The James Webb Space Telescope, launched late last year, may have enough fuel left to last for 20 years. That is a lot longer than the intended minimum lifespan of five years. Previously, a lifespan of ten years was assumed.
Mike Menzel, NASA’s Webb Mission Systems Engineer, said in a news conference that “roughly about twenty years’ worth of fuel is left.” According to him, there are two reasons for this favorable figure: the accurate way in which the Ariane 5 rocket delivered the telescope into space and the precision and effectiveness of the so-called mid-course corrections. Menzel still has a hand in his hand; he emphasizes twice that the fuel level and thus the twenty-year forecast still need to be determined in more detail.
Mid-course corrections is NASA’s term for the few additional course corrections made in the days following launch by firing the James Webb telescope’s own engine. Earlier it appeared that the space telescope had used much less fuel than had been calculated during its first and second course corrections on December 25 and 27, respectively. Those course corrections were necessary to get James Webb on course toward Lagrangian point L2, his final destination 1.5 million kilometers from Earth.
According to ESA There are a lot of factors and considerations that go into determining the lifespan of the James Webb telescope, but the European Space Agency says fuel is certainly one of the most important factors. Fuel is not only needed to get to the destination. It is also used for station keeping maneuvers to keep James Webb on course in L2 orbit and to point the telescope in the correct direction.
So fuel is very important, but another factor that will play a role in longevity is the extent to which cosmic particles will shoot holes in the solar shield. Particles can pass through the five layers of the shield, reducing the shield’s ability to block heat. This can affect the performance of the various instruments, which have to operate in very low temperatures. If those temperatures of between -233 and -260 degrees Celsius cannot be maintained, it will be more difficult to continue researching the frequencies in the infrared part of the spectrum.
The James Webb Space Telescope was successfully launched from French Guiana on December 25. A number of important steps were then taken, including the mid-course corrections. The two main events were the unfolding of the sun shield and the unfolding of the two wings to complete the primary mirror. The latter was successfully carried out last weekend and the solar shield was successfully unfolded earlier. This completes the most important deployments.
James Webb has now covered nearly 78 percent of the distance to L2. It will not be long before the telescope arrives there, although the first real scientific images will only follow in six months when the telescope actually becomes operational. Until then, all kinds of things are tested and calibrated, such as the very precise adjustment of each individual hexagon. Eighteen of those hexagons form the primary mirror.