Spaceflight Insider

NASA tests key system of $10 billion James Webb Space Telescope

James Webb Space Telescope NASA image

Image Credit: NASA

A program some 25 years in the making conducted an important test that should ensure that when the long-delayed mission is sent aloft – it will perform flawlessly. With this milestone complete, the launch of the James Webb Space Telescope edges closer to flight.

While one might think that both the primary science instrument and its navigational and propulsion systems as a single unit they are, in some ways, two separate sections. This test saw the two components combined electrically and was carried out to check and see if the spacecraft’s two components could properly communicate with one another. 
“What we did now was make electrical connections between the flight telescope and flight spacecraft to understand all the nuances of the electrical interface. Specifically in this test, the spacecraft commanded mirror motion on the telescope, and the telescope replied back with telemetry confirming it. Even though we have tested each half with a simulator of the other half during their parallel construction, there is nothing exactly like connecting the real thing to the real thing. While the sunshield was being reassembled to get back into its environmental testing, we took advantage of the time and did a flight-to-flight electrical dry run right now to reduce schedule risk later,” said Mike Menzel, Webb’s Mission System Engineer via a release. “The full complement of electrical and software tests will be run next year when the observatory is finally fully assembled for flight.”
This test was not needed before the JWST’s planned launched atop an Ariane 5 rocket from the Guiana Space Centre near Kourou. However given the extensive period of time and cost that it took to get the telescope to its current stage of development it was decided to check these systems out to be sure that things would go according to plan.
“This test also afforded us an early chance to ensure that the two teams, who had been working separately over the years building and testing the two separate halves of Webb respectively, were able to operate as a single observatory test team. We are enthused that the early communications and commanding risk reduction test has been successfully executed. The procedure was designed and executed by an integrated set of team members from Goddard Space Flight Center, Northrop Grumman, and Ball Aerospace,” said Jeff Kirk, Test Operations Lead.
It is hoped that Webb will help to answer many questions about the universe. Exoplanets, black holes and finding the light from the first stars – are all on the spacecraft’s “to do” list.
As the saying goes, no man, or spacecraft in this case, is an island. The mission is an international partnership between NASA, ESA (European Space Agency) and the Canadian Space Agency. 
NASA has worked on an array of what have come to be called, the “great observatories”which include the HubbleSpitzer, and Chandra space telescopes. The agency’s latest space-based telescope, JWST, is planned to reside at a position about million miles away from Earth.
Built by Northrop Grumman, the JWST’s primary flight components were gathered together in the company’s Los Angeles facilities. From this location, all flight hardware will undergo final assembly and testing. If things go according to the present schedule, the JWST should come together as one piece next year (2019). Its launch is currently scheduled to take place in 2021.


Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

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