PART 1: WebChat with David Mittman
PART 2: Challenge question #7: arriving at Mars
at different times
PART 3: Mars 96 launch failure
PART 4: Planet Explorer Toolkit Activity
PART 5: First LFM Broadcast Available on Videotape
PART 6: The "Please Copy This Disk" Project
WEBCHAT WITH DAVID MITTMAN
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 David Mittman from NASA's
Jet Propulsion Laboratory in Pasadena, California. He will discuss
his role in planning the Mars Pathfinder's activities and in sending
commands to the spacecraft during its flight to Mars. (MPF will be
launched Sunday, Dec. 1, 11 p.m. EST.)
David's chat is scheduled for Tuesday, December 3 from 9-10 a.m.,
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* chat room 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 chat room does not become overly crowded.
To best prepare, please have your students read the biography of
David before the WebChat:
A schedule for the December WebChat's will be published shortly.
Watch the LFM Web site for the date and time of next week's chat.
CHALLENGE QUESTION #7: ARRIVING AT MARS AT DIFFERENT TIMES
Recently we asked:
The Mars Global Surveyor (MGS) takes off in November and is
scheduled to arrive at Mars between September 11-22, 1997. The
Mars Pathfinder (MPF) takes off sometime in December. No matter
when it leaves, it is scheduled to arrive on July 4, 1997. Why does
the Pathfinder get to Mars earlier, even though it leaves later? And
how can the Pathfinder have an exact arrival date even though its
lift-off date may vary?
Answer from Cheick Diarra:
There are several reasons for Pathfinder's earlier arrival at Mars.
Pathfinder is much smaller and lighter than Mars Global
Surveyor. As a result, the rockets sending it to Mars can get it going
at a faster velocity. Also, Pathfinder goes on a much more direct
route to Mars than MGS, which takes a longer, more looping path. So
not only is MPF going faster, it has less miles to travel.
There is a good reason for MGS's more looping path. The arrival
velocity depends on the type of trajectory. The more looping
trajectory provides a slower arrival velocity. Since MGS is an
orbiter, NASA wants it to arrive at Mars with as little speed as
possible. This is because it will need to be slowed down with a retro
burn to be captured by Mars' gravity. That maneuver is called the
Mars Orbit Insertion maneuver, or MOI for short. The slower MGS is
going relative to Mars, the smaller the retro burn. And a smaller
retro burn mean less fuel (and weight and dollars). So that
is why MGS is on a more looping trajectory which will allow for a
slower arrival speed. MPF, on the other hand, is not going into orbit,
so it can arrive at a faster speed, and thus its more direct route to
To help understand why a more looping trajectory results in a
slower arrival speed, consider a golf ball being putted on a slanting
green toward the hole. A golfer can hit the ball hard right toward the
hole and the ball will arrive relatively quickly. Or else, the ball can
be putted more gently toward the uphill side of the hole; in that
case, the ball will loop down towards the hole and arrive at a slower
Finally, about the issue of the fixed arrival date for MPF. When we
travel to Mars, we have the opportunity to do Trajectory Correction
Maneuvers (TCMs) that let us correct not only our aim point at
Mars arrival but also the time of arrival. Early on, NASA decided July
4 would be a good day to arrive. This was partially historical. In
1976 when the Viking spacecraft went to Mars, it was expected to
land on July 4 for national reasons (July 4 is America's Independence
Day). But when Viking arrived, there was a raging dust storm that
prevented this scheduled landing so the team missed a July 4 landing
and decided to remain in orbit until July 20 (July 20 is the
anniversary of the first Apollo landing). So this time NASA has
decided that Pathfinder should land on July 4. The TCMs for
Pathfinder will be performed to remain true to the July 4 landing
This is the last Challenge Question until sometime in March (six
weeks before the second LFM broadcast in April). However, this
doesn't have to be the end to sending out challenging questions.
