It’s been somewhat of a tradition amongst Boggs’ past graduate students to blog while on balloon campaigns. I volunteered/was peer pressured into being the main blogger of the COSI ’14 balloon campaign to Antarctica and the adventures which will most definitely ensue. (Other members of the COSI team have promised to help me out a bit!)
A little back story:
I work as a physics graduate student on a balloon borne gamma ray telescope, the Compton Spectrometer and Imager (COSI), which is based out of the Space Science Laboratory at UC Berkeley. If any of you out there are in the gamma-ray astrophysics community, then you may have heard of COSI’s precursor instrument, the Nuclear Compton Telescope (NCT)…but that’s a story for another time.
As the name implies, COSI is an imager, a spectrometry, and, not so obviously, a polarimeter. The heart of COSI consists of 12 high-purity germanium detectors (shown below) which are sensitive enough to detect out-of-this-world objects, literally. With COSI, we hope to answer questions about the births and deaths of stars, further unveil the mysterious source of positrons in our galaxy, and probe extreme astrophysical sources, such as pulsars, active galactic nuclei, and black holes.
Twelve germanium detectors that make up the heart of COSI. Each crystal is 8x8x1.5 cm$$^3$$.
This December, COSI will be launching from McMurdo Station, Antarctica. We will be the first science payload on NASA’s new ultra-long duration balloon (ULDB) flight and we’re hoping to get a record breaking 100 days at float! A question a lot of people have is “why Antarctica?”. There are three main reasons to launch a balloon from Antarctica: 1. very very little air traffic, 2. the balloon can circumnavigate the globe but remain above land for weeks, 3. a lot of scientists are interested in the space environment in/around Antarctica (but not us – see Anita).
Getting our instrument and our team to Antarctica is no easy feat. First, we personally need to pass rigorous medical examinations to show that we are healthy enough to survive in the extreme environment of Antarctica while being far from any real medical facilities. Second, we need to prove that our instrument is equally healthy, i.e. it can perform in the low pressure and temperatures expected at float. This includes communication with the ground, electronics not freezing or overheating, high-voltage breakdown, etc.
Prior to deployment down to “the Ice”, we had to pass a compatibility test… The Columbia Scientific Ballooning Facility (CSBF) is the ballooning program headed by NASA. CSBF provides the balloon, the power during flight (solar panels + batteries), and the communication system. Every payload that will be flying with CSBF needs to spend time in Palestine, TX, to prove to NASA that the instrument works as expected. We had to build up the gondola to it’s entirety and have the science instrument and the CSBF communications running at the same time to confirm there is no interference or weirdness.
The COSI team was in Palestine (pronounced Pal-e-steen) from July to August of this summer. Alex and I took two and a half days to drive the cryostat from Berkeley and meet the rest of the group in Palestine on July 4th. Instead writing about our life in Palestine, I figured it would be easier to just include picture’s which show some highlights from our time there:
Alex and I leaving for our three day’s drive to Palestine. We’ve got a rental mini-van packed to the brim with the cryostat and scientific equipment.
Palestine celebrates Christmas in July, so our amazingly creative undergrads stayed up late and snuck over to the lab on Christmas in July Eve to decorate the gondola! Alan took this artsy picture with the cryostat (the housing containing the detectors) in the forefront of the Christmas gondola. Notice the reindeer antlers on the GPS antenna mounts?
After a couple hiccups, we finally got the cryostat onto the gondola where it belongs. Here’s the happy and accomplished team.
I had Clio’s help with the harnessing. With 888 channels for our detector, we have a lot of delicate cables and it’s a very time consuming process.
We were fortunately enough to have had the ANITA team in Palestine at the same time as us. The passed their hang test just days before we did (thus winning one of our many whiskey bets). Here’s to more good times in McMurdo!
Myself, Alex and Clio standing proud in front of our fully integrated gondola (apart from the back door panel that was left off) during our successful compatibility test – August 12th, 2014.
After our successful time in Texas, Alex and I drove the instrument back home to Berkeley for a two month’s “break” before heading to the Ice in October…