Project manager, Galileo Millennium Mission
Eilene Theilig: Faith, by Jupiter
By Porter Anderson
(CNN) -- "I did my graduate work on Mars."
That's not quite what Eilene Theilig means. But when she catches the way it's come out, her laugh rings as clear as a Galileo photo of the massive planet she studies.
Since January 29, Theilig has been the manager of NASA's Galileo spacecraft mission to Jupiter at the Jet Propulsion Laboratory (JPL) in Pasadena, California.
And on August 5, she may be less prone to giggles. That's when the 12-year-old Galileo spacecraft makes a north-polar pass at the Jovian moon Io.
"It's always a nervous time for us," Theilig says. "Io encounters are particularly challenging. They're in closer to Jupiter than most of the moons we fly by. And they deal in a radiation environment, the spacecraft gets socked pretty well with radiation on these passes.
"Galileo has already taken three times the dosage of radiation it was designed to take. So there's a risk to the electronics. We're already starting to see some degradation in the science instruments, but there's always a risk there may be something that could happen to one of the more critical systems. Of course we have redundant systems on board, but it's always a challenging time."
No one's going to ask for his money back if Galileo doesn't make it through this flyby or the two more scheduled at Io before a pass at the smaller moon Amalthea and a final controlled impact on Jupiter in 2003.
"After the primary mission" -- a six-year trip to Jupiter and a two-year exploratory orbital mission there -- "we scaled back to a more streamlined operation with fewer people, which had its own challenges. We've continued now for four years beyond Galileo's primary mission."
Theilig says the scaling back for the past four years to the team of a total 50 or 60 people she directs, however, isn't a function of funding cutbacks -- quite the opposite.
"It was a matter of asking, 'What could we do with more time and a smaller team to get extended life out of Galileo?' We went to NASA saying, 'OK, at this point, we still have a good spacecraft. We really did survive. And we still have excellent science that can be done. We need more money than was budgeted. And we've gotten very good support from NASA" -- a $9 million extension of its science program, to be exact.
"Some of our long life is a result of the way the mission was designed: six years to get to Jupiter, then the two-year orbit. But even beyond that, the spacecraft has been so robust and the science has been so great. Our flight team just keeps rising to the challenges."
One of the most poignant of those challenges is scheduled for September 2003, when this "workhorse of a spacecraft," as Jay Bergstralh, NASA's acting director of solar system exploration calls Galileo, will be sacrificed in order to prevent any chance of human-exploratory contamination of another world.
Galileo will make one last elongated loop away from Jupiter, then turn and zoom directly into the planet's atmosphere, a fiery end approved in December by the Research Council of the National Academy of Sciences.
"At the time the Galileo mission was designed," Theilig says, "we didn't have any indication that there may be life -- well, that's kind of a strong statement -- let's say that there's a high potential of a layer of liquid water on Europa, the second moon out from Jupiter. That water might occasionally interact with the surface.
"With that in mind, we don't want to cause any contamination of that moon. It wasn't an issue when we launched, but through our own discoveries, we now have to plan a different end.
"NASA takes those issues very seriously. We've been working with a planetary protection officer at NASA headquarters on this."
It's Galileo that produced the evidence of a melted saltwater ocean under the ice layer surface of Europa. (That sea is the site of Arthur C. Clarke's imagined effort by the monolith to develop intelligence in "3001: The Final Odyssey," published in 1996 by Ballentine.) The Galileo craft has also sent back indications that similar layers may exist on the moons Ganymede and Callisto.
"Ultimately, if we kept trying to fly the mission, we would use up all our propellant," Theilig says. "And personally, I like the impact idea. I like the definitive conclusion."
Working her way up
Theilig is 47 and grew up in Houston, Texas, the daughter of a father who was a CPA and a mother who at one time ran a crafts store.
Hers is "a career type that could eat you up," Theilig says. "I think you have to be very careful with that. I don't have family. I balance my life with a faith community. I'm very active at my church, the Disciples of Christ," near her home in Monrovia, California.
"I can get away from the laboratory. Our society is so mobile that very few of us live in areas with the large extended family that we used to have. I think faith communities can help fill that gap.
"I'm up at church probably an average of three times a week. A lot of it is meetings. I chair the worship committee, and I'm an elder." Earlier in her life, Theilig says, she was "in and out of organized religion," her parents having been churchgoers in Houston.
Theilig didn't grow up a kid stuck on the stars. "Of course, I was always fascinated by the lunar flights, watched them on TV. I found the whole idea of space exploration fascinating. But I was much interested in geology, the sciences and history.
