[ Oran/NASAChatHost - 1 - 09:32:39 ]
Hello to our early arriving Women of NASA chat participants! Today's Women of NASA chat with Linda Spilker from NASA Jet Propulsion Laboratory will begin at 10:00 a.m., Pacific Standard Time. Be sure you have read Linda's autobiography at http://quest.arc.nasa.gov/women/bios/spilker.html before joining this chat.

[ Oran/NASAChatHost - 2 - 09:33:02 ]
Once the chat begins, Linda will attempt to answer as many of your questions as she can, but please be patient. The first part of today's chat will be "moderated. This means that only a few questions will be posted to the chat room at a time. Don't worry if your questions do not appear on your screen immediately. They will be posted as Linda answers those ahead of you. We may use moderation during the remainder of the chat if Linda falls behind with our questions.

[ Oran/NASAChatHost - 3 - 09:33:27 ]
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[ Oran/NASAChatHost - 4 - 09:34:01 ]
At the conclusion of today's chat, we ask that you take a few minutes to let us know what you thought about it. For your convenience, you may use our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys. We look forward to hearing from you!

[ LindaSpilker/JPL - 5 - 09:58:07 ]
Hello everyone, I am online and ready to go.

[ Stephanie/Edmonton - 6 - 09:59:56 ]
How is Titan similar to Neptune's moon, Triton?

[ LindaSpilker/JPL - 9 - 10:04:36 ]
Saturn's moon Titan is actually quite different from Triton. Titan has a thick atmosphere (about 2x the density of Earth's) which is rich in hydrocarbons. Triton has a very tenuous atmosphere and is actually probably more like Pluto. Titan probably formed along with Saturn and its moons. We think Triton was captured by Neptune.

[ LindaSpilker/JPL - 10 - 10:07:43 ]
RE: [BurtonValley/students] When did Cassini launch and how long is the mission?
Cassini launched on October 15, 1998. It will arrive at Saturn in July of 2004. First Cassini will drop a probe into Titan's atmosphere and then spend 4 years in orbit about Saturn studying its moons, rings, atmosphere and magnetosphere. If we still have fuel left in 2008 an extended mission will be planned then.

[ LindaSpilker/JPL - 12 - 10:11:42 ]
RE: [IleanaCotes] I am a Science teacher from Panama, Rep. of Panama. My students are so interested on the Cassini project that I decided to submit some of their questions. I am really delighted to be able to contact a scientist like you. They want to know why Nasa is so interested on the planet Saturn instead of Jupiter? What are the probabilities of success at the time of the arrival in the year 2,004? What planet is Cassini passing by right now? These questions were asked by my 4th. grade students that adore Astronomy! Thanks in advance for your answers. I am unable to attend the chat at that time because I will be working at school.
NASA is sending Cassini to Saturn since they have already had a successful mission to Jupiter (Galileo). Galileo is still in orbit around Jupiter and sending great data back to earth. We think the probabilities for success in 2004 are very high. Since the mission is so long, all of our key computers and important parts have backups. If one part fails, we switch to another. Cassini flew by Venus in March 1998. Next it will fly by Venus again on June 24, 1999 and then fly by the Earth on August 18, 1999. After that, we fly by Jupiter and then on to Saturn!

[ LindaSpilker/JPL - 16 - 10:14:04 ]
RE: [mrsmcd] Which is your favorite planet to study?
My very favorite planet is Saturn because Saturn has such spectacular rings! I enjoy trying to figure out how the rings work. Small moons outside the rings create interesting wave patterns inside the rings.

[ LindaSpilker/JPL - 17 - 10:15:34 ]
RE: [mrsmcd] Are there many women working on projects with you?
Quite a few women work on Cassini. Some are scientists, others write computer programs and some are engineers that actually helped build Cassini.

[ LindaSpilker/JPL - 21 - 10:17:35 ]
RE: [mrsmcd] What other sports did you attend?
I enjoy jogging and playing volleyball. I had a chance to see the Cassini launch last October and I also saw the Voyager launch over 20 years ago.

[ LindaSpilker/JPL - 22 - 10:19:21 ]
RE: [mrsmcd] Do you travel around the world?
Cassini is an international mission. The European Space Agency built the Huygens probe which we will send into Titan's atmosphere. Since we are an international mission we have about 1 meeting a year in Europe. I have also traveled outside the U.S. on my own. Two years ago I went to New Zealand. That was great!

[ LindaSpilker/JPL - 24 - 10:23:22 ]
RE: [mrsmcd] How many test steps do you have to go through before being hired by NASA?
The main thing I needed to be hired by NASA was a college degree. Since I am not an astronaunt I did not need to take any special physical exams. NASA also likes people who are interested in exploring space and the planets.

[ LindaSpilker/JPL - 25 - 10:26:52 ]
RE: [Ann/AERO] Aloha from Maui, According to JPL reports, Cassini will orbit several planets, one which will be Earth during August '99 in order to gain speed. When this occurs, the Earth will lose some speed. Would you explain this concept please?
Cassini is flying by several planets on its journey to Saturn. We have two flybys of Venus, one of Earth and one of Jupiter. As Cassini flys by each planet it picks up some energy and goes a quite a bit faster. As a result, each planet goes just a little bit slower. Cassini is very, very, very small compared to a planet so the amount each planet slows down is much too small to even measure. By using the planets, Cassini can get to Saturn faster and it also has to carry less fuel. This technique is called a gravity assist because we use the gravity of the planets to slingshot us on to our next target. The Galileo mission also used gravity assist to get to Jupiter.

[ LindaSpilker/JPL - 29 - 10:29:46 ]
RE: [mrsmcd] Have you ever tried astronaut food?
I have tried freeze-dried strawberry icecream. Not bad! Most of the NASA centers have "astronaut food" that you can buy.

