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A look back in time

Lee Feinup and the James Webb Space Telescop

As the optical telescope element manager for the James Webb Space Telescope, Lee Feinberg '87 has overseen the overall development of the telescope, including three critical technologies: lightweight mirrors, lightweight cryogenic structures, and wavefront sensing and control. (Photo courtesy of NASA)

As the James Webb Space Telescope heads toward its launch date, dozens of Rochester faculty and alumni await the results of their contributions to the project, when the telescope begins sending images from 13.5 billion years ago.

By Bob Marcotte

Jim Fienup already knows what to expect when the first images arrive from the James Webb Space Telescope.

“They’ll look horrible,” says the Robert E. Hopkins Professor of Optics at the University of Rochester.

And no wonder. The largest ever, 14,300-pound, space-based telescope will have to be folded like a drop-leaf table to fit into an Ariane rocket, then endure a bone-jarring liftoff later this year to reach orbit 940,000 miles from Earth and nearly 700,000 miles beyond our moon.

When Webb is deployed—when the telescope is unfolded, along with a sun shield nearly the size of a tennis court—the primary telescope’s 18 hexagonal mirrors will be out of alignment.

“They’re going to be way off, maybe by a millimeter of where they should be,” Fienup explains. “So, we’ll start getting these images that are horribly blurred.”

Only after the mirrors are aligned to within one-ten thousandth of a millimeter will Webb be able to transmit what no human has ever seen before—remarkably clear infrared images from 13.5 billion years ago when galaxies and stars were first forming.

This marvel of engineering—this exquisite balancing of sheer bulk and exacting precision—owes much to Fienup. And to scores of other Rochester faculty members, students, and alumni who have contributed to the project.

Fienup and his talented team of PhD students developed the phase retrieval algorithms that can be used to finely tune the 18 hexagonal mirrors. The algorithms will compare the blurry images of a bright reference star taken by the telescope to how the star should actually appear—and adjust seven actuators on each of the mirrors accordingly.

And just in case the National Aeronautics and Space Administration (NASA) team using the algorithms runs into unexpected difficulties, Fienup and his students will be standing by with even more robust algorithms they’ve developed specifically for worst-case scenarios.

To fully understand why the Webb telescope is so unique—and why Fienup and two other key contributors with Rochester ties became involved in its development—you first need to need to understand what happened with Webb’s predecessor.

image of hubble

Despite an embarrassing debut, the Hubble Space Telescope proved to be one of NASA's most successful missions.

Hubble: We Have a Problem

The Hubble Space Telescope, launched in 1990, has revolutionized astronomy with more than 1.4 million observations of stars, galaxies, and planets during its 31 years of operation.

However, the initial images that the Hubble telescope sent were blurry. Unlike the “horrible” initial images expected from Webb, Hubble’s “nearsightedness” was not expected. NASA, coming off the Challenger space shuttle explosion four years earlier, faced a public relations disaster as politicians questioned the agency’s competency and comedians made the telescope a butt of their jokes.

Duncan Moore ’74 (PhD), the Rudolf and Hilda Kingslake Professor in Optical Engineering Science, was vacationing in Maine when he got a call from NASA to fly to Washington, DC, for a one-day meeting of experts to help figure out what went wrong.

“It seemed like there were a gazillion people there,” Moore recalls. The problem was quickly traced to a miscalibration during the mirror’s manufacture. Moore ended up chairing the Hubble Independent Optical Review Panel, which was formed to determine how the mirror shape differed from specifications and correct it. Against high technical odds, political machinations, and severe budget limits, the panel succeeded. 

Fienup, then a scientist at the Environmental Research Institute of Michigan, also played an important role. He led a project that helped determine the telescope’s exact aberrations by using phase retrieval algorithms to analyze Hubble’s blurred images.

And Lee Feinberg ’87, an Institute of Optics graduate who began working for NASA in 1991, helped conduct independent optical tests of the corrective optics and new instruments that were eventually installed on Hubble by space shuttle astronauts in 1993.

The contributions of Moore, Fienup, and Feinberg would be remembered by NASA when it came time to build Hubble’s successor.

Webb: The Next-Generation Telescope

Even before Hubble’s launch, astronomers and engineers began thinking about a next-generation space-based telescope. In 1996, a committee led by astronomer Alan Dressler formally established NASA’s ambitious expectations for Hubble’s successor.

With a primary mirror surface area more than six times larger than Hubble’s, Webb will have even greater light-gathering power and sensitivity for discerning faint stars and galaxies at the edges of time. Unlike the Hubble, which gathers images primarily at visible and ultraviolet wavelengths, Webb will gather infrared images.

That’s important because the ultraviolet and visible light emitted by the first luminous objects that formed in the universe has been stretched by the universe’s expansion so that it reaches us today as infrared light. With its enhanced ability to detect infrared light, Webb will be able to peer even further back in time.

However, the telescope will need to be kept below -370 degrees Fahrenheit to capture infrared images. To accomplish that, the telescope must orbit at a point nearly one million miles from Earth, where it can be continually shielded from the light of the sun, the Earth and its moon.

