Chandrayan-1 moon mission

[vdutta]

i think isro is talking about the decent velocity i.e. the rate at which mip will fall. not the actual rotational velocity of the probe. so that way the probe will travel sideways at a faster rate, but downward velocity will be less.
its just a guess. i could be wrong too.

[svinayak]

The Moon Impact Probe is expected to be detached (from Chandrayaan-1) at around 10 pm on Friday

Keep your telescopes ready. you may get a nice view or none at all. 10 pm.
Since the CY-1 is in sun sync polar orbit it may be difficult for MIP to transmit bright video since it will always be travelling between darkness and light. All the more because moon lacks atmosphere and there is no twilight on moon. Perhaps ISRO may slightly alter the orbit of MIP for this purpose.
JMT.Corrections awaited if any.

What about stars in the sky on those videos and photos

[prao]

The Moon Impact Probe is expected to be detached (from Chandrayaan-1) at around 10 pm on Friday

Keep your telescopes ready. you may get a nice view or none at all. 10 pm.
Since the CY-1 is in sun sync polar orbit it may be difficult for MIP to transmit bright video since it will always be travelling between darkness and light. All the more because moon lacks atmosphere and there is no twilight on moon. Perhaps ISRO may slightly alter the orbit of MIP for this purpose.
JMT.Corrections awaited if any.

Actually CY1 is not in a sun sync orbit - it is a polar orbit though. The problem is that the Moon has a more complex motion than the Earth (orbiting both Earth and Surya). It appears that CY1 will concentrate on various regions of the Moon during different "viewing seasons". See earlier link to paper on the TMC.

[hnair]

What about stars in the sky on those videos and photos

printing mistakes

[ramana]

S^3, What probe? Its an instrumented pile driver if it has to get any soil properties. BTW thanks for you insights.

[svinayak]

What about stars in the sky on those videos and photos

printing mistakes

[p_saggu]

Boss you are talking about a really really high powered scope here. Assuming that you manage to locate the Chandrayaan, it will surely not be possible to see MIP (Unless you are sitting with a telescope the size of a bus) Also it would be very difficult to differentiate the MIP lunar cloud from the numerous asteroids that pound the moon at any given time.

[svinayak]

http://www.newscientist.com/article/dn1 ... rface.html

TV-sized probe to strike Moon's surface

* 00:01 12 November 2008 by Padma Tata, New Delhi
India's Chandrayaan spacecraft is set to eject a television-sized probe that will crash onto the lunar surface on Friday. The probe will make observations as it descends, testing systems needed to land future robotic spacecraft on the Moon.

Chandrayaan, which launchedMovie Camera on 22 October, has been travelling on an elongated path around the Moon since it went into orbit there on Saturday. But engine firings on Tuesday and Wednesday should move the craft into a circular orbit that brings it just 100 km from the surface.

After letting the spacecraft circle the Moon for two days, mission planners will release the 29-kilogram Moon Impact Probe (MIP) on Friday evening India time. Scheduled to hit the surface near the south pole, it is not designed to survive the impact.

The probe, which was built by the Indian Space Research Organisation (ISRO), will take 20 minutes to descend to the surface.

During that time, it will film the surface with an onboard video camera, says T K Alex, director of ISRO's Satellite Centre (ISAC) in Bangalore.

Soft landings

An altimeter will measure the probe's height as it nosedives, helping to test technologies needed to make 'soft' landings on the Moon. India's next lunar mission, scheduled for 2010, involves not only an orbiter but also a Russian-built lander that will study samples of lunar soil.

"I think the main purpose [of the Moon Impact Probe] is preparations for future soft landings," says Christian Erd, mission project manager at the European Space Agency in Noordwijk, The Netherlands. "It is a demonstration of the separation mechanism and getting to the surface."

The probe will also carry a mass spectrometer that will measure traces of gas and dust floating above the Moon. Signals from all three onboard instruments will be relayed back to the spacecraft and from there to ground stations on Earth.
Dust plume

"It is a sort of mini-satellite, equipped with its own instruments, batteries, and telemetry," says Rajagopal Sreedharan, head of the space physics laboratory at the Vikram Sarabhai Space Centre (VSSC), which built the six Indian instruments onboard Chandrayaan.

