Talk:Moon Impact Probe

Can't be flying

Congratulations to India for the successful landing, but a flag (or anything else for that matter) can't be flying on the Moon, as there is no air. Rewording should be done?

CielProfond (talk) 21:52, 14 November 2008 (UTC)

Good point. I removed the word (the sentence still works). 67.184.14.87 (talk) 23:57, 14 November 2008 (UTC)

misleading use of words

It is quite misleading to say that the MIP "landed" on the moon. It gives the impression that this was a soft landing, thanks to some kind of thruster, and the use of landing legs. If I understand things correctly (and i'm not sure because of misleading terms) the MIP in fact crashed on the moon at high speed, as it was planned that it should do. --AlainV (talk) 00:28, 15 November 2008 (UTC)

Noted.--PremKudva^Talk 04:54, 15 November 2008 (UTC)

This is a very good point, and I also object to using verbs in the present tense to describe the dubious feat. For example, in the Pay Load section, the first sentence should read, "The MIP carried three instruments", note past tense "carried". All of these fine instruments, including a high resolution quadrupole mass spectrometer (which any university natural science department would love to have), are now scattered around the south pole of the lunar surface, in a spray of high tech trash from yet another post industrial culture. Fantastic! India (crash) landed a probe on the moon! What new has really be learned here? That a developing country can erect a missile, shoot it at the moon and actually hit it! News Flash? Not! Been there, done that. This fourth rate stunt is more of a political coup than a break through in science. A pity that science is now the bitch of politics in this once great country and culture. 212.149.207.242 (talk) 10:57, 15 November 2008 (UTC)

Read my post below regarding the crash landing and stop imagining things. 67.169.0.250 (talk) 08:04, 16 November 2008 (UTC)

Let's all lower the rhetoric, please. We are here to help improve the article; let's focus on that. Thanks, Johntex\^talk 17:59, 21 November 2008 (UTC)

Did the flag reach the Moon?

This article says that India became the fourth nation to have an image of its flag on the Moon, but it sounds as if this must have been quite an explosion on impact. Would the flag have remained intact long enough to touch the Lunar surface, or would the explosion from the first contact of the probe to the surface have separated it into little monocolor pieces just beforehand? ;) Wnt (talk) 21:55, 15 November 2008 (UTC)

It could be the third nation if the Japanese probe Hiten was not carrying the image of the Japanese flag on it. So far I have not been able to get evidence on the web that it carried a flag.--PremKudva^Talk 09:58, 22 November 2008 (UTC)

Landing on South Pole

In this section, someone has recently added, "Following the successful deployment of the MIP, the other scientific instruments aboard the orbiting Chandrayaan-1 would be turned on one by one, starting the next phase of the two-year mission.", and gave a media link to support this statement, which it does not. There is nothing to suggest that anything will be turned on after the crash landing. I've removed this statement for that reason, but kept the media reference. Although the referenced media link does not support the sentence above, it does mention the following: "Kalam’s rationale for including the MIP was that since Chandrayaan was orbiting the Moon at an altitude of 100 km above the lunar surface, a landing would make India’s presence felt on the Moon’s surface. He believed that if this was done, India could always stake a claim to a portion of the Moon." So, like dog pissing on a tree, India has, indeed, used its science and technology for astro-political purposes; i.e. to mark its territory. In other words, India crash lands some high tech trash on the Moon, like tourists tossing away a soda can in some foreign country, and expect this will suffice as a future claim to property, and being the fifth in line to do so. HmmmmJace1 (talk) 23:50, 15 November 2008 (UTC)

A controlled crash on moon would eject subsurface material (hopefully water ice) into lunar space where it could be analyzed and detected by the instruments on board the orbiting satellite - that is perhaps the only cheap way at present to detect subsurface water ice on moon. How else would you do it? And that is why the probe fired retro rockets to slow itself down to 1.5km/sec before crashing into the moon. Future moon missions from other countries are planning to do the same to dig up water-ice if any. Besides that the probe serves as a testbed to validate a lot of technologies that would go into a future soft-lander. Anyone who things the purpose of this crash was to put a flag on the moon is crazy :-) There is a lot of time, effort, and instruments that went into that probe. thinking that its only purpose was to piss and mark territory on the moon is ridiculous. :-) 67.169.0.250 (talk) 07:56, 16 November 2008 (UTC)

