UPDATE # 13 - December 6, 1996
PART 1: Mars Pathfinder Update
PART 2: WebChat with Guy Beutelschies
PART 3: Connecting with Other Teachers
PART 4: Learning About Future Projects
PART 5: Planet Explorer Toolkit Proposal Form
PART 6: All in Order to Head to Mars
PART 7: Mars Global Surveyor Solar Panel Status
MARS PATHFINDER UPDATE
Mars Pathfinder was successfully launched from a Delta II rocket on
December 4 at 1:58 a.m., EST (10:58 p.m., PST) and is on its way to
the Red Planet! To see a detailed profile of the launch sequence visit
Check Donna Shirley's journals next week for an eyewitness account
of this spectacular event,
WEBCHAT WITH GUY BEUTELSCHIES
Weekly WebChats offer an opportunity for your students to virtually
meet the people on the front lines of the Mars exploration adventure.
Teachers have reported that the chats really enliven students'
enthusiasm. Next week our guest will be Guy Beutelschies, currently
in residence at NASA's Kennedy Space Center at Cape Canaveral,
Florida. Guy is the test director for the Pathfinder spacecraft. He
leads a team to test the spacecraft to make sure that it does
everything it's supposed to!
Guy's chat is scheduled for Friday, December 13 from 9-10 a.m.,
PST. Join us!
To best prepare, please have your students read Guy's biography and
very interesting journals before the WebChat:
To join in the fun, point your Web browser to
to follow the links to the *moderated* chatroom for experts. If you plan
to participate in this event, please RSVP to Andrea by sending a brief
email note to firstname.lastname@example.org telling her that you plan
to join the session. This RSVP is very important, as it will allow us
to ensure that the chatroom does not become overly crowded.
WEBCHAT SCHEDULE FOR DECEMBER
Friday, Dec. 13, 9-10 a.m. PST: Guy Beutelschies, PF test director
Wednesday, Dec. 18, 9-10 a.m., PST: Greg Wilson, planetary geologist
Dec. 23-Jan. 3: Christmas vacation
Week of Jan. 6: Chats resume with Steve Stolper, PF, software flight
engineer (exact date and time forthcoming)
CONNECTING WITH OTHER TEACHERS
A big part of Live From Mars is the connections that form between
people. Not only connections between students and NASA experts, but
bonds between teachers and LFM staff. If you are not a part of
these conversations, you may be missing something of great value.
Not only can other teachers help you figure out things, they can be a
sounding board for your brainstorms. As well, the LFM team is easily
influenced. Your ideas may sway the entire direction of the project
(as past history demonstrates).
There are two different ways to participate: chats and discuss-lfm
Every week, two, hourly chats are regularly scheduled. Each Thursday
at either noon or 3:00 PM Pacific (schedule alternates), folks gather
in the chatroom for an hour. Also, each Wednesday at 11:00 AM
Pacific, a special home school forum is hosted by master home
schooler Gayle Remisch, from London, Ontario, Canada. For more info,
see the WebChat section of
In addition, discuss-lfm offers teachers an opportunity to send more
composed messages. Last month, LFM people contributed over 200
gems in the vigorous discussion. Many people channel this
information directly to their mailboxes. If 200+ messages are too
many for you, an option exists for a digest. The digest sends just one
daily message with all of the day's traffic gathered
together. To participate, send an email message to:
In the message body, choose one of the lines below to send
If you prefer, you may also take part in the discuss-lfm group via
the Web. In that case, point your browser to:
LEARNING ABOUT FUTURE PROJECTS
Besides Live From Mars, NASA and Passport to Knowledge are
developing future online projects for the K-12 audience.
This spring will bring:
- Live From Antarctica, a learning adventure to the ends of the
Earth where scientists study wildlife and global climate change.
- Shuttle Team Online, providing the chance for students to meet
the wonderful people who make the shuttle fly.
To best stay informed about these and other projects, join the
Sharing NASA maillist by sending an email to:
In the message body, write these words only:
You will receive only a few messages per year with news about
exciting new projects.
