Space

Extra fuel may keep James Webb Space Telescope going for over a decade

Extra fuel may keep James Webb...
Artist's concept of the James Webb Space Telescope
Artist's concept of the James Webb Space Telescope
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Arianespace's Ariane 5 rocket seen in this false color infrared exposure as it launches with NASA’s James Webb Space Telescope onboard
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Arianespace's Ariane 5 rocket seen in this false color infrared exposure as it launches with NASA’s James Webb Space Telescope onboard
The last view of the James Webb Space Telescope as it separates from its booster rocket
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The last view of the James Webb Space Telescope as it separates from its booster rocket
Artist's concept of the James Webb Space Telescope
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Artist's concept of the James Webb Space Telescope
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The James Webb Space Telescope (JWST) hasn't even finished unfurling itself after its December 25 launch and NASA says that its mission could already be extended beyond 10 years thanks to excess fuel for its onboard thrusters.

After a long-delayed launch, NASA's flagship space telescope is now on its month-long journey to the second Lagrange point (L2), where the gravitational forces of the Earth and the Sun balance out one another, allowing the 13,584 lb (6,161.4 kg) spacecraft to orbit the point in space about one million miles (1.5 million km) from Earth.

While on this passage, the JWST had to execute a pair of course correction burns using its main rocket engines. The first was carried out on December 25 at 7:50 pm EST and lasted about 65 minutes. The second was on December 27 at 7:20 pm EST for nine minutes and 27 seconds.

Because navigating a spacecraft is a matter of combining course corrections with a series of increasingly precise estimates of its trajectory, NASA's Webb team analyzed the JWST's initial trajectory after its launch atop an Ariane 5 rocket from ESA's Centre Spatial Guyanais in French Guiana. They found that the Ariane 5 did its job better than expected and the course corrections required less fuel than was originally estimated.

Arianespace's Ariane 5 rocket seen in this false color infrared exposure as it launches with NASA’s James Webb Space Telescope onboard
Arianespace's Ariane 5 rocket seen in this false color infrared exposure as it launches with NASA’s James Webb Space Telescope onboard

As a result, the main engines and the eight smaller attitude thrusters of the spacecraft have a larger remaining supply of the 43 gal (159 l) of hydrazine fuel and 21 gal (79.5 l) of dinitrogen tetroxide oxidizer originally loaded aboard. Rocket fuel is the biggest limiting factor of a craft's lifespan. Because it's needed for station keeping and attitude control, the more there is means the longer a mission can be.

In the case of the JWST, the original mission plan was for a minimum of five years and an upper limit of 10 years. Now NASA says that the space telescope has enough fuel to remain in service for over a decade, assuming that nothing else fails.

As the JWST travels to L2, mission control is going through the complex task of guiding the giant telescope through the process of deploying its collection of components that were folded up for launch. So far the solar panels, the antenna array, and the pallets carrying the sun shield have been deployed and the Deployable Tower Assembly has been extended, separating the telescope from the spacecraft for better heat insulation. This will be followed by unfurling the shield and unfolding the giant primary mirror of the telescope. Full deployment of all parts will take up to 24 days from launch.

Source: NASA

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3 comments
3 comments
anthony88
It would be good if humans came with attitude thrusters.
paul314
By 2031 maybe we'll even have the resources for an autonomous servicing mission.
Ralf Biernacki
Hopefully, by the time this telescope is used up, we will have the resources to put one way out in the Sun's gravitational lensing focus. Now that will really up the resolving power, using the Sun for a lens.