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Wednesday,
January 31, 2001
TopHat is on the Ground!
We've
just received word from Scott Hadley that the balloon
is on the ground and that a Twin Otter presumably
carrying Alex and Peterzen has landed at the impact
site. The last anyone heard from Peterzen was early
this afternoon when he called in to say that he
and Alex were taking an Otter out to see if there
was a decent terminate opportunity. Apparently he
felt that there was. The exact location of the payload,
according to the last GPS reading is: LAT: 85 deg,
5.7 min. South LON: 164 deg, 54.72 min. ALT: 2800
ft.
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Wednesday,
January 31, 2001
Greetings from the South Pole
By
A. Bier
As
most of you are undoubtedly aware, TopHat continues
to hover over the Queen Maud Mountains, trying to
decide if it’s going to land on the Amundsen Glacier
or the Axel Heiburg Glacier. It hardly matters—they
are both equally horrible. The amount of snow and
ice has flattened the landscape, so there is no
shortage of landing areas for either the balloon
or the Twin Otter recovery airplane. The problem
lies in making sure you can get from one to the
other. The flowing ice has created crevasse fields
everywhere. Crossing one of these would require
more people and money than we have.
South
Pole Station is an interesting place. After McMurdo,
it’s tiny and quiet. The galley can seat dozens,
not hundreds. Nearly all the facilities are located
under the dome. Access is through giant steel culverts
with an inch of frost on the inside—the frozen moisture
from people’s breath. The dark corners can get spooky.
The
dome is scheduled to come down in a few years, of
course, so it’s hard not to get a bit nostalgic
about it. Seems a bit silly since I’ve only been
here for nine hours or so. It’s likely the altitude
is making me silly: I was at sea level this morning,
and now I’m at the equivalent of about 10,500 feet.
We are under orders to avoid caffeine, smoking,
and alcohol, and to drink at least a gallon of water
a day. This is not something to mess around with;
I develop a small headache after spending too much
time inside or thinking too hard. Don’t expect this
update to go on much longer...
Accommodations
are surprisingly good. I am in the temporary summer
dorms, a field of Jamesways that will be taken down
in a few weeks. I even have a private room—if you
can call a 7x7 foot cubicle partitioned with a curtain
private. In truth it’s much nicer than I was expecting,
and about two orders of magnitude better than what
I’d be willing to endure to get our disks back.
Tomorrow
we will see if the balloon has moved over the high
plateau, where recovery will merely be difficult
as opposed to impossible. In addition, the Twin
Otter arrives, so we will be able to perform the
termination from here rather than waiting for an
LC-130 flight to the pole with room for the NSBF
pallet.
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Saturday
- January 27, 2001
By E. Cheng
The
past day or so has not seen much improvement in
the balloon location. The payload has been wandering
in and around the transantarctic mountain range,
making it impractical to cut it down. It also seems
like it is more likely to head south (towards the
pole) rather than come back north onto the Ross
Ice Shelf (it is only about 3 degrees from the pole).
Nothing
much else we can do but wait some more ... fortunately,
it is right in the flight path between McMurdo and
the South Pole, making it possible to hitch a ride
on any of a large number of aircraft that are now
diligently stocking up the pole for the winter.
We
will fly out there again in a day or so.
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Thursday
- January 25, 2001
By
E. Cheng
This
morning, two of the NSBF ballooning staff hitched
a ride on a plane going to the South Pole to observe
the area underneath TopHat The intent was to cut
down the payload if the terrain looked amenable
to recovering the equipment.
They
concluded that it was not suitable for recovery,
so we continue to wait for TopHat to move to a more
convenient area.
Those
watching the unfolding drama of the TopHat trajectory
will note that it has drifted fairly far South,
being only about 5 degrees from the South Pole (it
started at McMurdo, which is about 12 degrees away
from the South Pole). The winds are no longer very
regular, and it has been wandering about at the
far edge of the Ross Ice Shelf for a few days now
(meaning the edge away from McMurdo).
We
will try again tomorrow.
At
this point, it would be very convenient for it to
start drifting North again, which will bring it
back onto the Ice Shelf proper, and make recovery
relatively straightforward. Drifting South some
more would be bad since this would put in well into
the transantarctic range.
