Why don't we send another space telescope up into space?Date: Tue Sep 2 20:22:36 1997
Posted by Jordan Decker
Grade level: 10-12
School: Naperville North High School
City: Naper ville State/Province: IL
Area of science: Astronomy
Why don't we(NASA) send another space telescope into space? I mean, send one way out into the solar system so that we could see even farther, but still be able to send commands to it? I know that the problem might be that it is too expensive or that it would be unrepairable, but I would like your expert knowledge.
Well, the short answer to your questions is : we are! Currently, NASA plans on launching the "Next Generation Space Telescope" sometime around the year 2008. NGST is not a strict replacement for the Hubble Space Telescope, but will instead be an infrared telescope, designed to look extremely deeply into the Universe, to see what things looked like when the Universe was young. It is part of the "faster better cheaper" NASA plan. Instead of the 4 billion or so dollars for Hubble, NGST will cost about 500 million. It is in the preliminary design stages right now, and current plans call for it to be placed far enough away from the Earth that there will be minimum interference.
One possible placement of NGST puts it at the L2 point, which is a position of relative gravitational stability just outside the Earth's orbit from the Sun. The 'scope itself will have a large shield that will keep the Sun's light off the mirror. The mirror itself is huge: NASA wants at least a 4 meter mirror (compare that to Hubble's 2.4 meter mirror)!
Lots more info can be found at NASA's NGST web page
Other telescopes have also been launched:
There are also many more! Granted, these are all in Earth orbit, but that is mostly because getting to orbit is much easier than sending something far away. Most of these missions are not repairable if something goes wrong, or if the hardware can be updated like Hubble's. But it is usually simpler and cheaper to design a one-shot deal than something like Hubble which can be serviced. However, this will shorten the lifetime of the telescope, typically. Not many telescopes have Hubble's 15 year (at least) lifetime! One notable exception is the International Ultraviolet Explorer, which lasted for 18 years, although the design specs called for a 3-5 year lifetime!