NASA Says Webb’s Excess Fuel Likely to Extend its Lifetime Expectations – James Webb Space Telescope

Authored by blogs.nasa.gov and submitted by uh_excuseMe_what

After a successful launch of NASA’s James Webb Space Telescope Dec. 25, and completion of two mid-course correction maneuvers, the Webb team has analyzed its initial trajectory and determined the observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime. (The minimum baseline for the mission is five years.)

The analysis shows that less propellant than originally planned for is needed to correct Webb’s trajectory toward its final orbit around the second Lagrange point known as L2, a point of gravitational balance on the far side of Earth away from the Sun. Consequently, Webb will have much more than the baseline estimate of propellant – though many factors could ultimately affect Webb’s duration of operation.

Webb has rocket propellant onboard not only for midcourse correction and insertion into orbit around L2, but also for necessary functions during the life of the mission, including “station keeping” maneuvers – small thruster burns to adjust Webb’s orbit — as well as what’s known as momentum management, which maintains Webb’s orientation in space.

The extra propellant is largely due to the precision of the Arianespace Ariane 5 launch, which exceeded the requirements needed to put Webb on the right path, as well as the precision of the first mid-course correction maneuver – a relatively small, 65-minute burn after launch that added approximately 45 mph (20 meters/sec) to the observatory’s speed. A second correction maneuver occurred on Dec. 27, adding around 6.3 mph (2.8 meters/sec) to the speed.

The accuracy of the launch trajectory had another result: the timing of the solar array deployment. That deployment was executed automatically after separation from the Ariane 5 based on a stored command to deploy either when Webb reached a certain attitude toward the Sun ideal for capturing sunlight to power the observatory – or automatically at 33 minutes after launch. Because Webb was already in the correct attitude after separation from the Ariane 5 second stage, the solar array was able to deploy about a minute and a half after separation, approximately 29 minutes after launch.

From here on, all deployments are human-controlled so deployment timing – or even their order — may change. Explore what’s planned here.

FrostyMittenJob on December 30th, 2021 at 15:40 UTC »

Just following the trend of NASA under promising and over delivering. At this point I'd be more surprised if James Webb didn't run for the next 30 years

noping_dafuq_out on December 30th, 2021 at 14:30 UTC »

One way I choose to interpret this good news is as follows: any additional mission life buys time and opportunity for creating an automated refueling mission to Webb.

Fraun_Pollen on December 30th, 2021 at 14:15 UTC »

I remember the person narrating the launch for nasa was caught off guard by the early deployment of the solar array. Great to see that that was because of unexpected efficiency in reaching the correct altitude attitude earlier than expected rather than a premature deployment

Edit: thanks for the correction