The most expensive telescope in the known universe has begun its journey to a vantage point a million miles from Earth with its launch from French Guiana.
Today’s liftoff of an Ariane 5 rocket from the European Space Agency’s South American spaceport, coming at 9:20 a.m. local time (4:20 a.m. PT), was just the first step of what’s expected to be a monthlong trip for NASA’s $10 billion James Webb Space Telescope.
“Everything fell together on this Christmas Day to send a new present to the world’s astronomers,” NASA launch commentator Rob Navias said.
Flight controllers broke into applause when the telescope separated from the Ariane 5’s second stage. “Go Webb!” range operations manager Jean-Luc Voyer cried.
NASA Administrator Bill Nelson noted that the James Webb Space Telescope is designed to look back to an age when the first stars and galaxies formed, more than 13.5 billion years ago.
“It’s a time machine,” Nelson said. “It’s going to take us back to the very beginnings of the universe. We are going to discover incredible things that we never imagined.”
JWST is due to settle into a region of space known as the Sun-Earth Lagrange Point 2, or L2, where the gravitational pulls of Earth and the sun align to help keep spacecraft in a stable position within Earth’s shadow. Along the way, the telescope will have to unfurl its sunshield and its segmented mirror in a process that’s said to have 344 potential single points of failure.
NASA’s project, taken on in partnership with ESA and the Canadian Space Agency, had to weather billions of dollars in cost overruns and years of delay. When the project was conceived in the 1990s, the Ariane 5 was the only rocket powerful enough to conduct the liftoff, which meant the telescope had to be transported by ship to the launch site.
Because of the telescope’s far-off destination, it can’t be repaired by a crew of astronauts after launch. There’s no opportunity to fix any optical shortcomings, as was the case after the Hubble Space Telescope’s deployment. Making sure the telescope is as fail-safe as possible is one big reason for the $10 billion cost.
“Those who are not worried or even terrified about this are not understanding what we are trying to do,” Thomas Zurbuchen, NASA’s associate administrator for science, said in a pre-launch blog post.
What NASA is trying to do is take astronomy to a level beyond what’s achievable with Hubble, which is currently in its 32nd year of operation. To get there, scientists and engineers designed a telescope with a gold-plated, beryllium mirror so big (6.5 meters or 21.3 feet wide) that it had to be folded up origami-style for launch.
The Webb telescope’s 18-segment mirror has almost seven times the light-gathering capability of Hubble’s mirror, and a significantly wider field of view. NASA says Webb’s instruments are 100 times more sensitive than Hubble’s.
JWST is optimized for infrared observations, which are particularly suited for studying the dusty places where planets are born, and the redshifted edges of the observable universe.
James Davenport, an astronomer at the University of Washington who played a role in selecting which projects will get the telescope’s observation time, said JWST should open a new window on the universe.
Previously: High cost, high risk, high hopes: There’s a lot riding on the James Webb Space Telescope
“Astronomers at UW have been making predictions of what JWST will observe for years,” he said in an email. “From measuring the atmosphere compositions from nearby extrasolar planets, searching for ‘Planet 9,’ and even studying individual stars in other galaxies.”
He said he and his colleagues at UW will be watching the telescope’s journey to L2 “with bated breath,” but without a sense of impending doom.
“Honestly, I’m not nervous at all,” Davenport said. “The very best minds have been working on this facility for almost my entire life … the delays have been to make sure everything goes smooth.”
UW astronomer Emily Levesque was up early Christmas morning for the launch.
“Great to see the launch go so beautifully, and that call of “Séparation Webb Space Telescope, GO WEBB!” was spectacular and emotional to hear,” she told GeekWire in an email. “We got a beautiful view of JWST as it separated and opened its solar array, and now the long adventure of deployment and the journal to L2 begins. … Back to bed over here for a couple hours, but hooray!!”
Update for 10:20 a.m. Dec. 25: In a post-launch follow-up email, UW astronomer James Davenport admitted to feeling a sense of relief:
“Well, a very merry Christmas for all astronomers this morning!! It’s a big sigh of relief and joy to see this mighty telescope begin its journey.
“Already astronomers are chattering about how to catch a glimpse of JWST as it travels to L2 with telescopes on the ground! Even at its parking position, we should be able to ‘see’ JWST with our observatories on the ground, and maybe even in space with a near-Earth facility like TESS! It’s a silly, but incredibly human reaction to such a monumental thing as Webb, wanting to catch a glimpse.”
Five fast facts about JWST
- The telescope was named after the late NASA Administrator James Webb, who led the space agency from 1961 to 1968. Some astronomers have called for Webb’s name to be removed, saying that he went along with government discrimination against LGTBQ employees in the 1950s and 1960s. But NASA says the name is here to stay.
- JWST was built by Northrop Grumman under the supervision of NASA’s Goddard Space Flight Center in Maryland, and had to be shipped from California to French Guiana via the Panama Canal. Details about the trip were kept under wraps, in part to frustrate pirates who might seek to hold the telescope hostage. Under the terms of its partnership with NASA, the European Space Agency was guaranteed at least 15% of the observing time. (It got 30%.)
- The telescope has four science instruments: the Near-Infrared Camera, or NIRCam; the Near-Infrared Spectrograph, or NIRSpec; the Mid-Infrared Instrument, or MIRI; and the Canadian Space Agency’s Fine Guidance Sensor / Near Infrared Imager and Slitless Spectrograph, or FGS/NIRISS.
- JWST’s mirror and detectors will have to be cooled down to a temperature of about 388 degrees below zero Fahrenheit (40 Kelvin or -233 degrees Celsius) to operate properly. That’s a big challenge, since solar radiation is expected to heat up the “hot side” of the telescope’s sunshield to near-boiling temperatures, as high as 185 degrees F (85 degrees C).
- The telescope is designed for at least five and a half years of operation (six months for calibration, plus five years of science operations), but scientists are hoping it’ll be around far longer. The limiting factor is expected to be fuel to maintain its halo orbit at L2. There’s enough fuel for at least 10 years, and it’s theoretically possible to refuel the spacecraft if NASA really, really wants to.