Chandrayan-1 moon mission

[Nitesh]

http://www.hindu.com/2008/11/10/stories ... 230100.htm
CHENNAI: After successfully accomplishing the most crucial and tricky manoeuvre of safely inserting Chandrayaan-1 into the lunar orbit on Saturday, the Indian Space Research Organisation on Sunday executed the first manoeuvre of reducing the orbital height of the spacecraft around the moon. While on Saturday, Chandrayaan-1 reached the lunar orbit with an aposelene (farthest point from the moon) of 7,502 km and a periselene (nearest point from the moon) of 504 km, the periselene was reduced to 200 km on Sunday. The aposelene continues at 7,500 km. The periselene was reduced by giving commands to the engine on board Chandrayaan-1 to fire for about a minute from 8.03 p.m.
More manoeuvres

Three more manoeuvres of reducing both the aposelene and periselene will be done in the coming days. This includes the manoeuvre of putting Chandrayaan-1 in the final circular orbit of 100 km above the moon on November 15. After this is done, ISRO will command the spacecraft to eject its Moon Impact Probe on the same day.

The Terrain Mapping Camera, an Indian scientific instrument, has already been switched on. It has taken clear pictures of the earth and the moon.

[sumishi]

ISRO's press release: http://isro.org/pressrelease/Nov10_2008.htm
First Lunar Orbit Reduction Manoeuvre of Chandrayaan-1 Successfully Carried Out

The first orbit reduction manoeuvre of Chandrayaan-1 spacecraft which is orbiting the moon, was successfully performed yesterday (November 9, 2008)? night. As part of that manoeuvre which began at 20:03 IST, the 440 Newton liquid engine of the spacecraft was fired for about 57 seconds. With this, the nearest point of Chandrayaan-1’s orbit (periselene) from the moon’s surface was reduced from 504 km to 200 km while the farthest point (aposelene) remained unchanged at 7,502 km. In this elliptical orbit, Chandrayaan-1 takes about ten and a half hours to circle the moon once.

It may be recalled that the lunar orbit insertion manoeuvre of Chandrayaan-1 was successfully performed on November 8, 2008 and the spacecraft entered into an orbit around the moon with a periselene of 504 km and an aposelene of 7,502 km.

The health as well as the orbit of Chandrayaan-1 spacecraft is being closely monitored from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network (ISTRAC) in Bangalore with crucial support from Indian Deep Space Network antennas at Byalalu. The spacecraft performance is normal.

Further orbit reduction manoeuvres are scheduled in the coming days to take Chandrayaan-1 to its final operational orbit of 100 km height from the lunar surface. After this, the Moon Impact Probe, one of the eleven scientific instruments (payloads) of Chandrayaan-1, will be released to hit the moon’s surface.

[SSSalvi]

Excerpts from another forum. Request not to post comments. Just read and forget!


For the following post

http://www.upi.com/Science_News/2008/11 ... 226195216/

ISRO Chairman G. Madhavan Nair said the maneuver to break free of the Earth's gravitational field and to put the spacecraft in orbit around the moon was "the most crucial moment in the whole mission."
"We have done it so precisely that, as far as I know, nobody else has got this kind of precision," he said. "Our precision proves that in competence, our scientists and technologists are quite ahead of the global standards. With this, we have achieved more than 90 percent of the main objectives of the mission."

A comment was received

These indian scientists need to take a page from that book called politeness and humility...when India actually manages to get more than a couple of medals in the Olympics, I'll be impressed, not until then...contrast this with the chinese, who kept a low profile on bombastic statements when they did the more impressive space walk....

For which yours truly replied

No comments! Let the numbers talk.

7502 Km x 504 Km orbit against a targeted 7500 x 500 Km orbit in the firstever attempt of going out of Earth's gravitational field and entering Lunar attempt.

As a General Knowledge : If anyone has the data , how was the performance for other missions to moon in regards to Target and Achived precision please post it here.

I thought that settles the thing.. but ( none other than ) Andrew Brown replied

Hi sssalvi, I agree completely, that is incredible navigation & accuracy. The hardest parts of the mission are now over, launch, cruise & Lunar Orbital Insertion & a damn good LOI at that to boot.

It is similar to the NASA Lunar Orbiters in the 1960s. I know thay were over 40 years ago now, but think of the different circumstances. NASA was funded to a reasonable level back then in preparation for Apollo, with the Soviet Union breathing down theirs necks.

India, with only a tiny fraction of the funding has pulled off something as accurate, really is a major achievement here.

.....

Lets hope we start seeing some lunar imagery over the next few days.

Andrew Brown

Need any further certificates??

[UPrabhu]

SSSalvi,

Can you give me name of the forum?

