The Mudcat Café TM
Thread #170768   Message #4129974
Posted By: robomatic
25-Dec-21 - 05:06 PM
Thread Name: BS: SPACE - James Webb Telescope LAUNCH-Dec 2021
Subject: RE: BS: SPACE - James Webb Telescope LAUNCH
As you all know, the James Webb Telescope 'package' was launched successfully from French Guiana this morning. A few facts:

The launch site was selected because it's closer to the Equator than Continental U.S. launch sites. This gives the rocket a small but palpable boost to trajectory due to the rotation of the Earth. Which saves fuel.

This is a space project as finely detailed as it is ambitious. Which is Very Very.

I got a thrill from hearing so much French in the background and foreground, right down to the ten count.

The telescope package is now in a phase where it is relatively slowly proceeding to its general area of operation, which will be around the L2 (Lagrange Point 2) area of space a million miles from Earth in a solar orbit which is maintained in sync with Earth, kept there primarily by Earth's gravitation and secondarily by small expenditures of thrust from the fuel aboard.

The mission is known to be limited because of fuel expenditure. It is planned to be useful for ten years. Due to the fuel requirement, it is not likely to last much longer, as opposed to the luck of the Mars rovers, several of which have lasted years longer than their design life.

This telescope is all about heat, particularly separating the detection apparatus from any. It's kind of like when telescopes on Earth are located away from nighttime light sources. Their function is to detect and record starlight. In the case of the JWTS the purpose is to detect and record heat signatures. So the umbrella part is to isolate the hardware for this from the sun, the earth, and the support apparatus in the rest of the package.

There are other unknowns- the effect of micrometeoroids on the structure and of course the science to be done. I understand that over the years of design and planning the astronomers of the world have distributed every minute of anticipated observation.