PLANET EXPLORER TOOLKIT PROPOSAL FORM
Tuesday, December 10, marks the first day participants in the Live
From Mars online collaborative activity (Planet Explorer Toolkit)
may post their *best* P.E.T. proposal. Each class or participant will
be posting their proposal to the debate-lfm forum (sent to debate-
Be sure you have subscribed to the debate-lfm mail list.
Send a message to email@example.com and leave the
In the message body, type: subscribe debate-lfm.
Send your message and you will be added to the debate-lfm list.
All participating classes are encouraged to download and share each
P.E.T. posted, weigh the merits of the proposal, and prepare for the
online debate coming up in January 1997. Keep in mind that over
2000 students in a wide range of grade levels (elementary through
high school) are involved. We are sure to see a wide range of ideas
and various levels of sophistication, but remember we are working
as one big team to reach consensus on a universal best P.E.T.,
therefore *all* proposals are valued and respected.
Remember, your P.E.T. proposals should abide by the guidelines set
forth in the P.E.T. Procedure Overview found online at the Live From
Mars Web site: http://quest.arc.nasa.gov/mars/events/pet.html
To facilitate the process of posting P.E.T. proposals the following
form must be used. Please be sure to fill in all details *before*
posting. If several classes from the same school/location are
participating, be sure to distinguish them by a special name, class
period or hour, etc. so that their proposal remains uniquely
Participants are asked *not* to comment on each other's proposals
until the debate begins January 6. Further details about the debate
and consensus-reaching process will be posted to the discuss-lfm
forum and the debate-lfm forum.
If you have questions, please post them to the discuss-lfm list or
send to Jan Wee at: firstname.lastname@example.org
P.E.T Proposal Form
Live From Mars Collaborative Activity
(12/10/96-12/20/96 Posting Period)
Name of Sponsoring Teacher/Educator:
School Name (if applicable):
Special Group Name (if needed):
Number of Students Participating:
Our P.E.T. Proposal includes the following instruments/items:
Special Comments or Extended Information:
[Editor's note: Guy Beutelschies is the test director for the Mars
Pathfinder. He leads a team of people who tests the spacecraft to
make sure it does everything it's supposed to do! Guy has relocated
from Pasadena, California to the Kennedy Space Center at Cape
ALL IN ORDER TO HEAD TO MARS
Guy Beutelschies -
Week of September 30, 1996
We finished our work on the lander. Experts came in and inspected it
to make sure that it was ready to be put inside the aeroshell. One of
the experts discovered that the latches that are used to hold the
petals tightly together during launch vibrations might not have
enough clearance to release smoothly on Mars under all
circumstances. A couple of days of schedule contingency were used
to fix this problem.
On Sunday we had a project picnic. It was pouring down rain but we
had fun anyway.
Week of October 7
Finished fixing the petal latches. Next on the list was a broken wire
on the wind sensor. This science instrument uses extremely fine
wires to measure how fast the wind is blowing. A small amount of
current is run through the wires and the resulting voltage is
measured. As the wind blows, it cools the wires thus changing its
resistance. The faster the wind blows, the more the resistance
changes. Somehow one of these wires broke so a new one was
soldered into place.
Had a basketball game with some visiting engineers. We crushed
them like bugs. It sure helps to have home court advantage!
Week of October 14
Installed the lander inside the aeroshell. The aeroshell is the
container that looks like the old Apollo entry vehicles (kind of like
an upside-down top). It has a heat shield on the bottom that uses the
friction of the Martian atmosphere to slow it down. Several tests
were run to make sure that everything works as expected in this
Put the aeroshell onto a spin table, a device that looks like a giant
record player. Because the spacecraft is spinning when it enters the
atmosphere, we have to make sure that it is balanced. If not, it
would wobble and possibly tumble out of control. The spin table
whirls the spacecraft around and provides data on how out-of-
balance the craft is. Aluminum weights are then attached at certain
points inside the aeroshell for balance. Access doors are installed to
enable us to do this.
