Telescope rocketing hope
Though it won’t receive the hype given to actor William Shatner’s recent joyride to the nearest edge of space, a daring voyage of enormous scientific promise will lift off in coming days from a base in South America.
The James Webb Space Telescope, decades in the making, is designed to travel nearly 1 million miles to reach a very particular spot to take up orbit. For comparison, the Hubble Space Telescope is about 340 miles from Earth. Shatner went up about 66 miles. The difference between 340 miles and 1 million miles is roughly comparable to the difference between a leisurely 20-minute stroll and a hike from New York to Los Angeles.
Even more extraordinary, the new telescope is much larger than Hubble, with a primary mirror so big engineers had to figure out how to fold it to fit onto a rocket. Such a large mirror, placed so far away, will — scientists fervently hope — allow the telescope to examine the formation of early galaxies and greatly accelerate the search for Earthlike planets.
Webb’s scheduled launch from French Guiana on Dec. 22 atop a European Space Agency rocket will begin one of the most harrowing and potentially stunning moments in the history of human engineering. Like an $11 billion origami, the 7.2-ton telescope will use advanced motors, firing pins and springs to open itself like a flower. A multilayered sun shield, as big as a tennis court, with each layer paper-thin, must be pulled taut. A rip in the shield could doom the entire mission.
Then the secondary mirror will snap into place, and the highly polished golden panels of the primary mirror — more than 21 feet across — will come together and focus in movements smaller than the width of a human hair. All this will happen as the craft is speeding through the extremely harsh environment of space.
Perhaps you’ve visited a desert in summer, where temperatures can climb above 125 degrees. Or maybe you’ve traveled to the other extreme; in Antarctica, Soviet scientists recorded a temperature of 128 below zero.
The Webb telescope is built for much worse conditions — at the same time. On the sunny side of the sun shield, temperatures will climb as high as 230 degrees. Hot enough to boil water. A few feet away, the mirrors will operate close to absolute zero: some 390 below.
(Note to Elon Musk: Are you sure you want to go there?)
Led by NASA, the project is a joint effort of the United States, the European Space Agency and the Canadian Space Agency. Originally conceived in the 1990s with a lowball budget of $500 million, the Webb telescope fended off threats to pull the plug as the complexity of the mission added years and billions to the accounting.
It will be a bargain if the thing works. Placing a telescope this big in an orbit where it is possible to shield it from virtually all competing heat sources should allow it to read infrared radiation from some of the earliest stars. Hubble reads primarily visible light, which limits how far it can see. At the greatest distances, the wavelengths of light grow so long they leave the visible spectrum and become infrared.
The Webb telescope is designed to see light that has been traveling for hundreds of millions of years longer than the light from even the faintest visible stars. It will look billions of years back in time to observe the early formation of molecular hydrogen from a universe void and without form.
Other instruments aboard the telescope will give it powers to peer through intergalactic dust clouds and analyze the composition of planets in faraway solar systems.
Like the Perseverance rover that landed on Mars early this year, the Webb telescope uses the ingenuity of engineers to boldly go where human carbon-based life forms cannot survive. These amazing machines extend our eyes, our ears and most of all our brains beyond the low Earth orbits where astronauts have been stuck since the dawn of space exploration and are likely to remain stuck for the foreseeable future - if not forever.
So as we mark another solstice and bring this sometimes bitter year to an end, spare a thought for astrophysicists, engineers, technicians, programmers, builders and administrators whose past labors and future hopes will be riding a rocket toward outer space. Fingers crossed as their best efforts are tested beyond the point of no return and their instruments power up to train an eye on places and times never before glimpsed.
We’re all along for the ride. Every human who ever wondered at the majesty of the universe. Every person who feels grateful that from dust and gravity and unseen matter everything good and beautiful and true in the world is somehow made.