All
of the TopHat crew are now back at their home institutions
with the exception of the 4 brave souls who will
be performing the recovery feat. They continue to
consume the exquisite McMurdo cuisine, and bask
in the light of the midnight Sun (which is getting
more and more dusk-like as the days progress). First
sunset (however momentary) is February 20, and the
last flight out of McMurdo is February 24. We were
noticing even this week that one can definitely
tell that "night" is coming soon. Perhaps
this is the cause of some of the strange behavior
we are hearing about ... cafeteria murder attempts,
arriving at work late and incoherent, harassment
of local creatures ...
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Wednesday
- January 17, 2001
By E. Cheng
The
main activities for the past few days are recovery
preparations, analysis, packing, and resting up.
First,
recovery. We have been having many discussion about
this with the NSBF and NSF people here. It is getting
to be the end of the season, and airplane flights
are getting very short. (In fact, some of our folks
down here have been waiting almost a week to get
back to Christchurch.)
An
additional complication is a paperwork issue that
caused the NSF people here to think that we did
not need recovery support. Fortunately, this is
getting all worked out. While we may not be able
to recover the entire payload this year, there is
general agreement that we will have the resources
to try to retrieve our hard disks that contain the
flight data. Meanwhile, Bob and Peter and the folks
at home are busily practicing and testing the high
speed data dump in case we need to use it to read
these disks. Some of these tests will be run through
the equipment here at McMurdo that will be used
for the actual event, if we decide to do it.
The
payload is still moving at about the projected (slow)
rate. We are a little more than half way around,
and it has been about 13 days. Were still
thinking that it should complete its trip in another
week and a half.
Some
of the folks here and at home have been analyzing
the first two days of data that we got at the beginning
of the flight through the line-of-sight telemetry.
These are looking good, and the pointing reconstruction
is very encouraging. We can see preliminary maps
of the sky that show things like the galaxy and
other features in the correct places. All this is
very good news and it will get us more ready to
analyze the full data set when we get our hands
on it!
Packing
is going well, but there is still a lot of time
to complete this onerous but necessary task. You
may notice that the lab webcam is no more, and the
outdoor webcam is now in McMurdo town. They are
even starting to look into taking down the structure
we are working in! (We wont move until after
the package is cut down, and we are certain that
we will not need the ground station setup for the
data dump. This setup is currently working, and
we do not want to take the risk of ripping it apart
just to move it into the next building over.)
Resting
up is good. I think weve all caught up a little
on sleep. Were now all awake enough to notice
that the food may be better elsewhere, and it is
time to think about going home. On Sunday, we went
on a short boat ride on the Coast Guard ice breaker.
That was a fun diversion. Look for some pictures
soon.
Unfortunately,
the airplane schedules are very full these days,
and some of the crew here have been waiting since
Sunday to return to Christchurch. This problem is
compounded by mechanical failures in two of the
LC-130 planes recently. For example, the next flight
out is Thursday, for which we need to "bag
drag" (or check in) this evening (Wednesday).
Currently, there are over 100 people scheduled for
that light, which can only take 40 passengers. The
next flight out would be the following Tuesday!
Well, better to take the time to repair the airplanes
...
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Thursday,
January 11, 2001 p.m.
By E. Cheng
We
have looked at the data from last nights underflight,
and have confirmed that the payload was in excellent
shape except that the cryogen had run out. This
was only a short data fragment, but it was enough.
The
payload was shut down at 10:30 pm January 10 (McMurdo
local), after 6 full days in flight. The powered-down
payload will be circling Antarctica until the balloon
base folks decide that it is over an area that is
good for recovery. They will then terminate the
flight.
The
payload is moving very slowly, and is about 100
degrees around the 360 degree path. It is farther
South than McMurdo, which is good because it allows
for more margin to land on the Ross Ice Shelf, which
extends from McMurdos latitude to the south.
The Ice Shelf is the best place to land for straightforward
recovery. We expect that it will be over the Ice
Shelf around January 24, but wind conditions may
change. Check the web site for realtime information
on the balloon location.
We
are cleaning up the lab, and some of us will be
leaving in a few days. Alex, James, Jeff, and Tom
will be staying for recovery and final packing.
Alex will be going to the landing site.
I
will post updates as we get new information on recovery
plans, and well continue to post pictures
on the web site.