Week of October 21
Mated the entry vehicle with the cruise stage. This section carries
all the equipment that we need to journey from Earth to Mars. It has
the solar array that provides power, small thrusters for steering and
attitude sensors. These sensors look at the sun and stars to tell us
where the spacecraft is pointed. One of the tests we performed was
a phasing test to make sure that when the sun or stars move past a
sensor from left to right, the software shows the same thing (and
not right to left). It's pretty easy to make a sign error so it is
always good to do an end-to-end test after everything is done.
We also did a test to make sure that when we command thruster 1 to
fire, thruster 1 actually fires and not some other thruster. To do
this, we filled the propellant tanks with nitrogen and listened for
the gas escape when the thruster valve opened. It is far too
dangerous to actually use rocket fuel and fire the thrusters inside
Volleyball league started! This is six-person, co-ed indoor. There are
a lot of fun people on our team, mostly people who work at Kennedy
Week of October 28
Finished testing the cruise stage. Our next activity is to load rocket
fuel into the propulsion system. The fuel our spacecraft uses is
hydrazine. This is a very hazardous operation because if any fuel
spills it could start a fire. Hydrazine is extremely caustic and will
burn your skin if it touches you and is toxic to breathe. For these
reasons, the crew loading the fuel wears self-contained suits with
air packs that look like space suits.
I flew back to Los Angeles to sit on a review board for another JPL
project called Deep Space 1. The review was on how they planned to
do assembly, test and launch operations. I was brought in to explain
how Pathfinder worked and to give my opinion on their plans. It was
fun to see how another project does things. They even had bagels at
Week of November 4
We moved the spacecraft back to the spin table. Now that the cruise
stage is mated to the aeroshell, we need to balance it again. The
most important reason is that the third stage of the Delta (with us
on top of it) spins at 70 rpm when it fires in order to give it
stability. If we are not balanced to within very tight tolerances,
then the third stage might start to wobble, thus affecting the
pointing of the burn. We need that burn to be very precise in order to
head to Mars. Another activity we had was a test with the Deep
Space Network (DSN). This is the system of ground stations and
antennas that is used to communicate with interplanetary
spacecraft. There are three stations: one at Goldstone, California,
another at Madrid, Spain, and the third at Canberra, Australia. To do
this test, the DSN sent us a semitrailer loaded with electronics that
simulates one of those ground stations. We hooked up the trailer to
our spacecraft and verified that we could send commands and
Week of November 11
We loaded our final version of flight software. It contains all of the
final fixes and changes to perform our mission. Although this is the
last version, we do have a laboratory back at the Jet Propulsion Lab
in Pasadena, California that contains spares of most of our
electronics. We will use this area, called a "testbed," to continue to
test the software looking for bugs. If we find a serious enough
problem, we have the capability to modify the software during
We also practiced our countdown procedure again. Everything
happens very quickly during the countdown so we want a lot of
practice so that everything runs smoothly.
A couple of us managed to get in a round of golf in. One nice thing
about Florida is that even though it is November, it is still nice and
warm. There is a lot of water down here and I managed to lose quite
a few balls in all of the water hazards around the course.
Week of November 18
We are heading down the home stretch! The launch vehicle people
showed up with the third stage of the Delta. We hooked our
spacecraft to a crane and lifted it onto the stage. We then put the
whole "stack" into a shipping container and loaded it onto a truck to
take it over to the launch pad. We then craned it up the nine story
launch tower where it was put on top of the first and second stages.
We then did a test to make sure that the spacecraft was not damaged
during the move. We also practiced the countdown again. Everything
Over the weekend a bunch of got together at a restaurant showing a
bunch of football games. Although most of the people there were
watching the Bills game, there was one TV in the corner showing my
team, the Broncos. They won again and are now 11 and 1 (best record
in the NFL)!