The distance is too great for Webb to be serviced as easily and efficiently as Hubble was by space shuttle astronauts. This has increased the need for NASA to carefully test every aspect of the Webb prior to launch—even at cryogenic temperatures.

Moore, who had recently completed a stint as associate director for technology in the White House Office of Science and Technology Policy, was named cochair of the Webb Telescope Optical Product Integrity Team in 2002 to help ensure that no shortcuts were taken. Fienup later joined him on the panel.

Feinberg, who had left NASA to work with a start-up company, was lured back shortly after 9/11. The Webb project had just been endorsed by the Decadal Committee—an organization of astronomers and astrophysicists who survey the field every 10 years or so and make recommendations for future projects. Webb was also getting a lot of funding, and John Mather, an eventual Nobel Prize winner, was the project scientist, Feinberg says. “And for an optical engineer, the project was about as interesting as one could ever imagine.”

In 2001, Feinberg was given one of the Webb project’s most important leadership roles. He had no idea it would turn into a 20-year commitment.

Collage of Fienup, Moore, and Feinber

Jim Fienup, the Robert E. Hopkins Professor of Optics, at left, and Duncan Moore ’74 (PhD), upper right, the Rudolf and Hilda Kingslake Professor in Optical Engineering Science, served on the Webb Telescope Optical Product Integrity Team. Lee Feinberg '87, lower right, the Webb’s optical telescope element manager, says his most important contribution was successfully planning and then overseeing the cryogenic testing of the Webb telescope and its optics in Houston in 2017--even as Hurricane Harvey devastated the region.

The Webb Project Perseveres

Feinberg remembers working as an undergraduate at the Laboratory for Laser Energetics, using software and optical testing to help solve a problem when the fusion energy lab switched from red to blue lasers. The experience “helped me become a better student, and also helped prepare me for the future,” he says.

As Webb’s optical telescope element manager, Feinberg has overseen the overall development of the telescope, including three critical technologies: lightweight mirrors, lightweight cryogenic structures, and wavefront sensing and control. He also cochaired a review board that chose beryllium as the material for the primary mirror and has been a significant contributor to the telescope flight and test architectures.

Feinberg proudly recalls how he and his team “worked crazy hours” to develop the new technologies in three and half years. Actual fabrication of the mirrors, done by multiple contractors, kept him “traveling all over the country” for eight years, “figuring out how we were testing the mirrors, how they would all work together, and dealing with both management and engineering at the same time."

His most important contribution, Feinberg says, was successfully planning and overseeing the cryogenic testing of the telescope and its optics. The ultimate testing took place in 2017 at Houston, in a 90-foot-tall chamber at Johnson Space Center originally used for testing the Apollo spacecraft in the 1960s.

The work was completed despite a near catastrophe.  

Just as cryo-stable temperatures were reached, Hurricane Harvey slammed into Houston with devastating force. It took “an amazing team effort” by 120 international engineers and scientists to keep the tests going, Feinberg later told attendees at a conference of SPIE, the international optics and photonics professional society. Four team members who owned “big Texas pickup trucks” shuttled people to and from the facility every 12 hours. “We had some leaks we had to deal with; we had people sleeping on the floor; but we got through the storm without any risk to the flight hardware,” Feinberg told the group. “I think everyone went beyond what they signed up for in engineering or astrophysics school.”

Most important, the optics performed admirably.

However, amid all these successes, an increasing, demoralizing chorus of public criticism began in 2010 as the costs of the Webb project began to escalate dramatically.

“It was hard to have worked so hard on something and felt that we had done so many things right, only to get a lot of negative publicity for the increased cost,” Feinberg says.

Will Webb Be Worth It?

In April 2017, Duncan Moore sent a photograph to Rochester from the Goddard Space Flight Center in Maryland. The message read: “I am standing in front of the James Webb Space Telescope—the replacement of Hubble. It is leaving Goddard in two weeks for testing at Johnson SFC. I started working on this in 2002 when the launch date was 2009 and the price was $1.5B!”

A US Government Accountability Office issue released in May 2021 estimated the cost at $9.7 billion. The report also cited yet another delay in the scheduled launch because of “anomalies” with the launch vehicle, compounding a series of previous delays that have resulted from a multitude of causes, including problems uncovered during integration and testing.

Even in 2002, it was clear to Moore, Fienup, and Feinberg that NASA had severely underestimated costs given the daunting scope of the project and the engineering challenges it entailed.

“I think there was a little bit of hopeful thinking early on,” Feinberg says. “I had it in my mind that this is going to be a lot harder than they think.

“Remember, however, this is the first lightweight, segmented telescope NASA has ever built. There was no road map. We had to invent almost everything, from how we modeled it, to how we tested it. So how do you cost estimate something like that when you’re literally inventing it as you go?”

Nonetheless, even fellow scientists in the field have expressed concerns that NASA is putting too many eggs in its Webb basket, at a cost to other projects.

