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Unmanned Spaceflight.com _ Telescopic Observations _ Herschel: the first science highlights

Posted by: Paolo Jul 16 2010, 06:34 PM

The special issue of Astronomy & Astrophysics on the first results from Herschel is now available, with hundreds of papers freely accessible!
http://www.aanda.org/index.php?option=com_toc&url=/articles/aa/abs/2010/10/contents/contents.html

Posted by: dilo Jul 16 2010, 08:20 PM

Grazie Paolo! smile.gif

Posted by: Paolo Aug 11 2011, 07:06 PM

according to Herschel's twitter (ESAHerschel) they will observe comet Honda-Mrkos-Pajdusakova on Aug 15/16. This small, short period comet has always fascinated me since it was to be flown by "tail first" by Sakigake. Too bad contact with the probe was lost before sad.gif

Posted by: Paolo Aug 21 2011, 04:28 PM

from Herschel's twitter:

QUOTE
Quick look analysis of the Comet 45P/Honda-Mrkos-Pajdusakova observations by Herschel is revealing some wonderful data.


can't wait for publication...

Posted by: Paolo Oct 5 2011, 06:54 PM

just published in Nature: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10519.html?WT.ec_id=NATURE-20111006
and this is ESA's release http://www.esa.int/esaSC/SEMER89U7TG_index_0.html
this is one of the most amazing solar system discoveries of 2011!

Posted by: Paolo Sep 29 2012, 05:21 AM

according to tweets by Daniel Fischer (@cosmos4u), Herschel should run out of coolant in March 2013 and ESA is considering end of mission scenarios. Warm observations are not possible, so one idea is to deorbit it from L2 and crash it on the Moon to perform scientific observations.

Posted by: Paolo Oct 27 2012, 07:29 AM

the story has been picked up by Spaceflight Now
http://www.spaceflightnow.com/news/n1210/26herschel/#.UIuNFvLI_5A

Posted by: nprev Oct 27 2012, 08:21 AM

Exciting idea; very innovative!

Posted by: Paolo Oct 27 2012, 11:28 AM

funny enough: it was also one of the possible end of mission scenarios for Chang'e 2. flying it back from L2 to impact the Moon for science

Posted by: tanjent Oct 27 2012, 01:13 PM

Is the hardware actually damaged by the lack of coolant? If Herschel were placed somewhere where it could conceivably be restocked with consumables at some future time, could it be returned to service? I guess the people who don't want to crash it probably envision some Hubble-inspired scenario like that. I recall though, that the last Hubble service call had to be performed before the gyros and other components ceased to function entirely. It wasn't something that could wait 100 years.

Posted by: Paolo Oct 27 2012, 01:57 PM

I see at least three reasons why this is not doable:
1. unlike the HST, Herschel was not designed to be serviceable
2. you need to use fuel to keep it into the halo orbit or to redirect it somewhere else to wait for servicing. I understand that fuel remaining is not a issue now, but it will become at a certain moment
3. orbital refuelling has been carried out until now with storable, room temperature liquids (hydrazine and water mostly). transfer of cryogenic fuels has yet to be tested, not to speak of the transfer of super-cold (less than 5K IIRC) liquid helium

Posted by: Phil Stooke Oct 27 2012, 08:14 PM

Paolo said "funny enough: it was also one of the possible end of mission scenarios for Chang'e 2. flying it back from L2 to impact the Moon for science"



Strictly speaking the Toutatis flyby is not an end of mission scenario. The question is, what is the post-Toutatis trajectory? I am assuming for lack of other information that the spacecraft will not get very far from Earth and its orbit will bring it back, rather than heading off into a more distant heliocentric orbit. Is there any description of its current orbit?