MIP will strike the surface near the lunar south pole, a region that shows hints of water iceMovie Camera in the soil. Parts of the terrain there also receive near-constant sunlight, providing prime spots to set up future solar power stations.

"We are impacting the Moon's south pole because of the huge amount of interest in the region," he told New Scientist.

When the probe hits the surface, it is expected to kick up a huge amount of dust that will be analysed by instruments on the Chandrayaan orbiter.

[svinayak]

http://www.sundayherald.com/internation ... 54.0.0.php


Space saving
INDIA: Moon mission set to take outsourcing industry to the final frontier

From Raymond Thibodeaux in Bangalore

INDIANS CROWDED around televisions in tea shops and streetside electronics stores to glimpse the launch of the country's first-ever Moon mission last month, a huge ego-boost for a country trying to shrug off its former standing as one of the world's poorest and least-developed nations.

In a moment of national pride, Prime Minister Manmohan Singh described the launch as the "first step" in India's exploration of space, cementing the country's status as a serious contender in a new space race with China and Japan.

Still, the two-year mission is not without its detractors. Among the patriotic machismo of most headlines and talk shows, a few critics griped about spending more than $80 million to map the Moon when there are urgent problems closer to home: crumbling roads, grinding poverty and child malnutrition rates higher than in many African countries.
advertisement

But the spin-off benefits of India's space programme are too good to pass up, say analysts. It boosts India's military and diplomatic clout, coming on the heels of a nuclear deal with the US that ended its status as a nuclear pariah.

Its satellite capability is focused on helping speed up telecommunications development, weather forecasting, educational broadcasting, and resource mapping to help farmers improve their crop yields.

Arguably, one of the biggest benefits of the mission, Chandrayaan-1, is that it helps India's bid to win a larger share of the world's estimated $15 billion-a-year commercial satellite launch market. It is outsourcing with serious potential.

"People are recognising that our space technology is reliable. And we can do more with less money. That's why we're starting to attract other countries to our satellite launch programme," said S Satish, a spokesman for the Indian Space Research Organisation (ISRO).

India's space agency crossed a milestone in April when it launched a rocket that dropped 10 satellites in space, all in one go. For $8000 a kilo, India can put your satellite in orbit, and you'd be hard-pressed to find a better deal. That's the sales pitch from the final frontier of India's outsourcing industry: space.

It seems to be working. In the past few years, India has launched satellites for space agencies and research institutions in the US, Germany, Canada and Israel. Last year, India's satellite launches brought in more than $500m in revenue, about 75% of that from foreign clients.

Of the 52 commercial satellites put into orbit in the past year, nearly two-thirds were launched by the Big Three: the US's Sea Launch and Boeing, Russia's Krunichev and France's Arianespace. Experts predict that, within two years, China, India and Japan should capture at least 15% of the global launch market.

Still, the big money is in telecommunications satellites but these can weigh up to six tonnes and, for now, India's launch capability is limited to "nano" satellites, some only 3kg. ISRO adviser Jayant Narlikar said: "As India's space programme goes deeper into commercialisation, we need to develop our own technology for putting telecommunication satellites into space."

However, not everyone is ecstatic about India's new skills in the exosphere. Some industry experts are concerned that India might use its capabilities for military purposes, an unsettling prospect for its uneasy neighbours, particularly Pakistan and China.

But for the most part, India's aims in space have been to improve conditions for Indians on the ground, according to A S Padmavathy, a scientist at the space agency's Bangalore headquarters.

"Some Indians in the past asked, When India is so poor, why waste money on programmes in space?' But the new generation sees the value in making sure all citizens enjoy this technology. Fisherman get satellite advice from us and students in remote villages can attend a virtual lecture from Mumbai," she said.

[cbelwal]

Dont know if this helps but the link is of the on-board video cature of Delta 2. The video gives a clear picture of the jettisoning of solid boosters while the stage 1 separation is at the end.

http://www.youtube.com/watch?v=f0Qr1g70 ... re=related

I'm still in the market for
anyone has a graphic showing the stage separation of a rocket as it injects the sat ? the kind we see regularly in magazines like frontline when sats are launched.

