01-04-2022, 11:52 AM
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#41
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Lifetime Suspension
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Quote:
Originally Posted by You Need a Thneed
It’s not slowing to zero, if that’s what you based your calculation on.
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Okay then what speed will be at and relative to what when fully deployed.
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01-04-2022, 12:11 PM
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#42
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Franchise Player
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Quote:
Originally Posted by zamler
Okay then what speed will be at and relative to what when fully deployed.
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The problem is it appears to be report velocity in rectilinear cordinates relative to the earth. You really need to know it’s radial velocity away from the sun and it’s angular velocity
It will have an angular velocity relative to the Sun of 365/360 degrees per day and equal to the earth.
But if you want the satellites linear velocity relative to the earth perpendicular to the earth/sun. The Earth moves at about 67000 MPH and is 93 Million miles away. The Lagrange 2 is 1 million miles away. So 18.6/93 = (X+18.6)/94 So X = .211 MI/second.
Last edited by GGG; 01-04-2022 at 12:27 PM.
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01-04-2022, 12:16 PM
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#43
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Franchise Player
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Did you just do space math using miles? We are better than that!
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01-04-2022, 12:19 PM
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#44
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First Line Centre
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Quote:
Originally Posted by Scroopy Noopers
Maybe it would be better to understand what you think is happening.
They burn to eject earth orbit (which doesn’t mean it doesn’t feel the effects of earths gravity), with enough steam to carry the to their location (with correction burns factored in). It’s part of what takes so long. They can’t cruise there burnin the whole way and then burn retro to stop (the telescope can’t turn around, that would take a ton of extra fuel, also would likely need addition front facing boosters to complete, etc…). They utilize as much gravity slowing as they can.
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The bigger problem than fuel is that they can't turn JWST around because exposure to the sun would damage the instruments.
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01-04-2022, 12:20 PM
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#45
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Franchise Player
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Quote:
Originally Posted by Fuzz
Did you just do space math using miles? We are better than that!
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If it’s good enough to crash a Mars rover it’s good enough for me.
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01-04-2022, 12:20 PM
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#46
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Pent-up
Join Date: Mar 2018
Location: Plutanamo Bay.
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Quote:
Originally Posted by BoLevi
The bigger problem than fuel is that they can't turn JWST around because exposure to the sun would damage the instruments.
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Yup, first point in my list. Although I didn’t provide reasoning.
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01-04-2022, 03:37 PM
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#47
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Voted for Kodos
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Quote:
Originally Posted by BoLevi
The bigger problem than fuel is that they can't turn JWST around because exposure to the sun would damage the instruments.
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Which is why they have been slightly under burning each time they burn the engines. They cant go too far.
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01-05-2022, 08:37 AM
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#48
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The new goggles also do nothing.
Join Date: Oct 2001
Location: Calgary
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__________________
Uncertainty is an uncomfortable position.
But certainty is an absurd one.
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01-05-2022, 09:15 PM
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#49
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A Fiddler Crab
Join Date: Jan 2007
Location: Chicago
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Just sitting at home on winter break and I did the math for fun. 13.3 hours to 1 million kilometers away from earth at current speed, though I think it's slowing down a little, so it might take just a little longer than that.
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01-05-2022, 09:50 PM
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#50
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#1 Goaltender
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Quote:
Originally Posted by driveway
Just sitting at home on winter break and I did the math for fun. 13.3 hours to 1 million kilometers away from earth at current speed, though I think it's slowing down a little, so it might take just a little longer than that.
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2/3 of the trip took 11 days
1/3 of the trip will take 18 days.
https://www.jwst.nasa.gov/content/we...ereIsWebb.html
Probably the best analogy I think of for how it will move, is a curling draw. Big push to have it slow down and land just inside a predetermined pocket.
Except as discussed earlier "stopping", is basically slowing down to an orbital speed just a little faster than earth.
