Space Things

[Spuds]

Originally Posted by NoHaveMSG

His next tweet will proclaim that SpaceX has performed the first commercial moon landing.

[Dadhawk]

Originally Posted by Spuds

His next tweet will proclaim that SpaceX has performed the first commercial moon landing.

Hmmm, close but doesn't qualify. A good landing is any landing where the pilot can fly again later. A great landing is where the craft can fly again. Don't think this qualifies for either.

But...that wouldn't stop Musk for claiming it.

[brewloc]

Starlink - yeah I pulled my reservation a couple months back when they extended delivery estimates out another year.
Those poor poor cybertruck reservations too....damn.

[Spuds]

Originally Posted by brewloc

Starlink - yeah I pulled my reservation a couple months back when they extended delivery estimates out another year.
Those poor poor cybertruck reservations too....damn.

I don't feel bad for anyone who reserved anything from a Musk company after about 2015. They should all know that what they are buying into is probably a pipe dream. How many years has Tesla been selling cars with the "FSD" package promising it could be activated "next year"?

[krayzie]

Originally Posted by Spuds

His next tweet will proclaim that SpaceX has performed the first commercial moon landing.

Don't forget the space mouse that hangs out at the thruster section. It can be the moon base mascot.

[Captain Snooze]

"To work together as a single mirror, the telescope’s 18 primary mirror segments need to match each other to a fraction of a wavelength of light – approximately 50 nanometers. To put this in perspective, if the Webb primary mirror were the size of the United States, each segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches."

I'm thinking that's impressive accuracy even if it is in inches.

blogs.nasa.gov

[Ultramaroon]

Originally Posted by Captain Snooze

"To work together as a single mirror, the telescope’s 18 primary mirror segments need to match each other to a fraction of a wavelength of light – approximately 50 nanometers. To put this in perspective, if the Webb primary mirror were the size of the United States, each segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches."

I'm thinking that's impressive accuracy even if it is in inches.

blogs.nasa.gov

It's decent but not amazing. The amazing part is that they can achieve that level of precision and repeatability in such a thermally hostile environment. It's easy in a temperature-controlled clean room.

[Captain Snooze]

Originally Posted by Ultramaroon

It's easy in a temperature-controlled clean room.

Yeah, I'm in a temperature controlled room and I move things around by nanometers too. Lots of nanometers but nanometers all the same.

[Spuds]

Originally Posted by Ultramaroon

It's decent but not amazing. The amazing part is that they can achieve that level of precision and repeatability in such a thermally hostile environment. It's easy in a temperature-controlled clean room.

I think you mean accuracy. I think the thermal environment at the Lagrange point is pretty consistent, but very different from the lab where it was developed. If all parameters remain constant then precision should be pretty straightforward regardless of environment. If the overall conditions are different than expected (but otherwise constant), accuracy will be degraded.

For the non engineers:
Accuracy: the ability to put an arrow on target
Precision: the ability to put two arrows in the same place when aiming at some common target

[Ultramaroon]

Originally Posted by Spuds

I think you mean accuracy.

No, I meant precision in the technical sense. I assumed there are thermal changes based on not just the orientation of the satellite relative to the sun, but also the changes in radiation.

[Spuds]

Originally Posted by Ultramaroon

No, I meant precision in the technical sense. I assumed there are thermal changes based on not just the orientation of the satellite relative to the sun, but also the changes in radiation.

Are you talking about solar storm kinds of radiation changes?

[Ultramaroon]

Originally Posted by Spuds

Are you talking about solar storm kinds of radiation changes?

Meh... Sun spins. It's not perfectly uniform but what do I know? Just guessing. Maybe it's easier than a cleanroom.

[Spuds]

Figured you all might enjoy this one. Aligning the Web reflectors is a process they are doing on site/sight.

https://blogs.nasa.gov/webb/2022/02/...star-18-times/

[Spuds]

U.S. NRO warning that Russia might attempt to attack/disable earth imaging satellites.

https://spacenews.com/nro-chief-warn...risis-unfolds/