Tomorrow,
Friday, we will be taking a day off. Rumor has it
that we will be looking for some penguins ...
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Wednesday, January 10, 2001
Evening Report
By E. Cheng
This
evening, at around 2230 (local McMurdo), Grant called
back from the airplane and reported that he has
acquired TopHat LOS telemetry, and that the cryostat
is warming up.
He
is shutting own the payload according to our command
plan.
TopHat
has completed its data acquisition after a little
over 6 days of flight. We are now anticipating a
rapid and successful recovery by the NSBF.
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Wednesday,
January 10, 2001
Late Afternoon Report
By E. Cheng
Fly-Under
Images
The
airplane with Grant and the telemetry equipment
has departed.
His
flight was a little delayed from the original plan.
Takeoff was supposed to be at 1600, and is actually
around 1830. ETA is around 3.5 hours, so first contact
is expected around 2200 (local time). We will have
about 2 hours on station before the plane has to
go on to Vostok for refueling. Total elapsed time
for Grant to return is approximately 10 to 11 hours
(around 0430 to 0530).
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Wednesday,
January 10 2001
Afternoon
Report
By
E. Cheng
Weve
had a very busy couple of days figuring out what
we can be doing that will be best for TopHat The
result is that we have an airplane to fly us out
to the payloads position to get some data
back, as well as allowing us to send commands as
necessary. This airplane is scheduled to leave McMurdo
at 1600 on January 10 local time, and will take
around 4 hours to get to the payload. It will then
refuel at the Russian Vostok station, which is quite
close to the payloads current position, and
then return to McMurdo.
Grant
Wilson has courageously volunteered to make this
trip, and is fully dressed in his Extreme Cold Weather
(ECW) gear in case the plane has to disgorge him
in the middle of the Antarctic plateau.
To
do this, we have dismantled the redundant part of
our ground station here at McMurdo, and put it on
to a pallet that will be loaded into an LC-130.
This took an entire day to complete and test. Grant
will have the ability to look at the data as carefully
as we can back at the lab.
We
have not received any more telemetry from the payload,
and we are anxious to find out how it is doing.
Here are a few ways things could happen.
1. If
the cryostat has run out of cryogen, then we turn
the payload off in order to eliminate any chances
of a malfunction affecting the data already recorded.
2. If
the cryostat is still operational, then Grant
will check on the payload status and then send
it on its merry way.
3. If
something unexpected has happened, and the cryostat
is still operational, then Grant will send the
necessary commands to correct the situation.
By
the time the airplane arrives at the payload location,
we would have completed almost exactly 6 full days
of flight. It would not be astonishing if the cryostat
has run out, though of course, we would prefer to
get a little more data.
Meanwhile,
back at the computers both at McMurdo and at home,
our team has looked hard at the data we collected
at the beginning of the flight. So far, everything
looks very good.
Were
busy getting things ready for Grants trip.
Well surely have more to report after we have
made contact with the payload.
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Monday
- January 8, 2001 p.m.
By
E. Cheng
We
are into the fourth day of the flight. Evidently,
the winds have slowed down, so were not even
a quarter of the way around yet. This may make for
a very long flight before the package can come "home"
to McMurdo. At the current rate, it will take at
least 20 days, so we would expect it back after
January 24. We are thinking very hard about what
we should do next, read on ...
First,
an update on the TDRSS data link situation. We had
been getting intermittent contacts with the payload
until recently, and this has served us well. Unfortunately,
we have not heard from it for about 10 hours now.
Heres
what our experts can figure out from the small amount
of data they have been able to retrieve. It looks
like the TDRSS "transponder", or communication
radio, is consuming much less power than normal,
and thus not transmitting properly. It also appears
that the transponder is cooling down, which is consistent
with consuming less power.
Unfortunately, this is a very typical "vicious
cycle" with hardware in extreme environments.
With the temperature dropping, the electronics are
less and less likely to turn back on, and the electronics
need to be on before the temperature can warm up.
We have some other indications that the problem
has been temperature related. For the past few days,
the dropouts have been occurring near high noon
on the package. This is one of the times of daily
temperature extremes. We do not know what is wrong
in detail, but it is clear that we need to seriously
plan for a complete loss of contact through TDRSS.
