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One of the things that was newly constructed and installed in Chamber A was a cold gaseous helium-cooled 'shroud' that enables the chamber to reach colder temperatures than it had ever reached before. This addition was necessary because Webb's telescope and scientific 'instruments' (cameras and spectrometers) will operate at temperatures of around 37 Kelvin (K), which is around minus 393 Fahrenheit (F) / minus 236 Celsius (C). Chamber A previously had only a liquid nitrogen shroud inside, and because liquid nitrogen is 77K, you couldn't get test articles any colder than that. "We added a cold helium gas shroud that we've run down to about 11K, which is (minus 440 F/minus 262 C, thus enabling us to get the telescope to its operating regime and even to as low as around 20K to reach 'survival' temps," Geithner said.
Once telescope testing is complete, this sequence will run in reverse and the telescope will be shipped to Northrop Grumman Aerospace in California to meet up with the Spacecraft Element [spacecraft bus and sunshield] and finally become one complete James Webb Space Telescope observatory.
From the very first galaxies after the Big Bang, to searching for chemical fingerprints of life on Enceladus, Europa, and exoplanets like TRAPPIST-1e, Webb will be looking at some incredible things in our universe," said Eric Smith, James Webb Space Telescope Director at NASA Headquarters in Washington. "With over 2100 initial observations planned, there is no limit to what we might discover with this incredible telescope."
The broad spectrum of initial GTO [Guaranteed Time Observations] observations will address all of the science areas Webb is designed to explore, from first light and the assembly of galaxies to the birth of stars and planets. Targets will range from the solar system's outer planets (Jupiter, Saturn, Uranus, and Neptune) and icy Kuiper Belt to exoplanets to distant galaxies in the young universe.
GSEG-1 [Ground Segment Test - 1], which completed on June 20, tested all of the communications systems required to support the telescope's launch, commissioning and normal operations once it is in orbit. The test showed successful end-to-end communication between the Webb telescope's spacecraft bus, currently located at Northrop Grumman Aerospace Systems in Redondo Beach, California, and the telescope's mission operations center at the Space Telescope Science Institute in Baltimore. Before this test, the flight operations team had only verified communication with the telescope piecemeal—in several smaller tests that were not end-to-end.
During the test, the team sent the same command procedures to the telescope that will be sent during its nearly 1 million mile journey to its orbit at the second Lagrange point, known as L2. The team verified the configuration of the telescope's onboard computers and also received telemetry from the telescope, including science data and health monitoring data.
William Jeffs, a spokesperson for Johnson Space Center, said in an email Monday there have been “no issues with operations.” “All backup facility systems required to maintain the telescope have been checked and readied for use if necessary,” Jeffs said.
Kendrew said staffers were feeling anxious, and many slept in offices or conference rooms at Johnson when they couldn’t get home or to hotel rooms. “It’s been challenging at times to concentrate on work whilst our phones are sounding emergency flood and tornado alerts several times an hour, and knowing that people just miles from our desks, maybe even family or friends, are in danger and possibly losing their homes,” she said. But “we’ve actually been able to continue amazingly well with the testing,” she said.
So what’s it like riding out a hurricane at Mission Control? Flight Director Royce Renfrew described it in a tweet shortly after he arrived to relieve another flight director on Sunday night as “kind of surreal with off duty folks crashed in the [flight control rooms].” Later in the day, he described JSC as an island surrounded by floodwaters.
NASA’s other facilities in the Houston area include Ellington Field, which is home to a fleet of T-38 jets used for astronaut flight training. Ellington formerly housed the infamous KC-135 “Vomit Comet,” which NASA decommissioned in 2004. “The NASA side of Ellington Field is doing fine and all aircraft are safe,” wrote the representative. Ellington is also home to a Texas Air National Guard unit, a Coast Guard air station, and a Civil Air Patrol squadron.
"The [Johnson Space Center] Recovery Team hasn't had a chance to do a full assessment of the storm's effect on the center yet," wrote the NASA representative. "The team has been handling issues as they come up and will conduct a full assessment when the storm threat subsides."
Part of the Webb telescope's ongoing cryogenic testing in Chamber A at Johnson includes aligning, or "phasing," the telescope's 18 hexagonally shaped primary mirror segments so they function as a single 6.5-meter mirror. All of these segments must have the correct position and correct curvature; otherwise, the telescope will not be able to accurately focus on its celestial targets.
These actuators can also be used to precisely reshape each mirror segment to ensure they all match up once aligned. The ability to change the mirror alignment and shape is critical because the mirror must be unfolded from its unaligned stowed position when the telescope deploys. This test verifies the actuators have enough range of movement once they are in space, at their operational temperature of about 40 K (or about minus 388 degrees Fahrenheit / minus 233 degrees Celsius), to put the telescope's primary mirror into its correct shape so it can accurately survey the universe.
"This verifies not only the alignment of the primary mirror itself but also the alignment of the whole telescope—the primary mirror, secondary mirror, and the tertiary and fine-steering mirrors inside the AOS," said Paul Geithner, the deputy project manager - technical for Webb telescope at Goddard. "Taken together, the half-pass and pass-and-a-half tests demonstrate that everything is aligned to everything else."
Engineers have determined that integration activities, such as the installation of more than 100 sunshield membrane release devices, will require more time.
For several years, JWST had maintained a development track that would have seen it launch in October 2018. But then late last year, Nasa announced that it was pushing back the lift-off from the European spaceport in French Guiana to between March and June 2019.
Officials cited the extra time engineers needed to complete integration of the observatory's components and then test them. In particular, additional margin was required to get the tennis court-sized sun-shield ready for flight.
Nasa stresses that all hardware has been fabricated; it is now just a question of joining the mirrors and instruments to the spacecraft bus and sunshield - and then testing the two parts as one.
The US Government Accountability Office regularly reviews the project and recently remarked that it thought a spring launch in 2019 was optimistic.
An independent panel will now review matters providing information to the space agency it can then forward to Congress.
Nasa's science director Thomas Zurbuchen said the May 2020 date had a confidence level currently of about 70%.