Chandrayan-1 moon mission

vishwakarmaa
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Re: Chandrayan-1 mission launched succesfully

Postby vishwakarmaa » 30 Oct 2008 16:58

Co-operation with Russia for Chandrayaan-II is a natural and good move.

Stubborn americans(NASA) had nothing to share with India because of their shyness with dual-use technologies. Its better to act mature and go ahead with Russian. We can't wait and cry if americans are having doubts about their relationship with us.

Those who are willing and open-hearted, we will co-operate with them. [:)]

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Re: Chandrayan-1 mission launched succesfully

Postby Lalmohan » 30 Oct 2008 19:00

NASA is asking the US Gov't to relax ITAR restrictions on them to allow more collaborative space development. until the USG does, ITAR will screw up all NASA attempts at working with others

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 30 Oct 2008 19:23

sumishi wrote:
sumishi wrote:Is anyone here aware that the moon's gravity is probably as high as 64% of Earth rather then 1/6th as we are taught in books? It can have implications for Chandrayaan's lunar orbital maneuver.

The neutral point of the earth-moon system is about 38,000 miles from the moon. This can be used to calculate the gravity of moon using inverse-square law.

It is probably because of this mis-information that the early mission probes of Russia and USA (Lunas and Rangers) to moon used to fail.


Sorry, I meant 43,495 miles, not 38,000, to arrive at the 64% figure . This value for the "Neutral Point" was published in Times Magazine (July 25, 1969) in reference to Apollo 11 landing. The same value is quoted in the 1969 edition of History of Rocketry & Space Travel by Wernher von Braun and Frederick I. Ordway III

If you consider other reputed information sources, the neutral point is variously mentioned from 38,000 to 43,495 miles. It is actually NOWHERE close to the 20,000 to 25,000 miles data that calculation were based on in days prior to moon probes from Russia and US.

The important point is: Does ISRO know about this Neutral Point discrepancy vis-a-vis common official knowledge in textbooks?


I just made this re-post so that you guys get the importance of this. If the above (the fact that the moon's gravity, instead of 1/6th, is more like 2/3rd of Earth's) is true and ISRO does not know about it, we have a disaster waiting to happen in this mission.

Is anyone here friendly with an ISRO scientific officer involved with the Chandrayaan mission, with whom the above can be unofficially discussed?

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Re: Chandrayan-1 mission launched succesfully

Postby prashanth » 30 Oct 2008 19:28

Hi sumishi,
Please stop worrying. If moon's gravity is indeed 2/3 that of earth our scientists would have already observed the effect by now. It simply isn't.
cheers!

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Re: Chandrayan-1 mission launched succesfully

Postby Raman » 30 Oct 2008 19:30

Sumishi,

Please don't be ridiculous. So you claim that you know the correct value of the moon's gravity, but ISRO doesn't? They can design and build launchers, a virtual zoo of highly sophisticated satellites, inject satellites into orbit with precision, build deep space networks ... but they don't know the moon's gravity?

What, exactly, are you smoking?

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 30 Oct 2008 19:47

Raman wrote:Sumishi,
Please don't be ridiculous. So you claim that you know the correct value of the moon's gravity, but ISRO doesn't? They can design and build launchers, a virtual zoo of highly sophisticated satellites, inject satellites into orbit with precision, build deep space networks ... but they don't know the moon's gravity?


What I am driving at is the "neutral point discrepancy," as came out post lunar-probe missions of Russia and US. If you use the new location of the Neutral Point that Apollo 11 astronauts crossed and do the inverse-square law calculations, you come out with a value of 64%. And anyways, these calculations are not mine to claim - they are by William L Brian II, an engineer with B.S. and M.S. degrees in Nuclear Engineering from Oregon State University. It is in his book published in 1982 -- Moongate: Suppressed findings of the US Space Program

What I am worried about is that this not common knowledge in the scientific circle, and at least should be looked into.

