Under the ice and more cryo progress

This week started off with the very important and always somewhat nerve-racking step of moving Theo (our cyrostat) to the gondola from its ground station cart. We are well practiced at this maneuver, but you always have to be on your A game when transporting a cryogenic vessel that’s under vacuum. Happily, this went off without a hitch on Sunday!

Theo mounted on the gondola, along with a bunch of people in hard hats.

Theo mounted on the gondola, along with a bunch of people in hard hats.

After that long day on Sunday, we were told to take Monday off in preparation for the very busy next month that spans from the first helium fill until launch. We took full advantage of the day, starting with a trip to the Obs Tube.

The Obs Tube is a tube situated in the sea ice just down the hill from town. It fits one person, and takes you via ladder down a few meters to a compartment with windows below the ice. I don’t have any more adjectives to describe these sort of incredible experiences I’m having down here, so I guess I’ll just go with how my buddy Romano described it: f—in’ badass. The sea is brimming with life, despite the cold. Tiny white fishes are everywhere moving in slow motion. Little transparent white skeletal looking creatures and tiny jellyfish-looking things make you double take as you realize they are alive. And the coolest part- the sounds of the whales or seals. We imitate them to each other and it sounds like we are making lame sci fi laser gun sounds effects: “Pew pew!” But that’s exactly what it sounds like.

After that, Ed and I hit the gym to do some climbing. There are three gyms here- the weights gym, the gerbil gym, and the big gym. Here are a couple pictures of the big gym.

Later on, 12 members of the SPIDER team participated in a dodgeball tournament. It was a lot of fun, despite the two SPIDER teams finishing last.

The next day, we took the dive and put liquid helium into the main tank. Cooling warm(-ish) thing down to 4 K causes a lot of boil off and high pressures in the tank, so we do it slowly and keep people around for the 72 hours it takes for everything to equilibrate, just to make sure Theo is happy. So far, so good! Tomorrow, we should have superfluid, and within a day or two after that, a fully functioning microwave polarimeter!


Cooling down and pressure ridge tour

Yesterday we took our next big step toward a functioning experiment- we transferred liquid nitrogen into the main tank of the cryostat. It’s always exciting to get to the cryogens step. Exciting meant only in the sense of happy anticipation, and not at all in the sense of being terrified something will go wrong in an unrecoverable manner, of course. I’ve never been one to worry. In all seriousness, though, 28 hours in and things are looking good.

While the nitrogen fill was happening, I recorded what I thought was an amusing series of photos. The task at hand was to fill a bucket with water. The bucket is used as a heat sink to warm up the exhaust pipe from the cryostat. This keeps the check valve at the very end from freezing. Since drinking water is a limited resource in Antarctica, we wanted to use non-precious water. Bill suggested snow. Ed and I filled the bucket, brought it inside, and got impatient. It needed to melt faster. Below is the sequence leading to the fulfillment of that goal.

Several of us woke up very early this morning to leave on a 4 am tour of the pressure ridges near Scott Base. Pressure ridges form from the sea ice flowing up against the point where Scott base is located. This makes waves in the ice that crack on the crests to make jagged ice structures and on the troughs to create pools filled from the ocean below. The ridges are the most stunning part of Antarctica I have seen to date- well worth the lost sleep.

It was a snowy, windy day, so the photos don’t begin to capture it. In real life, the blue ice stood out sharply against the grey hills toward McMurdo and the white ice everywhere else. I felt like I was on a different planet, or in some artist’s imagination, or in a Dr. Seuss book. Totally unreal, and an experience I will never forget.

A week of waiting

I haven’t written a post in a week. Reasons for this include a lack of exciting activity, a lack of pictures, and overall melancholy as we have been playing the waiting game, trying our best to get Theo ready for cryogens.

We have hopefully found and fixed the last of our leaks– it is really difficult to get an experiment with that many vacuum flanges to be vacuum tight! The smallest scratch on a surface or tiny piece of schmutz on an o-ring can break your vacuum. Despite our vast collective experience and careful work in closing up, mistakes are made. Thankfully, we have also become very adept at finding and fixing leaks! After today’s leak check, we think we are close to as low of a pressure as we can achieve with no detectable leaks. Hopefully we will decide to fill liquid nitrogen tomorrow, and then the real fun begins! Might have base temperature detectors this time next week! But I am getting ahead of myself.

Here are some pictures from this week. First, wrapping up my vehicles and buildings tour:

A year and a bit ago when SPIDER was getting integrated in Palestine, TX, a few of us had a memorable night of watching some of the riggers arm wrestle, and then joining in the contest ourselves. That inspired Natalie to organize a SPIDER arm wrestling tournament. We’ve been doing matches after lunch in the galley, and they have been a nice light-hearted break from work. Below, Ivan (undefeated) was teaching Johanna technique, and Sean was her guinea pig.

Today we arrived at LDB to find a seal in our backyard! It’s a long ways to the nearest water, so we are curious how he got there. He quickly scooted his way across and out of LDB, happily heading in the correct direction toward water.

I’ll close with a picture of Erebus because it looks cool every day and I only take a picture every other day, but that’s still a lot of pictures, so I have to post one.

Erebus often has its own clouds. Here, there is a strip of them, so you can see the top and bottom.

Erebus often has its own clouds. Here, there is a strip of them, so you can see the top and bottom.

Closing up timelapse

Jon set up some go pros around the high bay to take pictures every 10 seconds while we were closing up. The result is pretty sweet. You can see the various layers going on the cryostat, and the domes being closed up. I wore red for a couple consecutive days, so I’m easy to pick out!

On the pump!

Wow, what progress can be made in a week! We have gone from unpacking to on the pump in one week- a new record for the SPIDER team. Being on the pump is a big milestone for us because pumping all of the gas out of our cryostat takes a fixed amount of time, and no amount of will power or hard work can make it go any faster. Therefore, we use up all of our will power and work ethic in the time leading up to that stage and then relax just a little bit while the pump does the work for us once we’re all closed up.

We finished buttoning Theo up and started pumping a couple hours ago, and now Ed and I are monitoring it over night. We have to be very careful with the speed at which we pump down the cryostat, since we have very thin filters that can tear if they are subject to a big pressure differential. They are kind of like thin balloons- we don’t want them to pop. So we slowly open a needle valve bit by bit until sometime early tomorrow when we’ll have only a small fraction of an atmosphere left in there. We’ll repressurize with nitrogen a few times (this, in theory, helps dislodge water molecules that adhere to the surfaces inside the cryostat) and then leak check the system.

While we twiddle our thumbs (and occasionally the needle valve), I figured I would post some pictures. First of work done over the past few days, and then of the environment here at LDB, since I have heard a request for shots of buildings. I haven’t spent a lot of time in town lately, but I’ll take pictures of those buildings soon!

To get to and from LDB, there are a variety of vehicular options. Most mornings, we take the Cress, but I don’t have a picture of that just now. It’s basically a semi whose trailer is a big passenger compartment. It is cold and slow and I don’t like it all that much. On Sundays, when the number of people heading to LDB is drastically reduced, we take these awesome vehicles called deltas. Those are the first ones pictured below. They are nice because you can see out the windows, sit across from each other, and are reasonably fast. My most common means of transport (and also the least cool) is shuttle van, shown in the last photo. It is just a big van with big tires.

Today I walked around and took some pictures around LDB.

Very soon we will know if we have managed to make our system helium leak tight. This is a very difficult thing to do, and we have failed numerous times in the past, so send some positive thoughts our way!

Finally getting to work!

My mom sent me an email today saying that she figured we must be busy since neither my collaborators nor I have updated our blogs recently. Indeed, she was correct! We have been working overtime to make up for the schedule delays now that our cargo is here, and a ton of progress has been made in a few short days. Our last night off was Halloween, and a few of us managed to put together costumes. Mine consisted of long underwear, belts, and a pair of leggings tied around my head.

Three of the SPIDER crew dressed up for Halloween: me as a ninja, Steve as a fancy SPIDER, and Bill as Commondante Marcos (if you knew who Bill was dressed as, he bought you a beer. Bill didn't have to buy many people beers.)

Three of the SPIDER crew dressed up for Halloween: me as a ninja, Steve as a fancy SPIDER, and Bill as Commondante Marcos (if you knew who Bill was dressed as, he bought you a beer. Bill didn’t have to buy many people beers.)

The next day, Saturday, we received the first half of our cargo. With ten people, unpacking wasn’t too bad, and we were done and waiting on the second half of our stuff by early afternoon. We found ways to pass the time.

Unfortunately, the rest of our stuff didn’t show up until the next day, but with that long of a wait, we were all bursting with energy ready to get to work. In the three days we’ve had since getting unpacked, we’ve opened up the cryostat and each of the six telescopes, carefully inspected each, and reassembled and closed them up to the point where we will put them in the cryostat tomorrow. This is a lot of careful work, and while we are well practiced at it by this point, we have still had some long days at the high bay. Here’s a tour of where we’ve been spending our time:

Apart from finally getting to prepare our experiment for flight, which is exciting enough in itself, I am still awed every day to be in Antarctica. Every day I step outside for a break or to go home, there’s some new cool lighting, some new cool clouds, or my favorite new phenomenon here: Fata Morgana. It’s like a mirage you’re used to seeing when driving on a highway. There is a temperature gradient between the hot road and cooler air above it, and that caused light to refract in such a way that you see the sky on the road. Here, it’s the opposite. You have cold ice, and warm air above it, and when the conditions are right, that causes features to look extended. Jamil has a fantastic photo of it here. I see this everywhere, to different degrees at different times. It makes you constantly question whether what you’re seeing is real or in illusion. Antarctica is such a strange place.

In addition to the landscape, Antarctica also poses some unique… problems? Minor inconveniences? Things happen on a daily basis that you just wouldn’t expect to happen anywhere else. To close, here are a couple expamples from the past couple of days:

Looking forward to the surprises that we’ll meet in the coming weeks. Let’s all cross our fingers that they are not cryogenic in nature…