[ Oran/NASAChatHost - 30 - 10:31:31 ]
We would like to remind you to share your thoughts about today's chat with us. At the conclusion of the chat, please use our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys to let us know what you think.

[ LindaSpilker/JPL - 31 - 10:31:56 ]
RE: [mrsmcd] Will you work on the space station?
I would like to work on the space station some day but first it needs to get built! Both my husband and I would like to travel in space some day. We almost sent in applications to be astronauts who would be helping to build the space station, but we like our jobs at JPL and decided to wait until it is done. The space station would be a great place to put a telescope for observing the stars and planets!

[ LindaSpilker/JPL - 32 - 10:35:04 ]
RE: [Ann/AERO] The Cassini Significant Events report for last week refers to the Cruise 10 sequence being executed normally and the Cruise 11 sequence successful uplink. What are these Cruise sequences (from an insiders take).
A cruise sequence is computer program that contains all of the commands that the spacecraft will need to execute for about 2 months. Each sequence has a number. The first sequences after launch were only about a week long because we were busy checking out the spacecraft. Now each cruise sequence is about 2 months long. At Saturn we plan to use one month sequences to command Cassini to take pictures and other data on the Saturn system. When one sequence (program) is almost finished, we sent up (uplink) a new one.

[ LindaSpilker/JPL - 36 - 10:38:40 ]
RE: [Ann/AERO] How does it feel to work on a project that has such a long term goal?
It is exciting to participate in a big program like Cassini. I started on Cassini in 1988. Over the years the kinds of activities I do have changed from focussing on building the spacecraft, to launching it, to learning to fly it and finally to taking data at Saturn. I worked on the Voyager mission for 13 years and the time just flew by. I am looking forward to getting to Saturn AND learning lots of new things about this unique planet. Also, long missions offer great job security!

[ LindaSpilker/JPL - 37 - 10:41:23 ]
RE: [mrsmcd] About how many people work on the same project as you.
Now that Cassini is flying, the project has gotten much smaller. We have several hundred people at JPL working on Cassini. About 400 scientists around the world also work on Cassini at least part-time. They are planning what pictures and other data they would like to take once we get to Saturn. Before launch we also had lots of people in industry working on building parts of the spacecraft. At launch, lots of people helped put the spacecraft on the rocket and helped launch it.

[ LindaSpilker/JPL - 38 - 10:42:54 ]
RE: [mrsmcd] Do you play a musical instrument?
I enjoy playing the piano. I took lessons for a number of years when I was growing up and still enjoy sitting down and playing the piano.

[ LindaSpilker/JPL - 43 - 10:45:44 ]
RE: [Bob] Now that John Glenn has gone back to space will NASA be considering older scientists that may have missed astronaute selection when they fist applied. If yes, are you consideriong applying.
Yes, it's possible that NASA will consider older scientists as astronaut candidates. Both my husband and I are interested in space travel. We may yet apply for a chance to go up, especially once the space station is finished!

[ LindaSpilker/JPL - 44 - 10:48:11 ]
RE: [Stephanie/Edmonton] Do you know Bridget Landry, Cassini Sequence Virtual Team Lead?
I have met Bridget briefly. There are some very talented people as leads for the Cassini Sequence Virtual Team. They are responsible for building the command loads that go to the onboard computers on Cassini. These loads tell Cassini what to do for about 2 months at a time.

[ LindaSpilker/JPL - 47 - 10:50:48 ]
RE: [Stephanie/Edmonton] Have you met Donna Shirley?
I have met Donna Shirley and know lots about her. She is a great lady! She was actually my boss about 10 years ago and she encouraged me to go back to school to get my advanced degree in physics. I am so glad I did! Now I am the Cassini Deputy Project Scientist. My job is to find the best ways to maximize the science return from Cassini within the project constraints like fuel and budget.

[ LindaSpilker/JPL - 48 - 10:54:07 ]
RE: [Stephanie/Edmonton] Was the public's fear of Cassini's plutonium fuel overexagerrated?
The public fear over the plutonium fuel was greatly overexaggerated. The fuel is packaged in small spheres that are like hard glass that are heavily padded. Even if Cassini had blown up on the launch pad, the amount of plutonium released would have produced a radiation dose that is far less than we get over time from natural radiation sources on earth such as radon.

[ Oran/NASAChatHost - 49 - 10:55:30 ]
As we near the end of the chat, we would like to remind you to share your thoughts with us at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ LindaSpilker/JPL - 50 - 10:56:07 ]
RE: [Stephanie/Edmonton] Do Cassini's RTGs have the ablility to jettison if an accident were to occur?
No, the RTGs cannot be jettisoned in case of an accident. If Cassini had an accident (probability is less than one chance in a million) and fell into the earth's atmosphere the RTGs may even survive intact to the ground. In that case, we could get the plutonium spheres back and possibly reuse them.

[ Oran/NASAChatHost - 51 - 10:58:49 ]
We will now be ending our chat with Linda Spilker. We invite you to join us this afternoon at 3:00 p.m. Pacific Standard Time for our next WON chat with Nancy Dorighi from NASA Ames Research Center. More information about this chat is available at http://quest.arc.nasa.gov/women/won-chat.html.

[ Oran/NASAChatHost - 52 - 11:00:15 ]
To learn about upcoming chats with other NASA experts, visit our schedule of events page at http://quest.arc.nasa.gov/common/events.

[ Ann/AERO - 53 - 11:02:08 ]
Thank you for all the great information about Cassini mission.

[ Bob - 56 - 11:06:48 ]
Thanks from Rancho Aviation.

[ Oran/NASAChatHost - 54 - 11:02:51 ]
Thank you to everyone for joining us today, and a special thanks to Linda Spilker for her time with us online.