And don't give me that bit about scientists being Gods and knowing everything - the whole history of scientific achievements of humans is littered with mistakes being made out of ignorance/ego and corrected later on.

What, exactly, are you smoking?

That was funny! :D

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Re: Chandrayan-1 mission launched succesfully

Postby NRao » 30 Oct 2008 20:00

vishwakarmaa wrote:.

...because of their shyness with dual-use technologies. .............


Did not the nuclear deal deal with this aspect? "Dual-use" should be in the trash can I thought.

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Re: Chandrayan-1 mission launched succesfully

Postby Bade » 30 Oct 2008 20:17

AFAIk, ITAR restrictions still apply.

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Re: Chandrayan-1 mission launched succesfully

Postby SaiK » 30 Oct 2008 21:36

btw, I am all waiting for the real event to happen for ISRO!!! breaking earth's gravity and the journey towards moon. lets call it the mid-course breaking news!

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 30 Oct 2008 21:43

prashanth wrote:Hi sumishi,
Please stop worrying. If moon's gravity is indeed 2/3 that of earth our scientists would have already observed the effect by now. It simply isn't.
cheers!


Hi Prashanth,
Thanks for your cool reply.
There is more to the Space politics than normal people know about - you will be absolutely amazed how wool is pulled over peoples' eyes. For example, take the case of the Chinese Spacewalk -- want to see how they faked it in the video they released. Here is the link to the video on youtube. Watch carefully at 1:05 sec and 2:32 sec, and you will see a bubble rise up in each cases. Bubble in Space?? http://www.youtube.com/watch?v=36TR7RUVimU
Probably they tried (and did) the spacewalk somehow, but the video they released was probably filmed under water!

And watch it before this video too is taken down, as some other copies have been.

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Re: Chandrayan-1 mission launched succesfully

Postby SaiK » 30 Oct 2008 21:57

hey.. appreciate their good under water camera specs!

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Re: Chandrayan-1 mission launched succesfully

Postby vavinash » 30 Oct 2008 21:58

Most likely bought from Japan.

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Re: Chandrayan-1 mission launched succesfully

Postby harbans » 30 Oct 2008 22:41

Sumishi the guy who wrote the Moongate thing is a conspiracy theorist.

Start simply verifying what you are posting and check what that guy has to say..including that the Earth and Moon are hollow.

http://en.wikipedia.org/wiki/Gravity_of_the_Moon

http://en.wikipedia.org/wiki/Moongate_(book)

He according to his book he believes:

NASA is a wholly owned and operated front organization of the U.S. military.
Secret weapons were developed under the cover of a civilian space program
NASA/military suppression of (gravity) research discoveries.
Believes the US and USSR were in cahoots during their alleged Space race.
That secret discoveries put the Apollo astronauts on the moon.
The discoveries of Moon's true nature have been suppressed, especially its geology and atmosphere.
Contends that the Moonshots and space programs really never ended.


If ISRO goes even .0000001% by what this guy says, the rocket would'nt have made it past the launch pad.

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Re: Chandrayan-1 mission launched succesfully

Postby Lalmohan » 30 Oct 2008 22:43

Sumishi

you are right to bring up this important topic. In fact the USAF and NASA have been hiding a number of related informations, for example, there have been a spate of very mysterious cattle mutilation incidents around all the test sites in Nevada and New Mexico related to the space programme. Recently a number of highly qualified scientists from Minnewanka University published data on this which was also suppressed, by a shadowy Governmental agency.

Please carry on your excellent research and post it on the Nukkad thread, which is an ideal place for it.

In the meantime, lets carry on with the Chandrayaan discussion
thanks
Lalmohan

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 00:31

harbans wrote:Sumishi the guy who wrote the Moongate thing is a conspiracy theorist.

Hi harbans,

Thanks for your message.

Well, that guy might be a "conspiracy theorist" (not all of them are wakos, actually, although some are :D), but does the Times Magazine also fall under the same category?