Students should make up their own Challenge Questions for each
other. These are known as Student Stumpers and examples can be
found in the Kid's Corner at
Check out this Web site and send your stumpers to Linda Conrad at:
[Editor's note: Donna Shirley is the manager of the Mars Exploration
Program. Donna manages three flight projects and studies of future
missions to Mars. Everyday she deals with scientists trying to
understand Mars, and with the technology we need to go to Mars
without costing a lot. Donna was saddened by the failure of the
Russian 96 spacecraft to go into orbit and offers this account of its
MARS 96 LAUNCH FAILURE
Donna Shirley - http://quest.arc.nasa.gov/mars/team/shirley.html
November 18, 1996
We were all very sad to see the failure of the Mars 96 Russian
mission to Mars, which launched November 16. At first the launch
looked beautiful. I heard about it on television news, then read about
it and saw pictures on CNN's web site:
But then this morning Ed Stone, the director of the Jet Propulsion
Laboratory, called to tell me that the fourth stage of the launch
vehicle had only burned for a short time, the spacecraft had
separated from the fourth stage, and the spacecraft was in Earth
orbit instead of on its way to Mars.
Mars 96 was a huge orbiter with 20 different instruments from
many countries. The orbiter carried two "small stations" which were
to land on the Mars' surface and make measurements, and two large
penetrators which were to plunge into the Martian soil and make
measurements several meters below the surface. The Russians and
their international partners had worked for many years to pull the
mission together. The mission was originally supposed to be
launched in 1992, but had to be delayed first to 1994, then to 1996
because of lack of money in the Russian space program. If it had
worked it would have been a wonderful complement to the U.S. Mars
Global Surveyor mission (now on its way to Mars) and the Mars
Pathfinder lander mission, which will launch December 2.
There was a U.S. experiment on each of the two small stations called
the Mars Oxidant Experiment, or the MOx. It was supposed to measure
the chemistry of the soil to find out what was causing all the
organic material to disappear from the surface. (Viking discovered
this problem in 1976.) Since Pathfinder and Mars Surveyor 98 don't
have this experiment it will be 2001 before we can find out why this
There is more information about the Mars 96 mission at their home
On a more cheerful note, I was just on a Family Channel television
show with Buzz Aldrin (the second person on the Moon) and Jack
Schmitt (the next to the last person on the Moon). We talked about
human and robotic missions to the Moon and Mars, and speculated
about how and when humans might go to Mars. We took call-in
questions from around the country. The final guest on the show was
12-year-old Josh Slavin, who has been to Space Camp in Huntsville,
Alabama six times. He wants to be the first person on Mars.
Also look for me on "Good Morning America," probably on November
29 or December 2.
THE PLANET EXPLORER TOOLKIT (PET) ACTIVITY
Now is the time to join this exciting online collaborative activity!
Over 1700 students of all ages are already registered to take part in
the Live From Mars PET Activity. This activity strives to engage
students in the following:
- Think like the Mars Mission Team
- Conduct research on scientific instruments and determine
which data are most valuable in observing the environment
- Deal with the constraints of big science endeavors
- Use their problem-solving and critical-thinking skills
- Engage in classroom debate
- Prepare their best PET proposal and share online
- Interact online with real planetary scientist mentor Sanjay Limaye
and other experts & Passport to Knowledge staff
- Learn how to reach consensus
- Collect real data about their own local environment
- Share data online
- Interpret data and solve the PET Mystery Sites (a special online
activity for all grades)
- Have fun learning about the real work of scientists
You are **not** too late to join!
Planet Explorer Toolkit Timeline
October 17-December 10: Brainstorm the Planet Explorer Toolkit and
determine your proposal.
December 10-December 20: Share your *best* Planet Explorer
Toolkit proposal and rationale online via the debate-lfm forum. Each
class may post one PET proposal.
December 20-January 3: Break for the holidays
January 6-January 31: Classes debate online the relative merits of
the PETs presented. Advisors/mentors will be online to help
moderate the discussion and help us reach consensus. Reach
consensus by January 31.
February 3-February 28: Classes collect data from local
environments and submit their Planetary Data Input to NASA
Quest for sharing online.
March 3-7: PTK staff and advisors create five datasets and clues to
represent the Mystery Sites for the next activity and prepare the set
of clues for each grade level range (elementary, middle, high school).
March 10-April 16: Classes participate in the "Where in the World
are these Mystery PET Sites?" Students will also be able to
participate in activities relating to interpreting the data collected.
These activities will be presented at our LFM web site.
