New window opens on cosmos if all goes well
Telescope must avoid 344 ‘single-point failures’ to operate
NASA’s long-delayed James Webb Space Telescope, a $10 billion marvel of engineering and scientific ambition, is finally poised to rocket into deep space from a launchpad in French Guiana, on the northeast shoulder of South America. What happens in the following days and weeks will either change our understanding of the universe or deliver a crushing blow to NASA and the global astronomical community.
The Webb must cruise for 29 days to a unique orbit around the sun that keeps it roughly 1 million miles from Earth, four times the distance to the moon. At launch, it will be folded upon itself, a shrouded package inside the cone of the European Space Agency’s Ariane 5 rocket. After it escapes Earth’s gravity, it must begin opening up, blossoming into a functioning telescope.
That starts with the deployment of the solar panels to make the whole thing work. Next comes the unfurling of a tennis court-size expanse of multilayered foil — the sun shield, akin to a giant umbrella, ideally more reliable than what you would get from a drugstore.
Then, the telescope must deploy 18 hexagonal, gold-covered, beryllium mirrors, which collectively act as a light bucket 21 feet across, designed to capture ancient light emitted more than 13 billion years ago as the embryonic universe was still learning how to create stars and galaxies.
What could go wrong? NASA actually has an answer to that question: This mission is vulnerable to, and therefore must avoid, 344 potential “single-point failures,” according to an independent review board.
“If I’m not nervous, I’m not realistic,” said Thomas Zurbuchen, head of science at NASA. “This is a complex mission. There is no way of making this simple.”
The inescapable reality is that the Webb, or the JWST as some prefer to call it, is either going to provide a revolutionary new view of the cosmic firmament or become a very expensive piece of aerospace sculpture a million miles from Earth. There’s not a lot of in-between.
Heidi Hammel, an astronomer who has worked on the Webb for two decades and is guaranteed observing time with it, echoes Zurbuchen’s feelings: “I’m nervous. This is rocket science. We are putting this amazing telescope on top of a really big rocket, and lighting a fuse and sending it into space.”
This is an international endeavor, a partnership among NASA and the space agencies of Europe and Canada. NASA estimates 10,000 people have worked on the mission, many of them at its Goddard Space Flight Center in Greenbelt, Md.
Professional astronomers and amateur space buffs across the planet are emotionally invested in the telescope’s success. The Webb’s scientific potential has made it something more than a NASA project, in the same way the little telescope Galileo employed to discover the moons of Jupiter was more than just an object in Italian history.
NASA is taking no chances with the Webb.
It has delayed the launch twice in recent weeks to deal with technical problems. At one point, a huge clamp broke suddenly, shaking the telescope and rattling everyone’s nerves. A close inspection found no sign of damage.
Then came a glitch in the communications interface between the launch vehicle and instruments on the ground; a bad cable was deemed at fault and the problem solved.
NASA plans to launch early Saturday — Christmas morning. If something causes a further delay, there will be launch windows every morning, lasting 30 minutes, until Jan. 6, when the moon will cruise into the picture and create a gravitational disruption for a week.