Thursday, April 30, 2009

Day 36, 4/30/09 -- I can has EBEX pls?

Now that the entire experiment is together and running off of one flight computer, there's been a bit of pushing and shoving for access to the gondola and flight computer. Some people want to debug code, others want to run detectors, others want to do scan tests, etc, so it's become a bit of a logistical hassle coordinating work. It hasn't been too bad yet, but we'll see how it goes in the future.

Last night, during the scan tests, Will and others added 200 lb of balancing weight to the cryostat to allow the elevation drive to work properly. Of course, this is 200 lb we can't really spare, so I'm trying to come up with a solution that will save us weight but still allow reliable elevation motion.

Other work that went on today: Some work on fixing some little electronics issues, Ilan cycled our fridges so our detectors are now cold, Hannes and François are working on tuning SQUIDs and detectors, Dan and Michele got a lot of work done on setting up the artificial planet, and Shaul and I are having lots of problems with mirror alignment.

CREST might launch tomorrow (sort of marginal conditions), but I'll be here early anyway to do more work on the mirror alignment with Shaul before he heads back to Minnesota.


Wednesday, April 29, 2009

Day 35, 4/29/09 -- This post intentionally left blank

No 'real' post today. I've hit a wall of tiredness and decided that the time I normally use to sort through pictures and write a blog post would be better spent sleeping.

Nothing interesting happened today anyway.

Tuesday, April 28, 2009

Day 34, 4/28/09 -- Cryostat meets Doc Ock

Last night, after the installation of the cryostat, the gondola was handed over to Will, Joy, and Daniel for more ACS/scan tests. At some point in the very early morning, it seems that our elevation drive system malfunctioned and overheated. We're still investigating the cause of this, but we have both a spare motor and actuator

After starting the installation of electronics crates yesterday, that work continued today. For a while, everything was on, but Ilan found a short in one of the bolometer power crates so that had to come off for debugging. François basically spent the entire day on the gondola getting detector cables in place and getting our RF shielding 'dryer hose' buttoned up. Now the cryostat looks a little bit like Doc Ock from Spiderman.

After I dealt with a whole bunch of administrative stuff in the morning and then having our weekly telecon, Shaul and I worked on mirror mount alignment. On the first attempt, we were able to get the mount to within 0.050" or so of its nominal position -- not bad for trying to align two things that are roughly 50" apart, but not actually good enough for what we need (less than 0.020". The two mirrors are roughly 90" apart, and need to be aligned to the same tolerance!) . After puzzling over this for a few hours, we couldn't come up with a good reason for why the alignment procedure didn't work, so we're probably just going to try again tomorrow.

The weather here turned windy and rainy so CREST wasn't able to launch today. However, the weather the next couple of days is supposed to be better, so maybe they'll launch Thursday? We were informed that the high-altitude-wind 'turnaround' will reach New Mexico in about 2 weeks, after which there will be a 1-2 week period of relatively low-speed high-altitude winds. This corresponds well with our planned flight readiness date.

Also, now I can officially say I've been here over a month (for any month of the year!). We've made a ton of progress, but there's still a lot left to do and we're going into over-overtime mode to get everything done. As if we weren't getting enough sleep...


Monday, April 27, 2009

Day 33, 4/27/09 -- Cryostat and gondola, together again for the first time.

The big news today is that we got the cryostat installed on the gondola. We had done it before, last year at our pre-flight integration at Columbia's Nevis lab, but now it's for real.

All in all, it was a pretty smooth process. Since we've done it before once, we knew what to expect, and it took only a little bit longer than I predicted (four hours instead of three, start to finish). We then started the process of aligning our mirror mounts, installing detector readout electronics on the gondola, and just general "get it working"-ness.

Also, with the cryostat on the gondola, we were able to clear up a ton of floor space in the high bay, which we'll need when we do full telescope tests with our 'artificial planet'.


Sunday, April 26, 2009

Day 32, 4/25 -- The calm before the storm

Since the detectors are still cold, Dan and others spent a lot of today doing calibration tests. I'm happy to report that they were able to get all of the major tests done -- another big milestone, and what will hopefully be a big part of Dan's thesis! Great job, Dan.

I spent most of today thinking about the baffles -- mostly, how are we going to attach all of this crazy crap to the gondola and have it not fall apart. We have a plan, and some of the last bits of material will be ordered shortly.

I also spent some time today playing around with Google Analytics. I had set up an Analytics account for this blog a few days after I started it but then forgot completely until I was reminded by a post over at Uncertain Principles. With it, we found out that Jeff's mom not only checks this blog from work but also from their cabin (hi Jeff's mom!), and someone from Estonia has come (once). Also, apparently some of the CSBF people in Palestine, TX read the blog too. I was, uh, just kidding about having driven the forklift...

No pictures today. But tomorrow, we put the cryostat and gondola together (for the 2nd time), and then things get really fun. Stay tuned...

Saturday, April 25, 2009

Day 31, 4/25/09 -- The day after

Last night's test of the gondola/ACS was, by all accounts, a resounding success. The ACS team got the gondola scanning back and forth, with all of the sensors working, downlinking data over the transmitters and commanding through the telemetry system -- the whole works. Really awesome. Great job guys and gals! Also, big props to the NASA crew who stayed all night to support the effort.

Since I left early last night (2AM as opposed to ~9AM for the ACS team), the high bay was relatively deserted. Hannes flew back to Minnesota today for a little break, so François, Ilan, and Dan were the only other people in the high bay all morning besides me and Jeff. Dan continued doing calibration tests, and we had quite a scare when it seemed that some of Dan's data (a few hours worth!) accidentally got deleted from the computer's hard drive! It turns out that, besides there being another copy of the data on another computer (albeit in a less-accessible form), it turns out the data files weren't even deleted in the first place. Whew!

Shaul showed up today as well, and proceeded to get a rundown on the status of all major systems from the relevant parties. Jeff and I spent a fair part of the afternoon painting some of the exposed metal on the gondola. It turns out that, in the near-space environment of a high-altitude balloon, the sun can warm up bare aluminum to hundreds of degrees Celsius! Painting it white not only reduces the amount of sunlight absorbed, but also increases the amount of heat that can be radiated away, keeping the entire thing cool. Pretty neat!

A few pictures today at:

Day 30, 4/24/09 Part 2 -- Day 30 Strikes Back!

