Everyone hails the Ariane 5 rocket, which has doubled the lifespan of the Webb telescope

There was two incredibly good news on the James Webb Space Telescope this weekend. One of them has been widely reported: after a complex two-week process, the telescope completed its deployment without any difficulty. The next steps towards science operations are more conventional.

The other news item, less well covered but still important, appeared at a press conference on Saturday. NASA’s mission systems engineer for the Webb Telescope, Mike Menzel, said the agency had completed its analysis of how much “extra” fuel was left on the telescope. Basically, Menzel said, Webb has enough thruster on board for 20 years of life.

That’s double the conservative pre-launch estimate for Webb’s decade-long lifespan, and much of it comes down to the performance of the European Ariane 5 rocket that launched Webb on a precise trajectory on the day. of Christmas.

Prior to launch, the telescope was powered by 240 liters of hydrazine and dinitrogen tetroxide oxidant. Some of this fuel was needed for heading adjustments throughout the journey to a stable point in space, about 1.5 million km from Earth, where Webb will make scientific observations. The remainder will be used in Webb’s final orbit around Lagrange’s stable point for posture and orbit maintenance.

So every kilogram of fuel saved on Webb’s trip to Lagrange Point could be used to extend its life there. Because ten years seemed like a fairly short operational period for such an expensive and capable space telescope, NASA had already considered an expensive and risky robotic refueling mission. But now that shouldn’t be necessary anymore, as Webb is at least two decades old.

Much of this is down to the performance of the venerable Ariane 5 rocket. More than a decade ago, NASA and the European Space Agency struck a deal that Europe would use its reliable Ariane 5 rocket to lift the telescope into the air. space, and in return, European scientists would have time to use the telescope.

In an interview with The interplanetary podcastAriane 5 program manager Rudiger Albat explained how European rocket scientists approached the Webb launch. Every Ariane 5 vehicle is interchangeable, but the engineers and technicians involved in rocket production know which components go on which rocket. So when they were building a part of Webb, an engineer could say, “I’ll take a second look” to make sure the part was the best it could be.

The Ariane 5 program also selected the best components for Webb, based on pre-flight tests. For example, for the rocket designated by Webb, the program used a main engine which had been particularly precise during testing. “It was one of the best Vulcan engines we have ever built,” said Albat. “He has very precise performances. It would have been criminal not to do so.”

A similar attitude was taken towards other components, including the solid rocket motors that were used to build the Ariane 5 which launched two weeks ago.

Albat admitted the days leading up to the launch were grueling and nerve-racking. But shortly after launch, Albat said he and the entire European space community could be proud of Webb’s soaring and wings. Now he said, “I feel totally relaxed. The same can be said for many scientists who have watched the development of Webb for two decades.