[Victor]

It seems that ISRO engineers think the probe has a chance of surviving the impact and this jives with the fact that we are validating soft landing technologies here. So the impact speed and angle should not be much different than an aircraft landing (150 – 200 mph, about the same as 75m/sec), contrary to a nosedive as is being painted. If it impacts a level area, it might just bounce a few times and roll to a stop, dented but in one piece.

[vdutta]

Tricolour has a date with moon tonight

MUMBAI: If things go as planned, the Indian tricolour will mark its presence on the moon tonight (around 8.30pm IST) after having flown
3,86,000km from the earth. The timing of this proud moment has been specially designed to coincide with Children's Day.

The United States, the former Soviet Union and the European Space Agency comprising 17 countries already have their flags on the moon.

The Indian tricolour is painted on all sides of the 29-kg Moon Impact Probe which is attached to the main orbiting spacecraft, Chandrayaan-1, which was launched on October 22.

The inclusion of the MIP as part of the Chandrayaan mission came at the suggestion of former President A P J Abdul Kalam, a former rocket scientist, during the International Lunar Exploration Working Group conference held at Udaipur in November 2004.

The Indian tricolour has been hoisted on Mount Everest and Antarctica. And now it will be on the moon though it will not be hoisted.

The flight of the MIP on Friday is expected to be a forerunner to the second Indian moon mission, Chandrayaan-2, which will carry a Russian rover and alander slated for lift-off between 2010 and 2012. The crash landing of MIP will help in assessing future soft-landing technologies.

Chandrayaan project director Mylaswamy Annadurai explained to TOI on Friday that at about 8 pm on Friday, a command will be flashed to the MIP from Isro's telemetry, tracking and command network (Istrac) at Bangalore for it to detach from the orbiter. "The MIP will separate and with its three instruments, zoom towards the lunar south pole at a velocity of 1.5km per second," he said.

"At Istrac's mission control room, we will immediately come to know that the MIP has separated from the orbiter. The MIP's flight path will first take it over the Malapert crater for about nine seconds and then crashland near the Shackleton Crater about 25 minutes after its detachment from the orbiter. Malapert Crater is not far from the Shackleton crater," he added.

Annadurai said that after this, the orbiter will fly in the opposite side and thus data will not be immediately available. "The downloading of data from the MIP to the orbiting Chandrayaan and then to the ground station will start once the spacecraft comes over the north pole of the moon. It will take a couple of hours for the data from the MIP to be downloaded and processed," Annadurai said.

He said that once the MIP crashlands on the moon, its own survivability and that of the three instruments will be in question. The probe uses solid propellants. "India's physical presence on the moon with the tricolour will be assured," he said.

http://timesofindia.indiatimes.com/Tric ... 710598.cms

[SaiK]

I doubt the probe's functional modules can survive the shock of impact. I don't read that the probe was designed to bump with some design based on super duper shock absorbers for the moon impact. That would have been an over kill for the impact project, but doable. Furthermore, aren't we interested in the impact to create a near explosion so that we can study the moon matter from the C1 above? So, we do need to kick up a lot of moon matter perhaps few kilometers up the moon sky!.

[SwamyG]

Only three per cent of total budget of ISRO for three years has been spent on the mission. Most of the expenses have gone to create infrastructural facilities, which will be used for our plans to send satellites to Mars and Venus. Hence the question of spending an exorbitant amount does not arise," he said. He was inaugurating an international seminar on Emerging Scenarios in Space Technology and applications here.

Source: http://sify.com/news/fullstory.php?id=14797424

[prao]

There is a time delay integral tutorial for pushbroom imagers here that may be relevent to the TMC functioning..

In addition, with only a single pixel to collect photons for that very short amount of time, there's two serious limits on the sensitivity: dynamic range and signal-to-noise ratio of the image. Zipping past the ground in a few tens of microseconds can leave the image starved for light, especially in low illumination situations. The solution? Put a second row of pixels below the first. Now you have a 1,024 x 2 array. When the spacecraft travels one pixel height's worth, rather than dumping the accumulated charge into a register, you dump it "down the column" into another row of pixels where it accumulates more charge. When the accumulated charge is now read out, there's twice as much charge as you'd have gotten from the single-pixel-high array.