After going home to try and get some rest (and failing miserably, on my part), we went back to the high bay to help the gondola/ACS crew roll the experiment out and have it picked up and deposited away from the building to calibrate sensors and do scan tests.

I should point out that this is HUGE. This is the first time EBEX has ever been outside. It's the first time we have all of the sensors. It's the first time we're talking to EBEX and having it do things over the flight telemetry link.

Jeff and I went back mainly for manpower support. I ended up driving our articulated boom arm to make the crane connections/disconnections because it's way easier to get that thing in place than NASA's bucket lift. And, of course, we took lots of pictures. The new pictures in today's album were taken by me, Britt, Joy, and Jeff.

Check 'em out:

Friday, April 24, 2009

Day 30, 4/24/09 -- EBEX in Flight, early edition

Tonight, we're planning on doing a full outdoor test of the gondola's attitude control system, so some of us have come back to try and get a little rest before heading back to the high bay to meet up with the NASA peeps.

Jeff learned how to operate our cherry picker so he could replace some bolts on the triangle support that we installed yesterday. I saw the launch vehicle driving around this morning in preparation for activities tonight.

We (meaning Will and the NASA guys) were able to get our computers talking with the NASA equipment -- a critical interface needed for flight. Not only that, we can now send commands from our computers wirelessly, and receive data from the transmitters as well! Pretty sweet, if I do say so.

Just a few pictures today (so far, I'll probably get a lot more tonight). Bonus video of the launch vehicle driving around!

Thursday, April 23, 2009

Day 29, 4/23/09 -- This title intentionally left blank

Today we achieved a pretty big milestone: We installed what we call the "triangle support", some long aluminum bars at funny angles that are intended to hold up parts of gondola when the experiment lands. Jeff and I spent a lot of time on these parts, both in machining as well as in fixing some manufacturing mistakes, so it was very satisfying to see it all come together.

The triangle support is one component that is important for the planned attitude control system test that the gondola team wants to do this weekend, before the cryostat and gondola meet. The gondola team is working hard to make this test happen, and the cryostat team is working hard to make sure we can get all of our receiver tests done. To that end, I cycled our sub-Kelvin refrigeration systems today while Hannes and Dan prepared to do tests.

I took a few minutes out of the day to try and sharpen the crappiest knife edge I've ever seen. I bought the knife from the local supermarket, and straight out of the box it was pretty much useless. So I took it over to the bench grinder in the machine shop and, after a few attempts got what looked like a reasonable edge. Once I got home, I tried it out and, wouldn't you know it, it actually cuts now! Kind of amazing, given that I'd never sharpened a knife before.

Also, we lowered the adjustable hoop outside our high bay door and had some fun pretending to be NBA superstars. Check it out in the pictures:

Wednesday, April 22, 2009

Day 28, 4/22/09 -- Booms, bugs, and bolometers

The weather here in NM is finally becoming what I expected New Mexico weather to be like: hot! Today it got up to nearly 90 degrees, and it was glorious. Of course, with the heat come bugs. We've seen a marked increase in the numbers of flies, moths, and other various kinds of bugs around the high bay. Strangely, all of the bugs here are VERY slow. I was actually able to just step on a fly a couple of days ago.

We got some new additions to the team today, and one subtraction. François drove Kevin to Albuquerque so he could fly back to Montreal, spent the day there, and then drove back with Ilan and Will, who both arrived last night. Once back in the high bay, they jumped right in to work. Will quickly fixed a configuration issue we were having with the serial ports on the flight computer. Dan spent the day taking data with the Ebert-Fastie monochromator he built, getting information on the receiver's spectral response. I spent a good part of the day working on the baffling mechanical design.

The big news here today was the arrival of our rented articulated boom lift. Let me tell you: This thing is FUN. We need it to do some calibration/systematics tests as well as eventually to deal with the gondola once all of its structure is in place. Speaking of structure, Jeff and I have spent a lot of time over the past few days dealing with what I can only assume are manufacturing or design errors in some of the parts for the gondola structure. Making what should be a simple task (bolting a couple of things together) difficult by having to fix others' mistakes is a great way to make a good day turn into an annoying and frustrating one.

Last, Dan had Ilan pick up a new rim for the sad basketball hoop just outside our high bay door. The new one is straight and round and actually has a net! We played a good amount of basketball today, and Britt even got in on the action for a little 3-on-3. Now we have two hoops to choose from. Maybe eventually we'll wheel our hoop over to where the new hoop is and set up a full court!


Tuesday, April 21, 2009

Day 27, 4/21/09 -- Just a day in the life

Nothing particularly exciting happened today. We had our weekly telecon today, which is always fun. Milligan thinks he found a bug that's causing our flight computer to crash. Dan started some more calibration experiments today and is working on them tonight as well. Britt and Michele investigated some oddness in the gondola elevation drive. I spent a lot of the day trying to figure out how the rough idea for our extensive baffling's support structure will actually translate into a physically realizable structure, and I think I've got the basics worked out. We should be able to order metal soon.

Yesterday, I met Bill Stepp, who is the head of CSBF flight operations. Apparently, when he comes out, the flight season is getting close. He told us today that CREST, who showed up over the weekend, are looking to launch as early as next Tuesday! It must be nice to have an experiment that's that easy to put together. Then guts, no glory!

The new basketball hoop is ready for use too. It's much less forgiving than the old one outside our door, which of course means that Dan just gained an even bigger advantage over the rest of us hacks. To inaugurate, Dan, Hannes, and I played a game of 21 -- and I won! Total luck, for sure, but I'll take it.

Also, I got new shoes. My old ones were falling apart, so I ordered a pair from Zappos -- the same exact model as my previous ones (Adidas Samba Milleniums, size 10.5 if you must know). I think they're the only things in New Mexico that aren't covered in dust (yet). What really sucks, though, is that I have two more brand new pairs waiting for me in Minnesota -- I just figured I wouldn't need them. Oops.


Monday, April 20, 2009

Day 26, 4/20/09 -- We eschew pseudo-breezes*.

Today was a productive day in the high bay -- well, at least it was for Jeff and myself. Basically, what it comes down to is that we kick ass at building stuff. We have basically all of the gondola protection hardware completed (it's missing a few rivets, which are on their way from McMaster-Carr). We also got the sexy carbon-fiber GPS mount completely done -- the glue is drying as I write this.

