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Chandrayaan 1, India's First Lunar Probe
Bhas_From_India
post Sep 8 2009, 12:14 PM
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Not heat alone, radiation too crippled India's maiden moon mission, says Madhavan Nair
http://www.bombaynews.net/story/540340

Let's hope that these are the 'only issues' due to which Chandrayaan-1 failed. These 'known' issues can be 'fixed' for future missions (Chandrayaan-2).

also, most probably, ISRO will say Chandrayaan-2 will be a 6months to 1yr mission. smile.gif
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elakdawalla
post Sep 8 2009, 06:38 PM
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QUOTE (Bhas_From_India @ Sep 8 2009, 04:14 AM) *
also, most probably, ISRO will say Chandrayaan-2 will be a 6months to 1yr mission. smile.gif

This brings up an interesting point...it always struck me as odd that India promised a two-year primary mission from the start -- that seemed awfully long to me, compared to other lunar missions. If they'd only planned for a one-year primary mission with the possibility of extensions then they might not look as bad today.

I think we're seeing both clumsy handling of the press and translation issues (I am sure that when Nair speaks of "radiation," the connotations of that multiple-meaninged word are not quite the same to him as they are to us). I have many Indian in-laws and their English is perfectly good (more precise than mine, in daily use anyway) but although the words they use are the same as the ones I use, they don't quite always mean the same thing.

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centsworth_II
post Sep 8 2009, 09:25 PM
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QUOTE (elakdawalla @ Sep 8 2009, 02:38 PM) *
This brings up an interesting point...it always struck me as odd that India promised a two-year primary mission from the start -- that seemed awfully long to me, compared to other lunar missions....

So the same exact mission could be hailed as an overwhelming success, surpassing all expectations, or a dismal failure, falling way short of its goals, simply based on the stated mission objectives. Interesting.
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dvandorn
post Sep 8 2009, 09:44 PM
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Expectations are everything, centsworth. The village idiot being able to speak a complete sentence is either pathetic or triumphant, depending on your expectations... wink.gif

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centsworth_II
post Sep 8 2009, 11:43 PM
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So perhaps the Indian space agency's failure to fix minimal goals as the definition for mission success is the real problem here. Especially for a first mission.
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elakdawalla
post Sep 9 2009, 12:02 AM
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QUOTE (centsworth_II @ Sep 8 2009, 01:25 PM) *
So the same exact mission could be hailed as an overwhelming success, surpassing all expectations, or a dismal failure, falling way short of its goals, simply based on the stated mission objectives. Interesting.

Not the same exact mission. I haven't read carefully enough to know which ones, but I assume that some of the science goals of the mission couldn't have been accomplished in only one year. I'm just saying they may have promised more than they needed to, and now they're suffering for it. With NASA missions it's always entertaining to watch mission mucketymucks dance between touting their spacecraft as the greatest ever and making sure to keep expectations as low as possible. ESA recently got bitten by this too -- remember the Rosetta Steins flyby, and how OSIRIS shut down in an excess of caution right before closest approach? All the media reports on the flyby led with the fact that the camera failed to perform. Which was a bummer but it wasn't actually a spacecraft malfunction, and the data that they did get was cool. That probably taught Rosetta folks to keep mum about future encounter plans, more's the pity.

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centsworth_II
post Sep 9 2009, 12:23 AM
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QUOTE (elakdawalla @ Sep 8 2009, 07:02 PM) *
Not the same exact mission....

Right. I meant the same mission that occurred, not the same mission that was promised. If the goals for mission success were more modest, they may have been met before the untimely demise of the craft. And then the demise wouldn't be untimely. laugh.gif

I don't even know if there was an official list of minimum goals for mission success as NASA has, and if so whether the goals stated to the press were representative of those minimums.
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Bhas_From_India
post Sep 9 2009, 04:39 AM
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Tandem Lunar Observations Failed

The premature loss of India's Chandrayaan-1 lunar orbiter on Aug. 29 was a blow not only to the Indian Space Research Organization (ISRO), but also to lunar scientists who had just started using its U.S.-provided synthetic aperture radar in conjunction with a similar unit on NASA's new Lunar Reconnaissance Orbiter (LRO) for bistatic observations aimed at finding water ice at the moon's poles.

The first and only attempt to use both spacecraft for a look down into a deep crater from slightly different angles failed because of pointing problems, according to Stewart Nozette, principal investigator on the LRO's Mini-RF. Scientists had hoped the tricky maneuver Aug. 20 would help them distinguish ice and rock radar signatures. The spacecraft were only 20 kilometers (12.4 miles) apart, which gave enough of an angle for differences in the radar-reflection brightness to signify whether the source was rock or ice (Aerospace DAILY, Aug. 21). Ground controllers managed to get data back from both spacecraft, but it turned out to be unusable.

The two agencies were planning a retry when the Indian orbiter fell silent (Aerospace DAILY, Sept. 1). "ISRO should be congratulated," Nozette said. "They did a good job, but the moon is somewhat of a harsh environment."
...
"The gyros were drifting 0.8 degrees per hour," Nozette said. "That was about 10 times worse than we thought."

http://www.aviationweek.com/aw/generic/sto...andem090409.xml
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Bhas_From_India
post Sep 9 2009, 04:45 AM
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A statement issued by ISRO states: “In the next few months, interesting results about lunar topography, mineral and chemical contents of the moon and related aspects are expected to be published from the data obtained from Chandrayaan-1 mission.” The statement says that scientists have been able to map the polar regions of the moon from Chandrayaan-1’s orbit using the imaging radar for the first time. American scientists, who were a part of the peer review meet said that the mission has completed most of its objectives.

