BARREL 2008/2009 Piggyback Flight
A. cutdown and post-flight materials
The flight was terminated at UT 03:04:45 20Feb09.
We continue to collect data from the payload
ground location latitude: -79.8642, longitude: -45.4484, altitude: 746 m.
UPDATE: last payload contact at UT 23:42
quick-look pdf plots from the descent phase and after
From: Dwayne Orr/CSBF Deputy Site Manager
Subject: Flight Summary -
Flight No. 591 NT
Date: 19 February 2009
Flight Number: 591
Organization/Experimenter: NASA-WFF-BPO / David Pierce
ULDB (Ultra-Long-Duration Balloon) 7-MCF Test
This is the ninth in the
series of ULDB test flights, and the third test of the revised super-pressure
pumpkin balloon design. The test article is a 6.89-MCF scaled version of the
ULDB. The test will be to demonstrate the ability of ground personnel to
prepare and launch the super-pressure pumpkin balloon, as well as to deploy,
maintain altitude, and fly the balloon at operational pressures.
Launched: 28 December 2008 / 02:30:00 Z
Balloon Number: 1034
Mil Thickness (Shell/Caps): 1.5/0.8
Weight: 2374 lbs.
Experiment Weight: 1,500 lbs.
Suspended Weight: 1,500
Gross Inflation: 4,261 lbs.
Free Lift: 10%
Float Altitude: 112.2
Terminate Date / Time: 20 February 2009 / 03:04:45 Z
/ Time: 20 February 2009 / 03:59:16 Z
Location of Impact:
79-51.85 South / 45-26.92 West (1280 nm south southeast of McMurdo Station
on Berkner Island)
Total Flight Time (Hours, Minutes): 54 days 1 hour,
Condition of Payload: Good (estimated)
Remarks: This flight was an operations and science
success. All ULDB minimum and desired pre-flight requirements were met
and/or exceeded. The launch, ascent, float, termination, and parachute
separation were within nominal parameters. The ULDB vehicle maintained a
pressurized state throughout the entire 54 day record breaking flight.
Also, the new Micro Instrumentation Package (MIP) performed exceptionally
well throughout the flight. An Over the Horizon (OTH) termination using
Iridium was completed. The parachute cut away was successfully performed
using the Semi-Automatic Parachute Release (SAPR) system. Post impact
Iridium telemetry indicates that the gondola remained upright after impact,
with little probable damage.
B. main flight materials
quick-look pdf plots from the piggyback flight
The following show x-ray fluxes. The IRQ (dpu interrupt) rate counter
is accurate over the count rates we have. The LL (low level) and
PD (peak detect) counters roll over when the count rate exceeds
5100 per second. The fast spectrum channels cover energy ranges
10--180 keV (blue), 180--550 keV (green), 550--840 keV (yellow) and
840--1500 keV (red). The 3Jan events are low energy.
The 14/15Feb spectra show lots of activity, including
some high energy fluxes. Look at 15Feb 12:30, where an atmospheric line
near 5MeV was excited.
plots of TCM3 errors: These were made
by finding instances for which Bz differed from its smoothed trace by at
least 5 uT. There are 2 interesting features in the figures: first,
when Bz jumps, so also do the other 2 components; second, bad measurements
frequently appear as consecutive measurement pairs.
C. pre-flight materials
The CVI distribution kit for the UW testing gse uses the PC COM1 port.
A cable between the piggyback instrument and PC connects the
TX, RCV, and GND lines
from the PC to the interface board in the DPU box.
A toggle switch in the gui mimics the CARRIER/NO CARRIER messages and
sends the RCVD signals to the DPU at 10 second intervals when a connection
is present. This version works with 200 byte frames only.
Another recent feature is that, when started, the software begins storing frame
data in a file named for the start time (YDDDHHMM.dat).
The zip file includes
the source code, the uir file, and an executable at the top level. This means
a full installation is not necessary if the PC already has CVI software
zipped distribution kit and source code
for UW test gse
DPU box drawing, a half scale pdf drawing
of the dpu box
Here are some plots from CSBF testing.
Typical count rates should be on the order
of 200 counts/second. We do not see this at the hang test. Instead
count rates are 20 to 50 times higher than the expected background rates.
We do see typical background count rates for the files taken prior
to the hang test.
This shows best in the blue (IRQ) rate counter trace, taken from
a 16-bit wide counter that is read once per second. That means it can count
to 65K/second without overflow. The other 3 counters are 8 bits wide and are
sampled 20 times/second. Hence, they overflow when the count rate exceeds
5K/second. This is a holdover from MINIS that will be changed for BARREL.
Ideally IRQ=PD and LL is slightly larger than PD. HL should be small, and is.
For the time prior to hang test, the spectra show features
compatible with a local thallium-201 source, having a slight
thallium-202 contamination, when the count rates are high. This same kind of
spectrum was also present during the hang test. It is reasonable to
assume that most, if not all, of the high count rate is due to the thallium
source, and not due to instrumental problems. However, since the thallium
source was always present in the hang test, we don't yet have unambiguous
evidence that all is well.
rate counters prior to hangtest
rate counters from hangtest
counter comparison prior to hangtest
counter comparison from hangtest
spectra prior to hangtest
Five 5-minute spectra accumulations;
color codes for time with blue earliest
running through the rainbow to red latest.
spectra from hangtest
Five 5-minute spectra; color coding as before.