Webb Telescope: L2 or Bust

If all goes according to plan, on December 22, a Arianespace rocket will lift off from the European Space Agency’s launch complex in French Guiana. The Webb Telescope will be onboard. This launch and the deploying of the telescope are perhaps the most audacious and risky technological challenges sponsored by NASA since it first sent astronauts to the surface of the moon (and brought them back), conducted the first Space Shuttle launch, and successfully placed the Curiosity Rover on the surface of Mars.

How so, you ask?

This mission aims to park the telescope in a gravitationally stable Lagrange Point (L2) one million miles from Earth. That is something, for sure, but it is by no means the most complex thing to be accomplished on this mission. It’s just the first step.

The telescope and its associated equipment are wrapped-up tight for launch. The package, once at L2, will need to unfold and assemble itself over the span of a month through thousands of mechanical steps that MUST GO ACCORDING TO PLAN — ALL OF THEM! There is no mission redundancy. No room for error. No way to send a repair flight if any of the unfolding and integration processes get gummed up.

All together the starting cost of the mission is $10 billion. Billion.

If it all works out, a successful launch followed by delicate unlatchings, unwindings, unveilings, pivotings and relatching of equipment, then we will have one million miles from Earth a new telescope with a mirror nearly 3-times the size of that on the Hubble Telescope and a field of view (breadth of view) 15-times that of Hubble. It will be capable of viewing infrared light dating back nearly to the beginning of time. The platform will be the size of a tennis court, approximately. On the backside (underneath) of that “court” temperatures will be around 300 degrees F. On the upper (telescope-side) surface of the court, temperatures will be around -300 F. A six-hundred degree difference. If that temperature differential isn’t achieved as planned, well then bollocks!

The package has been tested time and again. Tested in facilities that create a vacuum like that encountered in space. Tested in facilities that ensure the telescope is ready for the shakes and vibrations of launch. Tested in facilities that put the telescope through swings in temperature. The unfolding mechanisms have been run through its paces.

The JPL staff who handle Mars missions talk about the “7 minutes of terror” that come with landing rovers on that planet’s surface — as the vehicle passes through atmospheric entry, begins a fast descent and then lands smoothly. For Webb, buckle up. We are in for weeks of terror (or maybe silent prayers on a frequent basis) as this remarkably complex and complex telescope unfolds and prepares for 5-10 years of operation.

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