Discussion
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...
https://www.dailymail.co.uk/sciencetech/article-72...
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...
https://www.theguardian.com/world/2019/jul/15/indi...
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.
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.
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. 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.
With unmanned missions where visual lighting conditions are not required to execute a landing, then the window is not so restricted.
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. With unmanned missions where visual lighting conditions are not required to execute a landing, then the window is not so restricted.
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.
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.
Webcast starts 19:40GMT, with landing between 20:00 and 21:00 GMT
https://www.space.com/17933-nasa-television-webcas...
https://www.space.com/17933-nasa-television-webcas...
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