For much of the world, Saturday was just another weekend day full of the problems and dangers of this planet. The Omicron-fueled pandemic raged across the world. New York has had its first snow storm of the season. The unrest in Kazakhstan and elsewhere continued
But in space. In space. On Saturday there was a great triumph in space.
After a quarter of a century of efforts by tens of thousands of people, more than $ 10 billion in tax dollars, and about 350 delivery mechanisms that just had to work like that, the James Webb Space Telescope fully unfolded its wings. The giant spaceship finished its final missions and, by God, the process went smoothly.
Thanks to NASA and space agencies in Europe and Canada, the world has a brilliant new space telescope that will enable mankind to look far deeper than ever into the depths of galactic time and possibly identify the first truly Earth-like worlds around other stars .
I dare say that 99 percent of the world doesn’t know, or want to realize, or understand the amount of work, engineering, and paperwork that went into building, launching, and deploying the James Webb Space Telescope. But those of us who know we know. And we are in awe.
NASA’s head of science, Thomas Zurbuchen, said after the full deployment, somewhat understated: “This is an amazing milestone.”
In the 1990s, serious planning began for a successor to the Hubble Space Telescope, and scientists were eager to look further back, into the early universe. To do this, they would need a dark, cold environment far from the earth. Because in order to collect light from the faintest, furthest objects in the universe, you not only need a very large mirror, but also no background interference.
To do this, the scientists planned to build a telescope that would make observations in the infrared part of the spectrum, where the wavelengths are only slightly longer than red light. This part of the spectrum is both useful for detecting thermal emissions, and such wavelengths are long enough that they are less likely to be deflected by interstellar dust.
However, such a telescope would have to be very cold, so scientists developed a large, tennis court-sized heat shield to shield light and heat from the sun. But since no rocket has a super-large fairing, this heat shield and telescope would absolutely have to be folded like origami to fit inside the protective cocoon on a rocket. Something like this had never been tried before. It took nearly two decades to build this heat shield, test it, and make sure it could be used in space.
So the launch of the Webb telescope two weeks ago on Christmas Day was significant, but it was only the beginning of the end of Webb’s journey from concept to scientific operation. As part of the deployment process, there were 344 actions in which a single mistake could sink the telescope. This is a remarkable number of cases with no redundant capability, which is why many of the scientists and engineers I’ve spoken to over the past few years felt that Webb had a pretty good chance of failure in space.
But now this ultra-complex heat shield works. The temperature on the sun-facing side of the telescope is 55 degrees Celsius, which corresponds to a very, very, very hot day in the Sahara. And the scientific instruments on the back of the sun visor have cooled down to -199 degrees Celsius, a temperature at which nitrogen is liquid. They will cool down even further.
Work remains natural. Webb has yet to cross about 370,000 km to enter orbit around a stable Lagrange point L2. Scientists and engineers need to check and align the 18 main mirror segments. Scientific instruments need to be calibrated. But all of this work is a bit routine when it comes to scientific spacecraft. While there are risks, these are mostly known risks.
We can therefore now be reasonably confident that Webb will actually begin scientific observations this summer. We should really be in awe.
This article was previously published on Source link