Is the James Webb Space Telescope Ready to Replace Hubble?

[meteor]

NASA have definitelly chosen the primary mirror for the JWST. It will be a berylium-based mirror. The JWST will be launched in 2011 to replace the Hubble
www.universetoday.com/am/publish/james_webb_mirror_approved.html

Woa! I can't wait til then!

 

[LURCH]

I'm right with you on that, Meteor! I also think that de-orbitting of the Hubble should be postponed until the JWST, just in case.

 

[brum]

LURCH -- you'd be willing to send up a whole space crew to fix up Hubble a bit to make it last a bit longer (so that there's no gap between the end of Hubble and the start of Webb)??

 

[enigma]

I'm sure you won't have any shortage of astronauts willing to go up and repair the Hubble.

That telescope has produced some of the most marvelous photographs that the world has ever seen. De-orbitting it without a replacement (assuming repair costs aren't holding back construction of said replacement) would almost be a disservice to humanity.

 

[Nereid]

Didn't John Bahcall head a panel which looked into options for extending the HST? I seem to recall that an awful lot of astronomers were really keen not to lose the HST, even after the JWST is up and running.

Also, look at the success of, for example, Galileo and the Voyagers compared with the Shuttle. Surely it's cheaper - in every sense of the word - to have probes and instruments do the space exploration than fragile, irreplaceable humans?

 

[LURCH]

Originally posted by brum
LURCH -- you'd be willing to send up a whole space crew to fix up Hubble a bit to make it last a bit longer (so that there's no gap between the end of Hubble and the start of Webb)??

No, I advocate leaving the Hubble just where it is and just as it is until the JWST is in place and functioning. Once the Webb is in place, that would be the time to deorbit the Hubble, IMHO. So if the Webb doesn't make it (launch failure or something), we can go ahead with repairs to Hubble. I know it's a terrible thought, but launches sometimes go awry, and with this plan, we don't lose both.

 

[brum]

if I'm not mistaken, the Hubble would need a repair mission to extend its lifetime to keep it from terminating a year short of JWST's beginning.

enigma--
yeah, I am sure there plenty of astronauts willing to go do the repairs, but financially? eh, not so sure there.. the cost of it is what might bring hubble's end a year earlier than JWST's beginning

 

[Phobos]

Originally posted by brum
yeah, I am sure there plenty of astronauts willing to go do the repairs, but financially? eh, not so sure there...

or the risk, now that we have 2 shuttle disasters behind us

 

[Astronuc]

Nasa unveils Hubble's successor

Well, finally!

http://news.bbc.co.uk/2/hi/americas/6645179.stm

The US space agency Nasa has unveiled a model of a space telescope that scientists say will be able to see to the farthest reaches of the universe.

The James Webb Space Telescope (JWST) is intended to replace the ageing Hubble telescope.

It will be larger than its predecessor, sit further from Earth and have a giant mirror to enable it to see more.

Officials said the JWST - named after a former Nasa administrator - was on course for launch in June 2013.

The full-scale model is being displayed outside the Nasa museum in the US capital, Washington DC.

'Birth of the universe'

The $4.5bn (£2.27bn) telescope will take up a position some 1.5 million km (930,000 miles) from Earth.

. . . .

http://www.jwst.nasa.gov/

http://www.st.northropgrumman.com/capabilities/space/science/jwst.html

 

[bassplayer142]

Couldn't they program some coordinates into the Hubble and launch it out to some planets. The Hubble orbiting say Mars could get some amazing pictures. Do that instead of taking it out of the sky. I would guess Hubble isn't even capable of this but its worth a try asking.

 

[Astronuc]

Couldn't they program some coordinates into the Hubble and launch it out to some planets. The Hubble orbiting say Mars could get some amazing pictures. Do that instead of taking it out of the sky. I would guess Hubble isn't even capable of this but its worth a try asking.

That would require developing a booster (rocket motor) and installing it on Hubble. To be functional out in deep space would require replacing solar with nuclear power systems.

Anyway NASA apparently plans to extend the life of Hubble until 2013 -

Hubble to be Serviced Again

Administrator Michael Griffin’s decision on October 31, 2006 to fly servicing mission SM4 in mid- to late-2008 will bring unique capabilities to Hubble in the form of two new science instruments, Cosmic Origins Spectrograph and Wide Field Camera 3. In addition, new gyros and batteries will extend Hubble's life through 2013.

http://hubble.nasa.gov/index.php

 

[Jimmy Snyder]

Couldn't they program some coordinates into the Hubble and launch it out to some planets. The Hubble orbiting say Mars could get some amazing pictures. Do that instead of taking it out of the sky.

Sending the Hubble to other planets just to get some amazing pictures of those planets is not a good idea. For instance, Hubble is not used to get amazing pictures of the earth.

One advantage of its current location is that it can be repaired. The Webb telescope is headed ultimately for the L2 libration point, closer to the moon than the earth. There are no plans to maintain it once it gets there.

I'm sure many people feel nostalgic for the Hubble because of the wonderful images it has produced not to mention the scientific data. However, it has to compete for funds like all Nasa projects and it may seem an extravagance once the Webb telescope is operational.

 

[cepheid]

Well, ESA's Herschel space telescope is scheduled to be launched next year some time, is also headed for L2, and will also be capable of imaging spectroscopy and photometry at submillimetre wavelengths. Furthermore, it will have a 3.5 m primary mirror diameter, if I remember correctly. That's larger than Hubble, and, until James Webb comes along, will be the largest telescope launched, and the largest one capable of being launched in one solid piece. James Webb's complex "unfurling" mirror is ambitious, from what I hear. I've been told NASA usually has an unwritten commandment..."thou shalt not have any moving parts" for such spacecraft . Unfortunately, Herschel has a limited ~3 yr lifetime due to the liquid helium cryogenic system required to cool the detector.

 

[Chronos]

That does not seem right, cepheid . . . need to check that one out. No argument about the moving parts part, but 3 years seems very short sighted. It takes nearly 3 years to plan a Hubble mission right now. The window is too narrow, IMO.

 

[cepheid]

http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16

The information is all here. My understanding is that certain PI's of the various research groups involved in the collaboration during the instrumentation phase will be given guaranteed time with the telescope, but are therefore charged with the responsibility of using that time in a sensible way, to do observing that is of greatest benefit to the astronomical scientific community as a whole. As a result, much of what Herschel will be doing has been predetermined (e.g. legacy surveys). There is, of course, also observing time up for grabs. Does that clear up your concern, or did I misunderstand the point you were making?

EDIT: I apologize if this is considered off topic guys. I just wanted to contribute to the general topic of "large space telescopes due for launch in the next few years." However, Herschel is not a successor to Hubble. That title falls on James Webb solely, from what I understand.