Here's a snip from "A Giant Leap for Mankind", Times Magazine July 25 1969 --
"...At a point 43,495 miles from the moon, lunar gravity exerted a force equal to the gravity of the earth, then some 200,000 miles distant. Beyond that crest, lunar gravity predominated, and Apollo was on the "downhill" leg of its journey...."


That's the mention of the neutral point, almost double of what it was perceived to be in the pre moon-probe days! Use that for calculation, and your get the 64% figure.

I had posted the info out of concern for the mission, for just like you guys, I do so very much want the mission to succeed. If ISRO has got that "neutral point" discrepancy covered, great! But suppose it hasn't, then does Chandrayaan carry enough extra fuel for needed maneuvers?

Judging by the reaction of the learned people here to my post (the extreme reluctance to even think over something which challenges an existing "truth"), I well fear that the same psychology applies to the learned ones inside ISRO, and so, on their own, they probably have not even considered it.

But then, extrapolating from the fact that the Russians are involved in the Chandrayaan-II project with a lander, it is a distinct possibility that they might have tuned in the ISRO scientists, for they know. Their probes have been there, done that! So, I am hopeful :)
Last edited by sumishi on 31 Oct 2008 00:36, edited 1 time in total.

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Re: Chandrayan-1 mission launched succesfully

Postby ramana » 31 Oct 2008 00:35

sumishi, Please stop. How many people have to beg you? I dont want to warn you yet but will if I see one more post on this line of thought. There is the "newbie misc posts" thread if you want to pursue the line over there. Dont do it here.

In fact I want you to delete all your posts here and take them elsewhere.

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 00:39

ramana wrote:sumishi, Please stop. How many people have to beg you? I dont want to warn you yet but will if I see one more post on this line of thought. There is the "newbie misc posts" thread if you want to pursue the line over there. Dont do it here.

In fact I want you to delete all your posts here and take them elsewhere.


Okay, I am sorry, moderator! I wont post any more. If you want me to delete them, I will do so. But how do I delete them? Kindly help me out there

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Re: Chandrayan-1 mission launched succesfully

Postby svinayak » 31 Oct 2008 00:48

harbans wrote: Sumishi the guy who wrote the Moongate thing is a conspiracy theorist.

Start simply verifying what you are posting and check what that guy has to say..including that the Earth and Moon are hollow.

http://en.wikipedia.org/wiki/Gravity_of_the_Moon

http://en.wikipedia.org/wiki/Moongate_(book)
NASA is a wholly owned and operated front organization of the U.S. military.

If ISRO goes even .0000001% by what this guy says, the rocket would'nt have made it past the launch pad.


I can confirm that this is true.
Last edited by Rahul M on 31 Oct 2008 01:01, edited 1 time in total.
Reason: edited font size. anyway, this is not the right thread. please post in newbie thread.

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Re: Chandrayan-1 mission launched succesfully

Postby Lalmohan » 31 Oct 2008 01:52

ramana wrote:sumishi, Please stop. How many people have to beg you? I dont want to warn you yet but will if I see one more post on this line of thought. There is the "newbie misc posts" thread if you want to pursue the line over there. Dont do it here.

In fact I want you to delete all your posts here and take them elsewhere.


:rotfl:

where is that icon for bowing smiley saying "I am not worthy!"?

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Re: Chandrayan-1 mission launched succesfully

Postby svinayak » 31 Oct 2008 02:14

shahab1561 (1 day ago) comment
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Reply | Spam

hi there,, I am from pakistan,,, But I am proud of India about this mission.. You deserve that. The clip of Indian flag on Moon is so emotional for me. I wish and pray for them to come back Safely. Ameen.



http://www.youtube.com/watch?v=ipBOotJDJ1k

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Re: Chandrayan-1 mission launched succesfully

Postby harbans » 31 Oct 2008 02:28

Acharya ji, maybe a point or two you have personal confirmation on. However i quoted Wiki on a list of points he makes. It's idiotic what he's implying. I was thinking i would highlight some points as "Think maybe true" or "Conspiracy stuff" in that list as my comments. I left it untouched as afterthought. I concluded some people will point the inane out. And pointing out the inane does not take the thrust away. These are jerk theories. Don't work. They fudge the real thing. Like pseudo liberals and pseudo conservatives.

