UPDATE # 15 - December 18, 1996
PART 1: NASA TV Schedule
PART 2: WebChat Schedule
PART 3: Blowing in the Wind
PART 4: Breathtaking and Unreal-- The Pathfinder
PART 5: Update on Demise of Russian Mars '96
NASA TV SCHEDULE
The first Live From Mars television broadcast "Countdown," will be
reshown on NASA TV on December 23 and 31 at 2-3 pm, 5-6 pm, 8-9
pm, 11-12 pm and 2-3 am (Eastern).
"Countdown" will also be rebroadcast on PBS satellites on Friday,
December 20 at 1-2 p.m. (Eastern).
Many cable television systems receive and redistribute NASA-TV.
Consider contacting your local system to see if they might
redistribute NASA-TV during the Live From Mars events. For those
with access to satellite reception, NASA-TV is carried on Spacenet
2, transponder 5, Channel 9, C-Band, located at 69 degrees West
longitude, with horizontal polarization. Frequency is 3880 M Hz with
audio on 6.8 MHz.
Dec. 23-Jan. 3: Christmas vacation
Jan. 8, 9 a.m., PST: Chats resume with Steve Stolper, software flight
engineer on the Mars Pathfinder project.
[Editor's note: Greg Wilson is a planetary geologist on the Mars
Pathfinder mission. Greg is primarily responsible for conducting
geologic research in the Mars and Venus wind tunnels at NASA's
Ames Research Center in Mountain View, California, but has also
done a lot of work in support of the Mars Pathfinder mission.]
BLOWING IN THE WIND
Greg Wilson - http://quest.arc.nasa.gov/mars/team/wilson.html
December 9, 1996
The last couple of years, since coming to NASA's Ames Research
Center and Arizona State University, I have been working with Dr.
Rob Sullivan on the Mars Pathfinder Windsocks. These little
aluminum cones and counterweights are connected to a strut by a
gimbal-joint, allowing both vertical and horizontal movement. Three
of these assemblies are attached at different heights above the
surface to the meteorological mast on Mars Pathfinder. When in
operation on the surface of Mars later next year, the Martian winds
will blow on these windsocks and cause them to deflect. These
deflections will be recorded by the Imager for Mars Pathfinder (IMP)
and sent back to Earth. It is anticipated that the wind speed will be
slowest near the surface and increase with height. The way the wind
speed varies with height can tell us a lot about the interaction of
the atmosphere and the surface.
How I got involved in all of this was that each of these windsocks is
slightly different and needed to be calibrated under Martian
conditions in the Mars Surface Wind Tunnel here at Ames. Rob, who
also works at Arizona State University in Tempe, AZ, came out to
Ames numerous times to test different windsock configurations
under both Earth and Martian conditions. Sometimes these tests
would go on almost 24 hours per day! With the final configuration
and calibration complete, we sent the windsocks down to the Jet
Propulsion Laboratory for further testing and integration with the
A couple weeks later the phone rang and it was Rob. "Greg, we have a
problem 55 seconds into the final 60-second shake test at JPL. The
#2 windsock failed. We have three weeks to solve the problem,
calibrate, and get them to JPL or we are off the spacecraft." This
began the longest and hardest three weeks of my life. At one point
Rob and I logged over 100 hours of wind-tunnel operation during a
six-day period. Needless to say, we have been close friends ever
So you can imagine how I felt last week when the Delta II rocket
carrying Mars Pathfinder (and the windsocks) lifted off! Rob and I,
along with other project scientists and some cool teachers from
Idaho and Washington spent the early hours of Tuesday and
Wednesday morning at Jetty Park, which is about 1.5 miles south of
the launch pad. We all had a great time both nights, although, the
night of the launch we were thinking about some teachers who had to
miss it. The launch was awesome! At one point in the trajectory, the
rocket was heading toward the Moon, and just above it to the north
was Mars! After the rocket was out of sight, we went back to our
hotel rooms and waited to hear word that the spacecraft was in
communication with the Deep Space Network.