With
the transponder down, we also have lost the capability
to command using TDRSS. This makes it difficult
for us to execute certain tests that are very desirable,
and which the payload cannot do by itself. Consequently,
we are working with the NSBF and NSF to arrange
for an airplane to "fly under" the payload
so we can use the normal line-of-sight communication
channels. This would allow us to send the appropriate
commands, as well as retrieve some data on how the
payload is doing.
Right
now, we have agreement that we can have a flight
two days from now, and we are working on whether
we can have one sooner than that. Given the extreme
shortage of available airplane flights and the fact
that they are already overbooked for normal operations,
we are really appreciative of this excellent support
from the folks down here for a situation for which
we had not requested resources.
We
are also getting a little concerned about the slowness
of the winds, and the long time that it will take
to circumnavigate the continent. Such long flights
increase the chances that the payload may end up
over the water.
That
would be bad, since with the TDRSS problem, we are
relying solely on the data that is being stored
in the on-board hard drives. Therefore, we are starting
the planning for a potential end-of-flight high
speed data dump, where we command the payload to
do a high-speed playback of the recorded data (at
a 10 to 1 increase in rate, or 1 day to transmit
10 days of data). We could choose to implement this
by an underflight, or with normal LOS should the
payload come close enough to McMurdo again. These
plans are still being discussed, so stay tuned.
The
slowness of the winds allows us to consider the
possibility of cutting down the payload near the
Russian base at Vostok. This has the advantage of
allowing us to terminate the flight early, thus
increasing our chances of getting the best recovery
support before the end of the season takes away
all the air transport resources. Of course, we would
have to be flying slowly enough so that our cryogens
run out while we are still within recovery range
of Vostok. Well have to keep an eye on the
winds to make this call. Right now, we are moving
very slowly, and are about a day away from Vostok,
so this option is viable.
The
condition of the payload was still very good the
last time we had contact with it. There is one major
unexpected configuration that we discovered while
looking at the returned data. It seems that, instead
of pointing straight up, the TopHat telescope axis
is tilted about 5 degrees.
We
are not sure what is causing this. We were anticipating
at most a 1 degree tilt, and expecting closer to
0.2 degrees. We are fairly certain that this was
not seen in the two instrumented test flights for
the top package, so it may be a peculiarity of this
particular balloon. We are still evaluating the
effects of this tilt. At first glance, there are
some advantages and some potential disadvantages
of this configuration. How it all works out will
not be known until we have done some more analysis,
but the data are looking good.
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Sunday
- January 7, 2001
By G.Wilson
Greetings
once again.
Please
forgive me in advance if I ramble along jubilantly.
Now that our telescope is aloft at 120,000 feet,
there is a sense of relief, euphoria, and general
happiness that has settled over our group. The launch
was as docile as can be, the flight is going well
so far, and the data pouring in looks a lot like
we expected it to. What more could we ask for?
With
the successful launch of the TopHat telescope and
its subsequent data acquisition, we have now moved
over to an official shift-based schedule. Ive
got to hand it to our Team 1 - Dave, James, Tom,
Alex, and Hans Ulrik. These guys ran continuously
on adrenaline for the entire launch day and then
pulled an all-nighter once we got to observing altitudes.
Not only did they stay awake and alert, they made
decisions and analyses that we are now happily operating
with. As someone who has driven long distances late
at night with Tom, Ive gotten used to trusting
him at times of low sleep. My only fear on our first
night of flight was that there was no McDonalds
off the highway to provide a late-night cherry pie
buzz.
Team
2 - myself, Steve, Jeff, DeLee, Tammy, Becky, and
Gwynne - pulled the long strawed 7:00 am to 7:30
PM shift. (Okay, so it helped that I made up the
shift schedule.) Our primary responsibility is to
watch the data coming in, perform analysis, and
seek out sources of trouble or inconsistency for
correction. As it turns out, the telescope is running
very well autonomously and we have yet to have to
intervene on its behalf. This is a fortunate state
of being since our telemetry contact through the
TDRSS satellite has been spotty and looks like it
is fading. As Ed explained yesterday, this puts
much more emphasis on our successfully getting the
onboard data storage disks back once the package
is cut out of the sky.
What
is a typical shift like? Well, you may be surprised
how unexciting it is when things are working well.