The detector guys were still doing tests today before handing the system over to Dan for calibration work. I think they were trying to get as much as possible done before Kevin leaves and Ilan returns and Will shows up.

The EBEX crew gained another house, and tonight we're going over there to hang out -- it's on Lake Sumner, and they have a pool table! First, though, a quick dinner of mac and cheese and then await Britt's call so she can ferry us out there.


*We live on Real Wind Drive.

Sunday, April 19, 2009

Day 25, 4/19/09 -- One step back, six steps forward.

Last night, I stayed late to cycle the helium adsorption refrigerators in our cryostat while Daniel and Joy did scan tests. When I was nearly done, we noticed that the gondola started making a horrific noise when moving in elevation. We decided that we would cease any tests involving elevation motion until Michele and Britt had a chance to give it a listen in the morning. I went home at 3 AM or so; the other two stayed until about 7:30 AM(!).

In the morning, Michele and Britt checked and found it was making the same kinds of noises as it did once before when there was some wear and debris in the trunnion bearing. with it's head! The inner frame had to be removed so the bearings could be inspected and repairs effected.

In the meantime, we were able to get a lot of work done on the gondola. Jeff, Michele, and Britt finished the last bit of drilling and bolting for the primary mirror rollbar. I started Jeff off on making a mount for our sun sensor while I started work on the GPS mount -- first, a slight redesign of the geometry to give more clearance for the launch vehicle and then drilling of some more holes. I had Jeff cut the carbon-fiber tubes to length while I -- yep, you guessed it, drilled some more holes (in the antenna backplanes). We were able to get the entire GPS mount assembly mocked up and basically ready for gluing.

Michele and Britt found a small chip of aluminum in one of the trunnion bearings, most likely from all of the drilling we've been doing on the inner frame. They removed it and smoothed out the damage and the inner frame went back on by the end of the day.

On the detector front, the detector team was working on getting the system back up to speed after the fridge cycle. Hannes reports that François was able to tune all of the SQUIDs in the system with a single command from his computer. Neat! While that was happening, Dan kept plugging away at setting up all of our calibration experiments.

Around the base, there's been some changes. The FIREBall team is basically all set up and ready for flight -- the personnel have tucked everything out of the way until their flight, and have left the premises seemingly until then. And another experiment showed up today: CREST, a cosmic ray telescope. I think they're planning to be flight-ready in about 2 weeks!

Jeff and I left the high bay early tonight -- 9PM. Jeff points out that it is indeed a sad state of affairs when 9PM qualifies as an "early night".


Saturday, April 18, 2009

Day 24, 4/18/09 -- Hot at any wavelength

Today was a productive day here at the high bay. The most noticeable change to the gondola is that it's now received some new hardware -- Jeff and I spent most of the day building up the rollbar for the primary mirror. Robin from CSBF spent the day lightweighting some additional hardware for the triangle support structure (this probably means nothing to those who don't know the construction of the gondola...but whatever, I'm leaving it in), and Michele got started on cleaning up and installing those parts once we got them back.

Joy and Daniel have been working the late shift lately, taking the advantage of the night to do scan tests with the star camera. Because we still have cold detectors, Dan started doing some of our baseline calibration tests (optical efficiency, rough beam checks, etc). The McGilligans have been probably writing detector tuning algorithms or something like that. What the hell do I know?

The big news today was our ice cream party -- Britt's husband arranged with the local grocery store to provide us with a veritable cornucopia of ice creams. Five or six different flavors and a variety of toppings, all brought to the high bay and set up by Dave, the owner of Dave's Venture Foods and former mayor of Fort Sumner. It was a great way to take a short break in the afternoon and enjoy some ice cream and the great weather.

It's currently about 11:15PM and Joy, Daniel, and I are still in the high bay. I'm cycling fridges so detectors will be ready to use in the morning, and the kids are doing more scan tests.

Also, be sure to check out a couple pictures that Milligan took yesterday that I posted in that day's album.

Friday, April 17, 2009

Day 23, 4/17/09 -- Worst. Helium. Transfer. Ever.

Today, work continued (what else?). We drilled some holes in the gondola to mount the protection hardware, Dan and Hannes started doing calibration experiments. Michele did some work on the rotator to add a tilt-meter and a connector for the slip-ring.

Of course, it being Friday, we went to the hamburger stand for catfish and shrimp -- and this time, I took my camera!

The highlight -- or lowlight -- of the day was our comical attempt to try and get the last remaining little bits of liquid helium out of the two dewars we had left. Basically, it didn't work. Luckily, our new 500L dewar to replace the empty ones we got yesterday showed up during our attempts to fill -- perfect timing. We just gave up on the little bits we had left (it wasn't going well anyway) and went whole hog with the new arrival. Much easier.


Thursday, April 16, 2009


It's kinda cold in the high bay. FIREBall has their door open for star camera tests, and we have our door open about a foot, also for star camera tests, and there's a cold breeze flowing through. I might need to start wearing pants to the high bay.

Instead of shorts, I mean.

Day 22, 4/16/09 -- Problems and solutions

Today started off with the gondola crew trying to figure out some oddness in the reaction wheel motor control. After lots of head-scratching, confusing tests, and emails across the pond, Michele finally noticed that the cables to the motor weren't plugged in all the way. The intermittent connection was enough to cause all sorts of non-repeatable weirdness.

This illustrates a point I often make: 90% of physics is trying to connect one thing to another. It could be a mechanical connection, electrical, thermal, data -- whatever. The hard part about experimental physics is always in the interfaces.

Jeff worked for most of today on his half-wave plate control system. I got started with the mounting hardware for the gondola protection stuff, though the gondola team was messing around with the gondola for much of the day so I didn't get a chance to drill some holes I need to drill. Perhaps tomorrow. Dan, who arrived last night from Minnesota, started setting up his calibration experiments.

The detector team is working hard on understanding the detectors we have operational. The fridges are still cold from yesterday, at about 260 mK. We had a bit of a snafu with our liquid helium order, though: When the truck was loaded, whoever loaded it neglected to secure our liquid helium dewars. Two of the three dewars fell over, the third was free to roll about on its casters in the back of the truck. Out of the 300L we were supposed to receive, we had only 28L delivered. Because we'll run out of helium in the cryostat on ~Sunday, probably, NASA is working hard to get us more by Saturday. Fingers crossed!