While at the Cape, I attended the ninth Pathfinder Project Science
Group meeting. At these meetings we talk about current status of
scientific experiments and planning for the landed phase of the
mission. Obviously everything on the spacecraft was ready to go, but
many more operational issues/problems still needed to be worked
through. During the first operational readiness test, a few computer
problems were encountered. For example, the computer reset right
before lander separation. In the simulation, the reset resulted in the
lander not separating, the heat shield not coming off, parachutes not
opening, etc. And while this is a serious problem, a senior project
scientist commented that the maneuver was called "litho-braking"
with the analogy to Mars Global Surveyor's "aerobraking" as a way of
slowing down when getting to Mars. Everyone got a good laugh out of
it, which should give you the idea that we all like to have fun even
though the work we do is very serious. Reset assured that every
detail is being looked into.
Back at the Mars Wind Tunnel, we are reducing the data for the sand
dune experiment. The results look very interesting and will be
presented at the Lunar and Planetary Science Conference in Houston,
Texas, in March 1997. I have also been trying to figure out why during
a dust storm, large particles get charged positive and small ones
negative. Very interesting.
Future work involving the windsocks will be and "end-to-end" test
where we will take a mast mock-up and the flight-spare windsocks
out into the desert somewhere and take images of it just like IMP
will do on Mars. At the same time we will take wind velocity
measurements from a 10-meter tower. We will take this data home,
convert windsock deflection images into wind speed and direction
measurements and compare it with the 10-meter tower data.
On the personal side, nothing new is really happening. I just want to
say "Hi" to all my new teacher friends in Idaho and Washington and
wish everyone a happy holiday season and a great new year!
[Editor's note: Fran O'Rourke is a teacher at Cedar Wood Elementary.
She and some of her students attended the launch of the Mars
Pathfinder spacecraft and wrote firsthand accounts of their
BREATHTAKING AND UNREAL-- THE PATHFINDER LAUNCH
December 14, 1996
Well we are back to Earth, after no sleep and a breathtaking view of
the Mars Pathfinder launch. Because of the launch delays, there was
very little sleep on the trip. Then having students along, we had to
do Disney World, Epcot, etc., so it has taken me a while to catch up.
The launch was unreal. Ken Edgett is right--do try and attend
one! We were treated like kings and queens. The tour of Kennedy
Space Center was great. We got to go on the space shuttle runway, to
the launch pad and to see many behind-the-scenes things. Of course
many scientists and engineers were there to help with explanations
and to talk to students.
Brian Cooper, the rover driver, spent the day at Disney World with
my students. We all had great fun and learned about the new rover in
the works; it is about the size of a matchbox car. Dr. Joy Crisp and
her husband Dr. Dave Crisp have agreed to work on a children's book
with my students. We will send it to the publishers in January (it's
Howard Eisen (rover designer) brought a mockup of the rover and
pulled it out to play with the students. Great fun for everyone.
Parents who attended were in awe and the kids were so excited. I
will never forget the whole thing. Oh we spent several evenings with
Peter Smith, (IMP camera lead) and got some inside news about
My students were treated as equals and learned so much. We went to
the VIP-viewing area the first night, which was actually north of
the rocket. Then Brian, Ken and Peter walked us into Jetty Park,
which was much better, not to mention that's where all the folks
from JPL were. The rocket seemed to go over our heads. As I look at
photos, when the rocket took off, it became so bright, my kids in
class asked if it was daytime.
To INFINITY AND BEYOND
Jenny Morris, Katie Myers, Lindsey Johnson & Maggie Ryan
5th graders in Ms. O'Rourke's class
December 2 was the official launch date of the Delta 2 rocket. It
was delayed (scrubbed) due to a hurricane passing through Texas. It
was going to hit Florida the same time as the rocket was to be
December 3 the launch was scrubbed again for difficulties on the
ground computers. On the 4th it launched! This is our point of view of
what happened on launch night:
It was pitch black and the only light at Jetty Park (where we viewed
the launch) was the rusty orange moon, the shooting stars and the
blue and white glowing rocket on the launch pad. Along with us, our
teacher Fran O'Rourke and our parents at Jetty Park were Brian
Cooper (the rover driver), Dr. Edgett (provides education for
teachers) Dr. Joy Crisp (geologist), Dr. Dave Crisp (works with
weather) and other scientists and engineers from NASA's JPL who
were excitingly waiting for the launch.