The unsigned user (above) has suggested that I might be "crazy", and that my suggestion of India being the 5th dog (i.e., country/nation) to come and piss on this tree (i.e., to Moon) was "ridiculous". I appreciate the :-), and I do not mean to be directly offensive towards India with these comments, but the unsigned reader is again referred to the cited India Times article, where former President A P J Abdul Kalam states this objective specifically (i.e. putting a flag on the Moon, and not pissing on a tree, per se). Is the unsigned reader also suggesting by his/her assertion that the former president is also "crazy"? Please consider that this project is described as former President Kalam's "brainchild", as cited in the India Times article. I hope the unsigned user will sign his/her comments in the future, take the time to read the referenced article(s) and also not be so sensitive about assertions of fact that may not be too flattering (i.e., that it was a primary objective to put the Indian flag on the Moon, supposedly intact, and that we have no idea if that aspect of the mission was even accomplished). The unsigned reader also suggests that another aspect of this mission was to investigate the possibility of lunar ice. That's wonderful, if true. I am not able to find a reference for this, and would welcome the inclusion of such a reference in this article.Jace1 (talk) 15:48, 16 November 2008 (UTC)

If you are referring to this article [1] it doesn't say anywhere that India is marking territory. The former president is mainly talking about scientific relevance, not being left behind, validating technologies, and establishing a presence on the moon - things that any country with an imagination would like to do. Plus he further outlines the "future" strategic importance of moon and mars - strategic for anyone who is thinking about outer space exploration and does not want to be confined to just earth. Feel free to insert it in that tone and language instead of your ridiculous hyperbole regarding "pissing and marking territory" on the moon.

And from the same article:

Disagreeing with Subrahmanyam was New Delhi-based strategic analyst Bharat Karnad who said that the moon landing by India had no strategic importance. ‘‘The landing has a symbolic value and certainly places India among the elite group of countries. But it has no geopolitical significance.’’ At the same time Karnad added: ‘‘Hundred to 150 years from now when the moon is colonised, India can be proud of the fact that it had a pioneering status.’’

From politicalaffairs.net [2]

Following this, the Moon Impact Probe (MIP) would be ejected from Chandrayaan to crash onto the Moon’s surface, conducting various observations mostly on the way down but also after impact. Contrary to a lot of chatter in the media about “planting the Indian flag”, the MIP, having crashed, would be in no position to do this, but has been painted with the Indian tricolor to symbolically register India’s arrival on the Moon.

As for the objectives of the moon impact probe. you would find an official version here [3] and also [4].

Now please have mercy on the dog that you are about to send to moon just for pissing :-) Best regards. My personal opinion is on the contrary: India is definitely not marking territory here with the moon impact probe, but Indian presence on the moon ensures that the developed countries won't form an exclusive club to control access to moon and mars in future (just like they have done with many other things). Indian presence on moon ensures that moon remains open not just for India, but others that will follow. My personal hope is that it opens the floodgates (i.e if a developing country like India can do it so can we!) rather than put up barriers by marking territories. The only people who would be concerned about this even are those who want to maintain some sort of exclusivity on the moon. Chandrayaan-1 carried payloads from EU, US, and Bulgaria. Chandrayaan-2 will carry a russian rover and most likely instruments from other countries as well. Don't be surprised if Chandrayaan-3 releases probes from Timbuktu, Burkina Faso, etc on the moon and marks their presence as well :-) The probe marks "loss of exclusivity" of the moon (and that is perhaps the only thing that is strategically significant here as opposed to marking territory) 67.169.0.250 (talk) 19:40, 16 November 2008 (UTC)

From [5] which mentions several objectives of moon impact probe:

The Shackleton crater has an undulating terrain with hills and valleys. Since the valleys are in the Moon’s permanently shadowed regions, it could harbour water ice. The dust kicked up when the MIP crashed would be analysed to check whether it contained water ice. The probe died within a few seconds of its crash.

