The Venture Crew consisting of
high school students in Huntsville, Alabama are flying an experiment on the
Deep Space Test Bed balloon engineering test flight*. The experiment contains a very low frequency
(VLF) radio receiver and a video camera.
The VLF receiver is donated from the INSPIRE Project and
named“Marina” several
years ago after the newborn daughter of Flavio Gori who originally suggested
flying VLF receivers on high altitude balloons.
The Venture Crew’s experiment includes
simultaneous measurement on the ground with a newer donated INSPIRE
receiver and by other volunteer VLF enthusiasts around theUSA. The video camera will include a text overlay
showing the experiment’s location based on an included Global Positioning
System receiver. The National Scientific
Balloon Facility (NSBF) personnel currently plan to stream this video signal
real-time through theirFortSumnerweb site (see below).
* The first science flight of the DSTB
Facility will carry successfully proposed and peer-reviewed science team
experiments to high altitude overAntarcticaeither later this year or next.
Flight Status:
May
19, 2005:
The DSTB gondola package was “hang tested” after
mating with its solar array skirt at the NSBF inFort Sumner,New
Mexico. This
test weighed the package and checked out connections between the two components
of the flight system.
May 20, 2005:
Nearly all of the experiments have been tested in
preparation for the compatibility test.
That includes the Venture Crew VLF/camera package. There are three possible antenna
configurations I am currently considering.
The first to be tested is to hang the antenna directly below the
gondola. I will use the compatibility
test to determine whether the flight telemetry system overloads the input to
the VLF receiver. If it does, then
during the compatibility test I will move the antenna to the end of one of the
booms that are part of the gondola. That
will move the antenna some 20 feet away from the gondola and the telemetry
antenna. If neither of these
configurations work, then I will be forced to use a short antenna (much less
than the 50 feet currently planned) that hangs downward from the experiment
package but not long enough to extend into the antenna pattern of the telemetry
antenna.
May 21, 2005:
The UC Berkeley gondola did not fly this morning; the winds
were too strong. Consequently an attempt
was made to perform the compatibility test for DSTB. The winds were too high for that to be done
as well. The decision not to perform the
full compatibility test was made after the main body of DSTP was brought
outside the building. Some parts of the test
were performed, but without the solar array skirt and without full operation of
the instruments. The main gondola was
fitted to the ballast weights and balanced.
The gondola was raised as high as the launch vehicle could lift it in
order to plan for the later full compatibility test. An isolation transformer was added to the
Venture Crew video camera output. There
was a problem with ground of the SIP to the gondola, but I believe the Venture
Crew package was determined not to be the cause. Once this test is passed, no major changes
are allowed on the package and planning starts for selecting a flight date.
May 22, 2005:
Again the winds were too strong for UCB to fly and to
perform the compatibility test. Since
the local support crew has been up early for several days in a row, the
decision was made to postpone the next attempt at a compatibility test until
Tuesday, May 24.
May 23, 2005:
The compatibility
test date has been postponed again to Wednesday, May 25. The UC Berkeley gondola did not fly
today. They are on automatic retry (regardless
of the weather prediction) until Wednesday when they are supposed to stand down
and let us try for the compatibility test.
May 24, 2005
The compatibility test took place this afternoon. The test was successful. Photographs have been added to the photo
album from the test. Three recordings of
the VLF are also included. These are
wave files. During the first recording
the gondola with solar array skirt was close to the ground and the SIP/CIP RF
antenna were coiled up on the gondola and pointing in random directions. During the second wave file the gondola was
raised and the RF antenna were deployed downward to a location just below the
bottom of the solar array skirt. The VLF
antenna remained deployed only down to just above the bottom of the solar array
skirt. In the third test the VLF antenna
was lowered to the ground with no other changes. During the first test I was able to determine
that there was considerable noise in the downlink even after the VLF receiver
was turned off. The noise appears to be
coming from the CIP computer. The VLF
receiver was turned off before the end of each recording.
I can see more interference in the
last of three tests than in the second when the antenna was held above the RF
antenna radiation patterns. That would
lead to a VLF antenna length of perhaps 11 feet if that were the length
flown. I am prepared to fly up to 15
meters of VLF antenna. The current
situation is that I have suggested I want to deploy this longer length. I am reconsidering that request due to the
enhanced noise at low frequencies with the antenna deployed into the RF antenna
pattern. My initial reason to deploy to
15 meters is because all the local sources of interference are short wavelength
and the desired signal wavelength is quite long comparatively. The longer VLF antenna might not pick up more
local noise, but will pick up more natural noise with the longer length.
I have been told that we
aren’t likely to launch for two weeks.
We may hear more about that tomorrow.
My plans for tomorrow are to replace the 9V lithium batteries in the
Venture package and do the final wrap with light blocking film and white duct
tape. I need to decide whether to stick
with the current antenna deployment decision as well.
May 25, 2005
Today I will close out the Venture experiment package by
replacing the 9VDC lithium batteries with two that will fly with DSTB. That was done this morning. I have also cut out a foil wrap I will
install this afternoon with tape to protect the package from the Sun’s
heat. Later today and tomorrow we will
finish out the UAH eMass experiment package.
