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China to Launch Solar Telescope
Dirak writes "China plans to launch the world's largest and most advanced space solar telescope (SST) into 735-kilometre-high earth synchronous orbit in 2008. Japan and the United States are also jointly developing an SST, coded as SOLAR-B, now scheduled for launch in the September of 2005. But with a diameter of 0.5 metre, SOLAR-B has half capability in optical resolution than that of the Chinese-made solar telescope."
My eyes my eyes! 100% to 0% vision in less than 3 seconds!
...I thought that the US was supposed to be the most technologically advanced country...what happened :D
Those who know, do not speak. Those who speak, do not know. ~Lao Tzu
Your sig...
I remember watching this in a vet health course and nearly vomitting...
What is the net result? We are subsidizing the expensive Chinese programs to launch satellites and space telescopes and militarize space. While we give more than $40 billion to China for development, the Chinese initiate massive space and space-militarization programs, including nuclear-weapons development.
We should immediately cut China off of the World Bank lifeline.
By contrast, when Japan was impoverished in the 1950s, the Japanese spent almost no money on space programs or nuclear weapons. The Chinese are playing Americans for a bunch of fools.
"China to Launch worlds largest Telescope Filter"
"A giant shutter will close when you do things like point the telescope at Google and Yahoo Headquarters."
Heil Sig! -Rob
Now, there is only one altitude at which a synchronous orbit is possible: that where the gravitational attraction matches the centripital force. Recall from high school Newtonian physics: GMm/r^2 = mv^2/r. Solving for v: v = sqrt(GM/r). The orbital velocity is also C/t, where C=2*pi*r. We note that t = 23 hours, 56 minutes, 4.09 seconds or 86164.09 seconds.
So, you solve for r, where GMt/4/pi^2 = r^3.
Turns out, this is about 22500 miles, or 37500 km.
A far cry from 735 km.
Of course, there is no need for a space telescope to be in synchronous orbit, and this one probably isn't: it would take a lot more energy to get it that much further out of Earth's gravity well. (But, that's a calculation for another day).
You could've hired me.
First off, keep your pants on. it's been less than a year.
Second, Bush has leaned on congress and got a funding increase for the Mars push when the Senate approved the NASA budget.
Thirdly, the Moon/Mars push will primarily take budget from the shuttle and ISS once those are done. Some additional funds will be diverted from other projects but science project stuff like this will continue.
Don't forget the science that will be obtained from manned Moon and Mars missions. Before you flame me about how robots are cheaper or whatever, ask yourself this: Do you believe mankind should settle other worlds? If so, do you think any number of robots will do if no humans are sent?
Blaze a trail to the New World
Just thought I'd mention that before some pedant rips my post to shreds.
You could've hired me.
Nitpicking - this is true of all orbits. A synchronous orbit is one where the orbital period matches the rotational period of the central body.
You calculated is correctly, mind you, and seem to have a clear understanding of the issue. Except for that one little part of your explanation.
"I do not agree with what you say, but I will defend to the death your right to say it"
Doh! need more coffee. :-)
You could've hired me.
Developing a telescope that can only be used during the day!
Surely, they meant sun synchronous orbit, which are usually just under 800 km. These orbits follow the sun all day, useful for a solar telescope I'd think.
I wonder what they'll end up crashing this one into?
I'm curious how that would work. An 800km orbit takes 100 minutes, it would circle the earth 14 times a day, and be in shadow half the time. If it was a polar orbit it would get a continuous clear view of the sun for maybe a few months of the year.
If you want an unobstructed view of the sun you need a much higher orbit, like the moon which is eclipsed at most twice a year IIRC. Or you need to leave earth orbit altogether, like soho which is at the earth-sun L1 point.
Dunno if an 800 km orbit can counter the earth's revolution around the sun though (and am too lazy to calculate that right now).
You could've hired me.
Sun synchronous orbits don't get a continous view of the Sun, they are polar orbits that pass over a point on the Earth at the same time each day.
This could be somewhat usefull for regular communication with the satellite from China, but I don't see why it would be worth the expense of a polar orbit for that.
a,e,i,o,u and sometimes w and y (at be if of up cwm by)
1. It in a high orbit, but not a sync orbit.
2. It has a very big mirror.
My Conclusion:
It's a giant magnifying glass for frying humans on the ground.