We watch the cryostat signals to see that they are
nominal. We monitor the temperatures of various
parts of the two payloads. And we watch the detector
and pointing signals to confirm that we are still
performing our standard observing pattern. Really,
the excitement never ends out at Willy Field!
Since
it is so mind numbing to continuously watch data
pour into your lap, we have started thinking about
the next step - data analysis. This is, after all,
our new vocations and we are overjoyed with it.
As balloon-payload instrument builders, we generally
spend 3-5 years building and testing an experiment,
2-4 months preparing for the flight, 8 hours at
float (for a Texas based flight) and a single year
analyzing the data. Analyzing data is great! You
get to sit still at a computer writing code, no
traveling, no incessant opening and closing of dewars,
no physical problems at all ... ah ... You can even
scream and yell at your computer with no worries
of hurting its feelings. What a life. Of course,
with TopHat we are entering a new regime in terms
of the total amount of data we will have to work
with. Instead of the typical 8 hours, we now have
three days of data in the can and we are expecting
more to come.
So
if you check out the web cam tonight and see us
smiling, youll understand why. Weve
got work ahead of us but we are looking forward
to it more than ever.
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Saturday
- January 6, 2001
Update
for the Morning at McMurdo
By E. Cheng
Well
folks, it has been a hectic few days. While you
have gotten used to the exquisite prose from Grant,
he is to busy raveling in the data, entertaining
thoughts of fame and fortune, to be writing any
updates for a while. I figured we should get something
out to our loyal readers soon.
We
are into the second day of our flight, and things
are still going very well.
The
balloon will soon have traveled far enough to lose
line-of-sight telemetry and command contact. This
is what we use when the payload is within 300 miles
or so, and we can get radio contact with the payload
directly. As it flies farther away, we use the NASA
Tracking and Data Relay Satellite System (TDRSS)
for our communications. This is the same system
that supports Space Shuttle missions (and all the
live video we get from them), the Hubble Space Telescope,
and other near-Earth orbit missions. It only underscores
that being in Antarctica is more than a little like
being out in space!
Our
first problem is that the TDRSS data coming back
is not reliable. We lose some of this data intermittently.
This is not too bad, since we still get a pretty
good idea of how the payload is doing, even with
intermittent contacts. If we lost this capability
entirely, the mission can still go on because the
payload is capable of operating autonomously. However,
we would not *chose* to do this for obvious reasons.
It's a little like sending a child by itself on
a commercial airline flight as an "unaccompanied
minor"! So far, the data have been sufficiently
reliable for us to execute the normal flight plan
which is controlled by people on the ground.
You
may wonder what effects this may have on the scientific
data. In the short term, it means that Grant will
not have the data analyzed and published before
the payload lands. This is because there will be
missing gaps in the data from the telemetry, and
these will probably prevent a full analysis. However,
all of the data are recorded on hard disks inside
the bottom payload. After recovery, we will have
the entire data set, free from these gaps.
As
far as we can tell, TopHat is doing great. The detectors
are working, the telescope is spinning, we see signals
from the sky that we should be seeing, temperatures
are stable, the cryogenics are working normally
... overall, we have a pretty happy machine up there.
All
the temperatures and operating conditions are very
stable now, and have been after the first day or
so. This allows us to perform very careful performance
checks on the machine. Our job in the near term
is to make sure everything is working as expected.
After that, it should get very routine.
You
can check our flight path in real time from the
link on our main web page. Our webcam inside the
lab is also working fairly well, so you can watch
us watch the data (actually, it should be and is
pretty boring most of the time).
Oh
... and check out the new launch movie that Tammy
and DeLee made.
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Friday
- January 5, 2001
Happy New Year!
By G. Wilson
I
see that it has been more than a week since I've
updated anyone on our progress. Well, it sure wasn't
because I've been napping with the seals out on
the ice flows. We've been super busy for the past
10 days; sleeping very little, working very hard,
and making great progress. In fact, we made such
good progress with the telescope that yesterday
we were able to take advantage of an anomonously
windless day and have a successful launch! Yes,
TopHat is off the ground and in the air collecting
data as I write. It's kind of hard to imagine ...
six years of our work is now circling Antarctica
and peering into the heavens to try to unlock some
mysteries of the universe. How cool is that?
