Today Kyle and I opened up the cryostat and started the disassembly and shipping preparations for the cold stuff -- removing SQUID controller boards, SQUID mounting boards, the instrument insert, and the half-wave-plate system. Kyle spent most of the afternoon then disassembling the instrument RF-shielded wiring towers while I disassembled and packed the half-wave-plate system.
On the north side of the high bay, the Columbians were hard at work packing up all of their stuff to be packed into shipping containers. In the afternoon, Britt was able to piggyback on one of the CSBF Bemco tests and verify that the new power system isolation diodes were sufficiently-well heatsunk -- and they were, to the tune of a 60-degree safety margin!
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120831
Friday, August 31, 2012
Day 94, 8/30/2012 -- High cube packed
The high cube container with most of the gondola bits is packed and ready for fumigation (Friday) and shipping to Port Hueneme (Saturday) for its eventual date with a boat -- and it was done about 20 hours ahead of schedule!
The gondola team has started packing up their equipment and have made a fair amount of progress. We still have to wait until the cryostat is warmed and fully prepared for shipping, as we will likely need many of the tools and other supplies as we do that. Still, Kyle successfully manged to get our CANBus programs working on his laptop and we made some wiring, both of which will help facilitate our Bemco tests next week.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120830
The gondola team has started packing up their equipment and have made a fair amount of progress. We still have to wait until the cryostat is warmed and fully prepared for shipping, as we will likely need many of the tools and other supplies as we do that. Still, Kyle successfully manged to get our CANBus programs working on his laptop and we made some wiring, both of which will help facilitate our Bemco tests next week.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120830
Wednesday, August 29, 2012
Day 93, 8/29/2012 -- Pack it up, pack it in, let me begin
Today we made a massive amount of progress in packing the experiment for shipping. We started early -- Britt and Michele at 6:30AM -- to get the gondola ready for the removal of the cryostat and the disassembly of the inner/outer frames. Kyle and I showed up at 7:30 to assist with cryostat removal, which went very smoothly.
After that, we then got the inner frame removed from atop the outer frame and set on the ground. At that point, Kyle and I went to attend to some matters with the cryostat (empyting its helium tank of liquid nitrogen to allow it to warm up further, backfilling with nitrogen gas, and wrapping the exterior with heater straps) while Britt and Michele proceeded to remove components from the gondola (flight computers, cables, sensors, etc).
Once Kyle and I finished the immediate cryostat work, I went back over to the gondola to assist in the disassembly whilst Kyle immersed himself in the vagaries of CANBus on Linux in preparation for our upcoming Bemco testing of various components.
Michele, Matt, and Kevin then left a little after 11AM; Britt and I then continued working on gondola disassembly and awaited the arrival of the riggers to assist us in loading the inner and outer frames into our large shipping container. They arrived around 12:45 and we had both large pieces plus the "triangle" spreader bar loaded into the container by 1:45, give or take a few minutes.
Britt and I continued to load things into the container for the remainder of the day. Kyle took a break from CANBus around 4PM to fill the helium tank with warm water to accelerate its warming, which causes it to reach 273K (ice water temperature) nearly instantly. The cryostat has been left to complete its warming overnight.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120829
After that, we then got the inner frame removed from atop the outer frame and set on the ground. At that point, Kyle and I went to attend to some matters with the cryostat (empyting its helium tank of liquid nitrogen to allow it to warm up further, backfilling with nitrogen gas, and wrapping the exterior with heater straps) while Britt and Michele proceeded to remove components from the gondola (flight computers, cables, sensors, etc).
Once Kyle and I finished the immediate cryostat work, I went back over to the gondola to assist in the disassembly whilst Kyle immersed himself in the vagaries of CANBus on Linux in preparation for our upcoming Bemco testing of various components.
Michele, Matt, and Kevin then left a little after 11AM; Britt and I then continued working on gondola disassembly and awaited the arrival of the riggers to assist us in loading the inner and outer frames into our large shipping container. They arrived around 12:45 and we had both large pieces plus the "triangle" spreader bar loaded into the container by 1:45, give or take a few minutes.
