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Zvezdichko
No, it's not something related to radioactivity. It's thermal radiation. Which basically means that the temperature in Low lunar orbit is very high. As the Lunar pioneer (lunarnetworks.blogspot.com) wrote to me yesterday - it's very hard to protect a spacecraft from this type of radiation.
Greg Hullender
QUOTE (Zvezdichko @ Aug 31 2009, 06:28 AM) *
It's thermal radiation . . . it's very hard to protect a spacecraft from this type of radiation.


So how does LRO manage it? And how did the Indian Space organization fail to know about it?

--Greg
ugordan
Probably boils down to inadequate modelling and/or insufficient thermal vacuum testing of the spacecraft.
Zvezdichko
Gordan is right and I'd add to this: Lack of experience with planetary spacecraft.
nprev
(Sigh)...The lessons that burn are the lessons we learn. There are few easy things in spaceflight.
John Moore
So...presuming we're looking at a 'dead duck' at this stage of procedures, will we be seeing soon another impact on the Moon -- according to staff writers from this Moon Daily article?

John
-------------
A Moon Site
Zvezdichko
http://www.novosti-kosmonavtiki.ru/content/news.shtml

According to Novosti Kosmonavtiki the spacecraft will remain in orbit until 2012.
blairf
From the DPS abstract on the M3 presentation scheduled for early October.

"Discovery of Volatiles across the Moon by the Moon Mineralogy Mapper (M3)

The data also allow fundamental absorptions due to OH/H2O that occur near 3000 nm to be evaluated and mapped. These latter results are unexpected and have important implications for lunar science and exploration."

http://www.abstractsonline.com/plan/ViewAb...79-e98c22643ad2


Hope someone has made sure that the Augustine commission know this is coming down the line...

nprev
Link inoperative.
Bhas_From_India
Reason for failure is officially out...

India's ambitious moon mission Chandrayaan-I lasted less than half its expected life span because of excessive heat, the Indian Space Research Organisation (ISRO) has admitted.

The ISRO scientists had miscalculated the temperature on moon's surface which led to faulty thermal protection. Chandrayaan's orbit had to be raised from its originally planned 100 km from the moon to 200 km because of this problem. ISRO had then claimed that it was being raised for a better view of the moon's surface.

Admitting the lapse, director of ISRO satellite centre Dr T.K. Alex, said, "We assumed that the temperature at 100 km above the moon's surface would be around 75 degree Celsius. However, it was more than 75 degrees and problems started to surface. We had to raise the orbit to 200 km."

http://indiatoday.intoday.in/index.php?opt...amp;issueid=122
nprev
I'm surprised that they apparently used an original model for the expected radiant energy flux instead of legacy data from previous manned & unmanned lunar flights. Maybe I'm wrong, but you'd think that such information would be readily available from several sources. Was this just an assumption that got "yeah, yeah'd" rather than reviewed & challenged?
marsbug
QUOTE (blairf @ Sep 7 2009, 01:49 AM) *
From the DPS abstract on the M3 presentation scheduled for early October.

"Discovery of Volatiles across the Moon by the Moon Mineralogy Mapper (M3)

The data also allow fundamental absorptions due to OH/H2O that occur near 3000 nm to be evaluated and mapped. These latter results are unexpected and have important implications for lunar science and exploration."

http://www.abstractsonline.com/plan/ViewAb...79-e98c22643ad2


Hope someone has made sure that the Augustine commission know this is coming down the line...


Myself I'm trying hard not to get too excited before the actual papers come out, as abstracts can be decieving, but it's taken an effort of will....
mcaplinger
QUOTE (nprev @ Sep 7 2009, 01:19 AM) *
I'm surprised that they apparently used an original model for the expected radiant energy flux instead of legacy data from previous manned & unmanned lunar flights.

It's hard to know exactly where they went wrong, but there haven't been a lot of low polar orbit missions (I can't think of any before the most recent batch, except for Lunar Prospector, which was a spinner so the thermal design was much simpler.) Also, it's more likely to be more a case of not modeling the specific spacecraft response correctly than not understanding the basic environment. Low polar lunar orbit is a very challenging set of cases; it can be both really hot and really cold on the same orbit, the sun direction varies over all angles during the mission, etc, etc.
dvandorn
I find it interesting that one of the Lunar Orbiters had a similar issue with overheating, and IIRC it wasn't the first LO to be flown. Again IIRC, ground controllers had to change the spacecraft state, opening or closing a thermal door to manage heat within the vehicle even though this had an effect on the usability of the camera system.

So, while I'm sure there is enough blame to go around in any situation like this, I think it's also important to note that the Big Boys, the people who did this kind of thing for the first time a couple of generations ago, ran into similar problems even after they thought they knew what the environment was like. So, cut the ISRO people a little slack... wink.gif This is an excellent learning opportunity that will make their follow-on missions even better.