But
I'm getting ahead of myself. It was only Christmas
the last time I wrote and Christmas now seems like
it came years ago. Well, right after Christmas we
were back at work hammering away on getting the
experiment ready. These days were tough; get up
from the sleeping bag at 7:00 am, work until our
lunchtime meeting, back to work after grabbing a
bite at the galley, push on through until dinner,
and then back to work afterwards until midnight.
Where in that schedule is there time to shower?
Well, if I was quick I could usually get to my toothbrush
and deodorant in the mornings before getting too
busy. If not ... well ... people would think twice
before getting too close - an effective way of getting
some privacy in a very public place!
Yes,
over the past few days we've been working hard.
We tested the telescope. We built some last minute
flight pieces. We even opened the cryostat (the
"brains" of the experiment) and fiddled with one
of the detectors a bit. We put our proverbial noses
to the grindstone and cranked away until, finally,
we were ready to fly on Thursday morning. This would
be our first possible launch opportunity according
to the weatherman - and if we missed it, we would
not get another chance until the following Sunday
and if the weather stayed bad for the following
two weeks, we would not fly at all and our efforts
would be for naught.
Fortunately,
luck and hard work paid off and Thursday morning
we were ready for the NSBF folks to take us out
to the launch pad. The weatherman had predicted
that there would be nice low winds between 1:00
am and 1:00 PM and then the situation would deteriorate.
We knew we wouldn't make it for a launch in that
time frame but we decided that it would be good
practice to try anyway. Imagine my surprise when
I walked out of the lab for the first time on Thursday
morning and found that it was snowing! The weatherman
was right, not a bit of wind around ... but it was
SNOWING! We can't launch in the snow! ... well,
we continued with our preparations hoping that fate
would smile on us and the skies would clear for
just long enough to get the balloon off the ground.
Now
the way we were set up was quite peculiar. In the
morning they came to first pick up our bottom gondola
- the traditional gondola that hangs below the balloon
and supplies the telescope on top with power and
our instructions. Our telescope was, in fact, already
on top of the balloon, but remember, the deflated
balloon is nearly 3000 lbs of mylar stored away
in a huge wooden box big enough to throw a tea party
in. Our telescope was perched up above this box
and, in the end, stood about 8 feet off the ground.
Meanwhile, workers for the balloon base and scientists
scurried around underneath getting things ready.
And still it continued to snow.
Roll
out to the launch pad was very cool. First, a big
ladder truck came to pick up the bottom gondola.
The Balloon Facility support staff hung their solar
panels (to give power to their own electronics)
and then it was time to head out to the pad. Yes,
it was snowing all the while. Good thing we had
taken the time to cover all our electronics well.
All we needed was for a few snowflakes to get inside
and POOF .. . we'd have to take it all apart and
repair the shorted pieces. Fortunately, nothing
like that happened and the roll out of the bottom
gondola to the pad went smoothly.
The
top package was next. How do you get a 250 pound
telescope sitting on top of a 3000 pound balloon
inside of a 1000 pound box out to the launch pad?
Well, it helps to have a snow driveway, a 1000 pound
sled, and a snow-tread equipped bulldozer, that's
for sure. This monster bulldozer pulled right up
inside the lab, hooked the sled, and dragged the
entire show out to the pad. It was amazing to see.
I walked along behind the sled as the tail end of
the parade and simply marveled at the sight the
whole way.
The
launch pad itself is nothing more than a very large
circle cut into the snow. The diameter of the circle
is about 1/2 mile - making it a very long walk around
the circumference. The pad is plowed and leveled
every day to keep the snow packed and smooth. This
is very important for the safety of the launch vehicle
that needs to be able to chase a rising balloon.
Out on the pad were several bulldozers (the heavy
lifting vehicle of choice in Antarctica), several
snowmobiles for covering the large distances quickly,
a crane, and the launch vehicle itself. The entire
operation requires about 30 support personnel to
pull off safely.
When
we got to the pad it was still snowing (the light
an wispy variety) and we were getting mighty nervous.
Our telescope was well covered so we weren't worried
about accumulating snow but we were concerned about
depositing a layer of water on our telescope mirrors.