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Re: Chandrayan-1 mission launched succesfully

Postby svinayak » 31 Oct 2008 02:31

harbans wrote:Acharya ji, maybe a point or two you have personal confirmation on. However i quoted Wiki on a list of points he makes. It's idiotic what he's implying. I was thinking i would highlight some points as "Think maybe true" or "Conspiracy stuff" in that list as my comments. I left it untouched as afterthought. I concluded some people will point the inane out. And pointing out the inane does not take the thrust away. These are jerk theories. Don't work. They fudge the real thing. Like pseudo liberals and pseudo conservatives.

That is correct. I was referring to only one point in the list.

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Re: Chandrayan-1 mission launched succesfully

Postby p_saggu » 31 Oct 2008 13:00

While I certainly agree that these are mere conspiracy theories, there is also truth in the fact that some oversimplifications and some misguiding data have been perpetrated all around by all, more so by the agencies who were pioneers in the space exploration.

Meanwhile, from ISRO's website itself:
Image

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Re: Chandrayan-1 mission launched succesfully

Postby Lalmohan » 31 Oct 2008 15:52

i guess i'll have to join sashimi in the nukkad thread with moon landing fakings, chupacabras, alien abductions, cattle mutilations, giza pyramid microwave powerplants et al., ...

i hope ISRO has allowed for the microwave beam projecting towards alpha centauri from giza... its right in the path of chandrayaan...

(the yeti is real though, i've seen it)

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Re: Chandrayan-1 mission launched succesfully

Postby Rahul M » 31 Oct 2008 15:55

ok, give it a break. :)

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 16:09

Rahul M wrote:ok, give it a break. :)


Thanks moderator!

Just for the record, I am myself leery of a lot of these conspiracy theories, except those which seem compelling. It is just recently that I came across this "neutral-point" stuff that i got worked up, since it has also been stated in Times magazine, and Von-Braun's work.

Meanwhile, as I responded to the other Mod's 'slap-on-the-wrist,' I don't think I can delete the posts. Can you do it for me, if that is required.
And lalmohan, that "nukkad" thing was a scream :D

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Re: Chandrayan-1 mission launched succesfully

Postby narayana » 31 Oct 2008 16:27

Lalmohan wrote:i guess i'll have to join sashimi in the nukkad thread with moon landing fakings, chupacabras, alien abductions, cattle mutilations, giza pyramid microwave powerplants et al., ...

i hope ISRO has allowed for the microwave beam projecting towards alpha centauri from giza... its right in the path of chandrayaan...

(the yeti is real though, i've seen it)



Lal Mohan sir,you forgot to mention 2012, Pole shift and solar flares, i can foresee 2012 with pigs running for cover from solar flares under their Timber homes and being roasted alive :).

By the way can anybody give me link of nukkad thread,is it same as Humor thread,sorry i couldnt find the link

Thanks in Advance

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 17:33

Chandrayaan-1 Camera Tested. Working Fine
http://isro.org/pressrelease/Oct29_2008.htm
Cheers!

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Re: Chandrayan-1 mission launched succesfully

Postby SSridhar » 31 Oct 2008 17:37

The correct link for the above

ISRO has also released nice pictures of the Earth ! Excellent

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 17:39


Yeah sorry! Copied the wrong page link

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Re: Chandrayan-1 mission launched succesfully

Postby Neela » 31 Oct 2008 18:19

^^

Above pics taken from 9000km.