MARS GLOBAL SURVEYOR SOLAR PANEL WILL NOT HINDER MISSION
Mission engineers studying a solar array on NASA's Mars Global
Surveyor that did not fully deploy during the spacecraft's first day
in space have concluded that the situation will not significantly
impair Surveyor's ability to aerobrake into its mapping orbit, or
affect its performance during the cruise and science portions of the
The solar panel under analysis is one of two 11-foot (3.5-meter)
wings that were unfolded shortly after the Nov. 7 launch and are
used to power Global Surveyor. Currently, the so-called -Y direction
array is tilted 20.5 degrees away from its fully deployed and latched
"After extensive investigation with our industry partner, Lockheed
Martin Astronautics, using a variety of computer-simulated models
and engineering tests, we believe the tilted array poses no extreme
threat to the mission," said Glenn Cunningham, Mars Global Surveyor
project manager at NASA's Jet Propulsion Laboratory (JPL),
Pasadena, CA. "We plan to carry out some activities in the next
couple of months using the spacecraft's electrically driven solar
array positioning actuators to try to gently manipulate the array
so that it drops into place. Even if we are not able to fully deploy the
array, we can orient it during aerobraking so that the panel will not
be a significant problem."
Diagnosis of the solar array position emerged from two weeks of
spacecraft telemetry and Global Surveyor's picture-perfect
performance during the first trajectory maneuver, which was
conducted on Nov. 21. The 43-second burn achieved a change in
spacecraft velocity of about 60 miles per hour (27 meters per
second), just as expected. The burn was performed to move the
spacecraft on a track more directly aimed toward Mars, since it was
launched at a slight angle to prevent its Delta third-stage booster
from following a trajectory that would collide with the planet.
Both the telemetry data and ground-based computer models indicate
that a piece of metal called the "damper arm," which is part of the
solar array deployment mechanism at the joint where the entire
panel is attached to the spacecraft, probably broke during the panel's
initial rotation and was trapped in the two inch space between the
shoulder joint and the edge of the solar panel, Cunningham said.
Engineers at JPL and Lockheed Martin Astronautics, Denver, CO, are
working to develop a process to clear the obstruction by gently
moving the solar panel. The damper arm connects the panel to a
device called the "rate damper," which functions in much the same
way as the hydraulic closer on a screen door acts to limit the speed
at which the door closes. In Global Surveyor's case, the rate damper
was used to slow the motion of the solar panel as it unfolded from
its stowed position.
Engineers have been reevaluating the aerobraking phase of the Global
Surveyor mission, which begins in September 1997 after the
spacecraft is captured into an elongated orbit around the planet
using its on-board rocket engine. The solar arrays are essential to
the aerobraking technique and will be used to drag the spacecraft
into its final, circular mapping orbit. First tested on the Magellan
spacecraft at Venus, aerobraking allows the spacecraft to carry less
fuel to a planet and take advantage of its atmospheric drag to
gradually lower itself into the correct orbit.
"Since we launched early in our window of opportunity, we will not
have to aerobrake as fast to reach the mapping orbit, and this
reduces the amount of heating that the solar panels are exposed to,"
Cunningham said. "In the event that our efforts to latch the solar
array properly in place are not successful, this reduced heating
should allow us to tilt the array in such a way to prevent it from
folding up and yet still provide enough useful aerobraking force."
Additional analysis and testing will be performed over the next
several months to verify this hypothesis.
Meanwhile, Mars Global Surveyor continues to perform very well as
it completes its first two weeks in space, with ongoing science
instrument calibrations being performed this week. At the same
time, the Mars Relay radio transmitter has been turned on for a
post-launch checkout. Radio amateurs around the world are gearing
up to participate in a radio tracking experiment in which they will
become receiving stations for the low-power beacon signal
transmitted by the Mars Relay radio system.
Mars Global Surveyor is approximately 3.4 million miles (5.5 million
kilometers) from Earth today, traveling at a speed of about 74,000
miles per hour (119,000 kilometers per hour) with respect to the
Mars Global Surveyor is the first mission in a sustained program of
robotic exploration of Mars, managed by JPL for NASA's Office of
Space Science, Washington, DC.
Note: A line-drawing of Mars Global Surveyor showing the
current position of the solar panel in its fully deployed position,
including a blow-up which shows the area in which the broken
deployment mechanism is located, can be found under "News Flashes"
on JPL's World Wide Web home page using the following URL:
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