Voyager 1 and 2 still alive!!!! 38,000 mph!

[HWYCRZR]

I think I am getting the grasp of this as well. (As much as my tiny brain can absorb). The challenges seem to be:
1. Keeping it in a consistent orbit without too much power required to keep it on track (L2) and keep the shadows from ruining the “pictures “.
2. Having solar power to fuel it, but not fully in direct sunlight so the Sun’s Infrared output doesn’t interfere with with the pictures which are also captured in infrared (overexposure?)

It seems the heat shields protect the instruments so direct sunlight isn’t an issue for them. In my mind the key is to protect the “pictures” from over exposure from the sun’s IR.
Maybe I am a little off, but this is how my mind dumbs it down so I can comprehend.

 

[amazinblue82]

thx @thethee & @HWYCRZR . good illustration/comments

i will amend my understanding.

i guess the "Jupiter" reference means the brightest EM emitting/reflecting object the TELESCOPE (eg., the mirrors on the cold side) can see is in fact Jupiter ...everything else is star light (not the Sun tho).

the hot side ... is definitely is getting cooked by the sun. remarkable that the heat shield .. in essence creating the thermal "shadow" .. works as well as it does protecting the mirrors et.al.

 

[thethee]

thx @thethee. good illustration.

i will amend my understanding.

i guess the "Jupiter" reference means the brightest EM emitting/reflecting object the TELESCOPE (eg., the mirrors on the cold side) can see is in fact Jupiter ...everything else is star light (not the Sun tho).

the hot side ... is definitely is getting cooked by the sun. remarkable that the heat shield .. in essence creating the thermal "shadow" .. works as well as it does protecting the mirrors et.al.

Oooh now I get it, Jupiter is the brightest object the COLD side will see.

 

[HWYCRZR]

First pictures in 6 months? If all goes well?
Can’t wait, this is so wild.
Now watch Voyager I or II Photobomb them.
(Not sure if is possible but would be cool)

 

[amazinblue82]

Oooh now I get it, Jupiter is the brightest object the COLD side will see.

if thats NOT the case, I am definitely missing the point somewhere.

First pictures in 6 months? If all goes well?
Can’t wait, this is so wild.
Now watch Voyager I or II Photobomb them.
(Not sure if is possible but would be cool)

indeed ... we'll get spectrographic data (or whatever technology(ies) can do it) of exoplanets in their stars' "goldilocks zone" (Kepler found a dozen or so out of the few thousand it found)to look for organic signatures in their atmospheres, see all the way back in time to fossilized light from after the Big Bang just after the first stars turned on. see primordial black holes ... plus all kinda stuff we can only/can't even imagine. Gettin' nerdy giddy here .

yeah it would be cool IF one of the "V'Gers" could make a cameo ..but also seems that might be like trying to see an atom with the naked eye. but ..maybe they (Webb) can? Surely (Webb) can get something "new' from whatever section of interstellar space the V'Gers are flying through -- thats kinda breakthrough science is why we spent $10B on the thing.

 

[Turboomni]

I find it interesting the computer is on the hot 185 f side of the telescope. Either it can work fine at these temps or it is easier to cool it down there rather than warm it up on the cold side. Don't know.

thanks to thethee for the pic.

 

[amazinblue82]

I find it interesting the computer is on the hot 185 f side of the telescope. Either it can work fine at these temps or it is easier to cool it down there rather than warm it up on the cold side. Don't know.

lotta relatively "layman" engineering and design information here: How Does Webb Stay Cold?

my guess why the computer is on the "hot" side is because the "cold" side (where the IR collection -- telescope work -- takes place) needs to be near absolute zero to do its thing. low temp enough, apparently. there's still a cooling system (the "MIRI") on the cold side, even though its open to the deep freeze of the vacuum, to make the IR collection apparatus even colder (7 Kelvin).

all that to say -- i guess IF the electronics/computer was in deep cold (cold enough to virtually stop atomic particles from moving), they in fact wouldnt work. furhter, because the electronics also make heat, to put them on the cold side further taxes the cooling needed to give the (near 0 Kelvin) additional cooling that's optimizes the IR stuff operation.

i conclude the engineering/system optimization, with 50/50 math of a basic telescope design that required a hot side/cold side spec, the heat generating systems (that can't operate near absolute zero temp) going on the Sun side made the most sense?

 

[3175375]

lotta relatively "layman" engineering and design information here: How Does Webb Stay Cold?

my guess why the computer is on the "hot" side is because the "cold" side (where the IR collection -- telescope work -- takes place) needs to be near absolute zero to do its thing. low temp enough, apparently. there's still a cooling system (the "MIRI") on the cold side, even though its open to the deep freeze of the vacuum, to make the IR collection apparatus even colder (7 Kelvin).

all that to say -- i guess IF the electronics/computer was in deep cold (cold enough to virtually stop atomic particles from moving), they in fact wouldnt work. furhter, because the electronics also make heat, to put them on the cold side further taxes the cooling needed to give the (near 0 Kelvin) additional cooling that's optimizes the IR stuff operation.

i conclude the engineering/system optimization, with 50/50 math of a basic telescope design that required a hot side/cold side spec, the heat generating systems (that can't operate near absolute zero temp) going on the Sun side made the most sense?

