Chandrayaan 1, India's First Lunar Probe Options

[Bhas_From_India]

‘Once Chandrayaan goes near the moon, we will be there to track it’
Full Story : http://www.hindu.com/2008/10/22/stories/2008102255641100.htm
Has more information about IDSN.

[Guest_Zvezdichko_*]

There was a huge press-conference here, in Bulgaria. Please, be patient - I'm going to publish some interesting information about the mission.

Doug, Stu - was there a press-conference in England about the mission and the UK-built instrument?

[djellison]

There was going to be : http://www.sstd.rl.ac.uk/c1xs/C1_Launch.htm - however, it was cancelled. (I was going to attend that ) There was an 1000 meeting, but I couldn't make that. I've not seen anything on the media -( apart from very short pieces just showing the launch )

Doug

[Guest_Zvezdichko_*]

And some interesting data:

It was estimated that Bulgaria spent 60 000 Bulgarian levs on RADOM-7. I can't say for sure, but it's about $40000! Compare this to the instruments of NASA and ESA. RADOM-7 is one of the cheapest instruments aboard Chandrayaan-1.

When I asked when the instrument is going to be switched on, they said that it depends on the Indian coleagues. But we expect that it will be switched on when we pass the Van Allen belts. Then we hope to collect information about the radiation levels during the trip to the Moon and in lunar orbit.

RADOM-7 is a successor of several other instruments which were flying aboard Mir and ISS, but this is about manned exploration and I will stop here. However I will say that our results are often cited in international scientific journals and that's why our participation aboard Chandrayaan-1 must not surprise anybody.

[Bhas_From_India]

Bhas, we are told the impact probe will hit the rim of Shackleton. Do you have any source that gives a precise target point, in coordinates or on an image?

Phil

Phil,

May be the "actual target point" is not decided yet.
also, Since this is going to be "impact" probe, exact location may not (my guess) be that important.

as far as ISROs update : It would travel for about "28 minutes" from time it is released from the orbiter to impact point at polar region.

[Phil Stooke]

Hi - the target is important. The nominal descent trajectory has to intersect the surface somewhere, so the first question is, where is that point? But where it is is very important for another reason - if you are taking images on the way down, the area to be imaged has to be illuminated, and that's a big issue at the poles. My point is that there must be a precise target, though it might not have been publicly announced yet.

Phil

[Bhas_From_India]

Antennae turn to Chandrayaan - From "The Hindu"

Training their gaze on India’s maiden moon launch on Wednesday are antennae at Mauritius, Brunei, Biak (Indonesia) and Bearslake (Russia), Goldstone, Maryland, Hawaii (U.S.), Brazil, Russia, Lucknow, Sriharikota, Thiruvananthapuram, Port Blair and, of course, the giant antennae at Byalalu, which will feed ISTRAC with telemetric information on the health of Chandrayaan.
....
“For the first 48 hours we will be receiving telemetry data on the health of the satellite from all these stations. Typically these stations have 10 metre antennae which are sufficient to track the satellite at this stage,” said O. Chiranjeevi, Group Director, ISTRAC. The antennae at Byalalu will begin to pick up signals within six hours after its launch, said Dr. Shivakumar. The Indian Deep Space Network Facility includes two antennae – a 32 metre one and an 18 metre one. However, the true work of these antennae will begin later once the satellite reaches a distance of over one lakh kilometres in a couple of days".

Hi - the target is important. The nominal descent trajectory has to intersect the surface somewhere, so the first question is, where is that point? But where it is is very important for another reason - if you are taking images on the way down, the area to be imaged has to be illuminated, and that's a big issue at the poles. My point is that there must be a precise target, though it might not have been publicly announced yet.

Phil

Phil,

Ok. I will keep looking for the information about MIP.

- Bhas

[Guest_PhilCo126_*]

Hi Bhas,

thanks for the information on the " Destination Moon " book but in Your post # 65, the drawing shows a GSLV launch vehicle
(Geosynchronous Satellite Launch Vehicle)

Compare with:

[Guest_Enceladus75_*]

I think that this is a fanstatic achievement for India. This mission will really give their aerospace, science and engineering sectors a real boost and further the development of the country.

Will the probe be able to photograph surface features with the same resolution os the planned LRO? It would be great if we could discern some of the Apollo landing sites. Also, what are India's long-term plans with respect to the Moon? I very much hope that this is the beginning of a whole range of exploratory missions.

[Bhas_From_India]

Interesting Update
=============

Why ISRO changed the orbit-transfer strategy - From Hindu

The revised strategy will have five earth-bound orbits
The Indian Space Research Organisation (ISRO) had earlier planned two earth-bound orbits for the spacecraft before it moved towards the moon. Much like in the case of the earth orbits, two lunar orbits were planned for before the spacecraft reached the final lunar orbit destination — circular orbit of about 100 km from the moon’s surface.
But ISRO had revised the orbit-transfer strategy. In the revised strategy, there will be five earth-bound orbits. The first orbit will have an apogee (farthest point from the earth) of 23,000 km and perigee of 255 km.

Increasing apogees
The second orbit will have an apogee of about 1,60,000 km and the third orbit will have an apogee of about 2,60,000 km. The fourth earth-bound orbit will have an apogee of about 3,87,000 km. It will take about 11 days to complete the fourth earth-bound orbit. During the fifth earth-bound orbit, which will have an apogee of about 3,84,000 km, the spacecraft will approach the moon’s North pole at a safe distance of a few hundred kilometres.

