Mirror, Mirror…It’s On Its Way! James Webb Space Telescope: Mirror, Mirror…It’s On Its Way!

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Mirror, Mirror…On Its Way! James Webb Space Telescope

Webb continues its journey to its final halo orbit around L2 after completing major deployments.

Meanwhile, several smaller deployments are planned over the next few weeks, marking the start of a multi-month phase of aligning the telescope’s optics.

We started moving the mirror segments out of their stowed launch positions this week.

Here’s Marshall Perrin of the Space Telescope Science Institute, which houses the Webb Mission Operations Center, for more information:

“Each movable mirror has three rigid metal pegs on its back that can nestle into matching holder sockets in the telescope structure to support them during their journey to space.”

The mirrors were all positioned with the pegs snugly in the sockets prior to launch, providing extra support.

(Imagine Webb’s mirrors tucked up close to the telescope structure, extra safe during the launch’s vibrations and accelerations.) Each mirror must now be deployed out by 12.5 millimeters (about half an inch) to clear the pegs from the sockets.

This will give the mirrors “room to roam” and allow them to be ready for alignment in their starting positions.

“Getting there will take some time: the computer-controlled mirror actuators are designed for ultra-small motions measured in nanometers.”

Each of the mirrors can be moved with incredible precision, with adjustments as small as 10 nanometers (roughly 110,000th of a human hair’s width).

Instead of moving a centimeter, we’re now using the same actuators.

As a result, these are by far the largest moves Webb’s mirror actuators will ever make in space.

“We don’t do them all at once, either.”

The mirror control system is only capable of controlling one actuator at a time.

This method is both simpler (in terms of control electronics complexity) and safer (because computers and sensors can closely monitor each individual actuator as it operates).

Furthermore, each actuator can only be operated for a short period of time at a time to limit the amount of heat put into Webb’s very cold mirrors by the actuator motors.

As a result, each segment’s large 12.5-millimeter moves are broken down into a series of small movements carried out by one actuator at a time.

Under human supervision, scripts sent from the Mission Operations Center will direct this process, slowly and steadily moving one actuator at a time…

Summary of the latest news from Brinkwire.

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