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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 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,


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: http://quest.arc.nasa.gov/mars/team/beutelschies.html To join in the fun, point your Web browser to http://quest.arc.nasa.gov/mars/events/interact.html 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 andream@quest.arc.nasa.gov 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)

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 http://quest.arc.nasa.gov/mars/events/interact.html 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: listmanager@quest.arc.nasa.gov In the message body, choose one of the lines below to send subscribe discuss-lfm subscribe discuss-digest-lfm If you prefer, you may also take part in the discuss-lfm group via the Web. In that case, point your browser to: http://quest.arc.nasa.gov/mars/discuss-lfm-lwgate.html

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: listmanager@quest.arc.nasa.gov In the message body, write these words only: subscribe sharing-nasa You will receive only a few messages per year with news about exciting new projects.


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- LFM@quest.arc.nasa.gov). Be sure you have subscribed to the debate-lfm mail list. Send a message to listmanager@quest.arc.nasa.gov and leave the subject blank. 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 identifiable. 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: jwee@mail.arc.nasa.gov ****************************************************** 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): Grade Level: 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 Canaveral, Florida.] ALL IN ORDER TO HEAD TO MARS Guy Beutelschies - http://quest.arc.nasa.gov/mars/team/beutelschies.html 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 configuration. 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 the cleanroom. 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 Space Center. 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 the review. 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 receive telemetry. 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 flight. 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 looked great. 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)!
GOALS 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 mission. 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 position. "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 Sun. 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: http://www.jpl.nasa.gov
If this is your first message from the updates-lfm list, welcome! To catch up on back issues, please visit the following Internet URL: http://quest.arc.nasa.gov/mars/updates To subscribe to the updates-lfm mailing list (where this message came from), send a message to: listmanager@quest.arc.nasa.gov In the message body, write these words: subscribe updates-lfm CONVERSELY... To remove your name from the updates-lfm mailing list, send a message to: listmanager@quest.arc.nasa.gov In the message body, write these words: unsubscribe updates-lfm If you have Web access, please visit our "continuous construction" site at http://quest.arc.nasa.gov/mars


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