Lien Pham sometimes thinks of herself as a "spacecraft dressmaker."
She's been making thermal blankets at NASA's Jet Propulsion Laboratory, Pasadena, California, for 16 years. Just as clothing can be sewn too tight or too loose, thermal blankets -- the glinting material each spacecraft is wrapped in to regulate its temperature -- have to be cut to form. A thermal blanket has to provide just the right amount of heat -- not too much and not too little -- for the spacecraft to operate correctly.
Pham is a member of Flight Technicians Services, a group at JPL that contributes to all stages of spacecraft assembly. Her particular team, which designs and fabricates the protective thermal blankets, is called the shield shop.
At JPL, a place known for complex engineering, Pham has a different background: she began her career as a seamstress after her family immigrated to the U.S. from Vietnam. Her experience behind a sewing machine has informed how she makes thermal blankets.
We sat down to talk with Pham about her life and her work at JPL.
How did you start your career?
My family left Vietnam in 1978. At the time, we were persecuted as Roman Catholics in a Communist country. My family also had ties to the deposed South Vietnamese government and were targeted for political persecution.
When I first came to the U.S., my family settled in Los Angeles, and I found a job making lingerie for Olga. That was the only job I could get with my skills and limited English language ability. I made only $2.10 an hour.
To find a better job, I decided to learn a new skill. I attended a trade school in the San Fernando Valley [an area of Los Angeles] at night. They had basic courses in electronic assembly, which trained me in soldering and cabling.
In the 1980s, the aerospace industry in Southern California was booming. I found jobs at two big companies, Data Metrics and Litton, Inc., doing cabling for terrestrial vehicles and space satellites.
Spacecraft electronics are unique -- they're not like what you find at an electronics store at a mall. It takes a lot of skill to connect all the cables.
How did you find your way to JPL?
In 1994, I got hired on to the Cassini mission as a cabler for three years.
In 2000, my friend Mary Reave, a cabling engineer I worked with, told me they were hiring in the shield shop. She said, 'You should try it because you know how to sew.'
Although I loved sewing and had made some of my kids' clothes, I had never worked with thermal blankets. I told Mark Duran, my mentor at JPL, "I've never done it. But if you're willing to train me, I'm willing to try." I didn't know it would be something I'd enjoy and work at for 16 years.
What kind of materials go into a thermal blanket?
We use multiple layers of Mylar films with Dacron netting to separate them. For the outermost surface, we use Kapton film or Beta cloth, which resist temperature change.
We also use gold Kapton, which is good for conducting electricity. There's a black material called carbon field Kapton. That's for a charged environment, with a lot of electricity. It dissipates the charge.
What's the toughest material to work with?
Teflon. Some spacecraft require it, but tape doesn't stick to its surface. Tape is a part of the blanket-making process. At one point, we asked, "How are we going to build the material if the tape's not sticking?" We came up with a fabrication method that creates a hem like you would see in clothing, where the material is folded and then sewn.
What kind of tools do you use?
We use commercial sewing machines designed for thick material such as denim. It has a walking feed that pulls in the material and cuts our sewing thread automatically. We also use a variety of hand tools like a measuring scale, scissors, surgical scalpels, hole punches, a heat gun, leather punch and weight scale.
What do you enjoy about this work?
Most people don't see the end of a project. They just do their part and it moves on. I like blanketing because I'm able to contribute to a project from beginning to end.
On the Mars Science Laboratory, I was one of the last people to touch the spacecraft before launch. I was one of the last to touch the Curiosity rover that it carried to Mars. We had to install the last thermal blanket, called the Windbreaker, before sending the mission off to Mars.
Do you still sew clothing for yourself?
I still sew for my kids as a hobby. For example, my eldest daughter is getting married next year, and I'm spending a lot of time on bridal dresses for her and her bridesmaids.
Any advice for someone who is interested in space and JPL, but doesn't necessarily have a science or engineering background?
Work hard and keep an open mind. It's never too late to learn and take classes. There are a lot of people at JPL who didn't start in science or engineering, but almost all of them have the drive to learn new skills or search for training.