You do have to make sure that you've got the time interval matched correctly to the spacecraft velocity. Otherwise the sum of the charge in a particular column's readout will be from two different spots along the ground track, and you'll get smearing in that direction.

Now, the magic occurs! Add more rows to your heart's content. At each moment in time, each row contains the integrated charge of all the previous rows looking at one single line on the ground. (Hence, time-delay integration.) And the charge moves from row to row at the same rate that the image moves across the array.

Add 100 rows. Voila! Your signal is increased by 100 without having to increase the diameter of your telescope by a factor of 10.

The more rows you add, the more you have to be careful to get the timing correct, but the timing is basically just dependent on the spacecraft velocity (which is known and unchanging) and altitude (which changes, but is known for any image).

http://www.planetary.org/blog/article/00001547/

Thinking about this some more, I did some rough calculations and this is what I came up with:
The effective ground speed of CY1 (wrt the Moon surface) is about 1550 m/sec - obviously a pretty high velocity. Since it is looking straight down, that is the effective speed at which the camera will see the surface below passing by. So CY1 will see 310 strips, each 5 m long (along the direction of travel) x 20 km wide every second - so the rate is 310 Hz. In other words, CY1 will have only 1/310 s to image each strip of land. But to reduce (not eliminate) the blur caused due to the movement of the satellite, the exposure time must be much less than this. Let's say 1/10th in which case the exposure time is 1/3000 second! Which is a pretty high effective shutter speed. I'm assuming that the TMC does not use panning to eliminate the blur of the passing landscape - there are no indications that it does.

I don't know the effective ISO number of the CCD arrays used on satellites so I have no idea if the 1/3000 s estimate is too high. But I'm now wondering if satellite linear imaging CCD arrays are actually 2D arrays that are used for signal amplification as described above. That would then answer the question why satellites don't image a large area at the one time - they simply can't because the 2D CCD array is being used for signal amplification rather than area imaging. And if the software is flexible enough, the CCD array could be used both ways depending on the lighting conditions. I wonder.

The TMC paper doesn't mention anything like this (though I could have missed it, I kind of skimmed it) but it could be implied.

For comparison, the effective surface speed of Resourcesat-1 is about 6600 m/sec!

[Vipul]

From SwamyG's post of Shri Madhvan Nair's interview, we now have info (for the first time?) about ISRO's plan to send satellite to Venus.

[Victor]

Destruction of the MIP is not a given. From the article posted by vdutta above:

He said that once the MIP crashlands on the moon, its own survivability and that of the three instruments will be in question.

It would be great if the MIP continues to send signals after the impact, even a few plaintive bleeps!

Actually, the MIP could have been designed to survive the impact if it were fitted with 3-4 large inflatable bags like the Martian lander but that would have added a lot of weight and complexity to the project. Back in the planning stage, they must have been focused on the lunar orbit insertion and subsequent orbits. ISRO may be planning something like that for CY2.

Again, I doubt if the impact itself is expected to be an “explosion” because that would call for a steep dive instead of a shallower practice soft landing approach as it seems this is. If the probe does bounce a few times, it will kick up a lot more dust than just one impact.

[Amber G.]

The problem is that the Moon has a more complex motion than the Earth (orbiting both Earth and Surya)

FWIW - Don't know exactly what one means by "more complex motion" but both earth and moon orbit around the sun in a more or less an elliptical, orbit (with nearly same "e" and semi major exis) with small perturbation (moon a little more than earth). Specifically there are no "loops" or even "waves" in moon's orbit (wrt to sun).
This means, that the moon's orbit around sun:
1. has no closed loops (that is no point in orbit where moon happens to be twice in less than a year - or IOW moon never moves "backward" - )
2. The orbit (moon's) is always convex (that is if you join any two points of the orbit with a straight line, *the whole curve* of the orbit is always outside- away from sun- the straight line).
(From earth, moon may be seem to be going around earth, but if you look at the moon from sun, it looks like an ellipse - with about 12 small perturbations but still every part of the ellipse still convex- with time period of 1 year.)

[Amber G.]

The effective ground speed of CY1 (wrt the Moon surface) is about 1550 m/sec - obviously a pretty high velocity

Effective ground speed would be around the order of 70-80 m/s.