67.169.0.250 (talk) 19:58, 16 November 2008 (UTC)

The unsigned reader (above) has shared his/her opinion that depositing a flag on the Moon is not an act of marking territory, and goes on to explain why. It is not a very convincing explanation, in my opinion, but this is his/her opinion, and I will respect that. However, accusing me of being "ridiculous", for a second time, is not a very productive use of this space, and I will again suggest that the unsigned user refrain from personal attacks, simply because someone has written something in this space that does not fully agree with the unsigned user's personal opinions. Otherwise, such attacks could be labeled as oppressive. Let me remind the unsigned user that this is what this space is for, to share our opinions. I accept that the unsigned user may be emotionally invested in some aspect of this project, which is of no particular interest to me (either the project, per se, or the user's desire to defend certain aspects of it, for what ever reason). Again, let me share the quote from the India Times, which I used at the beginning of our exchange in this section, "Kalam’s rationale for including the MIP was that since Chandrayaan was orbiting the Moon at an altitude of 100 km above the lunar surface, a landing would make India’s presence felt on the Moon’s surface. He believed that if this was done, India could always stake a claim to a portion of the Moon." That last sentence, in particular, says to me that former President Kalam did indeed indicated that India could always stake a claim to a portion of the Moon (!). For the moment, I assume that the Times has made this statement correctly. While I appreciate the unsigned user's assertion that crashing this probe onto the lunar surface, with flags, was to break up some assumed monopoly of the Moon, supposedly held by other countries that have a clear history of acting in an imperialist way, the quote of Kalam's intent does not reveal even a hint of this particular objective, and I have seen no evidence of this suggestion outside of this box. Another thing I would like to comment on from the unsigned user's previous missive is his/he use of the word "imagination". This is used in a perjorative context, as "...things that any country with an imagination would like to do." This suggests that any country that would not like to crash land a probe onto the lunar surface must be without imagination. While I respect this opinion, I personally find it to be unimaginative. As for the fantasy of colonizing the Moon, well, if this remote possibility were ever realized by humanity, then it would certainly involve a very select few, while the rest are left on the surface of the Earth to pay for such folly. Has the unsigned user taken much time to consider the futher purpose or consequence of that desire? Assuming that the Moon is colonized, then what? Mars? OK, then what? Is the suggesting here that there are simply not enough space or resources on Earth, and that we "must" go further, or is this some irrational desire in our genetic make up that forces us to go further? These questions are simply rhetorical and beyond the scope of this thread, and I am not hoping to see a response. However, one useful question to consider would be this; will an elite few of our species ever be able to manage these newly colonized areas in a way that might somehow be significantly different than the way our species has behaved in the past? Again, this is a rhetorical question. I do appreciate the unsigned user's perspective on investigating the possibility of ice on the Moon with this crash landing, and I readily admit that I was not aware of this objective when I began to read about this project a few days ago, and I fully concur that this is a topic that may be worthy of crashing a probe on the Moon (with or without flags), :-), my very best regardsJace1 (talk) 10:29, 17 November 2008 (UTC)

Dubious speed precision

The referenced article on CNN uses an unnecessary degree of precision when it gives an obviously rounded 1.6 km/s as equalling 5760 km/h (1.6*3600) or the more bizarre 3579 mph (5760/1.609344). I suspect some lazy journalist rounded down a figure then started playing with his calculator. The Times of India give an impact speed of 1.69 km/s Fanx (talk) 11:36, 16 November 2008 (UTC)

References

Indian English

The idiomatic style of Indian English is probably all fine and acceptable in India, but elsewhere it sounds like a misplaced pseudo-aerospace-pseudo-impressive lingo:

deposited on the surface -- it is clear that it was far from deposited, but shattered, or smashed, in Indian-British speech.

put into lunar orbit -- should be injected into a lunar orbit

depicted pictures --should be sent images

required for crashing -- is not really impressive, rather embarrassing

controlled lunar descent -- not - this was a crash landing

spin up rockets -- professionally speaking, there is no spin-up, but roll, or pitch or yaw; there are also no rockets, but maneuvering engines, or jets.

We would enjoy the article immensely had it been written professionally. —Preceding unsigned comment added by 217.132.134.114 (talk) 14:02, 16 November 2008 (UTC)

There is practically nothing mentioned on the manoeuvring engines of the MIP on the ISRO site. The only evidence comes in their press release after the MIP was dropped on the lunar surface. Unlike mention of the "440 Newton Liquid Engine" on the Chandrayaan-1 probe, which crops up in every press release. So for the MIP they mentioned spin-up rockets and that is what we had to mention here.--PremKudva^Talk 10:08, 22 November 2008 (UTC)

Controlled descent?

