Meet the Woman Who Makes the James Webb Space Telescope Work

"Give me a telescope, and I can come up with something good to do with it," says Jane Rigby, an astronomer at NASA who serves as the agency's operations project scientist for the largest and most powerful telescope. She has used many of the world's premier ground- and space-based astronomical facilities over the course of her career, and she is helming one of the many " early release science" campaigns front- loaded for its first year of observations. The main goal of her work with the telescope is to make sure everyone who uses it can do something good, by looking after the full scope of scientific investigations the telescope will perform for researchers around the globe during its five-year primary mission. For those hoping to squeeze as much science as possible out of this one-of-a-kind observatory, each and every moment of Webb's time is precious.

She and her colleagues have been working nonstop to prepare the observatory to deliver breakthrough discoveries about the universe. With its mirrors and instruments ready, and its first batches of science images and data set to be released imminently, it is poised to truly begin. The delicate task of maximizing returns on a $10 billion investment in the biggest and best telescope in the known universe was one of the topics discussed by Scientific American.

The transcript of the interview has been changed.

It looks like things are going well for the man. We are on the verge of seeing the telescope's first science images, its performance has exceeded expectations, and its voyage to deep space left it with enough surplus propellant to operate into the 2040s. This amazing facility that may in some respects be the single biggest investment ever made in astrophysics requires decades of steady, diligent work and is worth $10 billion. I wanted to talk to you about how the project is protecting the investment and maximizing the juice for the squeeze.

The things are looking good. The telescope is as good as we said it would be. I am happy to discuss all aspects of juice making. I am excited to show the first science images from the team. We will put some juice out for the first time and everyone will be able to judge it for themselves. If we are not talking about steroids, this is a good metaphor.

Isn't the man "Hubble on Steroids"? It was a bad joke and I apologize.

A lot of steroids would be required. It is a hundred times more powerful than the others.

Okay. You're the project scientist for operations. Is that saying you're making all the juice?

Project scientists act as the conscience for the science. The telescope was mostly built by engineers and managers, but scientists had to be in the loop to make sure it could do the science for which it is being built. I worry about how the telescope will be used, from selecting proposed observations to making observing schedules, from operating the telescope to getting the data back to Earth. It doesn't matter what it takes to get the science done.

It's right. Just to be clear, you are an operations project scientist, but that doesn't mean you choose where you look or who uses it.

There is no one in the inside track. Peer review is where most of the time is spent. More than a thousand proposals from all over the world were reviewed and ranked by a panel of 200 experts. The top quarter was chosen. Reviewers don't know who wrote the proposals and the proposers don't know who reviewed them The ideas should be judged by their quality. It is possible for an autodidact from outside academia to get time to work on a project. You can still use the telescope if you live in a country that doesn't like our country or if you didn't do anything to help build it. We want the best ideas.

How do you decide which ideas take priority? It seems like it's a tough job.

This will be similar to explaining the difference between building a juicer and actually using it to make juice.

A third of the sky can be seen on any given day. It's important that the sun shield is always oriented so that it blocks light from the moon and the Earth. Over the course of a year, that field of observability can show 100 percent of the sky. Knowing that, we can calculate the number of days per year we can see it. For 60 days a year, our solar system's targets can be found in the plane. It's possible to find targets out of the plane at the north or south poles of the solar system. There are targets in the middle of the latitudes.

We need to look at some targets. Something like an exploding star, or exoplanets at certain points around their stars, is1-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-6556 is1-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-6556

How dark is the sky? Whether you look through hot dust toward the Sun or cold dust further out in the solar system, it matters a lot. For a target, how dark the sky is depends on the season. We don't really pay much attention to some observations. We want to schedule when the sky is as dark as possible if we are looking at faint objects.

We don't want the man to be busy. The data needs to be returned to Earth. During normal science operations we talk to Earth about a third of the time. The data rate is about 30 megabits per second, but it is slower than a cable modem. Users are asked not to be data hogs and we do a lot of data compression.

A family of acceptable solutions can be generated by scheduling the telescope over all the constraints. We assign a month-long time slot for every observation in our long-range plan. We will make a detailed schedule for that week every seven to 10 days. The process is adapted from Hubble, which has a lot of constraints.

That's such as?

The Earth is in the way of Hubble. Hubble gets ready by slewing to the next target. It is in deep space, so it doesn't have that problem. Hubble hides its slews behind the earth. The minute hand on a clock is quicker than the telescope's slew. It would take most of an hour to turn it 180 degrees. The scheduling problem is a classic example of how to use gendered language. We link up a lot of visits that are close together in the sky to save time.

It is important to schedule and take care of the telescope because they are different. A limit on the lifetime of the telescope is set by the fact that photon carries momentum. One of the main constraints on the lifetime of the man is the use of propellant.

Is it possible to unpack that for us a little?

The sun shield applies a lot of Torque. We want to point the telescope at targets instead of getting the sun shield perfectly balanced by sunlight. The photon hits the sun shield, they apply Torque, and the reaction wheels spin to counteract the effect and keep the telescope pointed. The wheels can only spin quickly. Occasionally, they have to stop. The reaction wheels are slowed down by the Earth's magnetic field. In deep space, that doesn't work out, so instead of pushing against the reaction wheels, he fires thrusters. Each time we do these dumps we use little propellant. At this point, we have enough propellant to get into the 2040s, so it is more likely that we will be limited by how long components last. It feels odd to be planning the nursing- home days of this telescope when it is still a baby.

If everything else stays the same, and propellant inevitably runs out, how will we know when it's time to die?

So we're talking about the death of this thing? I don't want to talk about it because it's a brand new telescope. Talking about the death of a baby is similar to that. We wouldn't be able to control the pointing to make sure the solar panels always see the Sun if we were to talk about being propellant- limited. Recovering from the solar panels falling into shadow would be hard. I suppose that would be the last time he would speak. It would be when we knew it was dead. It is difficult to know what will happen to the newborn in its twilight years.

We were surprised by a micrometeorite impact that had a greater than expected effect on one of the primary mirror segments. Micrometeorites are a fact of life in space that will degrade the quality of the mirrors and the sun shield over time. We are figuring that out. I still have a long mission in mind.

It's true. It seems like you and other people who work on it have an emotional attachment to it. Is it more difficult to navigate all the make-or-break moments in the telescope?

The feelings change for different phases of the project. There were a number of days when we knew we might lose the mission when we were doing major deployment. NASA made a video called "29 days on the edge" I tried to think that if it doesn't work we don't have a mission. I realized I was going through stages of grief after every deployment. I don't need the primary mirror to unfold its two wings so I want the secondary mirror out.

The secondary mirror has a question.

It sounds like it's not important or a backup. Secondary means the light hits it after the primary. The primary mirror is large and famous. The 0.7-meter secondary is absolutely crucial. If the secondary mirror deployment didn't work, the light from the primary mirror would fly out to space and be lost forever. If we still had the secondary mirror, we would have a functioning telescope. After working on this thing for the past 11 years, I realized how worried I was when the secondary mirror deployed.

We are done with those make-or-break moments and intense testing. The telescope has cooled and is ready to use. With the first science images we will show that the telescope is capable of doing all the amazing science that it was built for. It feels great.