Chandrayaan-2

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MartG

Original Poster:

20,610 posts

203 months

Thursday 11th July 2019
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On Sunday India will attempt to launch its Chandrayaan-2 lunar probe, with the intention of landing near the Lunar South Pole.

https://www.dailymail.co.uk/sciencetech/article-72...

Cold

15,191 posts

89 months

Sunday 14th July 2019
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Unfortunately it went tech just a short time before launch (T-56 mins). No specific details are forthcoming, but the Indian Space Research Organisation assures it is a delay rather than a cancellation.

https://www.theguardian.com/world/2019/jul/15/indi...

Beati Dogu

8,853 posts

138 months

Monday 15th July 2019
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No word on the next try yet.

I kinda hope it goes up on Tuesday, the 50th anniversary of the Apollo 11 launch.

Eric Mc

121,680 posts

264 months

Monday 15th July 2019
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I wonder how long the launch window remains open. Because the moon goes around the earth once every 28 days, if you miss the assigned launch date by more than 48 hours, you have to wait more or less a month for the next opportunity.

Beati Dogu

8,853 posts

138 months

Tuesday 16th July 2019
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Perhaps they have some leeway on that, as it's not going straight to the Moon. It's going to orbit the Earth for a while and then the trans-lunar injection burn is (or was) planned for day 17 after launch.

Lunar orbit insertion is intended for day 22. The lander won't be released until day 50 and the landing itself on day 54 (first week in September originally).

There's a lot of national pride riding on this and they're being very cagey on the technical issues.

They've issued a new NOTAM (notice to airmen) warning for July 17th (2100-2200 UTC) and 18-31 JUL (0830-1000 UTC) with a 10 mile exclusion zone around the launchpad.




Cold

15,191 posts

89 months

Wednesday 17th July 2019
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Apparently a small leak of a nipple joint caused fuel pressure to drop enough to mean a precautionary abort of the launch.
There's still a window available up to the end of this month to meet the September lunar day.

Eric Mc

121,680 posts

264 months

Wednesday 17th July 2019
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Lunar launch windows, especially for landers, are often predicated by the conditions that are required at the landing site on the moon.

MartG

Original Poster:

20,610 posts

203 months

Sunday 21st July 2019
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Having another go tomorrow ( 22/7 )


Launch time: 0913 GMT (5:13 a.m. EDT)
Launch site: Satish Dhawan Space Center, Sriharikota, India

Toaster

2,938 posts

192 months

Monday 22nd July 2019
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Eric Mc said:
I wonder how long the launch window remains open. Because the moon goes around the earth once every 28 days, if you miss the assigned launch date by more than 48 hours, you have to wait more or less a month for the next opportunity.
Clearly more than 48 hours and much less than 28 Days (maybe they know something about the trajectory of their mission) the Chandra 2 has made a successful launch and wish them well for the landing and research.

Toaster

2,938 posts

192 months

Monday 22nd July 2019
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Eric Mc said:
Lunar launch windows, especially for landers, are often predicated by the conditions that are required at the landing site on the moon.
Eric can I ask exactly what are the predicated differences, the only one I can think of is Transfer time what are the others?

Eric Mc

121,680 posts

264 months

Monday 22nd July 2019
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I was thinking more of manned missions where sun angles at the landing site were critical. They didn't want the sun too low in the sky casting long and deep shadows and they didn't want the sun too high in the sky either as that washed out all the detail. That gave them a limited take off window if they wanted to arrive at the landing site where the lighting conditions were within the boundaries.

With unmanned missions where visual lighting conditions are not required to execute a landing, then the window is not so restricted.


Toaster

2,938 posts

192 months

Monday 22nd July 2019
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Eric Mc said:
I was thinking more of manned missions where sun angles at the landing site were critical. They didn't want the sun too low in the sky casting long and deep shadows and they didn't want the sun too high in the sky either as that washed out all the detail. That gave them a limited take off window if they wanted to arrive at the landing site where the lighting conditions were within the boundaries.

With unmanned missions where visual lighting conditions are not required to execute a landing, then the window is not so restricted.
The context of landing in daylight will probably be or has been negated for manned missions particularly when a base is established. Can understand when a mission is only a few days but lighting conditions will become a thing of the past, after all we have vertical landing rockets (a little like the lunar lander). At one time planes took off and landed only in daylight.

Beati Dogu

8,853 posts

138 months

Monday 22nd July 2019
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The light is also important for this flight as the lander & rover are solar powered. Night and day on the moon are pretty much split 50/50. Clearly you want to get the most use out of the equipment before roughly 15 Earth days of darkness shuts it all down. The rover at least is designed to hibernate, but there’s a risk it won’t wake up again.

Eric Mc

121,680 posts

264 months

Monday 22nd July 2019
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Toaster said:
The context of landing in daylight will probably be or has been negated for manned missions particularly when a base is established. Can understand when a mission is only a few days but lighting conditions will become a thing of the past, after all we have vertical landing rockets (a little like the lunar lander). At one time planes took off and landed only in daylight.
Agreed.

Times have moved on so having the best visual approach during landing will not be so important in the future.

MartG

Original Poster:

20,610 posts

203 months

Tuesday 20th August 2019
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Successfully entered lunar orbit tonight

https://www.space.com/india-chandrayaan-2-moon-mis...

BlackLabel

13,251 posts

122 months

Friday 6th September 2019
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MartG

Original Poster:

20,610 posts

203 months

Friday 6th September 2019
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Webcast starts 19:40GMT, with landing between 20:00 and 21:00 GMT

https://www.space.com/17933-nasa-television-webcas...

MartG

Original Poster:

20,610 posts

203 months

Friday 6th September 2019
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Not looking good - data ceased updating, and a lot of worried faces in mission control frown

snake_oil

2,039 posts

74 months

Friday 6th September 2019
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Lost communication at an altitude of 2.1km on the descent. Place your bets!

Beati Dogu

8,853 posts

138 months

Friday 6th September 2019
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It's not looking optimistic for the lander.

However, they still have the satellite orbiting the moon successfully and most of their experiments are on that.