NASA’s James Webb Space Telescope has faced many delays and obstacles during its making, but the most difficult days lie ahead in the coming months. Webb has been set to launch an Ariane 5 rocket on Dec. 18, 2021, aboard from the European Space Agency’s launch site near Kourou, French Guiana. The development for this space telescope began in 1996 with an initial launch planned for 2007, which is the most powerful one.
According to NASA, about 28 minutes after liftoff, the space telescope will detach from its launch vehicle. It will begin the most complex sequence of deployments ever attempted in a single space mission. In this deployment, Webb will unfurl and unfold its shield once in space. NASA scientists say there are 344 single-point-of-failure items on average, and 80% of those are associated with the deployment. It’s hard to avoid when there is a realized mechanism and is to put full redundancy into that.
The space telescope has 144 release mechanisms which must work perfectly. To achieve a specific shape, proper folding and unfolding are necessary, like an origami object. The team decreased the number of release mechanisms as much as possible as per Mike Menzel, Webb, lead mission systems engineer for NASA’s Goddard Space Flight Center in Maryland. He said, “We found the sweet spot between getting the control that we want, with these large flexible membranes, without adding too many single points of failure”.
The team has done extensive work to ensure success because there are many single points of failure in the mission, especially the deployment stage. When a single point of failure is identified, the team game it exceptional treatment. The team had a critical item control plan and always threw in extra inspection points. They have done additional offline testing on these devices. For every one of these items identified, extra inspections have been done and tests to understand the different ways that it could fail, to be as prepared as possible.
Since the team can’t build in redundancy, extra care has to be taken with these aspects of the mission. The team do have multiple contingency plans. Getting the solar array out is time-critical. The contingency plan for the space telescope ranges from the super-simple to the very complex. In much of the Webb mission, there is”quite a bit of redundancy. The team has multiple ways of sending the same signal. The team has been working hard to make sure that their built-in redundancies and backup plans work as intended, just in case.
The team has been practicing these contingencies scenarios over the past two years, where an anomaly is introduced, and the team will try to solve it and rehearse plans. Since development began, it took 24 years for the spacecraft estimated to cost NASA $9.7 billion in total. Webb will peer into the farthest reaches of the universe, observing infrared light.
Scientists hope to use Webb –
- to see farther out into the universe
- learn about the universe origin where humans live
- finding information about everything from planet formation to dark matter.