"When I went into college," at the University of Texas in Austin, "I opted for geology, which was great because that and oceanography -- this was in the 1970s and they were just starting that whole phase of planetary geology, trying to understand other planets and the moon. I got to do some of that as an undergraduate, so that's probably when I decided I wanted to pursue space exploration."
In the mid-1980s, Theilig published research about the geological history of Mars -- that "graduate work on Mars" she's giggling about. She was taking a Ph.D. in planetary geology at the time from Arizona State University. And 10 years earlier, she'd spent a summer as an intern at the Jet Propulsion Laboratory in Pasadena, assisting the Viking imaging team.
"I joined the mission seven months before launch, in March 1989. I was then a sequence integration engineer, which means that I helped put together, design, plan, then build the command sequences for the spacecraft.
"I know what it takes to build the command sequences for the spacecraft. I'd joined the mission design team. The project was handed off to the sequence team, that took it to the command generation. Ultimately we merged the two teams. In 1997, we merged sequence with the spacecraft team, the engineering team, and I was team chief at that time. So I kind of worked up through the ranks."
Command sequencing and building is at the heart of an unmanned spacecraft's mission. "We build commands for the spacecraft that cover anywhere between three or four days up to several months. So everything the spacecraft does in that time is built into this one sequencing command. So it's a continuous process of building these for the next sequence or 'load' that goes up.
"While in orbit, in this extended mission, we have one sequence or 'load' of command for the encounter period, and one for the 'cruise' period in which we play back all the high-rate data recorded during the encounter."
After the mission is flown, "I move on to something else. I'm not involved in the science data analysis. That's done by the science teams. Our final responsibilities are coming up with the final report and closing down the project."
Theilig says she doesn't know yet what she'd like to do after Galileo dives into the Jovian clouds. "A lot of it will depend on what's available at the time. JPL is a great place to work. Most of the people who work here are really dedicated. It's not just a job."
What would she like to do if she weren't in planetary exploration? "Permanent retirement travel," the laugh catches up with her fast. "Seriously, I don't know, I've been so wrapped up in work that I haven't really thought about that.
"What I've enjoyed about JPL and working on Galileo is that it's changed character every few years. Always something new and different to work on. If it had stayed the same, it could have become somewhat routine.
"But our spacecraft has always presented us with challenges. And the changing complexion of the mission -- the six year trip, then the two-year primary mission, then the extension we're in now -- I've always learned on the job.
"There's a progression in management that one goes through. Each new level of responsibility brings a better understanding and more familiarity with the process. Each step has brought its challenges."
Some members of Theilig's team -- it's made of part-time as well as full-time employees -- already are working part-time on other missions at JPL. "I think that's great," she says, "they get the exposure and have something that's a natural stepping stone" after the Galileo program is closed.
"Ideally the lab is set up as a matrix organization. Our 'line management' is responsible for keeping up the skill base in the work force. And how the work force moves from project to project -- how we staff all that's going on. So that organization is in place to help people move between projects.
"My team is so great, that even though it's not my responsibility to help my team members move on, I want to help them" after the Galileo mission ends.
Theilig says that her faith hasn't been affected as heavily by her work as it has, say, some astronauts who sometimes talk about a new sense of spirituality after going into space.
"I've just always had a belief in God. It's part of me."
Rendezvous with Jupiter
December 7, 1995
Galileo finally comes through for NASA
December 8, 1995
A peek inside Jupiter
May 22, 1996
Life on ... Europa?
August 13, 1996
Galileo offers stunning views of Jupiter and moons
October 17, 1996
Jupiter has wet, dry areas mirroring Earth's
June 5, 1997
Galileo images reveal super-hot lava on Jupiter's moon Io
July 2, 1998
Galileo sends back details of Jupiter's rings
September 15, 1998
Jupiter's moon Callisto may hide underground sea
October 22, 1998
Dusty Jupiter moon gives clues to interplanetary rings
June 16, 1999
Scientists discover key to Io light show
August 5, 1999
Galileo returns closeups of volcanic Io
August 27, 1999
Scientist: Jupiter radiation could mean life on Europa
January 28, 2000
Roaming Galileo returns to heart of Jupiter system
February 1, 2000
Galileo images offer color-coded clues about Io
March 6, 2000
Galileo, Cassini to study Jupiter in joint expedition
March 9, 2000
Jupiter turns blue before in-depth exam
December 15, 2000
Spacecraft flyby paints new picture of Jupiter
December 30, 2000
Engineers working on Galileo camera mystery
February 22, 2001
Galileo spies Io's hot lava, tall mountains
February 27, 2001
Jet Propulsion Laboratory
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