[ramana]

After CY launches the MIP it will move on and be out of sight for a while. How do they plan to get the signals from MIP if CY is out of sight? There is the report that CY will be overhead in the next time around.

[prao]

The problem is that the Moon has a more complex motion than the Earth (orbiting both Earth and Surya)

FWIW - Don't know exactly what one means by "more complex motion" but both earth and moon orbit around the sun in a more or less an elliptical, orbit (with nearly same "e" and semi major exis) with small perturbation (moon a little more than earth). Specifically there are no "loops" or even "waves" in moon's orbit (wrt to sun).
This means, that the moon's orbit around sun:
1. has no closed loops (that is no point in orbit where moon happens to be twice in less than a year - or IOW moon never moves "backward" - )
2. The orbit (moon's) is always convex (that is if you join any two points of the orbit with a straight line, *the whole curve* of the orbit is always outside- away from sun- the straight line).
(From earth, moon may be seem to be going around earth, but if you look at the moon from sun, it looks like an ellipse - with about 12 small perturbations but still every part of the ellipse still convex- with time period of 1 year.)

You have to look at it from the point of view of Sun synchronicity not the characteristics of the shape of the orbit. The point is, whether the Moon's motion will allow for a Sun synchronous orbit without orbital maneuvers of any kind. The answer to that is no. Hence a complex schedule of observations for CY1.

Re: The effective ground speed, could you show how you get 70-80 m/s?

[SaiK]

venus had very good visits from russia and amrika. whats the plan? any interesting fusion/fission material abundant at 500*C?

[SSridhar]

After CY launches the MIP it will move on and be out of sight for a while. How do they plan to get the signals from MIP if CY is out of sight? There is the report that CY will be overhead in the next time around.

Ramana, CY-I will not be out of sight of the MIP after it lands. Soon after collecting data from MIP, CY-I will orbit to the far side of the moon and occlude to Bylalu. They would wait for it to re-emerge to download the data from the mothership.

[Shalav]

FWIW - Don't know exactly what one means by "more complex motion"

The Moons orbit is inclined by 5.2 deg w.r.t. the Earths orbital plane around the Sun.

You can imagine the complexity of the orbit in this way

1. An elliptical line depicting the Earths orbit around the Sun.

2. A corkscrew line wrapped around the Earths orbit depicting the moons orbit as it circles the Earths orbit.

see this image for a top-down 2D view

http://www.astronomyforbeginners.com/im ... -e-m-s.jpg

add on the ~5 deg. inclination and you can imagine the corkscrew - see below for a depiction in Gravity Simulator

http://www.jasondoucette.com/games/grav7l.gif

The blue lines are a good approximation of the Earth / Moon orbital relationship as they circle the Sun

Furthermore if the orbit was not tilted we would have a full eclipse (Solar and Lunar) every time the Sun / Earth / Moon crossed paths - ie about once a month for each.

[samavedi]

Found this info on the MIP. It has interesting details about the probe.

http://sci.esa.int/science-e/www/object ... ctid=41986

Samavedi

[SSridhar]

Unfortunately, we cannot have a sun-synchronous polar orbit of the moon as we have with the earth.

[Yugandhar]

SridharS Sir
What happens to CY1 at the end its mission? Will it crash land on the moon or will it be simply deorbited and flung out into deep space??? I know for earth satellites we have to either deorbit or send them to some junkyard orbit. What have people been doing with moon missions?

[Luxtor]

SridharS Sir
What happens to CY1 at the end its mission? Will it crash land on the moon or will it be simply deorbited and flung out into deep space??? I know for earth satellites we have to either deorbit or send them to some junkyard orbit. What have people been doing with moon missions?

Chandrayan-1 is so close to the Lunar surface at 100 km, that it would most likely be crashed on to the Moon, otherwise it wouldn't have enough fuel on board at the end of its service life to lift it to a higher "retirement" orbit. On the other hand, Earth orbiting satellites, if they're in low orbits then they are de-orbited and allowed to crash to Earth, burning up in the atmosphere. If they are on high orbits such as geo-sync orbits, these satellites are designed to have enough fuel on board at the end of their service life so they're pushed out to much higher "graveyard" orbits and left there forever with all their on board systems turned off.