On the bright side, the NASA crew was working hard today on a very important improvement to the site: A new basketball hoop! Hopefully it'll be ready to use tomorrow.


Wednesday, April 15, 2009

Day 21, 4/15/09 -- Tax day!

Another gorgeous day in New Mexico.

Today Jeff and I started the process of cutting metal for the gondola protection hardware. I say "Jeff and I", but really it was just Jeff. We figured out what needed to be done, but he actually was the one in the machine shop all afternoon and evening. I spent the better part of the day trying to place an order from my favorite industrial supply company, McMaster-Carr. I had to go through the gondola model and figure out exactly what kind and how many screws were needed for the structure we're building. I also did a bit of FEA on some mechanical parts that are clearly WAY overkill; hopefully we'll be able to remove a bunch of material and save some weight.

I also finally got the liquid helium level sensor working, using the current source on the dedicated level sensor board built at Weizmann. Using this board, we measured the liquid helium boiloff to be about a 12 liters per day, for a total hold time of about 5.5 days -- more than enough for an at-most-36-hour flight.

The gondola team has been having a frustrating day -- things that used to work don't anymore, and they've been working hard to try and figure it out. The detector crew came in to find all the power to the readout system gone -- turns out a fuse had blown overnight and they had to spend some time this morning getting everything back in an operational state.

The most exciting news for today is that I got my very own cowboy hat. It's an Atwood Low Hereford 7X, size 7-3/8. And I'll be damned if it doesn't look good on me.

Pictures are pretty meager today. Sorry.

Tuesday, April 14, 2009

Day 20, 4/14/09 -- Cold at last, cold at last...

Another gorgeous but windy day here in New Mexico, it was sunny with a high of nearly 80 degrees. Britt also returned last night from her short trip home to New York -- we actually saw her driving to the high bay when we left last night, and she ended up staying VERY late helping the rest of the gondola/ACS crew fix some problems. Welcome back, Britt!

This morning when we came in, we found that everything in the cryostat had reached about 4K, meaning we could run our sub-Kelvin refrigeration system and actually get working detectors. We also have our weekly telecon on Tuesdays, so we gave the rest of the group an update on activities here in Fort Sumner. Some subset of us also attended a gondola-specific telecon a half-hour after the aptly-named 'general' telecon ended.

We received some parts and materials for extra gondola structure we're adding to make working with the gondola easier as well as help protect some of the more-important components (mirrors, mostly) on landing. Jeff machined some parts for this today and we'll continue to work on it tomorrow as well. We also noticed that some of the parts were ridiculously overbuilt and we came up with a design for light-weighting those parts.

A couple of times today the FIREBall team wanted the lights out so they could do tests with their star-tracking camera. This isn't too much of a problem for us, and it made for some decent pictures. Here I am holding still while working at my computer so Michele could get his 1-second exposure without it being totally blurry.

The detector team is going to have a late night in the high bay now that they have cold detectors. Suckers.


Monday, April 13, 2009

Day 19, 4/13/05 -- The road to 250 mK

After a restful (hah!) weekend, work continues in the high bay. The cryogen boiloff situation has settled down substantially, and when I came in this morning I calculated roughly a liter per hour boiloff rate -- and things are still cooling. Based on the last run, though, we won't be ready to cool detectors until the 15th.

I spent a good part of the morning talking to Mark from CSBF regarding rigging and ballast hoppers. We checked with the CSBF electronics crew and it looks like we'll be able to put the ballast hoppers along the sides of the battery table, perhaps saving as much as 2 feet in height compared to mounting them at the bottom -- height that can be then used to lower our payload and provide much-needed clearance to our GPS antenna structure.

We noticed that the pressure in the cryostat has been slowly creeping upward starting yesterday, from a few microTorr to about 10-15 microTorr. Worried that there was a leak, we decided to leak check once more now that the pressure is low enough to check in the leak checker's more sensitive range. Luckily, we didn't find a leak, but we're still puzzled as to the origin of this strange increase. Also, I drove one of the NASA forklifts -- that was fun.

Jerry and Daniel stayed late last night after the clouds cleared and were able to take some images with the star camera that will be useful for debugging. Milligan found this morning that our spare flight computer board has been acting flaky and will need replacement. The gondola team also is finding that they're having issues with the serial ports on the flight computer crate and are actively investigating that (even as of now, roughly 11 PM). And the detector gang has been looking at SQUID noise in various hardware configurations of the instrument.

Luckily, while we've been waiting for the focal plane to cool, the weather has been nice: High 60's, fairly sunny, and not too much wind. Makes for good basketball weather. Sadly, it doesn't make for good basketball players -- watching a bunch of physicists play basketball is fairly comical.

Today's pictures:

Sunday, April 12, 2009

Day 18, 4/12/09 -- EBEX is risen!

This morning, Jeff and I once again got up way too early to fill the cryostat. I had set my alarm to wake up at 5AM, but I figured I could sleep a little longer and set the countdown timer on my phone for 10 minutes more and went back to sleep. Luckily I woke up about 25 minutes later, at which point I realized that I accidentally set my timer to count down for 10 hours. Oops. It ended up working out fine; I got up and woke Jeff up and we headed to the high bay, where we found that the cryostat boiloff had slowed during the night and we had plenty of helium left.

We filled anyway, and over the course of the day the boiloff dropped even further, down to 2.6 liters per hour as of the last measurement. For reference, last time we cooled it down, the cryostat boiled off roughly 0.5 liters per hour. Fun fact: Liquid helium costs about $4/liter in Minnesota, and probably more here in NM because it has to be delivered from Texas. We have already currently used nearly 900 liters of liquid helium just to get the cryostat to this point; we will probably go through another 700-1000 liters by the time we get to fly. So figure at least $6400 in liquid helium alone. Science is expensive.

I spent most of the day trying to get our liquid helium level sensor to work. I fixed the issue I had yesterday, but it still wasn't working. Later, I discovered that the power supply I was using to run the level sensor was acting funny, meaning we won't have a level sensor unless we use a different power supply (something I'll look into tomorrow).

Ilan and Matt spent the day continuing to debug the low-temperature thermometer readout electronics, while Hannes and the McGilligans looked at SQUIDs and worked on detector software. Jeff and Ilan worked on idiot-proofing the half-wave plate commanding, and Jeff had the HWP spinning at roughly 2 Hz by the end of the day today.