Martin Elvis, an astrophysicist at the Harvard–Smithsonian Center for Astrophysics, argued that “the dominance of a single mission like Webb can be a bad thing” in an interview with Scientific American in 2018. “It fosters a ‘too big to fail’ syndrome, where because it mustn’t fail you can’t realistically threaten it with cancellation, and people err on the side of caution to ensure it will succeed. More caution means more testing and more money, which you must provide to avoid failure, and so you get a feedback loop of inflating costs.”

So, will Webb be worth it?

The ‘Webb’ of Benefits

In 2011, Kyle Fuerschbach, a PhD student in the lab of Jannick Rolland, the Brian J. Thompson Professor of Optical Engineering, was performing a computer simulation using a model of the James Webb Space Telescope. During the simulation, Fuerschbach uncovered a graphical aberration field behavior that led Rolland, visiting scientist Kevin Thompson, and Fuerschbach to develop the aberrations of freeform optics. The observation by Kyle solved an analytic puzzle that had confounded leaders in the field for over 100 years. The discovery established the theoretical basis for designing systems with freeform optics guided by an understanding of the optical aberrations generated when folding or mounting the optics.  The findings also accelerated the creation of the National Science Foundation Center for Freeform Optics (CeFO), headquartered at the University of Rochester and directed by Rolland.

Since joining the Institute of Optics in 2002, Fienup has received 16 years of continuous funding from NASA, totaling more than $1.6 million, much of it to develop those more robust phase retrieval algorithms for the Webb project. Six of his PhD students have based their theses on research related to the Webb. Five of his students have subsequently gone to work for NASA’s Goddard Space Flight Center.

Benefits like these have doubtless accrued at other universities across the country. 

Feinberg cites other benefits. The project, for example, is “exciting young people into STEM (science, technology, engineering, and math) fields,” he says. “We’ve done a lot of technology development that’s had a lot of cross-over to the space program.” 

And if Webb performs as expected, 286 experiments and observations, proposed by scientists from around the world, will be performed with the telescope during its first year of operation. 

“What is really striking is that every one of these observations feels like it could be its own mission,” Feinberg says. In that light, he says, the costs of Webb, when weighed against the cost of launching nearly 300 separate missions, become more reasonable.

Moore says he can understand why critics might disagree. “We have so many social things that we need to be doing. When you compare Webb to programs that cost in the trillions, $10 billion, if that ends up being the cost, seems like small potatoes. But $10 billion dollars is a lot of money.” 

As an engineer, however, Moore says he is “extremely excited about the capabilities Webb will give us to look back further into time.” 

So are other members of the University community who are both grateful and proud that they’ve been able to contribute. 

“To be a part of something of this magnitude is a once in a life-time opportunity,” says mechanical engineering alumna Laryssa Sharvan Densmore ’83, who is director of space products and manufacturing at Northrop Grumman, the primary contractor for Webb. “Webb will change the way we see the galaxies, unfold our past and open our scientific aperture of understanding as it relates to astronomy, astrophysics and our place within this universe.”

Optics alum Richard Rifelli ’74, ’77 (MS) has served as Northrop Grumman's lead system engineer for the telescope since 2002. “To witness the development of this unique observatory from a concept to a fully functioning observatory has been remarkable,” he says. “It truly has been an honor to work with so many talented people on this program.

“The science will be amazing!”

A Community Effort

Here’s a sampling of how University faculty, students, and alumni have contributed to the James Webb Space Telescope: 

The Webb Telescope Optical Product Integrity Team, charged with making sure that proper testing was undertaken, was cochaired by Duncan Moore ’74 (PhD), the Rudolf and Hilda Kingslake Professor in Optical Engineering Science, along with optics alumnus Jim Wyant ’69 (PhD). Other members included Jim Fienup, the Robert E. Hopkins Professor of Optics; Greg Forbes, a former optics professor; and optics alumni Roy Frieden ’66 (PhD) and Robert Shannon ’54, ’57 (MA). 

Laryssa Sharvan Densmore ’83, mechanical engineering graduate, directs Mechanical Space Products and Manufacturing at Northrop Grumman, the prime contractor for the Webb project. About 225 members of her team worked directly on Webb-related products. In addition, Richard Rifelli ’74, ’77 (MS) of optics has served as lead systems engineer of the optics telescope element at Northrop Grumman since Webb’s inception, and Ben Weiss ’04 (PhD) of physics, a systems engineering lead at the company, will be at the console at the Missions Operations Center in Baltimore, Maryland, supporting Webb’s launch and commissioning as an anomaly response coordinator. 

Lee Feinberg ‘87 is the optical telescope element manager and Joe Howard ’00 (PhD) is the lead optical designer. They are among 43 optics faculty, students, and alumni who have contributed to Webb, according to David Aronstein ’02 (PhD), who wrote a chapter about their involvement for an update of optics professor Carlos Stroud’s history of the Institute of Optics, A Jewel in the Crown. Aronstein, a former optical scientist at NASA, also worked on Webb.

Learn more

Lee Feinberg discusses his role in the James Webb Telescope in this TEDx talk given at the University of Rochester and in this presentation to a SPIE conference.