Suddenly a blinding light and a booming sound filled Jetty Park
while cheers filled the air as the Delta II curved and sailed toward
the moon. Half way to the moon the rocket boosters were released
and looked like sparkling stars as they fell from the Delta rocket.
The rocket continued on and looked like it was going right over the
middle of the moon as it tore through the atmosphere. All you could
see was a bright dot fade into the darkness. The sight was too
amazing to describe. When it was all said and done we all agreed it
was an experience we will never forget.
[Editor's note: This press release on the Russian Mars '96 spacecraft
is provided by the U.S. Space Command (USSPACECOM) at Peterson
Air Force Base in Colorado.]
UPDATE ON DEMISE OF RUSSIAN MARS '96 CRAFT
November 29, 1996
The following is a chronological version of this space mission as
observed by USSPACECOM.
The Russians launched a SL-12 (Proton) four-stage rocket booster
from the Tyuratam space launch facility at 3:49 p.m. EST on Nov.
16. Aboard the booster was a spacecraft known as the Mars '96
probe destined for the planet Mars.
The USSPACECOM Space Surveillance Network (SSN) tracked the
rocket and boosters throughout the first three stages of launch,
and observed, recorded and reported an object re-entering the
Earth's atmosphere at 7:49 p.m. EST, Nov. 16. Absent an
indication at the time of any problems with the Mars '96 probe,
U.S. space observers ascribed the Nov. 16 event as the
booster stage re-entry--which would be normal for a multistage
rocket of this type. The planned separation of the fourth stage
booster from the Mars '96 probe was not observed because it
occurred out of view of U.S. space sensors. The USSPACECOM Space
Surveillance Network did track a single object associated with this
launch after monitoring the first three stages, which at the
time was believed to be the booster's fourth stage still attached
to the Mars probe.
On Nov. 17 it became apparent that the Mars '96 mission had not
achieved its intended trajectory to Mars. USSPACECOM continued
to track in near-Earth orbit a single object thought then to be
the probe attached to the fourth-stage booster. On that morning,
the Russians requested, through NASA, USSPACECOM assistance in
locating the Mars '96 probe. USSPACECOM impact predictions were
forwarded to the Russians and Australians since initial
predictions indicated that the re-entry would take place over
Australia. Updated analysis of tracking data and orbital
parameters placed the final impact of any surviving debris in the
Pacific Ocean 150-200 miles off the coast of Chile at
approximately 8:30 p.m. EST.
On Monday, Nov. 18, the Russians announced that a failure on
board their spacecraft prevented the probe from achieving its
intended trajectory. The Russians also said their probe had
likely re-entered the atmosphere on Nov. 16 between 7:30 and 8:30
p.m. EST. Based on this information, USSPACECOM analysts began a
detailed review of all available data which ultimately led to our
USSPACECOM is not able to estimate what portion, if any, of the
Mars '96 spacecraft might have survived re-entry. The United
States' interest in providing this information is to clarify
earlier preliminary U.S. reports that portions of the spacecraft
re-entered over the Pacific Ocean hundreds of miles off the
Chilean coast. We are now convinced that any impact of the probe
that might have occurred on Nov. 16 would be within the area
described which includes portions of Chilean and Bolivian
The Russians are in the best position to address the materials on
board their spacecraft and whether any portion of the spacecraft
might have survived the heat of re-entry. On Nov. 27, U.S.
officials shared this information with the Russians and provided
information to the governments of Chile and Bolivia concerning
the Nov. 16 Mars '96 re-entry over portions of their
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