7 ms·
If anything they seem to have overcorrected for this. This landing path stopped with a near hover at around 800m, then a prolonged hover at 150m while the land
by m0llusk 3y ago
If anything they seem to have overcorrected for this. This landing path stopped with a near hover at around 800m, then a prolonged hover at 150m while the lander scoped the situation, then an extremely slow descent that allowed for corrections the whole way down. Very impressive.
- morepork 3y agoIf they have the fuel available, may as well be very conservative. Either burn the fuel on descent or have it sit in the tank forever on the lunar surface.
- 8bitsrule 3y agoPossibly the lander had a choice to be more careful/picky if the remaining fuel permitted. (Just as Armstrong did.)
- hoseja 3y agoAlso incredibly inefficient.
- user_7832 3y agoA lot of things in the world trade inefficiencies for safety.
- hoseja 3y agoI was surprised they had the propulsion budget for it.
- ansible 3y agoIt helps a lot that the Moon's gravity is about 1/6th of Earth's.
- deleted 3y ago[deleted]
- devnonymous 3y agoNot only was the Chandrayaan 3 budget lesser than that of Chandrayaan 2, as a meme doing the rounds point out, it was lesser than the budgets of some Hollywood blockbusters like Interstellar. So yeah, safe to say they could have had the budget for more if necessary.
- dotnet00 3y agoI don't think they're referring to literal money, but rather that the lander had enough fuel.
- Sharlin 3y ago"Fuel budget", "mass budget", "payload budget", even "delta-v budget" are common terms in spaceflight and refer to how much of a valuable thing a spacecraft can carry given some pesky laws of physics [1], nothing to do with money (except insofar as more money would let you build a bigger spacecraft…) [1] https://www.kallmorris.com/columns/tyranny-of-the-rocket-equation https://www.kallmorris.com/columns/tyranny-of-the-rocket-equ...
- fit2rule 3y ago[dead]
- Zigurd 3y agoThis is one reason why low cost and efficiency are just a nice-to-have when it comes to to space exploration. Moreso the farther you go. A unique mission like a lunar polar landing should be conservatively engineered, where that is possible, on the first try. Early optimization and space exploration don't mix.
- layer8 3y agoFirst make it work, then make it right, last make it efficient.
- bagels 3y agoIt's a lot more efficient than having to send a fourth rocket.
- tshaddox 3y agoWhat numerator and denominator are you using to calculate the efficiency of an unmanned lunar soft landing mission?
- hoseja 3y agoThe most efficient landing - high impulse reverse gravity turn suicide burn vs. what they did - hovering mid-space two or three times, slowly inching toward ground while fighting gravity.
- ansible 3y agoYes, it was a very conservative landing trajectory. But it is very, very difficult to get a hoverslam right the first time, or the second, or the third... I did like seeing the live images captured during descent, I also hope those get made into a video and posted online. Looking forward to the rover deployment too.
- rst 3y agoThis doesn't seem to have been a hoverslam, though -- the probe was hovering at, I think, 150 meters for quite some time, and then maintained a steady and slow rate of descent while still under power.
- ansible 3y agoYes, Chandrayaan-3 definitely did not performance a hoverslam, the landing was much more conservative than that. With a hoverslam, everything has to go exactly right. A valve that is slightly sticky can be enough to wreak everything.