-the other Doug
ilbasso
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.
ugordan
QUOTE (ilbasso @ Sep 7 2009, 08:33 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."


Am I imagining things or hasn't the real reason of the orbit raise been known for quite some time? Off-the record if not publicly?
Zvezdichko
I can't say it for sure. Look at the earlier report:

http://kuku.sawf.org/News/58147.aspx

It was said it was being done for science.

I'm confused.
nprev
Ilbasso has a point; there are two conflicting reasons given for the orbit raising, and that doesn't help the team's credibility. However, I'd be willing to bet that this turns out to be a function of several things: translation difficulties (not only linguistics, but also tech-to-layman communication in the Indian popular media), last-minute heroics to understand the problem & save the mission ("let's raise the orbit to cool it off, and maybe we'll also get lucky & get better data from a higher perspective!"), and of course fear ("if we screw this up, the papers will roast us & ISRO will suffer in the budget!")

All of the above should sound pretty familiar from the history of the early days of most nations' space programs.
Bhas_From_India
Failure of key unit could have led to Chandrayaan-1 end
....the second (redundant) bus management unit, which ISRO was using after the first one failed within a few weeks of the mission launched on October 22 last year, stopped functioning resulting in loss of contact with the spacecraft....
NOTE: No official confirmation.

Scientists review Chandrayaan failure
Asked about the ISRO’s admission that a “miscalculation of the moon’s temperature” led to the satellite’s abrupt end on August 29, ISRO Chairman G. Madhavan Nair said: “Unfortunately, the reflection from the moon was much larger than expected and higher than what the literature data indicated.”
http://beta.thehindu.com/news/national/article16626.ece

"Aditya-1 may help satellites dodge solar radiation"
http://beta.thehindu.com/sci-tech/science/article16623.ece
NOTE: Should this be moved to any other thread??
ugordan
QUOTE (Bhas_From_India @ Sep 8 2009, 04:27 AM) *
ISRO Chairman G. Madhavan Nair said: “Unfortunately, the reflection from the moon was much larger than expected and higher than what the literature data indicated.”

And yet, according to an unsubstantiated report over at NSF.com, apparently American counterparts involved in the mission warned them about the thermal issue. Allegedly the Indians didn't listen to those warnings and Chandrayaan 1 flew insufficiently shielded.
Bhas_From_India
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
elakdawalla
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.

--Emily
centsworth_II
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.
dvandorn
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

-the other Doug
centsworth_II
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.
elakdawalla
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.

--Emily
centsworth_II
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.
Bhas_From_India
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
Bhas_From_India
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.

Phil Stooke
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.

Phil
Zvezdichko
http://www.isro.org/Chandrayaan/htmls/ImageMoon_llri.htm

LLRI results presented here.
Phil Stooke
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

Click to view attachment
Bhas_From_India
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
Zvezdichko
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.
Bhas_From_India
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....
Zvezdichko
The truth always comes out, of course. It's impossible to hide anything.
I'm mad at the official explaination by ISRO. They said the following: "The spacecraft in this higher altitude will enable further studies on orbit perturbations, gravitational field variation of the Moon and also enable imaging lunar surface with a wider swath."

This is misleading and made us think that the orbit was was raised because there's science that need to be done. It's a coverup.

By the way I think I can understand why they did this.

EDIT: There's NO Coverup and ISRO didn't hide anything. Link: http://www.exfn.com/india-moon-craft-hit-by-heat-rise . It was announced that the raise of the orbit will be done if the problem worsens. Case solved.
Pradeep
When this issue was raised on the forum earlier - thermal issue being a contributing factor to the orbit raise - I sent out an email and got a response from the Project Director M Annadurai that the press release stated was the reason. As an Indian citizen, I believe his word against everything else. At a later date he did clarify that they struggled to keep it in orbit despite the heat issues and failed star sensor had informed PIs of the issue and had asked them to gather as much data as quickly as possible and the orbit was raised only after this was done.

Radiation is the cause for thermal problems on board Chandrayaan-I. Radiation being from the sun. It was assumed that the temperature at the altitude as a result of radiation would be 75 degrees C. I'm not sure where this data came from.

ISRO does have a lot to learn PR wise. The Indian media also has to learn about deep space mission reporting. It is ISRO's first step in this info hungry world created by NASA. I think I had an inkling of this huge pressure for ISRO to release info. I'm quite happy with data and images released thus far while also proving India's capability to reach the Moon at low cost.

Chandrayaan-II is now being developed at a cost of Rs. 425 crores ($82 mn) in 2013. ISRO hardly makes a mistake twice (case in point is the single PSLV failure) and I do hope they don't.