To calibrate the systems
“Basically, we wanted to calibrate our systems, such as the ground tracking system. When we get out of earth’s influence [gravity], there will be an influence of other planets, sun and moon’s gravity. We have theoretical knowledge of this influence. But getting actual data will be more useful to calibrate our systems,” said Dr. Madhavan Nair, Chairman of ISRO.
“The fourth and fifth orbits go up to the final point before it [the spacecraft] comes back. So this will help us to calibrate the systems better,” he said.
“[The earth-bound orbits] will tell us how far our assumptions and models are correct,” Dr. Nair said.

To avoid errors
The earlier orbit-transfer strategy involving just two earth-bound orbits would have also provided the essential data. “When we do it [in fewer and smaller orbits] in a short period, we have to evaluate all the parameters in a shorter time. So some errors can arise,” said Dr. Nair, explaining why the orbit-transfer strategy was changed.
In the revised strategy, there will be two lunar orbits before the spacecraft reaches the final circular orbit of about 100 km from the moon’s surface.
But will the revised strategy, which will involve longer period in space before it reaches its final destination, lead to more fuel consumption and hence affect the total mission duration? “The fuel consumption will be the same and the mission life will also be the same,” he stressed.

== So, Ideally it should have taken 5.5 days to reach moon. and I was wandering why we have to wait close to 2 weeks to get data... Now we know.

[Bhas_From_India]

Byalalu tunes in to moon mission - From Hindu

Bangalore: At 1.20 p.m., exactly seven hours after the launch of Chandrayaan 1 from Sriharikota, the giant saucer-shaped antennae, standing out conspicuously amid the stark landscape of Byalalu village near Bangalore, began to rotate gently as it picked up the first signals from the lunar spacecraft.

On a rainy Wednesday afternoon the mood at the Indian Deep Space Network (IDSN) here was celebratory as scientists received data from the parabolic antennae indicating that Chandrayaan I was in good health and on track. The 20 space scientists at the IDSN who had kept awake through Tuesday night in preparation for this moment applauded and shook hands as the first signal flickered on the telemetry monitors. “Everything worked out just perfectly and we received the data exactly as scheduled,” said L. Srinivasan, General Manager of ISRO’s Bangalore Telemetry, Tracking and Command Facility.Not far, a much larger group of scientists at the mission’s nerve centre, ISTRAC (ISRO’s Telemetry, Tracking and Command Network), analysed the telemetric data from Byalalu sent through a communication link.

“For the next four or five days, Chandrayaan will be tracked by several small antennae around the world. After this period, when the satellite crosses one lakh kilometres, only three ground stations with large antennae will track it: those at Byalalu, Maryland and Canberra,” said Mr. Srinivasan.

The Byalalu centre will be one of only two ground stations by the time the payload data from the 11 experiments on board comes in, the other one being Maryland.....

[Bhas_From_India]

ISTRAC director S.K. Shivakumar says that
DSN got the first signals at 1.28pm yesterday.
and by that time spacecraft has already completed one orbit. (this is within 6.5hrs of launch).

also, It is now almost confirmed that Lunar orbit insertion must be done by Nov, 8th.

[Bhas_From_India]

New Stories are slowly coming out...

When the Moon Mission had a major scare
A "small" fuel spill mishap when the Polar rocket with the Chandrayaan-I spacecraft atop was being fuelled created a near "scare" during the final countdown for the launch of India's maiden unmanned moon mission, ISRO Chief Madhavan Nair said.
This was revealed by Nair who earlier in the day spoke of how space scientists at the Sriharikota spaceport faced an "ordeal" after rains pounded the area and surrounding parts for nearly five days.
"Yesterday, we had a small mishap during filling operation when some of the fuel spilled over from one of the courses of the ground system and this created almost a scare," Nair said.
The ISRO chief also said launch personnel had to clear the "pad" and then carry out repairs before proceeding with the blast-off preparations.
"We had to take a tough decision as to how much of fuel had to be loaded, how much as to be unloaded and number of operations to be carried out simultaneously which we have never done earlier," he said.
"We lost 10 hours in the countdown yesterday due to inclement weather and almost lost the hope of making the launch. But working against all odds ISRO team has won the game," Nair said. North-East monsoon usually peaks over the eastern coast around this time of the year.
"It was an ordeal and never before we had such horrible weather just ahead of the launch date," he added.

Kudos to the team for "successful launch" in spite of these issues...

[elakdawalla]

I dropped in this evening on a social event being held in connection with a Cassini project science group meeting, and chatted with a scientist who's working on one of the American-contributed instruments. He was very pleased the launch went well, of course, and I said something like "Well, India's already proven they can do launches; I didn't worry too much about that, but I'm glad the spacecraft is on its way." He shook his head and said that the mission was so bent on getting Chandrayaan-1 launched on the stated date that although they went through all the testing -- shake and bake and so on -- that after they were done with the shake test they buttoned the thing up and shipped it off to the launch site before they had even analyzed the data from the prelaunch testing. They were in too much of a hurry to look at the data. Another scientist laughed and said "Well I guess as long as nothing fell off during the shake test they figured it was okay." Still, kind of scary! The first scientist said it's just about two weeks to orbit "and then the fire hose opens up" in terms of data.

--Emily

[mcaplinger]

Another scientist laughed and said "Well I guess as long as nothing fell off during the shake test they figured it was okay."

Like a "scientist" would know how to interpret the results of a vibe test anyway. Beakers.