Britt and I continued to load things into the container for the remainder of the day. Kyle took a break from CANBus around 4PM to fill the helium tank with warm water to accelerate its warming, which causes it to reach 273K (ice water temperature) nearly instantly. The cryostat has been left to complete its warming overnight.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120829
Tuesday, August 28, 2012
Day 92, 8/28/2012 -- Warm it up, Kris
Another busy day in the high bay as we prepare to pack up and ship the experiment to the ice. First Kevin and I took a little bit more data through our downlink system at various rates while scanning to get a handle on how to deal with our signals as we will see them. Then, I regripped the half-wave plate and boiled off the rest of the helium in the tank. In order to warm up the instrument as quickly as possible, we then refilled the tank with liquid nitrogen to bring it up to 77K nearly immediately. The internals of the system (the lenses and detectors, mostly) still have to warm up, so we left it at 77K for the rest of the night.
We then removed all of the detector readout electronics and associated hardware from the gondola in preparation for the removal of the cryostat tomorrow and the disassembly of the inner/outer frame.
No pictures today, and likely not many for the next few days -- we're facing a pretty tight shipping deadline for our large shipping container (Friday!) and it has to have ALL of the large gondola items in it before it leaves. I'll try, though!
We then removed all of the detector readout electronics and associated hardware from the gondola in preparation for the removal of the cryostat tomorrow and the disassembly of the inner/outer frame.
No pictures today, and likely not many for the next few days -- we're facing a pretty tight shipping deadline for our large shipping container (Friday!) and it has to have ALL of the large gondola items in it before it leaves. I'll try, though!
Monday, August 27, 2012
Day 91, 8/27/2012 -- Get low
Today was a pretty busy day for us in the high bay. First thing in the morning, Jeff and I added a little bit of liquid helium to the cryostat so it didn't run out during the day. We then helped Michele remove the legs off the gondola to bring it down to a more manageable height to help facilitate the testing we were planning on doing during the day.
We then set up some hardware above the cryostat in order to repeat an experiment we did a few days back but hopefully get higher signal to noise -- and boy, did we ever. Our previous attempt used a small, millimeter-wave-absorptive chopper blade that alternately covered and uncovered a bit of bare aluminum, and gave us a small but measurable signal. This time, we had a big absorptive chopper blade that repeatedly eclipsed a large styrofoam cooler filled with absorber and liquid nitrogen. Instead of a few tens to a hundred counts of signal, we saw a thousand, and we clearly saw signals in every detector. So we set up our first experiment and then went to lunch.
Over lunch, Michele, Jeff, and I talked with a member of the SuperTIGER team about his experience recovering another payload, BESS, that had a similarly large and unwieldy main element -- in our case, the cryostat; in theirs, their magnet. It was an enlightening experience -- especially the part where he said they camped on the ice for 13 days while they disassembled the experiment!
Of course, having such a huge signal-to-noise can be a blessing and a curse, because then you can imagine many other experiments to do with more or less the same setup -- so what we had planned to be a 2-3 hour experiment ended up lasting the whole day as we did various incarnations of the experiments.
Matt was kind enough to organize a grillin' out on the patio area at CSBF and took it upon himself to cook and otherwise prepare a nice little social gathering before many people leave tomorrow.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120827
Bonus video (albeit overexposed and with jerky zooming and focusing) of the big chopper blade spinning:
https://vimeo.com/48345134
We then set up some hardware above the cryostat in order to repeat an experiment we did a few days back but hopefully get higher signal to noise -- and boy, did we ever. Our previous attempt used a small, millimeter-wave-absorptive chopper blade that alternately covered and uncovered a bit of bare aluminum, and gave us a small but measurable signal. This time, we had a big absorptive chopper blade that repeatedly eclipsed a large styrofoam cooler filled with absorber and liquid nitrogen. Instead of a few tens to a hundred counts of signal, we saw a thousand, and we clearly saw signals in every detector. So we set up our first experiment and then went to lunch.
Over lunch, Michele, Jeff, and I talked with a member of the SuperTIGER team about his experience recovering another payload, BESS, that had a similarly large and unwieldy main element -- in our case, the cryostat; in theirs, their magnet. It was an enlightening experience -- especially the part where he said they camped on the ice for 13 days while they disassembled the experiment!
Of course, having such a huge signal-to-noise can be a blessing and a curse, because then you can imagine many other experiments to do with more or less the same setup -- so what we had planned to be a 2-3 hour experiment ended up lasting the whole day as we did various incarnations of the experiments.
