cirrus clouds are the highest clouds and they are about 12km up.

There are three main layers of orbits, labelled LEO (low earth orbit), MEO (medium), and GEO (geostationary earth orbit).  Geostationary satellites have to be highest up and go the fastest to maintain their position relative to the surface of the planet.  Satellites cruise at around 200km from the earth, and they have to go really fast (8km/second or 17,500 miles per hour) to keep from falling back to the earth.  

NASA has a research satellite that was just launched May 5 this year.  It's the InSight mission and it intends to land on the surface of Mars.  The rocket that launched InSight also launched the first two CubeSats, which are small satellites that can be designed individually then connected together.  The high schoolers in Oregon are designing their own CubeSat, which NASA will launch!  They didn't expect to get awarded the opportunity to launch the satellite when they applied, but NASA called their bluff and now they're working on it.  All the software is open source.  The 2U (two unit) CubeSats from Oregon will get "hucked" from the space station into its orbit. It will stay aloft for 6-12 months, or maybe longer if they get lucky. 

The OreSat is scheduled to be deployed in fall 2019.  For the sake of the high schoolers, he's calling the OreSat a "400km selfie stick", because each time it flies over Oregon the high schoolers will be able to receive a packet of information from it, including a picture of their location.  

Then Andrew explained what he means when he says "Space Sucks".  Quite literally it sucks because it is a vacuum.  It speeds up the outgassing from any material that can, challenges welders to prevent leaks, and makes it tricky to keep anything at a reasonable temperature because it gets cold on the dark side and screaming hot in the sun.  The radiation from space does harm to transistors.  Solar cells are only ~30% efficient meaning it's not easy to power systems on satellites, and if they fail, they have to reboot without a mechanic coming to fix them.  "Watchdog systems" monitor the functions of the satellite and attempt to make things right before there is a system failure.

He also mentioned Planet Lab Doves, which are privately owned satellites that basically remap the earth's surface every day.  Exciting stuff.

Anyway, this talk was just a taste of what is happening.  Satellite technology is moving fast and the very first satellite put into orbit by anyone in the state of Oregon will be built by high school and college kids.  That's a fun way to approach STEM education.