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Re: Chandrayan-1 mission launched succesfully

Postby SSridhar » 31 Oct 2008 18:36

One at 9k Km and the other at 70k Km which is twice the altitude of the METSAT.
Last edited by SSridhar on 31 Oct 2008 18:38, edited 1 time in total.

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Re: Chandrayan-1 mission launched succesfully

Postby K Mehta » 31 Oct 2008 18:38

whats with ISRO and photos of Australia? IIRC Cartosat also took photos of Perth airport :wink:
Lovely images though, screensaver material.

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Re: Chandrayan-1 mission launched succesfully

Postby SSridhar » 31 Oct 2008 18:53

Image

Terrain Mapper & HyperSpectral Imager pictures from ISRO publication

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 20:16

SSridhar wrote:One at 9k Km and the other at 70k Km which is twice the altitude of the METSAT.


Beautiful photographs!! Can't believe they are from our very own spacecraft, and not from those of the West. :)
I already have the 70K km one as desktop wallpaper.

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Re: Chandrayan-1 mission launched succesfully

Postby Sonugn » 31 Oct 2008 20:26

The photos are black n white. I thought it would look like a blue ball just like in NASA pics. :cry: Anyway very beautiful and inspiring!!!

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Re: Chandrayan-1 mission launched succesfully

Postby SwamyG » 31 Oct 2008 21:09

How Chandrayaan-1 is raised to higher orbits
Chandrayaan-1 could have been fired to reach the moon, which is about 3,84,000 km from earth, in one shot. But that was not done. Instead the spacecraft is being moved towards the moon in increasingly elliptical orbits with an apogee (farthest point from the earth) increasing many times more than the perigee.

“We could have done it one shot, but there is a possibility of missing the moon,” said M. Annadurai, Project Director of Chandrayaan-1 to this Correspondent. “So we have adopted an incremental increase in the orbits’ perigee.”

That probably explains why the Indian Space Research Organisation (ISRO) has decided to settle for five increasingly elliptical orbits before Chandrayaan-1 reaches the moon’s sphere of influence. Why is the firing always undertaken at the perigee position?

Firing at perigee
“To increase the apogee, we must fire at the perigee [position]. And firing should consume less energy. So the firing is done at the perigee,” Dr. Annadurai explained.

One more reason to fire at the perigee is to ensure that the spacecraft can be tracked by 3-4 ground stations. “The spacecraft is allowed to complete one or more orbits till such time 3-4 ground stations can track it. But we will fire it at the earliest opportunity,” he said.

But not always can one assume that the firing will happen as planned. So any change in this will in turn affect the apsidal line (imaginary line that connects the apogee and perigee). This should be corrected and maintained if the rendezvous with the moon is to happen.

Increasing the apogee
And what ensures that the apogee increases many hundred kilometres after every firing while the perigee changes by only a few kilometres? “When the firing is done exactly at perigee, the velocity increases and the apogee keeps increasing. There will be no change in the perigee position,” he said.

But firing the spacecraft exactly at the perigee position is only theoretically possible. This results in a small change in the perigee altitude.

Duration of firing
“It is not an instant firing [at the perigee]. It takes a few hundred seconds to complete the firing,” he said. But great effort is however taken to centre the firing around the perigee position.

For instance, the first firing to take Chandrayaan-1 from the initial orbit to the first orbit (with an apogee of 38,000 km) took about 1060 seconds to complete. The second firing to take the spacecraft to the nearly 75,000 km apogee took 920 seconds. And the third firing to raise it to about 1,65,000 km apogee took 560 seconds.

The fourth firing to take Chandrayaan-1 to 2,67,000 km will take about 190 seconds and finally the last raise to 3,80,000 will take 150 seconds.

Though the original plan was to reach 2,00,000 km apogee in the third orbit, ISRO could only raise it to 1,65,000 km. So will that lead to any problems? “This can be made up for in the next firing,” Dr. Annadurai said.

