Date: Tue, 3 Sep 2002 22:17:15 -0400 From: Kimberly Strong To: MANTRA email list Subject: MANTRA 2002 - Tuesday, September 3 Status MANTRA 2002 - Tuesday, September 3 Status It has been a day of ups and downs, in several ways. Briefly, here is a summary of the flight and instrument performance - people have been busy through the day, diagnosing the instruments' performance and reacting in real time. We are still digesting all the data, although in a rather tired state. - the last ozonesonde launch was made yesterday, reached 42 km - a nice launch at 2:02 AM (8:02 AM UT) - the weather finally cooperated - had some telemetry dropouts for the first few km, fixed by moving ground antenna - one emission radiometer worked well on ascent, the other failed during the LN2 fill on the gondola prior to launch - the two ozonesondes worked well on ascent - lost azimuth control of pointing system at ~2:45, but recovered it at 5:00 AM by resetting STARS power system - 3:30 aerosol backscatter sonde launched, worked well - SAOZ acquired good sunrise solar occulation data - DU FTS saw sun briefly at sunrise before the azimuth top mount seized up (not clear whether this was due to a seized bearing or freezing of the azimuth top mount - we could tell from the onboard video camera that the mount was not rotating) - unable to do sunrise occultation measurements - 7:40 AM began limb scanning measurements with SPS-B1 and MAESTRO-B UV and visible channels - ~10 AM azimuth top mount began rotating again, so pointing system could control the gondola - 10:30 began opening the balloon valve to release helium in order to descend by 1-2 km, hoping to reach an altitude of lower winds based on sonde data - then began getting good solar spectra from the OH spectrometer - 10:40 MSC FTS obtained some spectra at high sun - 1:35 MAESTRO visible channel regained signal after an hour off - 2:00 DU FTS regained signal after apparently overheating in the morning - Ben tuned pointing system parameters during the afternoon, obtaining 0.5 degree control in azimuth or better - continued to release helium in the afternoon, but winds at lower altitudes were higher than expected (up to 42 mph), and mostly heading east - it was unclear whether we would be able to obtain sunset solar occultation measurements before the balloon left our telemetry range and had to be cut down - float altitude varied from ~38 km in the morning to ~34 km after valving down - video cameras aligned with the pointing system and pointed at the gondola provided interesting footage of the balloon and instruments at float - SPS-B2 made J-values measurements throughout the day - ~5 PM spotter plane went out in pursuit of the gondola - ~5 PM winds veered southwards and slowed, making it possible for us to make sunset measurements - 5:30 reacquired solar pointing with the pointing system, but lost it again at 6:20 - the large torque required seems to have tripped the circuit - reacquired the sun at 7:35 PM (-2 deg to -5 deg) and took sunset data with OH spectrometer, SPS-B1, SPS-B2 in direct sun mode, MAESTRO, DU FTS, MSC FTS, and SAOZ - final measurements finished up at ~8 PM local time Dale plans to terminate the flight soon after sunset when it moves to an easier recovery area. The recovery truck is on its way and we may have the payload back at Vanscoy tomorrow. We are now starting to pack up and most members of the science team are heading home tomorrow Wednesday. The ground-based instruments will be packed up after final sunrise measurements tomorrow. This will therefore be my last MANTRA 2002 update from Vanscoy. Many thanks to the science and launch teams for all their hard work over the past couple of weeks and before. All for now. Kim MANTRA Home Page: http://www.atmosp.physics.utoronto.ca/MANTRA/ MANTRA 2002: http://www.atmosp.physics.utoronto.ca/MANTRA/mantra_2002.html ---------------------------------------------------------------- Dr. Kimberly Strong, Associate Professor Department of Physics, University of Toronto Room MP 710A, 60 St. George Street Toronto, Ontario, M5S 1A7, Canada Telephone: (416) 946-3217, Fax: (416) 978-8905 Email: strong@atmosp.physics.utoronto.ca http://www.atmosp.physics.utoronto.ca/ http://www.atmosp.physics.utoronto.ca/people/strong/strong.html ----------------------------------------------------------------