8:00 am: NCT launched about half an hour ago and already is up 13 km. We’ve got another couple hours before we reach our final float altitude (25 miles/40 km). In the meantime, we’re watching the telemetry and checking that our systems are working as expected… You can track our flight path here.
8:40 am: Still heading up. Shield and detector rates are high, as expected–we’re shortly to pass through the Pfotzer Maximum.
12:00 pm: At float, pointing at the Crab, our primary science target. We’re having problems with the pointing system. We’re able to keep in the field of view, at least.
1:45 pm: Quieter here. Most people have gone home to sleep, with just a few of us left to monitor the data and take care of the pointing. Manual pointing appears to be working generally, although the data analysis will be significantly less fun. NCT is heading slowly southwest; no word yet from CSBF on an estimated flight path. We’re going to have to turn west pretty shortly to go through the night, I suspect. We were able to see the balloon overhead, though–pretty cool!
4:00 pm: Shift change, for those whose presence can be spared. Thankfully the rest of us don’t have to play the video game of “keeping the source on target.” I’m starting to look longingly at an inch-thick slice of insulating styrofoam propped up in the corner…
5:30 pm: Ah, even a little sleep in the CSBF lounge helps a lot. Since I never know when I’ll have a good napping opportunity, I can’t really even resort to caffeine…
7:00 pm: A stay for NCT? When we passed over some mountains, we dropped altitude and caught a different wind pattern which is pushing us back north. Current hope is to fly through the night–we’re discussing sending our crew downrange to extend our telemetry range. Given our need to point manually, this would be crucial. We’re switching to some alternate targets for the immediate future–the Crab is now low enough to be attenuated fairly strongly by the atmosphere.
8:15 pm: We just took a last look at the balloon at sunset. It was simply gorgeous as the light caught it. We were able to find with our theodolite’s telescope. The balloon had more of a diamond shape, and we could see the ribs and even the gondola dangling below…
NCT is heading north at the moment, so we’re prepping for an overnight run. The downrange crew led by McBride will depart for Winslow, AZ later this evening. As for me, I hope to head home for dinner and a bit of sleep shortly…
6:00 am: Back at the hangar, and the news isn’t so good. The overnight crew had to turn off the gondola power last night because the voltage supplied by our batteries was dropping. (Unfortunately, we had lost our detailed power housekeeping data midafternoon yesterday.) Our best guess is that one of the two batteries went bad and the other was depleted, because there should have been plenty of power to run through the night. We’re going to turn on the power again once we think we can get enough power from the Sun.
The other bad news is that CSBF is going to cut us down in an hour or so. While we’ve had a very fortunate flight path and are still far from the hard boundaries of Mexico and California, we are nearing Pheonix airspace, which we need to avoid. Also, it sounds like China Lake is planning a GPS jamming exercise for this morning, which is quite frustrating. (This happened to HEFT in 2005 also, apparently.)
One bright spot in all of this was that our automatic pointing was functioning during the night last night, giving support to the theory that there’s a thermal issue with a couple of gauges in the rotor that was blowing the feedback loop in the daytime. We’ll certainly be doing lots of tests on our return to Berkeley.
We’ve gotten over 20 hours at float already, so by all accounts this was a very successful flight. We’re particularly proud of the flawless performance of our detectors and their electronics as well as the nearly error-free performance of the flight code.
6:20 am: Trying to turn on the flight computer–the electronics bay is quite cold after having had everything off all night.
7:20 am: System is up! We were definitely cheering when we started getting downlinked data again. We got the flight computer started first, then ran the heaters for a bit in order to get the card cages going. Presently we’re pointing at the sun and charging the batteries, both of which appear to be working! This was a really good experience for longer flights to be sure we can take the system up after it’s been cold.
Apparently we weren’t the only ones impressed by our balloon’s appearance at twilight last night–check the links in the comments below for video of the balloon as seen from El Paso. Thanks, Luis, for finding these!
7:50 am: Woohooooo! Just got news that CSBF can let us fly quite a bit longer–we may cut down more like 4:00 pm! The GPS jamming may still complicate our lives, but we’ll do our best. Power looks good, we’re turning to Cygnus X-1 to take some data.
10:00 am: The Crab is coming back into the field of view! We’re pointing at the Sun for now, and in a few more minutes hopefully we can start nulling on the Crab itself. We’re getting close to losing line-of-sight telemetry, but McBride and company are set up and ready to go downrange in Winslow, AZ. (The loss of LOS is giving us a bunch of momentary heart attacks, because the values coming down in housekeeping are occasionally bizarre, but we figure out what’s happening pretty quickly.) We’ve also done some background tests by putting our BGO shields in “soft-veto” mode.
11:00 am: Rotor’s holding fairly steadily near the Crab. We’re keeping an eye on it–we lost automatic pointing about this time yesterday.
12:15 pm: Problems with the power systems. The batteries appear to be shot while the solar panels are giving strange values, so the total power to the system is sagging dangerously low–we think the power control unit is confused. We did a total system turn-off to see if it changed, but it came up as before. We’re just going to try to run until we start seeing abnormal behavior from the detectors. Balloon science: edge of your seat (of the pants)!
Pointing is offset at the moment but steady. We’re just trying to get as many counts as we can…
1:15 pm: System is off due to power problems, likely permanently. Unfortunately, we were just approaching our period to observe the Crab: the three hours when it was at highest elevation. Still, we weren’t expecting to get any data today, and we managed some solid pointing. CSBF is thinking about cutdown points, and our downrange team has left to go try to meet the recovery team.
1:30 pm: Cutdown estimated for 6:00 pm due to current proximity to Pheonix. CSBF will be looking for cutdown opportunities; we’re not going to turn on again.
5:45 pm: Still waiting for word on cutdown–we’re flying over some rough terrain. Sounds like there’s a thunderstorm coming into Arizona–hope NCT can handle a night outside! On the other hand, if we keep heading north, the recovery team can stop by the Grand Canyon… We’ve been at float almost 32 hours now, an extraordinary flight–particularly because the preflight forecast suggested we might only get eight hours or so!
7:15 pm: Still up–CSBF is actively looking for places to put us down, but the rough terrain and the thunderstorm have complicated their efforts. According to this unofficial tally, we’re already the longest-flying conventional flight from Ft. Sumner… CSBF and our recovery team have met and are finding hotels in Arizona. We’re going to dinner–it’s a bit unsettling having this hanging over our heads…
9:45 pm: We just received word that CSBF is going to cut us down shortly.
10:18 pm: NCT has landed! The CSBF pilot has confirmed that NCT is on the ground about 30 miles southeast of Kingman, AZ. Visual inspection will have to wait for late tomorrow when the recovery crew arrives.