The ACS team of Michele, Daniel, and Joy was able to get the gondola pointing using the magnetometer for feedback (Britt is back in New York for a long weekend). They had been trying to do this for the past couple of days, but the magnetometer was giving funny readings. They finally figured out that the floor of the high bay is somehow interfering with the earth's magnetic field (possibly the steel re-bar in the floor), and so by raising the magnetometer up to the top of the gondola they were able to get sensible readings and move the gondola back and forth.

All in all, a pretty productive Easter Sunday for the EBEX crew in New Mexico. And to think, some people took the whole weekend off.


Saturday, April 11, 2009

Day 17, 4/11/09 -- Cowboys

After our late-night fill, Jeff and I got up at 7AM for our planned field trip (Milligan got up too; we dropped him off at the high bay at 7:30). We were invited by the guy we're renting our house from to attend a calf branding on his son-in-law's cattle ranch. After driving for ~20 miles on dirt roads, we arrived at the pen where about 15 ranchers and ranch hands were well into the process of lassoing, vaccinating, castrating, tagging, and branding roughly-4-month-old calves.

The men there were remarkably efficient -- a guy on a horse would lasso a calf by the hind leg and drag it over to where 3 guys were waiting. One would give the calf a good shove on the shoulder with a boot while another grabbed it by the tail and whipped it over to get the calf on its side. Another guy would grab a foreleg and put his knee on the calf's neck while the guy who grabbed the tail then got a hold of a hind leg, removed the lasso, and immobilized the back end of the animal with his foot. Then four other guys would swarm in -- one with a vaccination gun, one with a gun for putting RFID tags in the calf's ear, one with the branding iron, and one with a knife. The guy with the knife slices off the bull's scrotum and presses on the calf's abdomen to get the testicles to pop out, and then he just slices them off. The calf, needless to say, doesn't like this one bit...but once released, the calf just went about his business as if nothing happened.

The guys there were VERY skilled -- they would shift jobs, but usually the younger ones were doing the roping, holding, and castration while the older ones dealt with the vaccination and tagging. All of them seemed to be very proficient riders -- in fact, everyone there, including the kids of a couple of the guys there, were excellent riders. All of the help were just neighboring ranchers, and they help each other out every time this sort of thing needs to be done. Afterward, we had lunch (prepared by our landlord, the rancher's father-in-law) and chatted with them for a bit. All in all, it was a great way to spend the morning and see something that I thought only existed in movies these days.

When we got to the high bay, we found people working hard. Milligan managed to reconfigure the high bay's networking hardware to make our internet connection to the outside world MUCH faster. In the morning, Michele gave our massively over-designed truck plate to the CSBF machinist here who removed a whole bunch of metal as well as added holes to better interface with the CSBF rigging. We filled helium and then Hannes and François needed to fix some cables so we lifted the whole cryostat plus cart up with the crane and set it on our scaffolding so it wouldn't move around (with the crane still connected, of course). While they worked on cables, Matt, Ilan, and sometimes myself worked on understanding some issues with our low-temperature thermometry electronics. Jeff and Ilan got most of the functionality of commanding the half-wave plate electronics figured out, and Jeff and I fixed a small issue with the new elevation actuator mount. It looks visually like the helium boiloff may finally be settling down -- perhaps one more late-night/early-morning fill tonight, but hopefully no more after that.

Ranch pictures:
Lab pictures:

Tired...of playing...ze game!

It's 2:15 AM and Jeff and I are back in the high bay to fill helium. We found that the cryostat had run out about 20 minutes before we arrived and the cold plate temperature had slowly drifted up to 8K or so. We also found Jerry, Joy, and Daniel in the high bay -- they had wanted to do star camera tests but were thwarted by clouds rolling in.

Bonus points for anyone who recognizes the post title quote...

Friday, April 10, 2009

Day 16, 4/10/09 -- 4.2K here we come!

Wow, has it really been 2 weeks? It really only feels like 12 or 13 days, tops.

Today was an eventful day for everyone in the high bay. Matt Dobbs from McGill (Kevin and François' advisor) arrived late last night and showed up at the high bay for the first time this morning. Shaul left around 10 AM to drive to Albuquerque for his flight back to Minnesota.

In the morning we talked to the CSBF guys Hugo and Mark about modifications to our truck plate to allow it to mate more easily with their launch hardware. The modifications should be quick and may even save us nearly 10 desperately-needed pounds.

Jeff and I filled the cryostat with liquid helium today. The first step in this process was removing the liquid nitrogen from the helium tank, accomplished by dropping a tube to the bottom of the tank and then pressurizing the tank to force the liquid out the tube. Once the nitrogen was gone, we were able to fill with helium. I worked on fixing our liquid helium level sensor, but I messed up and it's too long, and I'll have to fix it tomorrow.

Joy and Daniel spent the day working on the ACS sensors, culminating in suspending the gondola for preliminary scan tests. They're planning on staying late tonight to do some tests with the star camera. François and Hannes worked on getting the detector hardware ready to go while Matt and Kevin worked on software.

Because we've filled with helium, the superconducting bearing holding the half-wave plate can cool below its transition temperature. Shortly before we left for the evening, Jeff ungripped the HWP and was able to rotate the system inside the cryostat by hand from the outside shaft feedthrough -- a critical first test passed!

Because things inside the cryostat are still cooling, we have to fill helium fairly often as we draw the heat out of the components inside. Thus, Jeff and I will be headed back to the lab at about 4AM to fill the helium tank again. Hopefully we'll only have to do this once, and as a reward to ourselves we'll be taking a field trip in the morning -- but I'm not going to give away the surprise for those who don't already know...

As promised, more pictures today:

Thursday, April 9, 2009

Day 15, 4/9/09

Today was wicked windy once again -- constant 30mph winds with gusts up to 45-50mph.

The cryostat is still cooling. It looks like we might be able to fill helium late tomorrow. I spent most of today in various meetings. Jeff got his electronics crate mounted to its home at the front of the cryostat mounting structure. Joy and Daniel worked on indexing our attitude control sensors after having mounted them all to the gondola.

