James Webb Space Telescope nears completion
GREENBELT, Md. — This past week, on Wednesday, November 2, NASA celebrated the completion of the OTIS (Optical Telescope, plus Integrated Science instrument module) portion of the James Webb Space Telescope (JWST) during a “Golden Mirrors” media event in Building 29 at the agency’s Goddard Space Flight Center (GSFC). SpaceFlight Insider was on site for the event.
John Mather, Nobel laureate and Senior Astrophysicist at GSFC’s Observational Cosmology Laboratory. Photo Credit: Mark Usciak / SpaceFlight Insider
“This was a long time coming, and a long time coming because it’s so complex,” explained NASA’s Administrator, Charlie Bolden.
“Two decades of innovation and work and this is the result. We are opening a whole new territory of astronomy. We will see things that we’ve never been able to see before, because this telescope is much more powerful than even the great Hubble Telescope,” added John Mather, Nobel laureate and Senior Astrophysicist at GSFC’s Observational Cosmology Laboratory.
JWST is NASA’s (in partnership with the European and Canadian space agencies) next-generation space telescope and is intended as a successor to Hubble.
One key difference between Hubble and JWST is location. SpaceFlight Insider enquired as to the intended placement of JWST at Earth / Sun Lagrange Point Two (L2). Mather responded:
“We’re putting it a million miles from Earth and it’ll be overhead at midnight – so Sun, Earth, and telescope [are] in a row. We orbit around that spot because we actually don’t want to be in the shadow of the Earth – we need solar power.
“We’re putting it there because it’s the first and only place that is easy to protect the telescope from the Sun and the Earth at the same time. The telescope’s got to be cold. At that location, you can put up your one-sided umbrella and be cold. So, that’s the point of going there. And so it’s hard to get there, but not so hard. We know how to do that.”
Mather went on to explain what makes JWST so powerful, as compared to Hubble:
“Number one, it’s gigantic. You can see this beautiful gold telescope is seven times the collecting area of the Hubble Telescope, so that’s the beginning.
The JWST’s completed 18-segment mirror. (Click to enlarge) Photo Credit: Mark Usciak / SpaceFlight Insider
“The second thing is that it is designed to collect infrared light. Infrared light is something you cannot really see with your eyes. The Hubble Telescope can see a little bit of it, but it’s [(Hubble)] not cold, so the Hubble Telescope glows – it emits infrared light itself – so you can’t use it to do all of the things that astronomers have identified as their next priority.
“So this telescope is going to be in outer space. It’s going to be cooled to a very low temperature of 45 degrees [Kelvin] above absolute zero – pretty chilly – so it does not glow.”
GSFC engineers recently completed a “Center of Curvature” test on the 18-segment primary mirror to confirm its proper alignment.
The JWST OTIS will now undergo low-frequency vibration testing to simulate anticipated launch conditions. This testing will begin on Nov. 21, 2016, and last approximately three weeks.
Beginning the second week of December, OTIS will be subjected to rigorous acoustic testing to further simulate launch conditions. Upon completion of vibration and acoustic testing, engineers will inspect OTIS to confirm that it hasn’t been damaged.
Then, in February 2017, OTIS will be packed up and flown, via Lockheed Martin’s C-5 Galaxy, to Houston’s Johnson Space Center (JSC) for cryogenic and vacuum testing. This testing (along with pre and post-test activities) is expected to last 90 days.
After that, in late summer 2017, OTIS will again be packed up and flown (by C-5) to Northrop Grumman‘s Space Park facility in Redondo Beach, California, to be mated with the spacecraft bus and sunshield.
Assembly and testing, at Northrop Grumman, will continue until the summer of 2018 and, at that time, the completed JWST will be placed on a ship and transported, via the Panama Canal, to the launch site in Kourou, French Guiana.
The launch is scheduled for October 2018 on the European Space Agency’s (ESA) Ariane 5.
For more SpaceFlight Insider photos from the “Golden Mirror” event, click here.
And, here’s the NASA TV televised portion of the “Golden Mirror” event:
Video courtesy of NASA
Scott Johnson
Scott earned both a Bachelor's Degree in public administration, and a law degree, from Samford University in Birmingham, Alabama. He currently practices law in the Birmingham suburb of Homewood. Scott first remembers visiting Marshall Space Flight Center in 1978 to get an up-close look at the first orbiter, Enterprise, which had been transported to Huntsville for dynamic testing. More recently, in 2006, he participated in an effort at the United States Space and Rocket Center (USSRC) to restore the long-neglected Skylab 1-G Trainer. This led to a volunteer position, with the USSRC curator, where he worked for several years maintaining exhibits and archival material, including flown space hardware. Scott attended the STS - 110, 116 and 135 shuttle launches, along with Ares I-X, Atlas V MSL and Delta IV NROL-15 launches. More recently, he covered the Atlas V SBIRS GEO-2 and MAVEN launches, along with the Antares ORB-1, SpaceX CRS-3, and Orion EFT-1 launches.
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