Based on the current state of the article, I am uncertain as to how the landing of this probe qualifies as a "controlled lunar descent". Can someone clarify this? The claim is made in an apparently unreferenced statement regarding how this event is the first controlled lunar descent since the Soviet Union's Luna 24 probe. Steamroller Assault (talk) 20:24, 16 November 2008 (UTC)

I think so. It didn't use a free-fall trajectory and slowed itself down to aim at a target impact location and to use its on-board instruments. --Revth (talk) 04:34, 17 November 2008 (UTC)

Additionally information on the ISRO page Indian Tricolour Placed on the Moon mentions...

"Later, the probe slowed down with the firing of its retro rocket and started its rapid descent towards the moon’s surface."

This is the first time there is a mention of an on board rocket on the probe. Also that very page mentions...

"Finally, the probe had a hard landing on the lunar surface that terminated its functioning."

--PremKudva^Talk 05:15, 17 November 2008 (UTC)

Survival of the Indian flag

There was repeated edits here about the survival of the Indian flag after the crash of the MIP. Currently the entire question of it having survived or not is pure speculation and hence cannot be mentioned here even if ISRO says they feel it has survived. ISRO has not provided any proof thereof. As far as we are concerned the probe has landed and there is an image on four sides. It might be dented or damaged. It is after all an anodized plate mounted on the four sides.

Even if it has survived there is the question if it is visible at all, since the entire space craft including the MIP was clad in protective gold foil/cover.--PremKudva^Talk 05:20, 17 November 2008 (UTC)

Survived? Survived!!? Get real. The damn thing was going 1.69 km per second, faster than a bullet shot from a hunting rifle. I'd be surprised if it didn't simply vaporise on impact! —Quicksilver^{T @} 21:43, 17 November 2008 (UTC)

Vaporise on impact. Heh!;-)--PremKudva^Talk 03:55, 18 November 2008 (UTC)

Actually, it not only survived after an impact at 1.69 km/sec, but its also growing at rate of 1cm/month as a result of nano-meterials that were used. 67.169.0.250 (talk)

Yeah I know;-) I mean I knew for sure that rifle bullets survive after hitting concrete walls.--PremKudva^Talk 05:52, 19 November 2008 (UTC)

I changed the sentence to say the flag "reached" the surface of the moon instead of being "deposited on". I think that is more accurate and helps eliminate controversy about whether or not the flag(s) survived. Even if it was destroyed on contact with the surface, it still reached the surface. Johntex\^talk 17:25, 21 November 2008 (UTC)

Former president Kalam never said anything along the lines "India could make claim to lunar territory in future." What he said was that "India should establish a presence on the moon." Times of India seems to be have interpreted this as "may claim lunar territory in future." However, I agree that there has been a fair amount of media speculation regarding this both within and outside India and even on this discussion page, so a "controversy" section would be most appropriate. Best Regards 67.169.0.250 (talk) 04:35, 22 November 2008 (UTC)

Yeah and even if anyone had said anything about staking a claim it is a redundant claim. You stake a claim and then do what? You can't send troops there;-)--PremKudva^Talk 05:54, 22 November 2008 (UTC)

Off course, those few and lucky Indians who have bought land on the moon from companies operating in some of the western countries definitely have a claim on moon and naturally those imperialistic governments who let such companies sell moon land are trying to get a back door entry into laying their claim on the moon. 67.169.0.250 (talk) 06:49, 22 November 2008 (UTC)

According to the Times of India, he did say it would allow India to law a claim to a portion of the moon. We have to go with what the source says. Please feel free to expand the section citing contradictory sources if you like, but the citation from Times of India needs to stay in. Johntex\^talk 15:13, 22 November 2008 (UTC)

Please read the times of India articles carefully [6][7]. Times of India extensively quotes Kalam as follows:

After (the spacecraft) going so near the moon, I felt the mission will have more scientific relevance if the probe was included. I believe that the moon cannot be left to a few countries. I strongly felt that India cannot be left behind. So, I suggested the probe, and many in ISRO enthusiastically supported the plan ... The landing of the probe establishes India’s presence on the moon and prove that India can do it...I visualise that in another four decades, the earth, moon and Mars will have economic and strategic importance ... Well, my feeling is the way we have taken Chandrayaan and flown 3,80,000 km clicking a beautiful picture of the earth and putting it into the lunar orbit on November 8 is impressive. November 8 is, therefore, a very important day for us.