[manoba]

SSSalvi,

Can you give me name of the forum?

Data mining, my friend. Data mining...

Give a Google with "yours truly" and "Andrew Brown" and then there you go.

If you stumble after, never hesitate to give a "Chandrayaan" search.

[neelkamal]

http://in.news.yahoo.com/139/20081110/8 ... a-s_1.html

ISRO to develop Sun mission 'Aditya', says Nair
Bangalore, Nov 10 (ANI): After the success of Chandrayaan -1, the Indian Space Research Organization (ISRO) has conceptually developed a Sun mission called 'Aditya'.

Talking to ANI here, ISRO Chairman G. Madhavan Nair, said the success of Chandrayaan -1 has boosted the confidence of ISRO scientists to look beyond the moon.

"Aditya has been approved and its operations would begin soon. Sun mission is very critical and one of its kind in the global space research," Nair added.

....

[Singha]

recently saw movie named Sunshine. had a manned solar module hiding behind
a gold plated huge umbrella to protect against sun's rays.

[SSridhar]

The Terrain Mapping Camera, an Indian scientific instrument, has already been switched on. It has taken clear pictures of the earth and the moon.

That is a reference to the pictures taken earlier. Not new pictures.

[sumishi]

http://in.news.yahoo.com/139/20081110/8 ... a-s_1.html

ISRO to develop Sun mission 'Aditya', says Nair
Bangalore, Nov 10 (ANI): After the success of Chandrayaan -1, the Indian Space Research Organization (ISRO) has conceptually developed a Sun mission called 'Aditya'.
Talking to ANI here, ISRO Chairman G. Madhavan Nair, said the success of Chandrayaan -1 has boosted the confidence of ISRO scientists to look beyond the moon.
"Aditya has been approved and its operations would begin soon. Sun mission is very critical and one of its kind in the global space research," Nair added.
....

eh!! Never knew this was in the pipeline, and approved too! Any information on this mission, or this is not the right thread to post/discuss such info?

[neelkamal]

http://news.in.msn.com/national/article ... id=1695775

Having conquered Moon, ISRO eyes Sun


Apparently, the move was in the pipeline way backin Jan 2008!

http://www.spacedaily.com/reports/ISRO_ ... n_999.html

ISRO Planning To Launch Satellite To Study The Sun

Aditya will study the dynamic solar corona.
by Divya Gandhi
Bangalore, India (PTI) Jan 18, 2008
In the midst of the buzz about Chandrayaan, the moon mission, the Indian Space Research Organisation (ISRO) is planning to launch a satellite to study the sun. 'Aditya' should be up in space by 2012 to study the dynamic solar corona, the outermost region of the sun.
....
"Aditya will be a small satellite weighing 100 kg, placed most likely in a near-earth orbit of 600 km," said G. Madhavan Nair, Chairman, ISRO. "The satellite is intended to study one of the most fundamental problems of coronal heating, and other phenomena that take place in the magnetosphere. "This will be one of the first projects scheduled in a road map formulated by the Advisory Committee for Space Research, said Mr. Nair.

[SaiK]

we should compare this aditya mission with soho mission, perhaps in a separate thread by the BR gurus.

[SSSalvi]

SSSalvi,

Can you give me name of the forum?

http://www.space.com/common/community/f ... .space.com

[p_saggu]

Every post of ISRO mentiones the ISTRAC Deep Space Network at bylalu.
Google Earth is still sleeping and they have still not updated the pictures over bylalu so that we can see the DSN.

[Rahul M]

still no pic of the moon !
reports say MMS has already seen it. One wonders when the commoners will get a chance.

[p_saggu]

Wasn't this supposed to have been taken by CY-1? This was published in the Hindu and it specifically says that this was taken by the Chandrayaan. There is no pic on ISRO's site though.

[p_saggu]

File picture from ISRO's Website dated May 9, 2006.

Mr G Madhavan Nair, Chairman, ISRO (centre) and Dr Michael Griffin, Administrator, NASA (right), signing MOU on Chandrayaan-1 at ISRO Satellite Centre.

[sumishi]

still no pic of the moon !
reports say MMS has already seen it. One wonders when the commoners will get a chance.

ISRO was pretty quick at releasing the Earth's images, but no moon images! Can't we do some kind of "chipko aandolan" to force their hand?
BTW, what is MMS?

[anishns]

MMS is non other than our Adarniya PM sahib
ManMohan Singh!

still no pic of the moon !
reports say MMS has already seen it. One wonders when the commoners will get a chance.

ISRO was pretty quick at releasing the Earth's images, but no moon images! Can't we do some kind of "chipko aandolan" to force their hand?
BTW, what is MMS?