Ooops sorry, Yugandhar & Sridhar, I just noticed that the question was addressed to Sridhar. Sorry to have jumped the gun. I hope my explanation is still correct.

[Arya Sumantra]

The MIP has Tricolour painted on its sides. If MIP disintegrates on landing (most likely, free fall from 100 kms above, velocity 1.5km/sec) then that means Tricolour too will be smashed into pieces. Doesn't sound good.

[rakall]

The MIP has Tricolour painted on its sides. If MIP disintegrates on landing (most likely, free fall from 100 kms above, velocity 1.5km/sec) then that means Tricolour too will be smashed into pieces. Doesn't sound good.

Each face/side of the MIP cuboid shape is like a flat plate with tri colour printed.. If MIP breaks up - it will most likely break at the edges; so each of the flat plate surfaces will becomes separated -- that will be 4 indian flags, rather than flag splitting into pieces.

[Amber G.]

Few Items:
Few Items:
Shalav:

A corkscrew line wrapped around the Earths orbit depicting the moons orbit as it circles the Earths orbit.

No, if I understand you correctly this is not correct.

Please read my post, and many (including some scientists) make mistake here, but the figure has NO "corkscrew" or even "waves" as you pointed out. The orbit at every point is convex. (This is true, of course for earth/moon system , and not any general orbiting body)

The moon orbit around sun) is NOT like

But rather like:


(This is, of course an old classics problem, asked to many physics students when they first learn central forces and orbits - Check out wikipedia/physics book/or say http://www.math.nus.edu.sg/aslaksen/tea ... onvex.html
(Where I got the above two images).

(Hope this helps)
(Do not want to go on a tangent- but, yes, moon's orbit, wrt to earth is tilted about 5 degrees to the ecliptic - but as seen from sun.. moon's orbit (just like earth's orbit wrt to sun )- wobbles slightly up and down but it is *negligible* - negligible in the sense that astronomical latitude always remain much smaller than, say, a fraction of a degree)

Prao - Thanks. To be clear I do not know chandrayaan details, in fact did not know what exactly is sun-synchronous orbit is until a little-while ago by checking out wiki - so details about chandrayaan and other data is welcome - here is just a few points - (general physics based)

1. If you don't apply braking (say minimal energy spent in changing the "e" of orbit so that perigee hits the surface) - the speed would be about 1.5x10^3 m/sec (If my quick calculation is correct)..If I assume I can spare a few seconds of fuel burn - and make reasonable assumption for typical probes sent to moon surface - the speed is about 10^2 m/s...Hope some one gives correct/actual figures here.

2. For sun-synchronous orbit (if I understood it correctly from wiki - that is that the precession time period of the orbit is 1 year), Noe that the precession depends mainly on the shape of the moon and the satellite's orbit around the moon (moon's orbit etc around sun etc are not really relevant). Moon, like earth, is not exactly a sphere, so if I can choose right inclination of the orbit I can have that desired orbit with minimal extra fuel.

Hope this helps too.

Added later: Just googled it (looks like I was in right ball figure)
Added a little later: - The info was already posted.

[Amber G.]

Unfortunately, we cannot have a sun-synchronous polar orbit of the moon as we have with the earth.

SSridhar - can you expand on this a little. (why one can't have ?)
(I can do some checking, but if you have a link, or explain it further with some details)
Thanks in advance.
(Also, why would one want such an orbit on moon?)

[SSridhar]

Amber G, let's see how we get polar (or near-polar to be more accurate) sun-synchronous orbit for an earth-bound satellite. This is done using the natural perturbation caused by the oblateness of the earth without expending fuel. Otherwise the fuel budget is enormous (out-of-plane changes especially are very costly in terms of fuel budget).

