It’s a long, agonizing wait for astronomers. The James Webb telescope is coasting to its final orbit around the sun at “L2,” a point in space about a million miles farther out from the sun than Earth. It’s a spot that allows the telescope, the most sensitive and sophisticated instrument ever put in space, to keep all the major nearby sources of heat and radiation, whether Sun, Earth, Moon, or the telescope’s own electronics and attitude jets, safely to one side of its tennis-court sized heatshield.
A great deal has to go perfectly right. The heatshield, a stack of five unfathomably thin sheets of a material called Kapton, the thickest of them just five-hundredths of a millimeter thick, has countless points of failure in its unfolding machinery. The primary mirror, the first telescope mirror ever put into space in individually mobile segments, must deploy perfectly for the telescope to catch the hoped-for glimpses of the earliest universe. Reaction wheels, dozens of actuators that move and contort the mirror segments, a unique refrigeration system, the final correction burn delivering the telescope into its L2 orbit – all have to work perfectly, because no currently existing spacefaring technology will allow NASA to send anyone to fix it.
Webb is an astonishing gamble, a $10 billion megalith so complex and so promising it seems a hubristic provocation against the gods. Worryingly for the superstitiously inclined, everything seems to have gone extremely well so far. The launch from Earth was so perfectly aimed that NASA announced it would need less fuel for the correction burns, potentially extending the ten-year estimate for Webb’s operation by several years.
Shortly after Webb’s picture-perfect launch into space on Christmas Day, The Times of Israel caught up with Michael Kaplan, a former NASA engineer who headed the space agency’s telescope planning in the 1990s and was one of Webb’s initiators, for a video interview from his home in Colorado on how Webb has already pushed the boundaries of humanity’s engineering capabilities and will soon dramatically grow our knowledge of the early universe, on why Israel’s innovative culture can paradoxically make it bad at space engineering, and where the near future of space travel is headed.
Kaplan, 66, has spent a career in aerospace, from a decade at the US Naval Research Lab in Washington where he worked on space-based radars meant to counter Soviet ICBMs, to NASA, Ball Aerospace (the Colorado company that built Webb’s now-famous honeycomb mirror), Boeing to work on planetary probes, and finally, in a plot twist, a bittersweet five-year sojourn in Israel, where he became a citizen and worked closely with SpaceIL, the Israel Space Agency and the Israeli aerospace industry.
Kaplan moved back to the US in 2015, where he has worked on space missions and weather satellite systems at companies like Raytheon. He is now a vice president at Belcan, a major American engineering firm and government contractor.
The conversation, which is edited for clarity and length, began with the stupendously courageous decision to build and launch so complex a telescope in the first place.
The Times of Israel: You’ve said there’s an unwritten rule in spacecraft design: “You want the minimal number of moving parts. Anything that moves can fail.” We’ve heard about the James Webb telescope’s main purpose, to catch a glimpse of the early universe, and about the excitement and anxiety its launch has sparked in the astronomical community. But to do that, Webb must have many hundreds of moving parts, including hundreds of individual points of failure that, if they don’t deploy and operate perfectly, could scuttle the whole $10 billion mission. Why is Webb such a big deal? Why is it worth the risk?
Michael Kaplan: When Hubble was launched [in 1990], there were people protesting at the launchpad because they were afraid Hubble was going to see God, like he or she is behind the clouds and Hubble was going to reveal it. Hubble pictures have been on magazine covers because they look like art. There’s something profound and wonderful about the fact that the natural universe in all its splendor becomes art.
But Hubble was limited by its aperture size, the sensitivity of its detectors and instruments, and by the fact that it wasn’t very cold.
Most people don’t realize this, but Hubble only actually observes about 35% of the time. The other 65% of the time it’s dodging the Earth, Moon and Sun, because we don’t want earthlight, moonlight or sunlight getting into the telescope and ruining the instruments. It also can’t see longer wavelengths than the near infrared. The oldest bits of the universe [whose light has been traveling the longest through ever-expanding space, and so whose wavelengths have stretched the most] appear to us shifted far into the…