Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



STELLAR CHEMISTRY
Webb Telescope completes final cryogenic test
by Eric Villard for GSFC News
Greenbelt MD (SPX) Nov 21, 2017


NASA's James Webb Space Telescope sits inside Chamber A at NASA's Johnson Space Center in Houston after having completed its cryogenic testing on Nov. 18, 2017. This marked the telescope's final cryogenic testing, and it ensured the observatory is ready for the frigid, airless environment of space.

The vault-like, 40-foot diameter, 40-ton door of Chamber A at NASA's Johnson Space Center in Houston was unsealed on November 18, signaling the end of cryogenic testing for NASA's James Webb Space Telescope.

The historic chamber's massive door opening brings to a close about 100 days of testing for Webb, a significant milestone in the telescope's journey to the launch pad. The cryogenic vacuum test began when the chamber was sealed shut on July 10, 2017. Scientists and engineers at Johnson put Webb's optical telescope and integrated science instrument module (OTIS) through a series of tests designed to ensure the telescope functioned as expected in an extremely cold, airless environment akin to that of space.

"After 15 years of planning, chamber refurbishment, hundreds of hours of risk-reduction testing, the dedication of more than 100 individuals through more than 90 days of testing, and surviving Hurricane Harvey, the OTIS cryogenic test has been an outstanding success," said Bill Ochs, project manager for the James Webb Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The completion of the test is one of the most significant steps in the march to launching Webb."

These tests included an important alignment check of Webb's 18 primary mirror segments, to make sure all of the gold-plated, hexagonal segments acted like a single, monolithic mirror.

This was the first time the telescope's optics and its instruments were tested together, though the instruments had previously undergone cryogenic testing in a smaller chamber at Goddard. Engineers from Harris Space and Intelligence Systems, headquartered in Melbourne, Florida, worked alongside NASA personnel for the test at Johnson.

"The Harris team integrated Webb's 18 mirror segments at Goddard and designed, built, and helped operate the advanced ground support and optical test equipment at Johnson," said Rob Mitrevski, vice president and general manager of intelligence, surveillance, and reconnaissance at Harris. "They were a key, enabling part of the successful Webb telescope testing team."

The Webb telescope team persisted with the testing even when Hurricane Harvey slammed into the coast of Texas on Aug. 25 as a category 4 hurricane before stalling over eastern Texas and weakening to a tropical storm, where it dropped as much as 50 inches of rain in and around Houston.

Many Webb telescope team members at Johnson endured the historic storm, working tirelessly through overnight shifts to make sure Webb's cryogenic testing was not interrupted. In the wake of the storm, some Webb team members, including team members from Harris, volunteered their time to help clean up and repair homes around the city, and distribute food and water to those in need.

"The individuals and organizations that have led us to this most significant milestone represent the very best of the best. Their knowledge, dedication, and execution to successfully complete the testing as planned, even while enduring Hurricane Harvey, cannot be overstated," said Mark Voyton, James Webb Space Telescope optical telescope element and integrated science instrument manager at Goddard.

"Every team member delivered critical knowledge and insight into the strategic and tactical planning and execution required to complete all of the test objectives, and I am honored to have experienced this phase of our testing with every one of them."

Before cooling the chamber, engineers removed the air from it, which took about a week. On July 20, engineers began to bring the chamber, the telescope, and the telescope's science instruments down to cryogenic temperatures - a process that took about 30 days.

During cool down, Webb and its instruments transferred their heat to surrounding liquid nitrogen and cold gaseous helium shrouds in Chamber A. Webb remained at "cryo-stable" temperatures for about another 30 days, and on Sept. 27, the engineers began to warm the chamber back to ambient conditions (near room temperature), before pumping the air back into it and unsealing the door.

"With an integrated team from all corners of the country, we were able to create deep space in our chamber and confirm that Webb can perform flawlessly as it observes the coldest corners of the universe," said Jonathan Homan, project manager for Webb's cryogenic testing at Johnson. "I expect [Webb] to be successful, as it journeys to Lagrange point 2 [after launch] and explores the origins of solar systems, galaxies, and has the chance to change our understanding of our universe."

While Webb was inside the chamber, insulated from both outside visible and infrared light, engineers monitored it using thermal sensors and specialized camera systems. The thermal sensors kept tabs on the temperature of the telescope, while the camera systems tracked the physical position of Webb to see how its components very minutely moved during the cooldown process. Monitoring the telescope throughout the testing required the coordinated effort of every Webb team member at Johnson.