A ‘cooling system’ may be used as a heater or warmer too. We ran a liquid cooling system even if the radar was off, to use the coolant to keep the equipment warmer than the outside air temperature.
The pump spinning added a little bit of heat to the liquid, which then kept the equipment warm enough…

 

[3175375]

Webb appears to be on track, despite a few ‘adjustments’…

James Webb Space Telescope: Everything is 'hunky dory'

 

[cuda hunter]

I find it interesting that the hubble had a 31 year life span but the Webb only has a 10 year life span.

 

[thethee]

*Scheduled* 10 year life span. Besides, there have been five (?) maintenance missions to Hubble over those 31 years. I doubt they will do that for Webb

Didn't those Mars rovers also exceed the scheduled life span several times over?

 

[Mike66Chryslers]

I find it interesting that the hubble had a 31 year life span but the Webb only has a 10 year life span.

Hubble has exceeded its original mission lifetime, which was 15 years. This was possible because there were space shuttle missions to Hubble to refuel, repair and replace on-board instruments. Webb is not orbiting earth, so no resupply missions are possible. When it runs out of fuel for orbit corrections, it's finished.

 

[Fratzog]

I find it interesting that the hubble had a 31 year life span but the Webb only has a 10 year life span.

I wondered about that too. It is noteworthy that this equipment that gets fired into space is generally over engineered as evidenced by the longevity of the Voyagers and the Martian rovers. Saying 10 years might be a conservative way to keep expectations reasonable.

 

[Mike66Chryslers]

It's possible that a refueling port was added to Webb, so that some future space vehicle could be sent up to rendezvous with it and refuel it. Even if so, that would be a much more complicated feat than refueling Hubble was.

 

[thethee]

Let's just hope that Webb's pictures, unlike Hubble's, are good from the get-go.

 

[Fratzog]

Looks like the heat shield is in place. Next step the mirrors.

 

[LocuMob]

Let's just hope that Webb's pictures, unlike Hubble's, are good from the get-go.

I was just reading that they have accuaters to adjust each individual mirror.

James Webb telescope extends secondary mirror - BBC News

From the article;

Webb succeeds the Hubble Space Telescope, which, when it was launched in 1990, had a major defect in its primary mirror.

Scientists realised very quickly on receiving the first pictures that the reflector hadn't been polished correctly.

It wasn't until astronauts could take up some corrective optics that Hubble started to see the cosmos with clarity.

Webb won't have this problem.

"The segments on the primary mirror have actuators behind them that allow us to move them around, to even change their curvature," explained Lee Feinberg, the Nasa engineer in charge of Webb's mirror system.

"When first deployed in space, those segments will be misaligned. But all those actuators will take us from a misalignment measured in millimetres, all the way down to just nanometres. A factor of a million improvement."

 

[thethee]

I was just reading that they have accuaters to adjust each individual mirror.

James Webb telescope extends secondary mirror - BBC News

From the article;

Webb succeeds the Hubble Space Telescope, which, when it was launched in 1990, had a major defect in its primary mirror.

Scientists realised very quickly on receiving the first pictures that the reflector hadn't been polished correctly.

It wasn't until astronauts could take up some corrective optics that Hubble started to see the cosmos with clarity.

Webb won't have this problem.

"The segments on the primary mirror have actuators behind them that allow us to move them around, to even change their curvature," explained Lee Feinberg, the Nasa engineer in charge of Webb's mirror system.

"When first deployed in space, those segments will be misaligned. But all those actuators will take us from a misalignment measured in millimetres, all the way down to just nanometres. A factor of a million improvement."

And that's why they get to handle the billion dollar projects and I'm just working on my beat up Imperial

 

[thethee]

Just in case anyone was still struggling:
More Than You Wanted to Know About Webb’s Mid-Course Corrections! – James Webb Space Telescope

"Webb’s orbit is around L2—a point of gravitational balance on the other side of Earth from the Sun—but it does not reside exactly at the L2 point. Right at that point, Earth’s shadowing of the Sun would be large enough to greatly reduce the amount of power available for Webb’s solar arrays, without greatly simplifying the cooling challenges. In addition, when Webb’s communication antennas point at Earth to receive commands, they would be blinded by the huge radio emission of the Sun in the same direction. Instead, as the diagram indicates, Webb operates in a very loose orbit (many hundreds of thousands of km in diameter) around L2, in constant sunlight and with clean communications with the ground stations. Credit: NASA"

 

[Fratzog]

As successors to the Voyager missions, a future generation of probes are being theorised. The big difference with these probes is that they will be laser powered, interstellar and travel at a significant portion of the speed of light. In earth time that translates to about a 20 year trip to the nearest stars. The probes in the above article are still likely a couple of generations in the future.

Something that I might still see in my lifetime is a more conventional probe. I found this video to provide a good overview of where we are and what is most likely the next step.