A sunsynchronous orbit is one where the sun’s ilumination of the Earth is at the same angle in every pass of the satellite’s orbit. This helps in taking pictures more easily. The Earth shifts westwards by almost 1 degree with respect to the Sun everyday. If constant sun lighting is to be maintained, the satellite’s orbit should shift eastwrds by the same amount everyday. This is achieved with the help of nature as follows. The “oblateness” or the “bulge of the Earth at the Equator” increases the gravitational pull on the satellite as it crosses it. The effect of this is to cause the satellite to “appear” shifting eastwards to a stationary observer if the satellite is orbiting from east-to-west from the Southern to the Northern hemisphere (The shift would be westwards if the satellite’s orbit is from west-to-east from the Northern to the Southern hemisphere. But a sunsynchronous orbit needs to be from east-to-west to compensate for the westward shift of the Earth with respect to the Sun.) The sunsynchronous orbit can be achieved by matching the nodal regression rate (a node is the point of intersection between the Earth’s equatorial plane and the satellite’s orbital plane. There will be two nodes.) with the average rotation rate of the Earth around the Sun which is 0.9856 degree/day. Such a regression is called precession. The satellite will then pass the Equator and each lattitude at the same local time at each pass (For example, a satellite's sun-synchronous orbit might cross the equator twelve times a day each time at 3:00 p.m. local time).

Such an orbit is not possible on the moon because of its geometry. Also, earth spins around its axis in 24 Hrs whereas moon takes 27.3 days, the same as its orbital speed around the earth. So, the situations are different.

[svinayak]

Such an orbit is not possible on the moon because of its geometry. Also, earth spins around its axis in 24 Hrs whereas moon takes 27.3 days, the same as its orbital speed around the earth. So, the situations are different.

From earth Moon does not appear to spin. We see the same surface of the moon even though the earth rotates on in 24 hrs.





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

Libration
Animation of the Moon as it cycles through its phases. The apparent wobbling of the Moon is known as libration.

The Moon is in synchronous rotation, meaning that it keeps the same face turned toward the Earth at all times. This synchronous rotation is only true on average because the Moon's orbit has a definite eccentricity. As a result, the angular velocity of the Moon varies as it moves around the Earth, and is hence not always equal to the Moon's rotational velocity. When the Moon is at its perigee, its rotation is slower than its orbital motion, and this allows us to see up to eight degrees of longitude of its eastern (right) far side. Conversely, when the Moon reaches its apogee, its rotation is faster than its orbital motion and this reveals eight degrees of longitude of its western (left) far side. This is referred to as longitudinal libration.

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

[SSSalvi]

Here is a possible timeline for MIP drop today the 14th Nov.

1. Launch from Mother craft : 8.03 pm or 8.04 PM
2. It will fly over the Malapert crater for about nine seconds. ( Originally this was the planned landing site ... later changed )
3. Landing of Probe on Moon : Around 8:30 PM on the rim of the Shackleton Crater ... velocity at the time of impact is about 1.5Km/sec.

The Mothership( CY1 ) will collect the data from probe but it will not be visible to Earth because it will be behind the moon when it collects the data.

So the data will be downloaded when the Mothership re-emerges from near North Pole from behind the moon after half orbit period.

[UPrabhu]

If ISRO guys visit this site, please don't keep your "ANNADAATAA" .. the taxpayers in dark... we will happily foot the bill for future missions.. but keep us aam juntaa in the loop.. not a single picture released after LOI

[SSSalvi]

If ISRO guys visit this site, please don't keep your "ANNADAATAA" .. the taxpayers in dark... we will happily foot the bill for future missions.. but keep us aam juntaa in the loop.. not a single picture released after LOI

I ( as an ex-isro ), have requested today to ISRO website that now ISRO is being watched by the people around the whole world so please update the website continuously. ( Today the website says : Last update on 12th Nov ) .

Infact after writing that email I stumbled on your post.

Please help O God!

[UPrabhu]

If ISRO guys visit this site, please don't keep your "ANNADAATAA" .. the taxpayers in dark... we will happily foot the bill for future missions.. but keep us aam juntaa in the loop.. not a single picture released after LOI

I ( as an ex-isro ), have requested today to ISRO website that now ISRO is being watched by the people around the whole world so please update the website continuously. ( Today the website says : Last update on 12th Nov ) .

Infact after writing that email I stumbled on your post.

Please help O God!

Thanks SSSalvi, I appreciate it very much.

[krishnan]

Seems like they take the suggestions seriously. I had sent an email to the webmaster asking them to make the website more professional. They did change the website layout. This was few years back.

[Nitesh]

It is hurling towards moon to paint the tiranga. Congratulations to ISRO.