HS3 - Global Hawk #872 09/08/11 - 09/09/11 Science Report

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Thursday, September 8, 2011 - Friday, September 9, 2011
Mission Summary: 

HS3 Flight 2011-09-08


The primary mission goal is to test the Scanning HIS, HAMSR, and AVAPS instruments for science data acquisition and instrument intercomparison.  The secondary goals are to test: 1) FOR and POR communications, 2) the Ku and Iridium communication links, 3) the COMPASS system for real time mission monitoring, and 4) ATC and FOR communications for science operations.

1855      GH engine start

1900      GH populated with Instrument teams

1904      AC power on

Basic Fllght profile is to fly to a point off of the Ca coast (DINTY), procede directly to ~ 50N, 154W.  We then turn directly soutward and fly over Hawaiian airspace to 10N.  We turn eastward for a run of a few hundred km to about 146W, and then turn NE to return to DFRC.  The plot below shows the approximate track with dropsonde locations.  The superimposed temperatures are the NCEP AVN forecast (valid for 8;30 AM PDT on 2011-09-09 at 70 hPa).

1936      A bit of gustiness at takeoff time.  It may lead to a hold.

1951      taxi

2001      Crosswinds are too high at takeoff time.  Holding just short of the runway until winds fall off.

2008      Taxiing onto runway, winds have fallen off a bit.

2011      Takeoff.  Airborne at 2011:50

2118      Feet wet in the Pacific

2139      HAMSR reporting good data.  See http://hs3.jpl.nasa.gov/HS3/index.jsp

Below is a screenshot of HAMSR data showing Channel 9 – brightness temperature.  Warm colors show the land and the cooler T is the ocean.

2237      Having troubles with the Ku

2242      Turning the Ku transmit off.  The beam width of the Ku transmit is very narrow, and apparently the motion of the GH keeps throwing this off.  In order to not damage the Ku transmit, it is being turned off.

2243      35.8N, 127.9W, 54.6 kft. altitude.  Instrument status packets are good.  Preparing for dropsonde launch at the top of the hour.

2300      First sonde launch.  The image below shows the 11 micron GOES IR image at 2300 UT.

2318      Sonde probably hit the ocean surface.  A good profile. 

0106      Still proceeding to the northern point.  Nothing to report.  Ku still not transmitting.

0130      Scott arrives, time for Paul’s bed.

0245      10 mins before first drop on southern leg.

0254      2nd dropsonde released (first along the southbound leg).

0257      Air traffic below prevented 3rd drop (first of the double drops). Will pick up next drop and start double drops from there.

0315      First double drop begins.

0317      Second drop 2 min 12 sec after first drop.

0326      Second double drop begins.

0328      Second drop <2 min after first drop.

0239      ATC has cleared us all the way down to 35 deg N

0337      Third double drop begins.

0339      Second drop ~1.5 min after first drop.

0348      Fourth double drop begins.

0350      Second drop <2 min after first drop.

0400      Fifth double drop begins.

0401      Second drop <2 min after first drop. Done with double drops.

0417      Lost Iridium temporarily

0540      ATC cleared us for drops down to 30 deg N

0632      Sonde that was skipped earlier due to air traffic was dropped at 30.5 deg N into Atmospheric River

0704      Prolonged period of missing Iridium. Missed two launches at 29 and 28.

0800-0900           Dry run telecom

0900      Sonde drop 33 after prolonged Iridium instability. Previous sonde could not be launched, so three extra sondes at this point.

1030      After the turn, we accelerated the dropsonde rate along the 10N line to pitch out the remaining sondes prior to turning NE.

1100      The flight line along 10N appeared to have little Cb action, although there was a good system popping to the south of our NS track at 154.5W.  The bigger Cb system was at about 6N, 155W and had cold tops to about 200K from the 11 micron GOES IR channel.

1130      The final dropsonde (#45) was pitched out.  The sondes all worked, but a couple had GPS problems , so no winds on those.

The plot below shows a screenshot of the dropsonde pitched out at 1638UT or 0938 PDT. 

1513      Proceeding NE towards DFRC.  Overflying low level cloud with not much else going on.

1833      Began descent from 63,200 feet.  All instruments off for descent below 60 kft.  Instruments will come back up when below 45 kft.

1852      Levelled off at ~40kft, all instruments came back up to get heaters on.  Waiting for surface winds to decrease.  Cross wind gusts to 25-28 kts.

1856      Dropped to 32 kft.

1857      All instruments turned off prior to gear coming down.  Altitude ~ 26 kft.

1902      All power off, Alt = 18 kft.

1915      Landing.