Phil


Posted by: Paolo Oct 29 2012, 02:57 PM

some insight on the decision to crash Herschel and the possible alternatives on this blog
http://herschellife.blogspot.es/1342197754/july-12th-2012-218-days-to-nominal-end-of-helium/
I would have loved the Herschel trailblazer concept: placing Herschel at the Earth-Moon L2 point to perform tests for future farside communication satellites before crashing it to the surface. unfortunately, the option was apparently deemed too expensive

Posted by: Paolo Dec 10 2012, 05:58 PM

Finally, no lunar impact http://herschel.esac.esa.int/latest_news.shtml

Posted by: Phil Stooke Dec 10 2012, 07:55 PM

Too bad. I'm hungry for another point on the lunar map. Oh well - GRAIL coming up soon, presumably.

Phil


Posted by: dtolman Apr 30 2013, 04:45 PM

http://www.space.com/20883-largest-infrared-space-telescope-ends.html

Probably a stupid question, but I'm guessing that the wavelengths being observed are too far into the infrared to allow a warm mission, ala Spitzer?
Seems like a lack of foresight (or penny pinching) to put up such a huge mirror, and not leave any instruments that could take advantage of it in an extended mission.

EDIT: and let me answer my own question:
http://isnerd.me/2013/04/04/some-more-questions-concerning-herschel/

QUOTE
For a telescope operating at shorter wavelengths (about ten times longer in wavelength than visible light) a “warm mission” is feasible. This could have been done with Herschel, but it would have required that the surface of the telescope be made far more precise and smooth. That would have made it very much more expensive, leaving less money available for the rest of the spacecraft and the instruments.

Any space mission must be built within a certain budget, and it is usually best to design it to be as effective as possible for a certain wavelength range. Herschel actually covers a very wide range – from 55 to nearly 700 microns in wavelength. That’s more than a factor of ten, which is very impressive. To make a warm mission possible would have meant making the telescope good enough to work at ten times shorter wavelength, and adding a fourth instrument.


Posted by: Paolo Apr 30 2013, 04:58 PM

by the way, the radiation monitors are still useable, and there was a proposal to keep them on. hope they will do it...

http://herschellife.blogspot.es/1342197754/july-12th-2012-218-days-to-nominal-end-of-helium/

QUOTE
The ESA Space Weather Team is keen to maintain Herschel operational as long as possible because of the information that it provides on the radiation environment in Deep Space. Herschel will finish observing just as we reach solar maximum, so any time that it can spend after solar maximum will be a tremendous bonus, particularly if it could observe for a full solar cycle. For this, it does not matter of Herschel is in the Earth-Sun L2, the Earth-Moon L2, or in heliocentric orbit: the environment is similar and totally different to that in low-Earth orbit, where most satellites are, protected by the Earth’s magnetic field.

Posted by: Paolo May 18 2013, 10:22 AM

some updates from Herschel's twitter account (https://twitter.com/ESAHerschel)

QUOTE
Through the night of May 13/14 Herschel's thrusters fired for over 7 hours to put it into a non-return trajectory outside the Earth's orbit.


QUOTE
@ESAHerschel will now drift away from Earth, while continuing to work on technology tests into June.


QUOTE
Where is @ESAHerschel now? At midnight it was 1862398km from Earth and moving away at a leisurely pace, now working on SPIRE tests.


QUOTE
Around 15:30UT this afternoon HIFI was finally switched off after (almost) 4 years work in space. SPIRE is the last instrument left on.


meanwhile, monitoring of solar radiation using the SREM instruments continue. particles from a flare in sunspot group 1748 were recorded the past week http://proteus.space.noa.gr/~srem/herschel/data/2013/SREMHerschel_2013_P_flux.png

Posted by: Paolo Jul 29 2013, 06:46 PM

Herschel observations of comet Honda-Mrkos-Pajdusakova (see post #4) have been published in arXiv today:

http://arxiv.org/abs/1307.6869

very interesting. while most comets have D/H ratios unlike that of water in the Earth's oceans, comet HMP and Hartley 2 have Earth-like ratios

Posted by: TheAnt Dec 28 2013, 06:17 PM

Herschel detect comet belt around Fomalhaut C

http://www.ras.org.uk/news-and-press/news-archive/224-news-2013/2376-companion-s-comets-the-key-to-curious-exoplanet-system

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