Watch the James Webb Space Telescope glide to its deep-space parking spot today

[Judi Lynn]

By Elizabeth Howell published 3 minutes ago

Nearly a month after launch, the James Webb Space Telescope will arrive at its deep-space celestial destination today.


Today's the day: Nearly a month after launch, the James Webb Space Telescope will arrive at its deep-space celestial destination on Monday (Jan. 24).

Webb will be orbiting Earth-sun Lagrange Point 2 (L2), which is about 930,000 miles (1.5 million kilometers) away from our planet. Here, the spacecraft can use a minimum of fuel to orbit thanks to its alignment with the sun and Earth.

NASA will not be broadcasting from mission control during the burn, as the agency did for some previous key milestones. However, NASA plans to carry several follow-up events live today after executing the crucial burn at about 2 p.m. EST (1900 GMT).



An artist's depiction of the fully deployed James Webb Space Telescope completing its final burn to reach orbit around L2. (Image credit: NASA)

First the agency will host a broadcast at 3 p.m. EST (2000 GMT) live on the NASA Science Live website, as well as YouTube, Facebook, and Twitter, featuring scientists and engineers working on Webb.

More:
https://www.livescience.com/watch-james-webb-space-telescope-arrival?utm_source=notification

[JohnnyRingo]

1. Wow! Yesterday it was still going over 500 mph.

I followed along every step of the way, and it's amazing that they pulled it off. Not one glitch or failure and they're out of hazard. I think.

On edit: Perhaps that 500 mph isn't just the speed away from Earth, but may include some orbital velocity.

[Voltaire2]

2. I think there were two mirrors with

malfunctions in their rotators, but they engineered in enough redundancy to handle that.

[lagomorph777]

5. Hadn't heard that! I hope all is well.

I did see that two mirrors use a different positional feedback method, which seems odd. Maybe that's related?

[kirby]

9. Not quite accurate...

The problem was with position sensors. The position sensors are used as a backup to the actuators own sensors. They decided it was too risky to fix those backup position sensors and have to re-test the entire telescope.

[CloudWatcher]

12. Problem found long before launch

Indeed, two of the mirror's 18 segments had slightly defective position sensors. This
was found this during testing ... years ago ... and they developed a workaround that was
deemed to be acceptable. I was wondering why A3 and A6 were moved separately!

From https://space.stackexchange.com/questions/57762/why-are-the-jwst-a3-and-a6-position-sensors-different-from-all-the-others

See 2018 SPIE paper by Wolf et al. "JWST mirror and actuator performance at cryo-vacuum" (find it by searching on "JWST A3 and A6 position sensors" ).

See sec 1.2 and 2.4.2 of the paper.

It turns out that the mirror segments at A3 and A6 have "faulty" linear variable differential transformers (LVDT) (position sensors). Each LVDT is suppose to have two coils to cancel out differential thermal effects. In each of A3 and A6, one of the two coils is faulty. The engineers had to work out a way of getting accurate readouts using only one coil in each LVDT. So they developed a different readout procedure that could use only the one good coil in each LVDT. I do not know why it was impossible to replace the faulty LVDTs before launch.

The 2018 paper: JWST mirror and actuator performance at cryo-vacuum

[kirby]

11. Keep in mind...

The website is just an estimate for running calculation via Javascript. It is not the actual telemetry data.

However, when it enters the L2 orbit, it will not have a velocity of 0. In fact when it reaches L2, it will have to perform another burn to speed up and enter that orbit.

[IrishAfricanAmerican]

3. O Happy Day!

[Magoo48]

4. Looking forward to some images.

[lagomorph777]

6. Yeah - but not until summer.

Getting all those mirror tiles to line up is going to be really tedious.

[PoindexterOglethorpe]

7. My Son The Astronomer will be watching this.

[Moebym]

8. 29 days of terror, successfully cleared with hardly a glitch

Astronomers and physicists everywhere have breathed a sigh of relief.

Now to wait until June for the first photos.

[DEbluedude]

10. Science! Blah.

Who needs it?

[CloudWatcher]

13. Orbital Insertion Burn a Success, Webb Arrives at L2

Orbital Insertion Burn a Success, Webb Arrives at L2

Today, at 2 p.m. EST, Webb fired its onboard thrusters for nearly five minutes (297 seconds) to complete the final postlaunch course correction to Webb’s trajectory. This mid-course correction burn inserted Webb toward its final orbit around the second Sun-Earth Lagrange point, or L2, nearly 1 million miles away from the Earth.

The final mid-course burn added only about 3.6 miles per hour (1.6 meters per second) – a mere walking pace – to Webb’s speed, which was all that was needed to send it to its preferred “halo” orbit around the L2 point.

https://blogs.nasa.gov/webb/2022/01/24/orbital-insertion-burn-a-success-webb-arrives-at-l2/