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01-05-2022, 09:54 PM
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#51
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Franchise Player
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Man, space is crazy
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01-05-2022, 10:28 PM
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#52
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Franchise Player
Join Date: Oct 2001
Location: Vancouver
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Quote:
Originally Posted by driveway
Just sitting at home on winter break and I did the math for fun. 13.3 hours to 1 million kilometers away from earth at current speed, though I think it's slowing down a little, so it might take just a little longer than that.
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Yeah, at one point I think it was going over 2 km/second.
I was kind of curious, but is the timing of all the events preprogrammed to take place, or does someone from NASA have to send a signal? I was also wondering what the ETA is for the first bit of data to be transmitted back to Earth and images generated for the public to see.
__________________
"A pessimist thinks things can't get any worse. An optimist knows they can."
Last edited by FlamesAddiction; 01-05-2022 at 10:45 PM.
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01-05-2022, 10:43 PM
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#53
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First Line Centre
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Quote:
Originally Posted by FlamesAddiction
Yeah, at one point I think it was going over 2 km/second.
I was kind of curious, but is the timing of all the events preprogrammed to take place, or does someone from NASA had to send a signal? I was also wondering what the ETA is for the first bit of data to be transmitted back to Earth and images generated for the public to see.
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It's manual right now.
Images will come pretty fast but they still be for calibration. Actual science is a few months away.
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01-05-2022, 11:03 PM
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#54
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Voted for Kodos
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Approximately 6 months until we see real data coming back.
It has to cool down, which takes several months, and then after that, they have to align and calibrate everything.
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01-05-2022, 11:07 PM
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#55
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damn onions
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The super advanced alien race Lanny keeps talking about in the other thread probably thinks this little telescope is so adorable.
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01-06-2022, 03:19 AM
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#56
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Franchise Player
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Quote:
Originally Posted by #-3
2/3 of the trip took 11 days
1/3 of the trip will take 18 days.
https://www.jwst.nasa.gov/content/we...ereIsWebb.html
Probably the best analogy I think of for how it will move, is a curling draw. Big push to have it slow down and land just inside a predetermined pocket.
Except as discussed earlier "stopping", is basically slowing down to an orbital speed just a little faster than earth.
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That's probably the best analogy I've seen, and pretty much how it will reach it's point. Fast acceleration to start and soft enough at the end to land on the target. JW isn't going to slam on the brakes at the end. Will be a nice smooth arrival at L2 at the perfect speed to enter orbit.
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01-06-2022, 10:21 AM
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#57
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First Line Centre
Join Date: Oct 2001
Location: The centre of everything
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Quote:
Originally Posted by You Need a Thneed
Approximately 6 months until we see real data coming back.
It has to cool down, which takes several months, and then after that, they have to align and calibrate everything.
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Does it really take months to cool down? Seems like a really long time considering the on board helium cooling system, heat shield, and temp of deep space. Is the solar radiation that high that the cooling rate is pretty small? Love to see any links you might have (I'll google obvs).
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01-06-2022, 10:28 AM
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#58
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Voted for Kodos
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Quote:
Originally Posted by FLAMESRULE
Does it really take months to cool down? Seems like a really long time considering the on board helium cooling system, heat shield, and temp of deep space. Is the solar radiation that high that the cooling rate is pretty small? Love to see any links you might have (I'll google obvs).
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The hot side of the telescope is going to stay hotter than air temperature here on earth.
And it’s really quite hard to cool things off in space, since there’s nothing to conduct or convect heat to. Sone parts of the telescope have to be REALLY cold (7K or so).
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01-06-2022, 10:38 AM
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#59
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Voted for Kodos
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Looks like it’s going to pass 1,000,000 km from earth in the next couple minutes.
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01-06-2022, 10:47 AM
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#60
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Franchise Player
Join Date: Oct 2001
Location: Vancouver
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About to hit 1,000,000 km!
__________________
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