Back Webb Team Profile: Marcia Rieke
Marcia Rieke

Principal investigator for JWST's Near Infrared Camera (NIRCam)

Interview Date: August 2006


Received a bachelor's degree and PhD in physics from the Massachusetts Institute of Technology.


Marcia Rieke was born in Hillsdale, Mich., and grew up in Midland, Mich., where the presence of Dow Chemicals headquarters made science a topic of interest for kids throughout the school system. After completing her education, she became a faculty member at the University of Arizona, where she is still a professor of astronomy. Rieke has worked with the Spitzer Space Telescope as a co-investigator for the Multiband Imaging Photometer, an outreach coordinator, and a member of the Science Working Group. She was also involved with several infrared ground observatories, including the Multiple Mirror Telescope in Arizona.

Marcia Rieke has a deadline. It's not until 2014, but much remains to be done.

As principal investigator for JWST's Near Infrared Camera, or NIRCam, Rieke is responsible for making sure that the instrument gets built and delivered on time and on budget.

It's a great deal of effort, Rieke said, but with a great purpose: “There's going to be a big payoff one day.”

NIRCam will study infrared light. Because the universe is expanding, light from the earliest galaxies have been stretched, or “redshifted,” from visible light into infrared light. Humans can't see infrared light, but we can perceive it as heat. NIRCam will be able to visualize infrared light, making it essential for examining the early phases of star and galaxy formation and studying the shapes and colors of distant galaxies. NIRCam will also help astronomers learn the age of stars in nearby galaxies.

Rieke, a University of Arizona astronomy professor, became involved with the JWST project in 1997, when NASA requested studies on how to configure instruments for the proposed telescope. A group at the University of Arizona, including Rieke, responded with a small study that was greeted favorably. Soon she joined the Ad Hoc Working Group for JWST, the group responsible for taking a close look at the type of science JWST could perform. The group broadened the purpose of the telescope past its initial goal of seeing the earliest objects in the universe to many additional types of infrared observations. In 2002, Rieke became principal investigator for NIRCam.

As principal investigator, Rieke works with the engineers at Lockheed Martin who are building NIRCam. She helps the engineers decipher the instruments' requirements, massaging its plans into shape. The requirements are like a broad outline, and when questions arise about priorities and compromises, Rieke's scientific knowledge allows her to fill in the details. “If it says the instrument has to change filters in 10 seconds, does that mean all the way around, half-way around …” she said. She compared it to a person trying to decide on the settings for a digital camera — do you use the portrait setting, or the scenery setting, or just use the camera manually? Rieke gives the advice on the settings an infrared camera will use best.

Rieke spends a good amount of time in meetings, or working on computer simulations that mimic the telescope's performance with different conditions and configurations, helping to clarify those priorities. She also keeps a close eye on finances. “We have to meet budget goals but it can't be construed as fun, that part of it,” she admitted.

Rieke was interested in science as a child, drawn to the field by science fiction stories. Back then, when she thought about being an astronomer, she assumed she would use telescopes on the ground. Humanity had yet to set foot on the Moon, and the space telescope was barely even an idea.

Rieke was actively involved early in her career with developing ground-based infrared telescopes, which face a tremendous challenge: the water vapor in Earth's atmosphere blocks much of the infrared light from space.

Building an infrared telescope in space presents an entirely new set of challenges, Rieke said. For instance, the Sun’s outer atmosphere is constantly boiling off into space, sending a barrage of particles that JWST will have to be able to withstand. But its position beyond the atmosphere also solves many of the problems ground-based telescopes encounter. “The ease with which you can observe in space makes the hard work worth it,” she said.

Rieke has worked with the Spitzer Space Telescope, NASA's most recent and powerful infrared observatory, and she's looking forward to working with JWST. “Spitzer is very sensitive, but its mirror is rather small,” she said. “So (the image) looks like a blob. You need a telescope with a large mirror to get the detail at those wavelengths.”

Rieke will be on a science team that uses JWST observations in the future, once the telescope is in orbit. She's hoping JWST will find the most distant galaxies that formed in the early universe. “Finding the start of stuff intrigues me,” she said. “That's the holy grail for me.”

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