Matt was kind enough to organize a grillin' out on the patio area at CSBF and took it upon himself to cook and otherwise prepare a nice little social gathering before many people leave tomorrow.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120827
Bonus video (albeit overexposed and with jerky zooming and focusing) of the big chopper blade spinning:
https://vimeo.com/48345134
Sunday, August 26, 2012
Day 90, 8/26/2012 -- Downlink demons
The main issue we've been dealing with here in these last few days of having an integrated experiment is making sure we can downlink data reliably through CSBF hardware. Obviously, while in flight, we can't have any cables connected to the gondola to carry our data down, so we rely on CSBF to provide various sorts of telemetry links (a line-of-sight high-rate 1Mbps transmitter, a 92 kbps TDRSS high-rate transmitter, a 6 kpbs TDRSS low-rate transmitter, and a very slow Iridium system). The challenge for our software is to be able to deal with these data streams whose data rates vary hugely along with a dynamic allocation of which data we want to see over these streams and their update rates, which we plan to vary during the course of the flight (for example, during fridge cycles we want to make sure to downlink all of the fridge-related data, but all of those data are not super important when we're taking science data. So we need to be able to choose which channels to downlink when in order to optimize getting the most relevant data at a given time over our limited data rate connection).
So...this is hard. And it mostly works! But not quite completely. So the order of business for the past few days has been to try and work with this system as much as possible to try and work out the kinks so we (meaning Seth, our resident expert on this software who has left Palestine and is now working remotely) can get working downlinks. Still a work in progress.
Simultaneously, the gondola is slowly being disassembled as much as possible in preparation for the full disassembly. Today, Britt and Michele removed the flight power system and we went back to a scaled-down system so they can take the gondola legs off tomorrow.
Jeff and I also made progress in preparing to repeat a calibration experiment we did a couple days ago. The previous test seems to provide meaningful results, but the signal-to-noise ratio is a little low. We've thought about the experiment a little more and have devised a way to increase the signal in the experiment and have laid the groundwork for making this happen tomorrow first thing.
No pictures today.
No
So...this is hard. And it mostly works! But not quite completely. So the order of business for the past few days has been to try and work with this system as much as possible to try and work out the kinks so we (meaning Seth, our resident expert on this software who has left Palestine and is now working remotely) can get working downlinks. Still a work in progress.
Simultaneously, the gondola is slowly being disassembled as much as possible in preparation for the full disassembly. Today, Britt and Michele removed the flight power system and we went back to a scaled-down system so they can take the gondola legs off tomorrow.
Jeff and I also made progress in preparing to repeat a calibration experiment we did a couple days ago. The previous test seems to provide meaningful results, but the signal-to-noise ratio is a little low. We've thought about the experiment a little more and have devised a way to increase the signal in the experiment and have laid the groundwork for making this happen tomorrow first thing.
No pictures today.
No
Saturday, August 25, 2012
Day 89, 8/25/2012 -- Packing begins
Kind of another grab bag of things going on today -- we have started to do some packing in earnest today, loading some of the larger crates (mirrors, in particular) into the CSBF cubical sea shipping containers. Michele also completed the removal of the LCS from the gondola -- it's basically at the bare minimum in terms of the hardware needed to do a realistic flight simulation.
Speaking of flight simulations, the bolo crew attempted another "launch/ascent" simulation today after the fridge cycle ended. Today's was more successful, but was hindered by our downlink software crashing often. This turned out to have been a disk issue, and replacing the downlink relay computer's hard drive with a fast solid-state drive seems to have fixed the issue.
We found another issue, though, possibly caused by our poking around in the power crate yesterday to fix the heater problem, so we have to investigate a little more tomorrow.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120825
Speaking of flight simulations, the bolo crew attempted another "launch/ascent" simulation today after the fridge cycle ended. Today's was more successful, but was hindered by our downlink software crashing often. This turned out to have been a disk issue, and replacing the downlink relay computer's hard drive with a fast solid-state drive seems to have fixed the issue.