Where does Kalam actually say that India is or plans to or may stake claim on lunar territory? Times of India is mainly speculating and theorizing in their own infinite wisdom when it says: He believed that if this was done, India could always stake a claim to a portion of the Moon. Surely if Kalam actually said anything like this, it wouldn't have been missed by other publications? Are there any sources quoting Kalam saying anything about staking a claim on moon? If you are ascribing a motive to someone at least find a direct quote. We can't write an article on someone thinking as to what Kalam was thinking (i.e speculation - See WP:OR) specially when Kalam has himself clarified his exact reasons for sending the probe to moon (see bold text in quotation above). Also, I would appreciate it if we can discuss this a bit without getting into edit wars, etc. Best Regards 67.169.0.250 (talk) 18:31, 22 November 2008 (UTC)

Also see [8]:

Later, responding to the questions raised by Jubilee Mission Medical College students during an interaction with him on Chandrayaan Mission, Kalam expressed his opinion that no nation can claim the moon as its own. The resources of the moon should be a common property and that is one of the aims of the moon mission.

• The Time of India says "He believed that if this was done, India could always stake a claim to a portion of the Moon."[9] This is an exact quote that is supported by the source. Please stop removing it from the article. You are free to add other sources if you wish. Johntex\^talk 23:34, 22 November 2008 (UTC)

Yes, but that is irrelevant and meaningless chatter since what times of India says has been directly contradicted by Kalam himself. Not sure why so concerned about it, but I have kept it in the article. Best Regards. 67.169.0.250 (talk) 03:15, 23 November 2008 (UTC)

References

Japan flag on the moon?

Why does the article says that it's the 4th to have their flag on the moon after Soviet Union, US, and Japan? Never heard of Japan planting a flag on the moon, and the sources don't state it either, but I could be mistaken. —Preceding unsigned comment added by 128.54.74.146 (talk) 18:41, 18 November 2008 (UTC)

The line is probably talking about Hiten, a Japanese lunar probe that was intentionally crashed on the surface of moon after completing its mission.--Revth (talk) 03:58, 20 November 2008 (UTC)

Hiten was originally not even intended to reach the moon; it was designed to orbit the earth. Is there a reference for Hiten displaying a flag? Johntex\^talk 17:29, 21 November 2008 (UTC)

I have not seen any reference on the Japanese flag on the moon, the photo of the space craft didn't show a flag.--PremKudva^Talk 05:59, 22 November 2008 (UTC)

Richter scale on the moon?

I'm a little confused. What kind of a seismic impact would the probe's crash have produced, if it was indeed travelling at a very high speed, as the article implied? I think the main article could be improved if there were a link to the richter scale, and somebody could explain what was achieved by hitting the moon at such a rapid rate of descent. Were there mirrors somewhere on the moon, upon which subtle flickers of moonlight could be detected, even by earthbound telescopes? 198.177.27.15 (talk) 07:44, 20 November 2008 (UTC)

I don't think the mission intended to produce a seismic event. Strictly speaking any collision would create one, depending on whether you have instruments sensitive enough to detect the impact. What the impact was supposed to accomplish was to kick up sub-surface materials that could then be analyzed by the Chandrayaan-1, which remained in orbit around the moon. Johntex\^talk 18:14, 21 November 2008 (UTC)

Who shot it up?

Which rocket and country shot this spacecraft into spac? Was it put up by the space shuttle? Arianne? the russians? Who put it up? 70.88.110.14 (talk) 00:17, 21 November 2008 (UTC)

Read the lead.--PremKudva^Talk 04:00, 21 November 2008 (UTC)

In my opinion, the lead made clear that the spaceship and probe were made by India, but did not made clear that India also launched the mission. I have tried to improve this. Johntex\^talk 18:06, 21 November 2008 (UTC)

Chandrayaan I was launched by INDIA , by the launch vehicle PSLV, from Sriharikita Range, Andhra Pradesh , INDIA. —Preceding unsigned comment added by 117.241.57.164 (talk) 08:15, 7 October 2009 (UTC)

See also page

Yes, I could make one, but I'm just putting the idea out there for those of you ambitious and have some free time. Otherwise, I'll get to it later. Daniel Musto (talk) 18:34, 21 November 2008 (UTC)

Chandrayaan I was launched by INDIA , by the launch vehicle PSLV, from Sriharikita Range, Andhra Pradesh , INDIA.

