We keep getting delayed due to shipping, which is pretty frustrating. First, we had to wait to get the card cages sent from Berkeley. As soon as we got those last week, we thought there was nothing preventing us from getting the cryostat on the gondola. But that was before we noticed that our stycast (thermal epoxy) had dried out. We need the stycast to attach heaters and temperature sensors to the cryostat, the electronics boxes, and the gondola.
Brent ordered some more stycast from a place in Europe that claimed they could ship it in 2-3 days. But someone else from UC Berkeley also ordered something from this same company, so the company got confused and sent the stycast to Berkeley. Once we figured out what happened, the company re-sent us the stycast, this time to Wanaka, but it probably won’t arrive until Tuesday.
While we wait, we’ve been working on a lot of the other aspects of the instrument. Alex added some connectors to the flight computer (unfortunately I didn’t get a photo of the flight computer, which looks pretty cool when it’s opened up). Abby, Jimmy, and Alan got all the card cages on the gondola.
The card cages mounted on the gondola. Can you see Carolyn in there? Hint: look for her feet.
Carolyn in the gondola (from another angle). She was routing all the cables from the card cages to the electronics bay.
The inside of the gondola–the card cages are mounted on the other side of the metal plates. You can see the result of Carolyn’s cabling work. She wants me to assure everyone that it’s not finished yet and will look a lot better when she’s done (though I think it looks pretty good already). There will also be a lot more cables there when she’s done.
While the cryostat is on the bench, Carolyn turned on all the detectors and started taking some calibration data. All the detectors look good!
Looking at the data through the GSE, the program that monitors the instrument from the ground. The red display shows how a single detector is illuminated. Each detector has 37 strips on each side and can be divided into pixels. The brighter the red, the more counts each strip has. The plot in the upper left shows an energy spectrum of one of the detector strips.
I’ve been working on setting up the pump system. To better control the cryostat temperature in flight, we are going to pump fluid (kind of like antifreeze) through the cryocooler and then through a huge copper plate. The fluid will take the heat from the cryocooler and radiate it away when the pump is running.
The pump system on the bench in front of the cryostat. You can see the radiator plate and reservoir (the white can) that holds the fluid. The pumps are underneath the radiator plate. All of the bubble wrap around the cryostat is to protect the very sensitive signal cables that go between the cryostat and the card cages.
We’ve also been working on the shields. The shields block gamma rays from the bottom and sides of the instrument so that we only see gamma rays from space.
The shields on the other side of the cryostat. In flight, the shields surround the bottom and sides of the cryostat. Even though they’re not in their flight configuration, we can still calibrate and test them. You can also see the PDU (power distribution unit) below the cryostat.
Brent has been working on an alert system for flight. Because we’re hoping for a 100 day flight, we don’t want to be monitoring 24/7 during the entire flight. The alert system will text and email us if something goes wrong with the instrument.
Brent made the alert system talk every time there’s an alarm. We also found a cheap strobe light in an electronics store, so Brent hooked it up. Now every time there’s an alarm, Brent gets a text, the strobe light gets going, and we hear “COSI ALERT. ERROR ERROR ERROR” in a pretty weird computerized voice.
McBride worked on building a box to hold what we call the ‘ethernet switch switch’: a switch to turn on and off the ethernet switch.
McBride working on the box in a patch of sun. Alex described him as looking angelic.
We’ve also been having fun! (Today is Sunday funday after all.) Last night we went out for dinner and a couple beers after. Today we didn’t do anything as a huge group, but a lot of us hung out by various lakes. As I write this post, Brent and Carolyn are BBQ-ing what looks like a delicious dinner for everyone.
Brent, Abby and I split this watermelon margarita last night. It looked much better than it tasted.
Carolyn, Brent and I sat by the lake for a bit this afternoon. Carolyn was the only one who went swimming.
In other news, the cat is still desperate to get inside the house (but can’t because Brent is allergic). We opened a window in the kitchen and the cat immediately jumped in. Carolyn had to push her back out.