We found another issue, though, possibly caused by our poking around in the power crate yesterday to fix the heater problem, so we have to investigate a little more tomorrow.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120825
Friday, August 24, 2012
Day 88, 8/24/2012 -- Flight simulations, take 1
We started off today with a discussion of the procedure and goals for our flight simulations, which will take up a majority of the time we have upcoming before we disassemble the gondola. After a roughly 2.5 hour discussion, we came up with a plan -- which, as the best laid plans often do, went awry.
We were stymied by a peculiar failure of our fridge heater channels, which was that they wouldn't heat. After going through the likely culprits on the software and heater power distribution end, we determined the problem was localized to the DC/DC converters that generate the appropriate voltages for the heaters. So, Shaul and I removed the power crate containing said DC/DCs, poked around inside a little bit, pored over schematics, and finally found a solution that works despite it being specifically something that the schematics and what meager documentation exist say explicitly should NOT work. BUT...it actually works in the way that we had wanted it to work in the first place, so we're not complaining. Now at 11:30PM, we just started a fridge cycle so the detectors will be ready to go by the morning's attempt at another flight simulation.
In other news, Michele tested our other solar array, and now both arrays have been disassembled and the panels safely packed into their shipping crates. He and Britt, who arrived back in Palestine today, also swapped out our elevation actuator to our other actuator just to confirm that it works after degreasing with low-temp grease -- and it turns out it works better than the first de/regreased one! We also got some parts back from the powdercoater that we had done at the same time CSBF had some of their parts done.
Pictures from today (just a few powdercoated parts):
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120824
We were stymied by a peculiar failure of our fridge heater channels, which was that they wouldn't heat. After going through the likely culprits on the software and heater power distribution end, we determined the problem was localized to the DC/DC converters that generate the appropriate voltages for the heaters. So, Shaul and I removed the power crate containing said DC/DCs, poked around inside a little bit, pored over schematics, and finally found a solution that works despite it being specifically something that the schematics and what meager documentation exist say explicitly should NOT work. BUT...it actually works in the way that we had wanted it to work in the first place, so we're not complaining. Now at 11:30PM, we just started a fridge cycle so the detectors will be ready to go by the morning's attempt at another flight simulation.
In other news, Michele tested our other solar array, and now both arrays have been disassembled and the panels safely packed into their shipping crates. He and Britt, who arrived back in Palestine today, also swapped out our elevation actuator to our other actuator just to confirm that it works after degreasing with low-temp grease -- and it turns out it works better than the first de/regreased one! We also got some parts back from the powdercoater that we had done at the same time CSBF had some of their parts done.
Pictures from today (just a few powdercoated parts):
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120824
Thursday, August 23, 2012
Day 87, 8/23/2012 -- Odds and Ends, part 2
This morning I drove Kyle to Dallas so he could go home for a weekend trip he had planned for some time. While I was gone, Jeff managed to get the BTS completely disassembled while Michele did a test of one of our two solar arrays (the second will happen tomorrow).
After I returned from Dallas in the afternoon, Jeff did a "quick" test that will help us be confident of the optics and polarization alignment in Antarctica where we won't be able to do scans of a polarized source on a water tower. When I say "quick", I mean, of course, it took 4 hours, but that's not bad for a test whose barest idea was the only thing that existed before today -- we worked out all the details, did the entire setup, and took all the data in those 4 hours. A nice productive way to end the day.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120823
After I returned from Dallas in the afternoon, Jeff did a "quick" test that will help us be confident of the optics and polarization alignment in Antarctica where we won't be able to do scans of a polarized source on a water tower. When I say "quick", I mean, of course, it took 4 hours, but that's not bad for a test whose barest idea was the only thing that existed before today -- we worked out all the details, did the entire setup, and took all the data in those 4 hours. A nice productive way to end the day.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120823
Wednesday, August 22, 2012
Day 86, 8/22/2012 -- Odds and ends
We continue to check items off our list and prepare the experiment for shipping to Antarctica. In the morning, our SIP was removed from the gondola, so now we are operating through the SIP simulator. This afternoon, Michele, Kyle, Jeff, and I removed the two mirrors from the gondola as they are no longer needed for any of the tests we plan to do. Shaul, Michele, and I then did a full and thorough test of our lock pin system after Shaul and Joy spent some time in the morning figuring out some of the preliminaries.
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120822
Pictures:
https://picasaweb.google.com/104253244018605213307/EBEXInPalestine20120822
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