The James Webb Space Telescope is NASA’s most ambitious science project in its history. When launched in 2018, the telescope will, if all goes to plan, have 100 times the sensitivity of the Hubble Space Telescope and will peer into space in a manner nothing else has even approached.
James Webb Space Telescope is nothing less than ambitious
When operational, the James Webb Space Telescope will find life in space if there is any to be found. That’s how powerful it is and how far it’s expected to journey.
“If you put something this powerful into space, who knows what we can find? It’s going to be revolutionary because it’s so powerful,” said Matt Mountain, director of the Association of Universities for Research in Astronomy in Washington, D.C., in an interview with Science magazine.
The Webb is massive. It’s so big that in order for it to be launched in 2018, it has to be built in a way that allows it to fold up during launch and then unfold when it reaches its destination. Adding to the risk of constructing something this size is the fact that we no longer have a space shuttle program. The Hubble was launched by the Space Shuttle Discovery in 1990. Following the launch, four subsequent space shuttle flights repaired, upgraded, and replaced systems on the telescope. This will not be an option when the Webb is launched by rocket in the fall of 2018.
Following the launch, the Webb will begin a trip of 30 days that will take it over a million miles from Earth. During that trip, the Webb will begin unfolding itself to become operational upon arrival. The instruments and power supply will emerge first. Next, the Webb will unfurl and deploy its sunshield which is roughly the size of a tennis court. Finally, its mirrors made of beryllium and coated with gold will be deployed, fingers crossed, everything will work as planned but you can understand the nervousness felt by many involved in the project.
NASA’s making and testing of the Webb
Like the Hubble Space Telescope, the Webb has been hampered by cost overruns, redesigns, and failure to stay on schedule. The whole project itself which is largely on schedule and budget at $8 billion was nearly cancelled in 2010 and again in 2011. NASA accountants moved a bunch of money around from other projects just to keep the Webb from being scrapped.
Presently, all the instrumentation is being tested in something that looks like a giant pressure cooker in Building 29 of the Goddard Space Flight Center. Inside a vacuum is hard at work to keep the interior at a ten-billionth of an atmosphere (like space) while helium cools the “pressure cooker” to a spacelike –250°C.
Referring to the testing chamber as a “pressure cooker” is an apt metaphor as NASA is under tremendous pressure to get the Webb launched and deployed successfully. Once again, that pressure is only heightened by its distance and lack of a space shuttle that the Hubble required to fix its optics in the first service mission.
“We knew we would have to invent 10 new technologies” to make the telescope work, says NASA’s JWST Program Director Eric Smith, in Washington, D.C when asked about the project. He was referring to the collapsible nature of the Webb, the and its design that will provide “the first high-definition view of the midinfrared universe.”
The Hubble’s mirror was made from a single piece of glass while the Webb’s mirror is made up of 18 separate hexagonal pieces that will need to be brought together as the Webb assembles itself.
Science magazine recently published a brilliant piece that further details the challenges facing the telescope’s designers and engineers.