James Webb Space Telescope comes in from the cold with the completion of cryogenic checks
To the envy of all Canadians bracing for winter, the James Webb Space Telescope's exposure to deep freeze temperatures ended November 18 when scientists and engineers at Johnson Space Center in Houston opened thermal vacuum Chamber A's massive 12 meter-wide door.
Webb's optical telescope and integrated science instrument module spent over 90 days enclosed in the chamber, cooled by liquid nitrogen and cold gaseous helium shrouds. The frigid, airless testing environment replicated conditions Webb must withstand in space. Webb's science instruments, including the Canadian NIRISS (Near-InfraRed Imager and Slitless Spectrograph), operate at temperatures of about 40 Kelvin, or minus 233 degrees Celsius.
Having been slowly brought back to ambient temperatures, Webb's science instruments and optics are now destined for Northrop Grumman Aerospace Systems in Redondo Beach, California, where engineers will unite them with the spacecraft element, comprised of the sunshield and the spacecraft bus. Once combined, the entire James Webb Space Telescope will undergo further testing before its expected launch from Kourou, French Guiana, in Spring 2019.
James Webb Space Telescope science themes. (Credit: NASA)
Canadian scientists selected for early look at James Webb Space Telescope data
Seven lucky Canadian astronomers will be among the first to use data from the James Webb Space Telescope, scheduled for launch in the spring of 2019. They will study the effect of massive stars on their environment and of planets in distant solar systems. This initiative falls under the Space Telescope Science Institute Director's Discretionary Early Release Science (DD ERS) program.
Of the 13 proposals accepted from over 100 submissions, three involve seven researchers from across Canada:
Els Peeters (co-Principal Investigator), Western University
Jan Cami, Western University
Bjӧrn Benneke, Université de Montréal
Christian Marois, National Research Council of Canada
Brenda Matthews, National Research Council of Canada
Stan Metchev, Western University
Julien Rameau, Université de Montréal
Their observation projects are expected to occur within the first five months of Webb's science operations.
The chosen teams must now develop tools to do their work, like software that will help the global astronomical community benefit from their investigations.
Webb will include two important Canadian contributions: the high-precision Fine Guidance Sensor (FGS) and the Near-InfraRed Imager and Slitless Spectrograph (NIRISS). NIRISS is one of Webb's four science instruments and will be used in six of the approved DD ERS projects.
The telescope's powerful gaze will allow international research teams to look even deeper into the universe than its predecessor, NASA's Hubble Space Telescope.
Webb is an international collaboration between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).
Credit: NASA/Chris Gunn
James Webb Space Telescope cooling off for the summer
On July 11, the James Webb Space Telescope began a 93-day series of tests in an enormous thermal vacuum chamber at NASA's Johnson Space Center in Houston. The thermal vacuum chamber will be set at a chilling 37 Kelvin or minus 236 degrees Celsius to simulate the extreme conditions in space. These tests will prove that the telescope can withstand those bitter cold temperatures in space.
Once in space, the telescope's highly sensitive instruments will need to be kept extremely cold to be able to detect the infrared light from very faint, distant celestial objects. An huge five-layer sunshield will help protect the observatory from all potential sources of light and heat, like the sun, Earth, and moon and even the heat generated by its own spacecraft.
Canada contributions include Webb's Fine Guidance Sensor (FGS) and one of the telescope's four science instruments: the Near-InfraRed Imager and Slitless Spectrograph (NIRISS).
The FGS is made up of two identical cameras that will act as Webb's eyes. The images they supply will allow the Webb space telescope to determine its position, zero in on celestial targets, and optimize its ability to acquire valuable data.
NIRISS will strive to find the earliest and most distant objects in the Universe's history and help uncover the atmospheric composition of exoplanets.
When the tests in the thermal vacuum chamber are complete, Webb will be shipped to Northrop Grumman, an aerospace and defense technology company, for final assembly and environmental testing with spacecraft and sunshield. Finally, it will be loaded on a boat destined for French Guiana for the launch in October 2018.
Credit: NASA/Chris Gunn
Swarms of distant galaxies and nearby habitable worlds: prime targets for the James Webb Space Telescope's Canadian science team
Using the Canadian-built instrument, the Near-InfraRed Imager and Slitless Spectrograph (NIRISS), Canadian astronomers will study a wide variety of celestial bodies. The astronomers will aim Webb at distant galaxy clusters to study thousands of galaxies, peering back in time into the history of the universe when the very first ones were formed. The astronomers will also explore the atmospheres of a dozen nearby exoplanets (planets beyond our solar system), including several Earth-size that could potentially have conditions favourable for life on their surface.
Canadian astronomers will be allocated observation time on the massive space observatory in return for the Canadian Space Agency's contribution to the Webb telescope. In addition to the NIRISS, the Canadian Space Agency (CSA) is contributing the Webb's Fine Guidance Sensor (FGS). Both were designed, built and tested for the CSA by Honeywell (formerly COM DEV International) in Ontario, with technical contributions from the Université de Montréal, Mont-Mégantic Observatory, the National Research Council Canada and scientific guidance from the FGS science team.
Credit: NASA/Chris Gunn
Credit: Northrop Grumman
Construction of the James Webb Space Telescope is now complete!
On October 31, NASA completed the construction of the James Webb Space Telescope by adding the final layer of the telescope's gigantic sunshield. The sunshield is made of five layers, each as thin as a human hair, that will block out heat from the sun and help keep the telescope's science instruments cool.
Extensive testing has now begun on the telescope to prove that it will work in space. On November 2, NASA conducted the first of several tests of the Webb's giant primary mirror to ensure its integrity and accuracy.
Next, the observatory will be put through tests that simulate the rigours of launch, after which the mirror will be tested again to compare the results and see if there are any changes or damage.