The big news today was dinner. Since Shaul is leaving until after classes finish, we decided to have a dinner at our house, and we did it RIGHT. I made ribs; Jeff made stuffed peppers, Milligan made cornbread, Michele made sauce to go with pasta, and Britt made both hors d'oeuvres and dessert. After enjoying all of the food and a spirited debate on religion vs. atheism and the nature of scientific thought (which I checked out of pretty early on after making some fairly inflammatory remarks). Afterwards, we played Mafia, and good times were had by all.
Unfortunately, since I was basically in meetings all day, I didn't take any pictures from the high bay. I took a few after we came home, but it's a pretty meager gallery today. Sorry -- I'll try to do better tomorrow.

Wednesday, April 8, 2009

Day 14, 4/8/09 -- the cooldown begins

Today we made the necessary preparations for cooling down the EBEX cryostat. We still had some concerns about the cryostat's pump-down rate, so we leak-checked again this morning and again found nothing untoward. It seems that our rental turbopump is just kind of slow.

Hannes spent the day installing SQUID controller boards onto the cryostat and installing all of the necessary cabling inside the RF-tight enclosure at the bottom of the cryostat. I attended our mission planning meeting with CSBF where we laid out our requirements and desires for the flight and worked on a model of the launch vehicle geometry so we can figure out how much height we have to play with.

At the end of the day, we started pre-cooling the cryostat, filling both the liquid nitrogen and liquid helium tanks with liquid nitrogen. This was uneventful, as planned, and the next day or so will be waiting for the relatively-isolated cold optics inside the cryostat to cool down.

Also, cowboy hats are awesome. I'm pretty sure I'm going to buy one tomorrow.


Tuesday, April 7, 2009

Day 13, 4/7/09 -- tilting at wind turbines

After yesterday's long day of cryostat work, we decided to sleep in a bit. The day started off with excellent breakfast burritos that Jeff and I made at our house which included a beef chorizo made with awesome bits of the cow that you don't normally eat like salivary glands, lymph nodes, tripe, and cheek/tongue fat. Needless to say, it was delicious.

Today was mostly meetings for me. We rolled into the high bay at around noon, just in time for our weekly collaboration-wide conference call. Then, we had another conference call about gondola-specific issues, and then we had a meeting with the CSBF staff to work out some issues regarding the launch clearance of our payload to their launch vehicle and some other logistical stuff. We then switched the cryostat from its vacuum roughing pump to a turbomolecular pump so it would pump to a lower pressure.

On other fronts, Britt and Michele finished up the work on the flight computer crate and we should be ready to start scan tests tomorrow. Shaul instructed Joy and Daniel on positioning gondola housekeeping thermometers while Jerry worked on our flight batteries. I have no idea what Hannes, Ilan, or the McGilligans (Kevin and François) did today, but I'm sure it was important.

Milligan, Jeff, and I then took a little field trip out to the wind farm that we can see from the airport. Armed with Google maps and satellite imagery, we were determined to find our way along the dirt roads and get to the wind turbines. We found that Google maps is almost completely worthless for this sort of thing. Most likely their data is simply out-of-date, as many of the roads and intersections we were looking for simply didn't exist. Still, after about a half hour of taking turns that pointed us more-or-less in the direction of the wind farm, we got there.


Wind turbines are awesome. First, they're enormous. They look big on the horizon, but they're even more imposing when you're standing at the base. Second, they produce a ridiculous amount of power. Turns out that the one turbine nearest the road had its door just...wide open. So, naturally, we went inside. We found a monitor that was displaying some GE turbine control software, and found that the keyboard tray was, not surprisingly given the state of the door, unlocked. So, naturally, I clicked around, and found a "General Data" menu item. Upon opening, I was rewarded with a display of some statistics about the turbine, like Power generated (1520 kW), coil voltage (~340V), current (1400A), etc. I decided not to play around with the control menus, figuring that it might actually be possible for me to break a multi-million-dollar wind turbine.

After we got back from our little field trip, Jeff and I leak-checked the cryostat. Because the pressure was still pretty high, we didn't have particularly good sensitivity, but we weren't able to find any leaks -- good news. We'll leak check again just tomorrow when the pressure is lower just to be sure.

To make this day even better, when we got home Jeff found cowboy hats in the closet in his room.

Pictures (mostly of wind turbines, because, let's face it, THEY ARE AWESOME):

Monday, April 6, 2009

Day 12, 4/6/09 -- the cryostat strikes back

Well, it was too good to be true. Work on the cryostat had been progressing fairly steadily and without too many mishaps. Today we had planned on closing the cryostat and starting to pump on it in preparation for cooling it. In the morning, we envisioned at about 10AM that it would take a few hours to get everything closed and we'd take an early night. I started writing this post at nearly 1AM and we're still here.

The first issue that came up was relatively simple. We had issues getting the instrument in properly due to some concentric baffling that has to nest together, but any angle between them screws the whole process up. Somehow, when we did this last time, it all just worked on the first try. This time, we had many fits and starts as the angles weren't quite right, so we had to tweak the angle with our Science Brick (a.k.a. a 26-lb tape-wrapped lead brick) and try multiple times.

Eventually we got it in...and we realized we had forgotten to plug in one of the housekeeping connectors, which required removing the instrument from the cryostat and plugging it in. After fixing that, Ilan checked wires and found that some of our fridge heater wires had opened up, meaning we wouldn't be able to cool our optics to 1K -- an unacceptable situation. So we spent the next 2 hours fixing wires.

Once we fixed all of the wiring issues, all that was left was to put the various shell lids on, seal the last o-ring lid, and pump, so we blasted some heavy metal in the high bay and got to work.

It's now 2:30 AM and we just started the vacuum pump. We pump through a restriction at first so as not to damage the delicate thermal filters via differential pressure, but eventually we will remove the restriction and let the cryostat pump directly into the pump so it will pump faster.

All in all, the problems we faced today weren't actually any worse than ones we've faced before -- it's just that much more frustrating when the end is in sight.

I'm not putting any pictures up in the post because I'm feeling a little lazy. You'll just have to click through to the pictures:

Sunday, April 5, 2009

Day 11, 4/5/09 -- shackle, shackle, shackle

Say it really fast -- it's fun, isn't it?

Weather today: Clear, chilly, and a bit windy. New Mexico is significantly colder than I thought it would be, in general.

After yesterday's debacle with the half-wave plate (HWP) anti-reflection coating (ARC), we tried to see if there was some way we could salvage the ARC on the side that had only begun to come up a little at the edge. We took some of the separated ARC and tried to tape it with various types of tape down to a disk of fused silica, but neither of them held when cooled to 77K. We made the decision to completely remove the ARC from the HWP, and after removing the residue left from the ARC, Jeff got the HWP mounted in the cryostat.

We also basically have completed the ≤ 1K portion of the instrument. Ilan has to run a few more tests on our thermometry, and we can then put it into the cryostat, close it up, and start pumping. Hopefully this will all happen fairly early tomorrow and we can have a nice, relaxed evening.

Michele and Britt got the flight computer crate up and running (yay!) and are working out whatever kinks they introduced by pulling it apart completely, redoing all the wiring, and putting it back together. Joy and Daniel got the secondary hexapod mounted on the gondola and made measurements of the primary hexapod geometry. Jerry, Joy, and Daniel started painting the gondola with emissive white paint -- and I have to say it looks pretty good. Daniel enjoyed the crane ride in his safety harness too.

We had a meeting today to discuss the state and plans for the next few days. It seems that everything is moving along well -- no major disasters or showstoppers in the works, as far as we can tell. Also at one point in the afternoon, Kevin, Hannes, Ilan, and I took a break to shoot some hoops on the very deformed basketball hoop outside the high bay. I beat Hannes at Pig, Hannes and I beat Kevin and Ilan in 2-on-2, and then we switched it up and Hannes and Ilan beat me and Kevin.

What I'm most excited about is now having SolidWorks installed on my laptop. This computer is so much faster than any of the other computers that we have running SolidWorks that it literally makes me giddy. I was just giggling to myself and marveling at how fast the gondola baffle assembly would update when I spun it around on the screen. Did I mention that I love technology?

Pictures plus bonus video:

Saturday, April 4, 2009

Day 10, 4/4/09 -- the boss-man cometh

Today was clear and sunny, but VERY windy. It almost makes you wonder why they even try doing balloon launches from here.

Shaul, the project PI and my boss, arrived in Ft. Sumner today. The first order of business was to inspect the half-wave-plate's new anti-reflection coating (ARC) that I mentioned in the last entry. Even on initial inspection, it was clear that something wasn't quite right -- the ARC on one side was already starting to delaminate from the surface at some points around its edge. It was decided that we'd try cycling the half-wave-plate to liquid nitrogen temperature (77K) and observe what happens. During this process, the side that was already delaminating came off completely, and the other side started to peel up at the edge. It's unclear what our next steps are, but we have some tests we'll do tomorrow that will hopefully illuminate our path forward.

Hannes spent all of today wrestling with detector wires. We decided that it would make his life easier if we made some modifications to one of the parts in the wiring RF-protection assembly, so I took the part to the milling machine in the hangar machine shop and proceeded to make some very ugly but functional cuts to the part. It was a challenge to use a machine without digital readouts on the axes, but I think I was able to pull it off. After these modifications were made, Hannes was eventually able to get the RF-protection assembly in place.

Britt and Michele continued work on the flight computer crate while Kevin and François worked more on detector readout electronics. Ilan tested some of the cryostat's low-temperature thermometry readout electronics, and Jerry, Daniel, and Joy started to put on the star camera baffle but had to stop when I reminded them that it needed to be painted before installation. Later in the day, I showed Daniel and Joy how to use our Microscribe Coordinate-measuring arm and they used it to measure the hexapod geometry (as well as their faces and hands).

In other news, I talked to some of the Berkeley group working on NCT in the hangar. Seems like a cool bunch -- not surprising, given that they're from Berkeley (go Bears). The FIREBall team has set up a cleanroom/darkroom in their area of the high bay -- their near-UV detector is sensitive to NUV emission from the high bay lights, so they had to cover their portable cleanroom with tarps that they conveniently used in shipping their experiment.

Sign #4 that you know you're working too much: You go to find Hugo, the CSBF engineer only to find an empty room with none of the CSBF people around, and only then do you realize that it's Saturday.

And then you wonder why they're not there.


Friday, April 3, 2009

Bag o' spheres

We now have a series of tubes connecting our little house to the rest of the prairie, not to mention the big city.

I love technology.

Day 9, 4/3/09 -- on the road again

Today started off well-enough. The weather is getting better and better -- today we had about 75ish degrees, clear skies, and moderate wind. And, our liquid helium arrived from Waxahachie, TX (the home of what was to be the Superconducting SuperCollider). 1000L of liquid helium, and only a little bit of waiting.

Then, I got a call from UPS. Cardiff sent our half-wave-plate via international priority shipping to Albuquerque. We had intended for them to ship it via FedEx to a FedEx sorting/distribution facility; the plan was that either Shaul would pick it up on Saturday before driving to Ft. Sumner, or if we needed it sooner, I would drive out to Albuquerque on Friday to pick it up. Sounds simple enough, right? Wrong.

The half-wave-plate was shipped via UPS international. No problem, right? Wrong. The address on the package was the FedEx sorting facility. UPS tried to deliver it to FedEx, and I'd imagine much hilarity ensued, culminating with FedEx basically saying "Uh, we don't want it". Hence the call I received from UPS -- the package was on the driver's truck, and would be available to pick up at UPS between 6-8 PM.

So it turns out that Jeff didn't need the half-wave-plate until Saturday anyway, so we figured Shaul could just pick it up before driving to Ft. Sumner. No problem, right? Wrong. Unlike FedEx, the UPS distribution center is closed on the weekend. If we didn't pick it up today, between 6-8 PM, the next chance would be Monday -- an unacceptable delay. So...I had to drive out to Albuquerque to pick it up. If you look up "snafu" in the dictionary, I'm pretty sure you'll get a story very similar to the one above.

In between talking to UPS and getting in my car, I worked on getting the window closed (not done yet) and helping Jeff with a part for his shaft assembly. Jeff continued working on the shaft installation; after I left he and Milligan worked on the computer control of all his various motors in the half-wave-plate assembly. Hannes struggled with getting 1o lbs of crap into a 5 lb bucket (i.e. connecting 7 connectors in a space that comfortably fits maybe 4 and then closing it all up in an RF-tight way). I honestly have no idea what happened with the gondola/ACS crew.