We are waiting on a couple of parts for that. By tomorrow I hope both are completely ready
for flight. We still expect UC Berkeley
to try to launch Saturday and our earliest opportunity to fly would be around
the middle of next week. I have added
images from the Venture Crew in Huntsville, Alabama. They have gone into the field to get
experience making VLF recordings. Their
first site to practice was at a school, where they also gained experience about
what 60Hz power line noise was like in the field. The second site is the one they have chosen
for field recordings during flight of DSTB.
This site is on a farmer’s land and a mile away from any power
lines. They found no 60Hz interference
when recording at that site, but they did pick up spherics as expected.
May 26, 2005
We closed out the UAH eMass experiment today. All the student experiments on DSTB are now
integrated and working. That is a big
relief. At the weather briefing they
reported a 40% change of showers tomorrow and not much better for
Saturday. Of course it therefore follows
that they will come out and pick up the UC Berkeley gondola with the launch
vehicle at 3:30am in anticipation of
a possible launch tomorrow. That’s
what they are planning anyway. The
weather forecast starts to actually look good on Sunday and Monday. Maybe they can get it aloft at the start of
the new week. I gather that DSTB can be
anticipated to be on-deck to find good weather for launch about one week after
UC Berkeley launches. I also heard today
that they have extended the launch season at Fort
Sumner in order to be sure that
DSTB flies from this location.
Apparently the equipment at Palestine, Texas
is not in as good a shape as the equipment here. So stay tuned;“Old Fort Days”
start on June 8…here’s hoping we aren’t hear to see it.
May 27, 2005
As all reasonable people expected, Berkeley
did not fly this morning. They will
continue to try each morning for a while.
I finished out integration of the
Venture Crew experiment this morning.
That only entailed VLF antenna work and attaching a good sized Venture
Crew logo to the package. The antenna
deployer will be held by a squib to one corner of the solar array panel at
launch. While still over the airport the
squib will be fired by radio control to release the antenna deployer. Since it will have been held about 6-8 feet
toward the gondola from where it is connected, it will swing while it is
deploying. The deployer will fall away
at the end of the 15 meters of antenna length.
The orange canvas bag shown in the photograph of the squib deployer is
the radio receiver that initiates the squib firing. There are actually two squibs packaged
together. A sting will pass through two
eyelets and loop around the antenna deployer frame to hold it in place. Upon firing the squibs (two for redundancy)
the string is cut and the antenna will deploy.
I am leaving to return to Huntsville
for a few days tomorrow morning, but will try to keep you up to date on
happenings here. I’ll leave Huntsville
to return to Fort Sumner
on June 2.
May 27, 2005
Some photographs from Michael Midekey’s
practice session yesterday at Rosedale, New Mexico have been added to the Venture web photo album. He reports a pine forest is a rotten
environment in which to picture wire antennas!
The preamp unit is the original Ev Paschal "Stanford 1980" design. The receiver is his adaptation of Steve
Ratzlaff's radical simplification of Ev's unit.
In this case he built two identical circuits for orthogonal loop work,
with mic and line (WWV) inputs switchable to the right channel. He further reports his PMD 760 recorder looks
clean as a whistle out to 24 kHz.
Michael is planning to“hit” the road for the 90 minute trip
and setup so he can record while the DSTB gondola is in flight.
May 28, 2005
Berkeley failed
to launch yet another day; so goes the schedule slide. NSBF has decided that all three of the payloads
here should launch here rather than going to Palestine,
Texas, so they have extended the season
here through the month. I believe Berkeley
will stay active, looking each morning for launch, at least for a few days
longer.
May 30, 2005
As best I can tell, Berkeley
again failed to launch yesterday and today.
I followed the activity taking place outside the buildings this morning
and appeared to see the NSBF support personnel taking off for breakfast at
about 7:20AM local time. That has been
their recent routine when launch is scrubbed for the day. I’m back in Huntsville
for a few days waiting to hear about the launch of both experiment gondolas
that are ahead of DSTB. I plan to return
to Fort Sumner
close to when DSTB might launch.
I’ll keep you posted with news as I get it from those still
onsite.
Updated on June 2, 2005,
4:21PM CDT
As you all probably know by now, the UC Berkeley launched
yesterday in the last morning. The next balloon package is FIRST. The first
possible attempt for the next payload is Saturday. This will be
re-evaluated and discussed at tomorrow's weather briefing. From the discussion
today, Sunday actually look like a better chance of actually flying. If
the next balloon happens to go on Saturday the first possible day DSTB would
fly is Monday, but this is very, very optimistic.
Should any of the other participating individuals or groups
wish to have information about themselves, their recording sites, or anything
loaded into the photo gallery, please contact me at dennis.l.Gallagher@nasa.gov. I would be happy to put pictures and/or other
information onto these web pages.
.
Related Web Sites:
NASA - National
Scientific Balloon Facility
Fort Sumner, New Mexico
Fort Sumner, NSBF, Webcams
NASA
Website Privacy and Accessibility Statement
Author and Responsible Official: D.L. Gallagher, dennis.l.gallagher@nasa.gov, (256)961-7687