Discovery of water

It gifted the answer to the millennia-old question whether water is there in Earth’s moon when it led to the discovery of water in its vapour phase by the CHACE (CHandra’s Altitudinal Composition Explorer) payload onboard the Moon Impact Probe (MIP) and complementarily in its solid phase by the Moon Mineralogy Mapper (M3) payload onboard the main orbiter in the Chandrayaan I mission. This ‘discovery-class-of-finding’ by CHACE was achieved by direct in situ measurement of the lunar atmosphere during the descend journey of the MIP to the Lunar South Pole, while M3 discovered water in ice form by remote sensing techniques. As water cannot retain its liquid phase in the lunar environment because of its own vapour pressure and the ultra-high vacuum prevailing there, it can be found in solid (ice) and gaseous (vapour) phases. While the Moon Mineralogy Mapper (M3), a payload by NASA, onboard Chandrayaan I lunar orbiter has detected, by mapping almost 97 % of the lunar surface using remote sensing techniques, the presence of water in ice form in higher latitudes especially in the polar caps, the CHACE payload in the lunar impactor (MIP) has directly detected water in its gaseous form along 140E meridian from 45oN to 90oS latitude, with a latitudinal resolution of 0.10 and altitudinal resolution of ~ 250 m from 98 km altitude till impact . —Preceding unsigned comment added by Newscientist1234567890 (talk • contribs) 09:57, 6 October 2009 (UTC)

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Dispute of Water Detection

The CHACE results suffer from a number of problems.

The instrument was a quadrupole mass spectrometer (QMS), and under ultrahigh vacuum (UHV) conditions, the highest residual mass peak occurring in clean, leak-tight vacuum systems is that of water vapor (H2O) at mass 18. Removal of this adventitious, surficial water is essential prior to launch. Bakeout to remove water vapor from stainless steel surfaces requires temperatures in excess of 180 degrees C, and sealing of the instrument for flight under that baked condition, normally through a pinch-off connection to the vacuum system. If the instrument is simply removed from the UHV system after bakeout, even under N2 purge, water vapor in the laboratory air will reoccupy the baked, pristine surfaces of the instrument at supersonic speeds, unless the entire laboratory is flooded with dry nitrogen (N2). For this reason, a break-off cap is activated when the target space environment has been reached, allowing the environmental sample to enter the pristine vacuum of the instrument. Mass scanning can begin, before or after opening this hermetic seal. In the case of the Cassini Ion & Neutral Mass Spectrometer, the hermetic seal was broken by fracturing and jettisoning a ceramic cap out into the depths of space.

However, activating the instrument by now turning on power to the ionization filament is not enough preparation for stable mass readings. Readings can be taken at any time, but stable readings require stability in the instrument's background mass scans which occur once thermal equilibrium has occurred. The published performance of CHACE is suspect for multiple reasons. First of all, the nature of the laboratory handling of the instrument is questionable, because a published mass scan shows obvious signs of a leak in the laboratory calibration system that includes the telltale signs of molecular nitrogen (28), molecular oxygen (32) and argon (40). Either one of these peaks alone is ambiguous, but the presence of all three in the ratios shown in the published plot are unequivocally due to an atmospheric leak in the vacuum system. This is dismissed by the authors as being not only expected, but typical, which is utterly preposterous. When the published plot was shown to a colleague without comment, his very first words were, "Looks like somebody has an air leak." He was correct.

The explanation of the bakeout of the instrument is also suspect, because there is so little detail given, including how this was performed and how CHACE was sealed for flight to avoid contamination when removed from the system and placed aboard the spacecraft.

The issue of whether or not the instrument had even achieved thermal equilibrium is questionable, as the stability described by the authors mentions stability in the ion source current - an absolutely essential capability of the electronics - but not the thermal stability of the system. In short, the instrument will not stop producing outgassing products until it has reached thermal equilibrium and the metal surfaces have given up their inventory of volatile gases. As the instrument warms, water will evolve from its metal surfaces. This can take hours for any laboratory mass spectrometer. In fact, the water peak is the most expected and highest peak that will evolve when the filament is first activated to begin taking readings. This peak will grow until it reaches a maximum, and then it will decay as the inventory of water vapor begins to deplete, and water re-forming upon the metal surfaces reaches equilibrium with water that is desorbing. There is no indication that sufficient time had elapsed in order to outgas CHACE prior to impact.