It is now time to study the wealth of data generated by the lunar probe. According to ISRO, the detailed analysis of the data will take about six months to three years.

WHAT THE 11 PAYLOADS ACHIEVED

Amongst the 11 pay loads, four instruments — Terrain Mapping Camera (TMC), Moon Mineralogy Mapper (M3), Hyperspectral Imager (HySI) and Smart near Infrared Spectrometer (SIR-2) — have provided extensive data on the moon’s topography, mineralogy and chemistry.

TMC and HySI payloads of ISRO have covered about 70 per cent of the lunar surface, while M3 covered more than 95 per cent of the same. SIR-2 has provided high-resolution spectral data on moon’s mineralogy.

Besides, Sub KeV Atom Reflecting Analyser (SARA), a joint payload of Sweden and India, covered the lunar surface several times and helped the study of the interaction between solar wind and a planetary body like moon, which has a magnetic field.

Additionally, interesting data on lunar polar areas has been provided by Lunar Laser Ranging Instrument (LLRI) and High Energy X-ray Spectrometer (HEX) of ISRO, as well as the Miniature Synthetic Aperture radar (Mini-SAR) of USA.

Another ESA payload Chandrayaan-1 Imaging X-ray Spectrometer (C1XS) detected more than two dozen weak solar flares during the mission duration.

The Bulgarian payload called Radiation Dose Monitor (RADOM), was activated on the day of launch itself and worked until the end of the mission.

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Phil Stooke
post Sep 10 2009, 11:05 AM
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http://www.ias.ac.in/currsci/sep102009/630.pdf

Article in 'Current Science' about Chandrayaan 1 images of the Apollo 15 site.

Also, word is the Chandrayaan 1 data will be released for public use in a few months in PDS format.

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Guest_Zvezdichko_*
post Sep 10 2009, 11:39 AM
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http://www.isro.org/Chandrayaan/htmls/ImageMoon_llri.htm

LLRI results presented here.
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Phil Stooke
post Sep 10 2009, 02:10 PM
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Here's a comparison of the Chandrayaan 1 and Kaguya images of Apollo 15. Chandrayaan has higher resolution (5m vs 10m). Dark spots near the ALSEP and LM are visible - the LM itself is visible in the fore and aft versions of the image in the PDF, but here, without a shadow, only the dark soil around it can be seen with any certainty.

Phil

Attached Image


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Bhas_From_India
post Sep 11 2009, 10:43 AM
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There is some news in today's prominent news paper...
Looks like ISRO has learned some invaluable lessons in Chandrayaan-I

Some snippets...

...ISRO has decided to replace the processing units on all future satellites, including two scheduled for immediate launch...
...The haste with which the BMUs ( Bus Management Units) in both satellites Oceansat-2, GSat-4 ( to be launched soon) were replaced is further confirmation that Chandrayaan-I was let down more by internal factors (this is news for me??) than external temparature vagaries.
..The urgency was such that the replacement was done on Oceansat-2 while it was waiting to be integrated with the launch vehicle.
..Apart from this, ISRO has decided to raise the threshold value of all vehicles... values of thermvac (thermal and vacuum tests) has been raised by four times....

Hope these lessons will ensure that, Chandrayaan-II thread in UMSF runs for a long long time... smile.gif
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Guest_Zvezdichko_*
post Sep 11 2009, 11:52 AM
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It will run if there's a good PR and info to announce. Otherwise I won't lose my time.

QUOTE (ilbasso @ Sep 7 2009, 07:33 PM) *
What's inexcusable, in my book, is to find that there's an unanticipated heat problem, raise the orbit, and then tell the world that it was done for "a better view." You deprive the rest of the world of learning from your mission, condemning others to possibly making the same mistake. And for me, it would now make me more skeptical of any news released by the mission team - i.e., what are they leaving out that didn't fit their predictions or which failed to confirm their hypotheses? The whole thing starts to smack of being a propaganda tool rather than a scientific mission.


I agree with you and just started a thread on BAUT. It's really inexcusable. And what about us, people from Bulgaria, USA, UK who had our instruments aboard? This is dishonorable to us, the taxpayers!

I'm mad.
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Bhas_From_India
post Sep 11 2009, 02:31 PM
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QUOTE (Zvezdichko @ Sep 11 2009, 05:22 PM) *
It will run if there's a good PR and info to announce. Otherwise I won't lose my time.
I agree with you and just started a thread on BAUT. It's really inexcusable. And what about us, people from Bulgaria, USA, UK who had our instruments aboard? This is dishonorable to us, the taxpayers!
I'm mad.


What makes you think that the scientists involved were not intimated about these issues? ( May be they were asked not to make it public.)
Bad press ( fear of headings like Chandrayaan-I failed and ISRO does not know why)??
The orbit could have been raised to give enough time for other instruments to be used?
But good thing is ultimately the truth does come out from ISRO, though it takes sometime.
If we have more people passionate about "Space Exploration" here, then things would be very different.
I would say, lets check next such mission from ISRO and see....
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