Of course, because it was Friday, we went to the hamburger stand -- I got the catfish. It was quite good, though I have to say I like the shrimp better. In Albuquerque I called my friend Chris in Minnesota to give me a recommendation for a pizza place -- as there is no pizza in Ft. Sumner, I figured it was something that would be appreciated by people here. After some consulation with Yelp, he pointed me to Giovanni's, which was indeed an excellent pizza, and I brought most of it back with me to share with the meat-eating part of the crew.

Not too many pictures today -- not surprising since I spent about 6 hours of today on the road (including missing the turn-off for Hwy. 84 in Santa Rosa while talking to my mom on my cell phone).

Day 8, 4/2/09 -- work. What else?

Today we had the best weather yet -- about 65, perfectly clear and sunny with only a moderate breeze. For much of the afternoon we worked with the high-bay door open. Hannes continued getting the focal plane together, Jeff mostly worked on his shaft assembly, and I worked on the optics stack. Kevin and François continued work on detector readout electronics, while Britt and Michele's assault on the flight computer is hitting the home stretch. Jerry, Joy, and Daniel mounted the star camera on the gondola.

Because the weather was so nice, I decided to go for a little bike ride. I started off in one direction but was thwarted by a dirt road (I have a Fuji road bike with skinny tires). I then headed into town, intending to go past and see what lies west of the town, but once I got to the main intersection I noticed the telltale sounds of a flat tire. I knew it wasn't going to hold air for any length of time, so I ended up walking the ~3 miles back to the high bay.

After my failed bike ride, I pulled a major boneheaded move. I accidentally put a hole in one of our extremely thin (4-micron polypropylene) so-called 'thermal' quasioptical filters. The hole is small, and it's located in a place we can work around (hopefully), but I felt like a total idiot.

We also found out today that, besides having an unnatural fondness for goats, Jeff also hates The Police (the band, not the law enforcement agencies). Therefore, his opinion on music no longer holds any weight with me.

I noticed that a couple of vending machines have found their way around the site -- one in our high bay and one in the hangar. This is notable for two reasons: 1, they will apparently have Pepsi. I love Pepsi, and it seems Pepsi is sold nearly exclusively in this town (er, village) which pleases me greatly. 2, next to the one in the hangar, I spotted a grill. I may never get any work done again.


Thursday, April 2, 2009

Day 7, 4/1/09 -- Just talkin' 'bout shaft.

Damn right.

Today was Ilan, François, and Kevin's first day in Fort Sumner. They all got right to work on cryostat housekeeping and detector readout electronics. Jeff started with the assembly of the half-wave-plate driveshaft assembly, a slightly convoluted piece of hardware that allows a motor from outside the cryostat at 300K in the ambient environment to turn the half-wave-plate at 4K in vacuum. It's a tricky bit of 'kit' (as Will might say), with multiple bearings, flexible couplings, low-thermal-conductivity shafts, etc.

Before Ilan left Minnesota, he had sent a shipment via FedEx Freight with some additional hardware that we needed to close up the cryostat. Unfortunately, since Fort Sumner is a small town (in fact, a 'village', as Daniel likes to point out), FedEx decided that they didn't want to drive a truck from Roswell (yes, THAT Roswell) 80-some-odd-miles north to us just to deliver our shipment. They were planning on gathering up a few more shipments and driving it up tomorrow. I told Jeff we wanted our stuff ASAP, so he and Daniel drove the hour and a half to the FedEx facility to pick up the shipment.

Around the same time, Jerry drove out to Albuquerque to pick up Hannes, who got in around 6PM. Once they returned, they got right back to work -- Jerry on the star camera, and Hannes on the focal plane array of detectors that he brought with him in his luggage. I started putting the final bits on the optics stack assembly -- I ended up having to sand smooth an o-ring mating surface that had been scratched up inadvertently as well as make an o-ring to replace one that had been forgotten in MN.

On the base, the final experiment arrived. Called NCT, they're in an older high bay in the hangar building. It's much much crappier than the one we're in. And the Columbia crew got in a new set of computers that will be used for flight operations -- two computers with three 22" widescreen monitors between them (two on one, one on the other).

The new guys went to the burger stand for lunch and had what they claim were completely flavorless burritos. They were happier with Fred's in the evening.

Wednesday, April 1, 2009

Day 6, 3/31/09 -- If I see a "goat for sale" sign...

Jeff is, for some reason, obsessed with goats. He would like to own one and milk it. I just smile and nod.

The high bay is getting more crowded. On Monday, more of the CSBF crew arrived from Palestine, TX, and now they've started setting up in a heretofore unused corner of the high bay. In addition, three more EBEX team members arrived late tonight from Minneapolis and Montreal.

Today in the high bay was fairly relaxed. Jeff did some work on the half-wave plate stuff and fixing some threaded holes in some hexapod parts. Britt and Michele continued their heroic efforts flight-readying the flight computer crate while Daniel and Joy routed cables around the gondola. At the end of the day, we mounted the hexapod for the primary mirror onto the inner frame along with some extra weight to simulate the mirror. Maybe tomorrow, the secondary hexapod will go on?

In other news, I received a snazzy lens for the Fuji S3 Pro digital SLR that I'm borrowing from my little brother. On loan from my mom, this 70-200mm f/2.8 ED VR lens is AMAZING. I can't wait to try some night sky shots with it. Using a camera and lens like this makes me REALLY want a DSLR. Unfortunately, the lens alone is $1700. Ouch.

Our phone line in the high bay was installed today as well -- about an hour too late for our two conference calls. It will definitely beat having to huddle around a cell phone on speaker for conference calls in the future.

The best part about today, apart from the awesome lens arriving, was that Milligan, Jeff, and I moved into our new digs on Real Wind Drive in Old Fort Sumner. Not only that, we held a little dinner party to inaugurate -- I grilled up some steaks topped with crumbled blue cheese, Jeff made some delicious potatoes, and Michele made a great tomato and mushroom sauce to go with some not-so-great store-bought pasta. Regardless, it was the best dinner I've had yet here in Fort Sumner. I think I'm going to like living in a house rather than a motel. We might even have internets by the end of the week.

We have a couple more leads on non-motel housing as well. It turns out that if you need anything, the person to talk to is Dorothy Moyer who works here at the airport. Within a day of Britt telling her that we were looking, she came with two or three contacts who had places available. The plan is to have everyone who's more-or-less here for the duration of the campaign in real housing, while those who are here on a shorter-term basis can make do at the Super 8.

Bonus video in the picture album today!