An increase in water vapor detection would be expected after the initial jump caused by filament activation. Anyone who has used a QMS in the lab has seen this. Even the hot filament produces unwanted chemistry within the instrument. Consequently, what the operator will do is take many background scans - when that background is stable - and subtract this background scan from actual experiment mass scans. In this way, the resulting peaks, so filtered, represent the best guess as to what is actually being observed by the instrument.

For reasons cited above, and the lack of supporting background information regarding the techniques employed, the results reported for CHACE do not hold up to scrutiny. Many questions could be resolved if the authors were more forthcoming with both the flight data and the laboratory data, but these have been limited, and appear to address, in subsequent papers, concerns that have been raised from the community's review of previous papers.

The complete story has not yet been told, and too many questions remain for a type of instrument that ALWAYS produces water vapor when first activated, and will certainly deliver a water vapor detection on demand, except under the most pristine laboratory conditions. Water can be present in air in amounts as high as 3%. The authors have proven that an air leak was already present in their vacuum system prior to prepping it for flight. It would typical for a QMS like CHACE to show a water vapor peak upon activation of the ion source. Consequently, there is absolutely nothing remarkable about evidence of a water peak when it was activated in lunar orbit.

Full disclosure of the mass scan data would defend the results or impeach them. But based upon experience with this very mass spectrometer and many others in three decades of laboratory UHV experience, I am not willing to accept the conclusions of the authors for H2O detection at the Moon. Whether the MMM instrument detected water, or not, is irrelevant to this discussion, because of the poor "chain-of-evidence" for CHACE based on what has already been reported by the authors and what is already known by the space science community regarding the performance of QMS instruments in the UHV laboratory.Swarmphysics (talk) 23:31, 19 September 2016 (UTC)

I agree with above, M3 gave the conclusive results. And this claim should be fixed.  Ohsin  21:40, 2 December 2022 (UTC)

It goes further than this, because MMM is a remote-sensing instrument, while CHACE was an in situ instrument. While it's nice to have complementary measurements, there is no reason an why an instrument taking remote optical measurements of the mineralogy of the lunar surface would find its readings coincident with those of an in situ instrument sampling the environment around the spacecraft.

There is also proof of the outgassing of a mass spectrometer in lunar orbit going back to 1971 with the Apollo 15 Lunar Orbital Mass Spectrometer Experiment (LOMSE). Those data recently released to NASA's PDS show two mass scans immediately after the instrument was activated in lunar orbit. The signal levels in the mass channels were excessively high, so the instrument was turned off for 20 minutes to outgas.

The point being, from the entire release of MIP to its impact at the lunar south pole was a period of about 23 minutes. Are we to believe that the instrument was on, scanning, and fully outgassed prior to its release from Chandrayaan-1, or is it far more likely that the instrument's ion source was still in the process of thermally equilibrating when it impacted the lunar surface, and after it had shown a maximum H2O signal at an altitude and latitude at which no H2O has ever been detected by either in situ or remote sensing methods. If CHACE was operating continuously and prior to being released, then this should be stated by ISRO. If not, then there's no reason to believe the data are real, and that a non-physical "cloud" of H2O exists above the lunar surface within and exosphere where MIP was located at the time of the maximum H2O signal.

Extraordinary claims demand extraordinary evidence, and none so far exists for CHACE. In fact, what publicly-available evidence exists entirely impeaches the claim that CHACE in any way detected water. ISRO could silence the critics by coming forth with the evidence and disputing the claims made against CHACE, but they have not. Nevertheless, the unsupported myth still remains here on Wikipedia. 129.162.152.226 (talk) 18:31, 23 March 2023 (UTC)

For what it is worth former Director of ISAC (now URSC) Dr. M Annadurai has acknowledged in interviews that CHACE wasn't degassed properly and that they didn't calibrate the instrument en-route. But yes such acknowledgements from individuals often come post-retirement and not from agency itself.  Ohsin  06:48, 24 March 2023 (UTC)

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