James Webb Space Telescope: Observatory Likely To Operate A Lot Longer Than Expected Lifetime

The recently launched James Webb Space Telescope should be able to do science in space for longer than its planned 10-year lifetime.

The partners on the mega telescope project, the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Canadian Space Agency (CSA), provided the update on 29 December 2021.

The mission had a planned life of 10 years, with five years of operation guaranteed at the minimum, but after analysis of Webb’s initial trajectory, as per the ESA update, “the observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year lifetime…”

Webb is said to have used up less propellant than originally planned in order to be steered towards its home in space — the Lagrange point 2 (L2). It happened because of the “precise launch” of the spacecraft on board the French Arianespace Ariane 5 rocket.

Webb was launched successfully from Europe’s Spaceport in Kourou, French Guiana, at 7:20 am Eastern Standard Time (EST) on 25 December. The flight ran for about 27 minutes before the spacecraft separation stage kicked in. (Details of Webb’s launch)

Two of the three planned mid-course correction manoeuvres followed the launch. The first one was “a relatively small, 65-minute burn” that kicked in after lift-off to bump up the observatory’s speed by about 20 metres per second.

The second course correction occured 60 hours after launch, on 27 December, which led to a further increase of observatory speed, by about 2.8 metres per second.

As a result, Webb is on track for L2. It will take the spacecraft just under a month to get there.

Named after the Italian-born mathematician and astronomer Joseph-Louis Lagrange, the Lagrange point is a spot in space where gravity from the Sun and Earth balance the orbital motion of a satellite. A spacecraft at this point stays in a fixed position relative to the Sun and Earth.

There are five Lagrange points in all, and L2, where Webb will settle down for its life of science, 15 lakh kilometres (km) from Earth, is one of them.

L2 is not a fixed point, but follows Earth around the Sun. Webb will not occupy the prized L2 spot, but rather orbit it facing away from the Sun.

After six months (from launch), Webb will begin collecting scientific data. Immediately after, the first science images will begin to trickle down to the scientific community and the wider public.

But now is an important phase. As of 30 December, the observatory’s first major structural deployments have been completed.

“There are 50 major deployments that transform Webb from its stowed, launch configuration into an operational observatory,” Michael McElwain, Webb observatory project scientist, NASA’s Goddard Space Flight Center, said in an update.

There’s enough fuel for any further mid-course corrections if they are necessary and for insertion into orbit around L2. However, that’s not all — the fuel on board can be used for various purposes in the future, such as for thruster fires to adjust Webb’s location in orbit, for maintaining the observatory’s orientation in space, and for lining up the telescope with specific celestial objects.

The James Webb Telescope is walking in the footsteps of the Hubble Space Telescope and Herschel Space Observatory.

Webb’s mirror, 6.5 metres across and made up of 18 hexagonal, gold-coated mirror segments, is itself nearly double the size of the Herschel Space Observatory. Further, Webb’s sensitivity is 100 times greater than that of the Hubble telescope.

Additionally, while Hubble has been operating primarily in the visible light spectrum, Webb will use infrared vision. Therefore, working together with Hubble, this next-generation telescope promises to uncover new details about the universe that will transform our understanding.

According to ESA, Webb will allow scientists to directly observe the first stars and galaxies forming in the early universe from more than 13.5 billion years ago. This is a period not long after the Big Bang.

When the light from these objects falls upon Webb, the observatory will capture this information that was coded all those many years ago. It will give the effect of looking far back in time, acting, therefore, like a time machine.

Data taken from Webb will shed light on the workings of black holes in the early universe — especially their formation and evolution and how, if at all, they contributed to the making of the universe over time.

Additionally, questions of the lifecycle of stars, galaxies, formation and evolution of planetary systems (including our solar system), and exoplanets as well as of possible life-producing ingredients that may be found, say, in the atmospheres of exoplanets, will be explored.

“Webb will search for atmospheres similar to Earth’s, and for the signatures of key substances such as methane, water, oxygen, carbon dioxide and complex organic molecules, in the exciting hope of finding the building blocks of life,” ESA says.

Also Read: How Hubble Successor James Webb Telescope Can Greatly Expand Our Understanding Of The Universe