[Rahul M]

Wasn't this supposed to have been taken by CY-1? This was published in the Hindu and it specifically says that this was taken by the Chandrayaan. There is no pic on ISRO's site though.

I've seen that picture but from other sources. if it's TSS in hindu that's semi-official.

still small consolation for lack of official releases.

[putnanja]

Chandrayaan a day away from home

Chandrayaan a day away from home

Our Bureau

Bangalore, Nov. 10

The Chandrayaan-1 spacecraft that now orbits Moon is set to get closer and reach its final home on Tuesday or Wednesday. Two more manoeuvres are needed, on Monday night and on Tuesday, before the spacecraft is slotted in the planned orbit 100 km distant from Moon, ISRO’s spokesman, Mr S. Satish, said.

Soon thereafter, all eyes are on the next big Indian moment in deep space when scientists at the Spacecraft Control Centre here release the Moon Impact Probe on to the lunar surface; MIP, with the Tricolour painted on it, will herald India’s ‘landing’ on Moon. The 29-kg probe will record the descent as it crashlands.

MIP’s release is planned for between November 13 and 15, a day after checking the instruments onboard, Mr Satish said. The spacecraft launched on October 22 has been in the lunar field since November 8.

The SCC team made the first lunar orbit lowering operation late on Sunday night. This eased it from 500 km to 200 km at the nearest point to Moon (periselene). Till Monday night, the lunarcraft was going round Moon in the elliptical path once in ten-and-a-half hours. The ‘aposelene’ or the farthest point was at 7500 km from Moon. All instruments on Chandrayaan-1 are performing well, ISRO said.

[Jayram]

Ok corner case question for the gurus. As per some news reports ISRO plans to release the Moon Impact Probe the same day that the Chandrayann reaches the final orbit around the moon followed by swiching on of the rest of the payloads. My question is why this sequence? I can vaguly can comprehend that releasing the MIP at the earlierst will mean carry less weight (< 100 Kgs? ) so more fuel efficent for the life of the craft as a whole. But then if none of the other payloads turned on how can they do the analysis of the MIP impact? Is there a more scientific explanation perhaps?
--Jayram

[harbans]

Jayramji, the 11 payloads on Chandrayaan are for moon studies. Chandrayaan is not an empty box with these payloads. Without any payload being switched on it is a communications and data platform by itself. Remember the first piece of equipment switched on was the TMC. But CY was getting transmissions and sending data from Bayalu all through. So even if the MIP is dispatched to the ground without switching the Laser ranging or SAR equipt, CY will get data and transmit it back to Bayalu village.

[harbans]

The photograph snapped from the TV screen looks pretty similar to the one posted on this blog..so this may be the genuine one below: (mentioned in an earlier post by vavinash ji)

http://4.bp.blogspot.com/_dSDqUplIzIw/S ... larged.png

Not confirmed by ISRO though

[p_saggu]

You all do realize that with the Chandrayaan so close to the moon, it will not be able to photograph the moon with one full frame picture. Henceforth the moon that we will see from the CY will be bits and pieces, and a few weeks down the line ISRO will come over with a full 3D composite picture of the moon.
The time to take that full frame picture was when CY was still orbiting the earth.

[rachel]

So it looks like Chandrayaan will achieve its circular 100km orbit by Tuesday evening...I had earlier been under the impression that the final orbit and release of the probe will both take place on the 15th (Saturday).

Looks like they're speedig things up... final orbit by Tuesday, then MIP release between Thursday(13th) and Saturday(15th).

[Praveen]

ISRO want's to have MIP crash on Nov 14th. That being children's day, it was bound to get maximum publicity. I guess they still want to hit that date.

Also MIP sit's on top of the radome. I guess some of the scientific payloads depend on using the radome.

[Arun_S]

Ok corner case question for the gurus. As per some news reports ISRO plans to release the Moon Impact Probe the same day that the Chandrayaan reaches the final orbit around the moon followed by switching on of the rest of the payloads. My question is why this sequence? I can vaguly can comprehend that releasing the MIP at the earlierst will mean carry less weight (< 100 Kgs? ) so more fuel efficent for the life of the craft as a whole. But then if none of the other payloads turned on how can they do the analysis of the MIP impact? Is there a more scientific explanation perhaps?
--Jayram

When MIP hits the Chandrama surface one would prefer to:
1. Have the CY close by rather than too far out from Chandrama surface
2. Have CY as long as possible perch/dwell time to view the same spot below for eqpt to take measurement
3. Measurement perspective (attitude) to be largely unchanged for the duration

All the above are easier if the orbit is elliptic rather then circular, also 2 & 3 are easier if the orbit is higher and elliptic rather than lower.

Thus it is best done as the CY orbit is being changed from elliptic to circular one, thus first in the line of experiments.