Political comments removed
djellison
I think we should probably draw a line under this discussion. The allegations being made are exceptionally serious and I don't want UMSF to be a platform to make them.
Bhas_From_India
Scientists to decode moon mission data

ESA said that its payload C1XS, an imaging x-ray spectrometer, developed along with UK’s Rutherford Appleton laboratory and Isro, has been able to identify calcium on the lunar surface. “There are indications of iron and titanium samples as well,” said Dr Koschny.

http://economictimes.indiatimes.com/News/N...how/5008790.cms

Pradeep
An August 10, 2009 update to the Chandrayaan-I's official website has updated and put together the results of its various experiments. This is a good step but I do hope the various papers they are presenting in one place.

Here are the results page from various instruments:
1. Terrain Mapping Camera
2. Hyper Spectral Imager
3. Lunar Laser Ranging Instrument:
4. Chandrayaan-I X-Ray Spectrometer:
5. Radiation Dose Monitor Experiment

The European and Planetary Science Congress has also published some of the paper abstracts: ALL ARE PDFs
1. Observations by the Sub-keV Atom Reflecting Analyzer (SARA) on board of Chandrayaan-1
2. Initial results from the C1XS x-ray spectrometer on Chandrayaan-1

The page has results from various experiments on Kaguya, SMART-1 etc. and might be of interest to readers here.

Also, the Indian media came in for criticism from ESA recently on their reporting of the Chandrayaan 1 and he clarified with some results of C1XS and SARA. Some papers carried C1XS while others carried SARA.

Public apologies if the earlier post went haywire. If all goes well, I'll get to meet A P J Abdul Kalam and Annadurai during their visit to Mumbai on September 26, 2009.
Bhas_From_India
Did Chandrayaan find water on Moon’s surface?

An announcement is expected at a media interaction scheduled for Thursday at the Nasa headquarters in Washington DC featuring well-known lunar scientist Carle Pieters from Brown University. She is the principal investigator for M3.

A spokesman for Brown University also declined comment, saying there was an embargo. "It will be a major announcement of a major discovery and is something great for Chandrayaan. It will mark a major leap for India’s space programme," he said.

http://timesofindia.indiatimes.com/news/in...how/5044827.cms

NOTE: Not confirmed yet. But I couldn't wait.. biggrin.gif
Bhas_From_India
Water discovered on moon?: “A lot of it actually”
http://www.hindu.com/2009/09/23/stories/2009092357770100.htm

NASA Briefing To Reveal Evidence of Water on the Moon - Lots of It
http://www.moontoday.net/news/viewnews.html?id=1350
Hungry4info
Interesting, hopefully it's not just rumors.
If indeed the press conference is about water, I'm not going to hold my breath too much until after LCROSS does its thing. Not to say that I don't trust NASA's M3 instrument or India's Chandrayaan-1.
Phil Stooke
It's obviously going to be a very interesting announcement... but it will be difficult to reconcile with the Apollo sample evidence of a totally water-free environment for billions of years (no alteration products etc.) How can we have water everywhere and nowhere at the same time? Maybe what is being detected remotely (I mean the Cassini and EPOXI data, not MMM) is ephemeral and exospheric, with essentially no effect on the regolith. Then some of that migrates to cooler areas where it can be preserved. Resolving these contradictions will be very interesting.

Is NASA hiding old data? Well, wouldn't that be the PIs? If Faith Vilas's experience with Galileo data is anything to go by, the older data might have been very hard to publish earlier. Now it suddenly becomes feasible to publish it. That looks like a classic case of paradigm shift. Interesting!

Phil
Astro0
Sounds like it's being widely reported now that there's water on the Moon.

EDIT: Please note that I decided to pull the link to the report.
Phil Stooke
Well, I guess my question is answered already... the Apollo samples did contain a bit of water, but it was interpreted as contamination. Funny how we can be so certain about things that aren't true! I should be used to being wrong by now.

Phil
Greg Hullender
This is one of those times when it feels GREAT to be wrong, though. :-)

--Greg

dshaffer
QUOTE (Phil Stooke @ Feb 22 2009, 04:31 PM) *
Here is a clip on Youtube - from NDTV (New Delhi TV) reporting on the first 100 days of operation and the meeting in Bangalore - the one we hoped would lead to press releases etc. The clip includes images from the impact probe, showing how the rotating probe took images during descent.

Phil

http://www.youtube.com/watch?v=-f5qLMPIfe4



Were the full set of probe images ever released?
Phil Stooke
Not yet, but ISRO people have said the full Chandrayaan-1 dataset will be available online early next year. Also Kaguya data are supposed to be released in November this year.

Phil
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