April 17-onwards: This collaborative activity will remain online for
all interested students, educators, parents, etc. to enjoy over the
coming months as the Mars Pathfinder reaches its destination.
Need More Details?
Learn more about the PET Activity by accessing our Live From Mars
Web site at: http://quest.arc.nasa.gov/mars/events/pet.html where you will find a step-by-step plan to assist you and your
Want to Register?
All classes/groups should register by sending a note to Jan Wee,
education outreach coordinator at: email@example.com
Please indicate: teacher or sponsor's name, grade or age of students,
school name and location, and number of participating students.
FIRST LFM BROADCAST AVAILABLE ON VIDEOTAPE
NASA CORE distributes all Passport to Knowledge telecasts on
videotape for those folks who miss the live broadcasts or lack
access to the programs. To contact NASA CORE: e-mail:
or call: 216-774-1051 and ask
for extension 293 or 294.
The Live From Mars video conference's first episode, "Countdown,"
was aired November 19, 1996 at 13:00-14:00 EST. The videotape
will be available within one-two weeks after the air date. The tape
will sell for $16.00 plus shipping. Episode 2, "Cruising Between the
Planets" and Episode 3 "Touchdown" will also sell for $16.00.
Payment can be made with a check, money order, VISA, Master Card
or school purchase order which may be mailed to:
Lorain County JVS-NASA
15181 Route 58 South
Oberlin, OH 44074
THE "PLEASE COPY THIS DISK" PROJECT
Now available on IBM or Macintosh diskettes is the text from the
Live From Mars Web site, and also the text from the previous Live
From ... projects including Hubble, Stratosphere and Antarctica.
Many teachers either have no way to connect to the Internet or have
email only, have very little disk space allotted to them, or have to
pay hourly fees or long-distance charges for their connection. Those
are the people we have designed this service for.
Each diskette costs $10 and you are encouraged to make as many
copies as you need, for colleagues and students. When you make
copies, please treat the information and its originators with
respect. Think of the diskettes as an extension of the Internet and
treat the information with the same consideration as if you had
obtained it directly from the Internet.
We also hope that the material which you see and use on our disks
will give you a taste of the vast and rich resources available on the
Internet and will inspire you to get the kind of access that you need.
To that end, we also publish a free electronic newsletter, Internet-
on-a-Disk, which points to electronic texts and other educational
resources on the Internet and discusses Internet trends. (To
subscribe send email to firstname.lastname@example.org)
The text files from the Live From Mars site now comprise two
diskettes. We'll add new text as it becomes available and alert by
email those who purchase these diskettes when significant new
material is available. If you are interested in Live From Mars photos
in .gif and .jpeg formats, please send us email and request photo.txt.
We'll send you the list of what's available, with the file sizes, you
send us back your choices, and we'll put together custom diskettes
for you (at the same cost of $10 per diskette).
The text from Live From the Hubble Space Telescope is available on
one diskette (the images fit on two diskettes). Text from Live From
the Stratosphere fits on one diskette. Text from Live From
Antarctica fits on four diskettes (the images from that project fit
on two diskettes).
We also offer a wide range of other public-domain electronic texts
from the Internet in this same format and at this same price. Many
out-of-print books (especially literature published before 1920) are
available on the Internet and through the "Please Copy This Disk"
project. For the current list, send us email and request our catalog.
We frequently add new disks and if a public-domain text is available
on the Internet but isn't yet in our collection, we can custom-make a
diskette for you at the same price of $10. (Keep in mind that
Supreme Court decisions, federal legislation, UN resolutions and
documents, and NATO documents are all available this way).
We provide these texts as they are found on the Internet. We do no
additional editing. We believe the people who originally input or
scanned these texts made every effort to be accurate. But we cannot
guarantee the accuracy. We ask our customers to accept these texts
"as is," in the spirit of sharing which prevails on the Internet. If for
any reason you are not satisfied with a disk which you purchased
directly from us, you may return it for replacement or refund. (There
is no charge for shipping or handling inside the US. Outside the US,
add $2 per order.)
For information on how to order, check our Web site at
http://www.samizdat.com/(our catalog, back issues of our
newsletter, and lots of other information is available there), or
contact us -- email@example.com
617-469-2269 (leave a message on the answering machine)
PO Box 161, West Roxbury, MA 02132
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