James Webb Space Telescope (2 Viewers)

[GrandAdmiral]

Can’t we just send a couple of Celestial Mechanics to fix it? Hopefully NASA extended their new telescope warranty.

NASA: Look, gotta be honest. This is a one-way trip. But your family will be taken care of for life.

Astronaut: Uhhh... what?

 

[Saint_Ward]

So it supposedly suffered significant uncorrectable damage and yet "Despite this, Webb’s team has determined the overall impact on the telescope is small. Engineers were able to realign Webb’s segments to adjust for the micrometeoroid’s damage." So how significant was it?

This gets into the details

https://www.space.com/james-webb-space-telescope-micrometeoroid-damage

A micrometeoroid struck the James Webb Space Telescope between May 22 and 24, impacting one of the observatory's 18 hexagonal golden mirrors. NASA had disclosed the micrometeoroid strike in June and noted that the debris was more sizeable than pre-launch modeling had accounted for. Now, scientists on the mission have shared an image that drives home the severity of the blow in a report(opens in new tab) released July 12 describing what scientists on the mission learned about using the observatory during its first six months in space.

Happily, in this case the overall effect on Webb was small. That said, the report outlines the investigation and modeling that engineers are undertaking to assess the long-term effects of micrometeroids on Webb.

Alternatively, it may be that Webb is "more susceptible to damage by micrometeoroids than pre-launch modeling predicted," the team wrote. Modeling is ongoing to estimate the hazardous population of micrometeoroids and to figure out remedies, such as restricting pointing direction.

One remedy could be minimizing the amount of time Webb points directly into its orbital direction, "which statistically has higher micrometeoroid rates and energies," the team wrote.

Main mirror performance is assessed by how much it deforms starlight, according to Astronomy magazine(opens in new tab), and measured using what scientists call wavefront error root mean square. When Webb's mission began, the affected C3 segment had a wavefront error of 56 nanometers rms (root mean square), which was in line with the 17 other mirror portions.

Post-impact, however, the error increased to 258 nm rms, but realignments to the mirror segments as a whole reduced the overall impact to just 59 nm rms. For the time being, the team wrote Webb's alignment is well within performance limits, as the realigned mirror segments are "about 5-10 nm rms above the previous best wavefront error rms values."

They're talking Nanometers. For perspective, 1 gold atom has an atomic diameter of 0.292nm. So, the original 56nm, is like 192 gold atoms in a line.

 

[Scorpius the Allfather]

This gets into the details

https://www.space.com/james-webb-space-telescope-micrometeoroid-damage







They're talking Nanometers. For perspective, 1 gold atom has an atomic diameter of 0.292nm. So, the original 56nm, is like 192 gold atoms in a line.

If you can make corrections to where it's not really a problem then it couldn't have been significant.

 

[Saint_Ward]

NASA: Look, gotta be honest. This is a one-way trip. But your family will be taken care of for life.

Astronaut: Uhhh... what?

Yeah, so, the James Web is at the Lagrange 2 point, which is about 1 Million miles away from Earth.

For perspective. The ISS is 254 miles away from earth. And the Moon is 238,900 miles away from Earth. So, about 4 Moon distances away.

 

[Saint_Ward]

If you can make corrections to where it's not really a problem then it couldn't have been significant.

Significant to the single mirror, but correctable by the total. If this keeps happening, how long until it's all suckier. That's what they're trying to calculate. They seemingly assumed this would be a once every 1-2 year event and one happened in May.

However, their fix is to limit the time it's pointed in a direction where impacts are most likely. Seems like a good call.

Micrometeoroids are fast, depending on where they are. compared to ships in orbit, they can be 22,500 mph.

 

[Saint_Ward]

Think of it like Football. the QB has a significant injury to his non-throwing pinky finger, but it doesn't impact his performance, since it's on his non throwing hand.

 

[Scorpius the Allfather]

Significant to the single mirror, but correctable by the total. If this keeps happening, how long until it's all suckier. That's what they're trying to calculate. They seemingly assumed this would be a once every 1-2 year event and one happened in May.

However, their fix is to limit the time it's pointed in a direction where impacts are most likely. Seems like a good call.

Micrometeoroids are fast, depending on where they are. compared to ships in orbit, they can be 22,500 mph.

I understand but the headline makes it sound like the whole damn telescope almost blew up. "My car suffered catastrophic damage." "Oh no, what happened? You okay?" "I'm fine and the car is fine, tire blew out so I put the spare on." That's my analogy. I know it's not perfect because they didn't replace the damage part but they compensated for it.

 

[Scorpius the Allfather]

Think of it like Football. the QB has a significant injury to his non-throwing pinky finger, but it doesn't impact his performance, since it's on his non throwing hand.

In this analogy, if the injury doesn't affect performance then it's not significant.

 

[Saint_Ward]

In this analogy, if the injury doesn't affect performance then it's not significant.

Significant damage to the finger, not significant to the overall performance. It's a clinical, scientific way to state it.

This is my issue with most news not really understanding science or studies, but I'll avoid that topic.

 

[Scorpius the Allfather]

Significant damage to the finger, not significant to the overall performance. It's a clinical, scientific way to state it.

This is my issue with most news not really understanding science or studies, but I'll avoid that topic.

I understand the difference, just don't like the way they tell us, it makes it sound way worse then it is.

 

[Saint_Ward]

I understand the difference, just don't like the way they tell us, it makes it sound way worse then it is.

Only to some people. lol.

I dunno, I read so many scientific papers, that I don't get too bent out of shape about these phrases. They're specific and appropriate. "noteworthy" doesn't mean catastrophic. Significant basically means noteworthy.

Anyway, I laid out the details earlier. lol.

 

[Bleu Raeder]

The light from these galaxies that are 13 billion light years away traveled to us in a straight line, not blocked by other things. With the number of galaxies in just these few pictures, which is a tiny speck of the universe, the amount of open space is mind boggling.

Don't forget to take gravitational lensing into account.

 

[Optimus Prime]

Don't forget to take gravitational lensing into account.

You’d have to be a fool not to take gravitational lensing into account

 

[Grumpy Old Manatee]

You’d have to a fool not to take gravitational lending into account

That a reference to rising/falling interest rates?

 

[efil4stnias]

That a reference to rising/falling interest rates?

I took it more as signing up with a lender where several friends work.