After two decades, the Webb telescope is complete and on its way to its launch site – Spaceflight Now

A ship carrying the $ 10 billion James Webb Space Telescope left a southern California port last weekend to begin an almost two-week trip to Kourou, French Guiana, where it will begin final preparations for the launch on December 18 on a European Ariane 5 rocket.

“The James Webb Space Telescope is finished,” said Paul Hertz, head of NASA’s astrophysics division, in a presentation to the Astronomy and Astrophysics Advisory Committee earlier this week. “We stopped working on it. It’s on its way to the launch pad for a December 18 launch.

Eric Smith, scientist with NASA’s Webb Telescope program, confirmed on Wednesday that the observatory had left the United States after completing the final tests at a Northrop Grumman facility in Redondo Beach, California.

“We are in transit to Kourou, having left the continental United States now,” Smith said during the advisory committee meeting.

NASA is keeping details of the observatory’s specific travel schedule secret for security reasons. The ship carrying the Webb telescope will cross the Panama Canal from the Pacific Ocean to the Caribbean Sea, then complete the journey to Kourou, French Guiana.

Smith said mission heads have 13 days of slack for Webb to be ready for launch on December 18. Take-off is scheduled for mid-morning local time in French Guiana.

Besides the practical work on Webb himself, Smith said NASA and ESA will closely monitor the launch of an Ariane 5 rocket next month with a commercial SES communications satellite and a French military spacecraft. Webb’s launch date, December 18, depends on the success of this mission.

The Webb Telescope’s expedition to French Guiana follows a series of tests at Northrop Grumman to ensure the spacecraft can withstand the rigors of launch. The tests subjected the observatory to vibrations and sound energy that it will see inside the fairing of the payload of its Ariane 5 launcher.

Then, engineers performed final tests to deploy the observatory’s mirrors and sunshade, verifying that the deployment mechanisms are ready to go. This was the last time Webb’s components would deploy in flight configuration before takeoff.

Once these tests were completed, the crews of Northrop Grumman folded up the observatory and placed it in an air-conditioned sea container for the trip to French Guiana.

Webb, successor to the Hubble Space Telescope, is a joint project between NASA, the European Space Agency and the Canadian Space Agency. The total cost of the observatory is close to $ 10 billion, making Webb the most expensive and complex science mission ever to be launched.

Design work on Webb began in the 1990s, and NASA awarded a contract to Northrop Grumman in 2002 to oversee construction of the observatory. With Webb’s expedition to Kourou, the project is in the home stretch before launch.

One of ESA’s contributions is the Ariane 5 rocket that will launch Webb to its operating post nearly one million miles (1.5 million kilometers) from Earth.

After launch, the observatory will embark on a breakthrough sequence of deployments to expand its solar panel, high gain antenna, and mirror segments. Webb also has a five-layer lens hood to protect its mirrors, detectors, and scientific instruments, keeping the telescope cooler than minus 370 degrees Fahrenheit or minus 223 degrees Celsius.

Made from aluminum-coated Kapton, each layer of the lens hood is as thin as a human hair. The umbrella will expand to the size of a tennis court once Webb is in space.

The observatory’s infrared instruments will scan the oldest and most remote regions of the universe to study some of the first stars and galaxies that formed after the Big Bang more than 13.5 billion years ago.

Astronomers will also use Webb to examine how galaxies form and evolve, to study the birth of stars, and to learn more about the atmospheres of planets that may be hospitable for life outside our solar system.

Once Webb arrives at the Guyana Space Center, Ariane 5’s launch site in South America, teams will unpack the observatory from its shipping crate and begin “life” and systems testing to ensure that the spacecraft withstood intercontinental travel from California.

Ground support equipment for Webb has already arrived at the Guyanese Space Center.

“They’re starting to assemble the walls of the HEPA filter,” Smith said. “This will give us a cleaner environment in the processing facilities. So people have been on the ground in Kourou for about a week to settle down. “

Controllers at the Space Telescope Science Institute in Baltimore will take command of Webb after its separation from the Ariane 5 rocket about half an hour after takeoff. Smith said the monitoring team in Baltimore will conduct a final preparation exercise for the launch and commissioning of Webb next month.

“This will be Launch Exercise # 6,” Smith said. “Thanks to all, all aspects of the observatory’s deployments and commissioning will have been exercised.”

Other work planned at the Guyana Space Center includes mounting Webb on its payload adapter, the structure that will secure it to the top of the Ariane 5 rocket. Next, technicians will load toxic hydrazine and tetroxide propellants. nitrogen in the spacecraft.

The liquid propellants will power Webb’s maneuver thrusters to keep the spacecraft on course to its destination one million kilometers from Earth and maintain its course around Lagrange’s second point, or L2. Orbiting L2, the balance of the gravitational pull of the Earth and the sun will keep Webb in a relatively stable region, giving the observatory a breathtaking view of deep space.

Ground crews in French Guiana will then move the spacecraft to the Ariane 5 rocket final assembly building to stack it on the launcher. The fully assembled Ariane 5 will be deployed on the launch pad of the Guiana Space Center one day before takeoff.

It will take about six months to go live after Webb’s launch, Smith said. This time includes all observatory deployments, cruising to Webb’s viewing location beyond the moon’s orbit, and gradually cooling the telescope’s infrared detectors to cryogenic temperatures.

The very cold conditions will allow the telescope’s instruments to be sensitive enough to detect the faint old light of some of the oldest objects in the universe.

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Follow Stephen Clark on Twitter: @ StephenClark1.