That would be disastrous to our data and we would
never know it was there. The launch plan of lifting
the telescope by its sun shield had the unexpected
consequence that we had a rigid cover over the telescope.
For the time being, at least, there was no worry
about snow getting inside!
Once
set up on the pad, the seemingly interminable waiting
began. First we had to do our check-outs - a series
of tests designed to uncover any problems with the
telescope before we launch. We were under very heavy
pressure to get the checks done as quickly as possible
since the weatherman had said that the conditions
were deteriorating as the evening came on. But we
took our time anyway, testing our standard functions
as completely as we could. There is no sense in
launching a broken telescope after all! Don't get
me wrong though, we all wanted to launch and those
of us out on the pad who couldn't see the progress
were getting torn up inside with how long all the
testing was taking.
Finally
it was done, the balloon was laid out for inflation,
and we were ready to go.
But
what about the weather? This was the time to decide
if the launch would happen or not. Once the balloon
is unwrapped from its protective sheath it is either
launched or thrown in the trash can - and at $50,000
per balloon, that can make for a pretty tough decision.
Fortunately, during the long checkout the weather
had made a turn in our favor. In fact, I noticed
at the time that a patch of blue sky had opened
up right above us while a dense cloud cover had
set up in the distance all around us. I could no
longer see Erabus, McMurdo, or the surrounding mountains
but straight up was a beautiful cold blue sky. It
was as if TopHat were given a message that the only
place to go was up. The sign was there and it was
time to go for it!
So
how do you put a telescope on top of a balloon?
You may be surprised. The technique used was to
blow up a tow balloon (a much smaller balloon) that
would lift our telescope and the deflated balloon
into the air. This process took about an hour and
the telescope ended up hoisted about 200' in the
air trailing the upper portion of the deflated main
balloon beneath. Finally it was time for main balloon
inflation. This took another hour and required several
tanker trucks of helium to complete. When it was
all done we had a quite a sight to behold. On top
was a large balloon holding onto the top of TopHat
which was resting on top of a gigantic balloon.
That balloon was being held at its base by a 15,000
pound spool truck which acts as a pulley between
the launch vehicle (still holding the bottom gondola)
and the balloon.
With
the main balloon inflated it was now time for the
tow balloon release. NSBF had installed explosive
wire-cutters (squibs) to liberate the tow balloon
from TopHat It worked like a charm. The tow balloon
broke free just at the right time and carried all
its hardware away with it - just as NSBF had planned.
This provided our telescope with its first unobstructed
view of the sky for days.
At
8:03 PM Antarctic time, the spool was pulled and
the main balloon was released. It was simply spectacular.
With the momentary loss of tension in the flight
train the balloon twisted, morphed, and then began
climbing into the sky. It always strikes me how
much these balloons resemble a Chesapeake Bay jellyfish
at this stage. With helium rushing back and forth
inside, the balloon seems to swim skyward. This
time, our telescope was on top to enjoy the ride!
Once
the balloon had stood up, and with a bit of fancy
driving by the Balloon Facility rigging crew, the
gondola was brought underneath and the whole kit
and caboodle was released for its voyage. Up and
up it went as we cheered it on. It was truly an
inspirational moment for us to see it all happen
and we could do nothing more than stare as it flew
skyward.
So
now here we are a few days later (yes, it's taken
me a few days to find the time to write this note).
The data is coming in and for the most part it looks
just great! But this is just the beginning of our
long flight. We've got a long way to go so we have
some sleepless nights left before it's all over.
By
the way, there is now a film of the launch available
on our web site (http://topweb.gsfc.nasa.gov).
Next
time: how does all that data look anyway?
Still
in a celebratory mood
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TopHat
Launch Day Schedule for
launch opportunity January 4, 2001
(Schedule is subject to change)
Legend:
P
= Pickup
L
= Launch
Event
Time
(Duration)
1)
TopHat crew arrives at weatherport 8:00 am
- re-boot Antarctic flight groundstation computers
-
reboot Palestine flight groundstation computers
-
create free disk space on Antarctic computers (1.5
Mblocks)
-
create free disk space on Palestine computers (1.5
Mblocks)
-
start pre-flight archive per EC instructions
-
start preflight archive per EC instructions
-
push bottom gondola out onto deck
-
power up thread and connect to net
-
Bottom Gondola Checkout
2)
Long Top System Checkout 9:00 am (30m)
- be sure to run on solar panel power
3)
NSBF pickup of bottom package P = 9:30 am
- rigging does mechanical work of lifting ~30m duration
-
electrical mounts solar panels, etc. 1h to 2h duration
-
support NSBF activities
-
final compatibility test
4)
NSBF brings bottom package to launch site L-5h40m
(30m)
- spool of cable must go with
-
go to pad for remainder of pre-launch
5)
NSBF sets up launch equipment on pad L-5h10m (1h)
- last bottom gondola checkout
6)
NSBF returns to pick up top package on sled L-4h10m
(30m)
7)
Top package is brought out to launch pad L-3h40m
(1h)
- personnel ready to link bottom and top package
via spool
-
go to pad for remainder of pre-launch
8)
Long Top System Checkout with top package on balloon
box L-2h40m (30m)
9)
NSBF lowers top package to ground and lays out balloon
L-2hr10m (30m)
- connection made thru flight wiring when complete
-
1000' spool rolled back up and removed from pad
10)
Short Top Checkout on flight wiring and flight power
L-1h40m (10m)
11)
Tow balloon inflation L-1h30m (20m)
12)
Main balloon inflation L-70m (1h)
- end preflight archive, begin Antarctic flight
archives (DC)
-
end preflight archive, begin Palestine flight archives
13)
Tow balloon release L-10m
14)
Orientation of top package L-9m (3-5m)
15)
Spool release L
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Tuesday
- January 2, 2001
Check
out our world!
TopHat Movie (realplayer)
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(1 MB)
Greetings from the New Year.
Tonight's
note will be short and to the point ... I am too
tired to be verbose and witty. Our first possible
launch attempt will be Thursday (Wednesday in the
States). We are too busy to get overly excited but
the prospect of launching in a few days is looming
large. It is important that we not get our hopes
up too much though.
While our launch preparations are going very smoothly,
the weather is not cooperating. Currently, and this
changes every day, the forecast is for a brief lull
in the winds on Thursday followed by a few days
of stand-down while a new weather system passes.
Keep your fingers crossed!
Today was a mighty day. We have made the big move
of both TopHat packages from our weatherport to
the "pig barn" next door. The pig barn is quite
nice in that the heaters work better but it lacks
the ambiance of the big tent we call home - no music,
no coffee maker, and no web cam. What if I want
to change clothes for bed with 1000 Internet peeping
toms watching? Fortunately, I still have the key
to our old lab.
In
the pig barn we are mounted on top of the balloon
- about six feet off the ground. Imagine taking
your grand piano and mounting it at scalp-height
in your garage. Pretty daunting isn't it? Well,
having TopHat loom large over us with the balloon's
petal assembly radiating out from its base is quite
impressive. After spending much of the afternoon
working on getting the telescope in place our launch
director (the ever-impressive Victor from NSBF)
looked at the package, looked at me, and said, "This
is nuts ... but it's going to be great!"
Today
we also spritz-tested the telescope. This is an
important test because it tells us how much of a
contaminant the sun will be to our data. Fortunately,
the test shows that the sun will be, at worst, a
secondary concern of ours. The test also showed
that our new secondary is performing up to snuff.
This new secondary allows TopHat to probe the sky
with even better resolution than we had originally
planned.
With
great regret, today we suffered the loss of Jim
to civilization. For those who don't know him, Jim
is an undergraduate at the University of Chicago
who joined our group in the spring and has been
consistently impressing us ever since. After a few
months working for us in Chicago it was clear that
we wanted him to join us in Antarctica and fortunately
he took us up on our offer. And not without consequences.
During his stay here Jim finished his atomic physics
course and ended up doing his homework, labs, and
final exam by fax machine (I won't tell you his
final grade ... but it rhymes with the Canadian
word for "isn't that so?"). Now Jim is enjoying
Christchurch, NZ and we are left without his cheerful
presence. He won't get far though. Jim is on-tap
to help us monitor the package when it flies. He'll
spend hours in front of the computer yet. Isn't
that right Jim?
Well, it's starting to get exciting folks. We are
going to try to rest tonight and then start the
big push to get this guy off the ground! Stay tuned,
this show's opening its final act and it's promising
to be a big ta-doo.
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