Image
Use of propellant
Will the change in the orbit-transfer strategy from five-and-half days to nearly a fortnight lead to increased fuel consumption and hence reduced mission life? “The amount of propellant required to fire the spacecraft to 4,00,000 km is less, whether it is done in one shot or in stages. And the propellant is used only for changing the orbits and not for orbiting around the earth,” he explained.

Orbiting around the earth is mainly through the gravitational force of the earth. But the gravitational influence of sun and moon would still play a role, though minor. Since the spacecraft goes around only for a few days in each orbit, there will not be any change in the orbits and hence the need to use propellant to correct the orbits would not arise.

But that will not be case when Chandrayaan-1 orbits the moon for two years. “There will be a need to correct the orbit once in two weeks to maintain a 100 km circular orbit,” said Dr. Annadurai.

Less energy required
While earth’s gravitational force will exist even when the spacecraft moves further and further away from the earth, the force will decrease with distance. “So firing it to the fourth and fifth orbit will require less energy,” said Dr. Annadurai. “Since some propellant is already used in the previous firings, the overall mass would come down. So the effort required to fire reduces.”

Reverse firing
Five-and-half days after the fifth firing, Chandrayaan-1 will have its rendezvous with the moon. Chandrayaan-1 will get nearer to the moon on November 8 when it reaches the 3,81,000 km apogee.

Though the moon’s influence will be predominant, the velocity of Chandrayaan-1 has to be reduced to enable the moon to capture it. Else, it can fly past the moon.

Once captured by the moon’s gravity, the velocity of the spacecraft has to be reduced to help it reach its final destination of 100 km circular orbit around the moon.

This is achieved by reversing what was done to raise its orbits.

“First, the firing is resorted at both perigee and apogee positions. And the firing takes place only after the orientation of the spacecraft is reversed — turned 180 degrees,” he said.

While the momentum of the spacecraft allows it to move in the same direction, the reverse firing helps it to reduce the velocity. The reduction in velocity is again undertaken in an incremental manner to reach the predetermined 100 km circular orbit around the moon.

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Re: Chandrayan-1 mission launched succesfully

Postby sumishi » 31 Oct 2008 22:18

“We could have done it one shot, but there is a possibility of missing the moon,” said M. Annadurai, Project Director of Chandrayaan-1 to this Correspondent. “So we have adopted an incremental increase in the orbits’ perigee.”


Way to go!! They are doing it real carefully unlike the US/Russians potshots at the moon. I am happy now :) - me and my stupid fears :P

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Re: Chandrayan-1 mission launched succesfully

Postby Bade » 31 Oct 2008 22:25

But not always can one assume that the firing will happen as planned. So any change in this will in turn affect the apsidal line (imaginary line that connects the apogee and perigee). This should be corrected and maintained if the rendezvous with the moon is to happen.


The article cleverly avoided mentioning how this is done. :)

A good guess would be to fire the alternative orbit raising maneuver slightly earlier than the perigee point. This way you can bring the alignment to what is needed. Is that why they went from 3 as originally planned, to 5 and not 4. :twisted: In the absence of information speculation can have no bounds.

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Re: Chandrayan-1 mission launched succesfully

Postby Bade » 31 Oct 2008 22:48

There could be another explanation as in none required :eek:

From launch date (Oct 22) to lunar orbit capture date is less than the sidereal period of the moon which is 27.3 days as observed from the earth. So maybe, it does not need any correction using method mentioned above just need to catch up by incremental firing at or around perigee, and wait for the moon to show up at the right spot around apogee. Some tuning will be required of course and prior planning on the sequence.

Measuring the motion of the Moon around the Earth relative to the distant stars leads us to what is called the sidereal period. The sidereal period is the time required for a celestial body within our solar system to complete one revolution with respect to the fixed stars‹i.e., as observed from some fixed point outside the system. The sidereal period of the Moon is the time needed for it to return to the same position against the background of stars.

http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question32.html


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