Not to mention that as MIProbe separates from mother ship its rocket motor will throw / blowback matter on it and ISRO wants to open the port holes of the on board measurement instrument once and for all only after MIPobe has departed. And very likely MIP is covering/masking some onboard instrument's measurement aperture.

[SaiK]

do we need to put chandrayaan-1 into moon-stationay orbit for the MIP experiement? what is the window available for this MIP test for C1?

[Gerard]

Moon probe ejection on November 14 or 15

[cholaraja]

great, roll on friday!

[Arun_S]

do we need to put chandrayaan-1 into moon-stationay orbit for the MIP experiement? what is the window available for this MIP test for C1?

Not at all.
Best window is when last major orbit lowering is done and at a local time when optical cameras can also take good image in visible and near viable spectrums. Of course the most important instrument is the Hyperspectral camera for this measurement.

[svinayak]

Keep a watch for the stars in the sky in the photograph of the moon by CY

Photographs in the visible spectrum and the ultraviolet spectrum have to be scrutinized

[rbnataraja]

Another simple question.
How does the MIP exactly eject from the yaan? Is it as simple as a spring being offhooked?
Are there any animations of this? Can the MIP decelerate while reaching moon? Or just free fall?

[SSridhar]

CY in 187 X 255 Km orbit

The liquid engine onboard the spacecraft was remotely fired for 14.4 minutes from 9.58 p.m. to 22.12 p.m. IST

[SSridhar]

Another simple question.
How does the MIP exactly eject from the yaan? Is it as simple as a spring being offhooked?
Are there any animations of this? Can the MIP decelerate while reaching moon? Or just free fall?

This may not answer all questions. But, have you seen this ?

[SSridhar]

Moon probe ejection on November 14 or 15

From the above, this nugget

There have been dynamic changes in our manoeuvres to reach the Moon.

[vsunder]

The most important question is: Is this 100km circular orbit stable? If not how many days does it take
for Chandrayaan to wander away, if the time period is small then precious propellant is used to bring it back to the circular orbit. 750 miles above the lunar surface, Earth's gravity exerts serious tugs and also there are effects of radiation pressure. Thus lunar orbits are unstable and more so at increasing heights. Remember the situation is very tricky for a lunar orbiting satellite due to Earth's gravity tugging at it. Here is a paper with lots of detailed information about the stability of Chandrayaan's 100km orbit. It tells us what the optimal inclination of this 100km orbit should be for maximum stability. The "9th spherical harmonic" is identified as the one which causes the maximum perturbation to stability and how long before rockets will be fired to keep it in correct station. So now we see where Chandrayaan will be parked for its final position and roughly how many days apart ISRO will need to fire engines to bring Chadrayaan back to position.

http://www.ias.ac.in/jess/dec2005/ilc-7.pdf

[SSSalvi]

Sumishi,

Pl. go thru the paper above.

" However, with the moon’s gravity field heavily dependent on longitudinal variations, it becomes necessary to include non-zonal terms also in the orbital evolution process."

Perhaps what U were saying in your earlier posts ( Moon's gravity is NOT 1/6 ) may be the average of all the variable intensities of Gravity w.r.t Lattitudes.

Also note that the paper is by ISRO scientists in 2005.

[narayana]

Chandrayaan nudged closer to moon

"The spacecraft is at 187 km from the moon (periselene) and 255 km away (aposelene), orbiting elliptically once in every 2 hours and 16 minutes over the polar regions of the lunar planet," Indian Space Research Organisation (ISRO) director S Satish said.
"The complex exercise enabled Chandrayaan to move swiftly from 7,500 km aposelene late Sunday to 255 km, which is a remarkable feat. All sub-systems and instruments onboard are functioning satisfactorily," Satish said.

Chandrayaan-I will undergo two more orbit-lowering manoeuvres over the next two days to enter into its designated slot of 100 x 100km from the lunar surface for a two-year rendezvous with the moon.

[SSSalvi]

We may have to wait for sometime to get the correct pictures frm CY because for accurate pics it has to stabilize in the orbit and face the camera to moon's surface. Now the yaan must be with nose in front attitude and therefore the camera will not be pointing to moon. Whatever they are saying the pictures must be when the yaan was pointing to moon ( for a small duration ) in its elliptical orbits.

In elliptical orbit the pictures will be distorted. No doubt you can see the shapes but that will be without any accuracy ( Technically called as RAW Image ) and the image processing software will fail to work with so much of distorted Raw Image. Surely no satellite operator would like to publish distorted pictures and then keep on giving excuses for its inaccuracies.

In fact the current attitude may be the reason as to why they want to fire MIP first ... before the yaan is in imaging attitude.