"This test team spanned nearly every engineering discipline we have on Webb," said Lee Feinberg, optical telescope element manager for the Webb telescope at Goddard. "In every area there was incredible attention to detail and great teamwork, to make sure we understand everything that happened during the test and to make sure we can confidently say Webb will work as planned in space."

In space, the telescope must be kept extremely cold, in order to be able to detect the infrared light from very faint, distant objects. Webb and its instruments have an operating temperature of about 40 Kelvin (or about minus 387 Fahrenheit / minus 233 Celsius). Because the Webb telescope's mid-infrared instrument (MIRI) must be kept colder than the other research instruments, it relies on a cryocooler to lower its temperature to less than 7 Kelvin (minus 447 degrees Fahrenheit / minus 266 degrees Celsius).

To protect the telescope from external sources of light and heat (like the Sun, Earth and Moon), as well as from heat emitted by the observatory, a five-layer, tennis court-sized sunshield acts like a parasol that provides shade.

The sunshield separates the observatory into a warm, sun-facing side (reaching temperatures close to 185 degrees Fahrenheit / 85 degrees Celsius) and a cold side (minus 400 degrees Fahrenheit / minus 240 degrees Celsius). The sunshield blocks sunlight from interfering with the sensitive telescope instruments.

Webb's combined science instruments and optics next journey to Northrop Grumman Aerospace Systems in Redondo Beach, California, where they will be integrated with the spacecraft element, which is the combined sunshield and spacecraft bus.

Together, the pieces form the complete James Webb Space Telescope observatory. Once fully integrated, the entire observatory will undergo more tests during what is called "observatory-level testing." This testing is the last exposure to a simulated launch environment before flight and deployment testing on the whole observatory.

Webb is expected to launch from Kourou, French Guiana, in the spring of 2019.

STELLAR CHEMISTRY
Next Generation Astronomical Survey To Map The Entire Sky
Pasadena CA (SPX) Nov 20, 2017
The next generation of the Sloan Digital Sky Survey (SDSS-V), directed by Juna Kollmeier of the Carnegie Institution for Science, will move forward with mapping the entire sky following a $16 million grant from the Alfred P. Sloan Foundation. The grant will kickstart a groundbreaking all-sky spectroscopic survey for a next wave of discovery, anticipated to start in 2020. The Sloan Digital ... read more

Related Links
James Webb Space Telescope,
Stellar Chemistry, The Universe And All Within It


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

STELLAR CHEMISTRY
Can a magnetic sail slow down an interstellar probe

Robotic arm reaches out and grapples Cygnus

SSL Selected to Conduct Power and Propulsion Study for NASA's Deep Space Gateway Concept

MDA Selects AdaCore's GNAT Pro Assurance Development Platform for ISS Software

STELLAR CHEMISTRY
SpaceX postpones launch of secretive Zuma mission

NASA launches next-generation weather satellite

Baikonur for Russia, Kazakhstan offers UAE Baikonur for launches

Orbital ATK launches eighth cargo mission to space

STELLAR CHEMISTRY
NASA Selects Instrument for Future International Mission to Martian Moons

Fracture swarms on Mars driven by ancient tectonics

New partnership on Mars drone applications research

Russia's Roscosmos may take part in creation of 'Martian Town' in Dubai

STELLAR CHEMISTRY
China plans first sea based launch by 2018

China's reusable spacecraft to be launched in 2020

Space will see Communist loyalty: Chinese astronaut

China launches three satellites

STELLAR CHEMISTRY
Space Launch plans UK industry tour

Astronaut meets volcano

European Space Week starts in Estonia

New Chinese sat comms company awaits approval

STELLAR CHEMISTRY
UW researchers ready for era of "big data" astronomy

Lockheed Martin Achieves Long Range Discrimination Radar Critical Design Review On-Schedule

The environmental implications of 3-D printing

Scientific advances can make it easier to recycle plastics

STELLAR CHEMISTRY
Images of strange solar system visitor peel away some of the mystery

Lava or Not, Exoplanet 55 Cancri e Likely to have Atmosphere

Closest temperate world orbiting quiet star discovered

NASA plans mission to study why planets lose their atmospheres

STELLAR CHEMISTRY
Pluto's hydrocarbon haze keeps dwarf planet colder than expected

Jupiter's Stunning Southern Hemisphere

Watching Jupiter's multiple pulsating X-ray Aurora

Help Nickname New Horizons' Next Flyby Target




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement