As I understand it, it’s partially when they want to get there and partially how they want to land.
When spacecraft return to Earth from space, they have our planet’s atmosphere dragging on them and slowing their descent. But the moon has an incredibly wispy atmosphere, so to make a lunar landing, spacecraft have to slow themselves and make a much more gradual approach.
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The lander will touch down in the south polar region of the moon, at a speed of under 5 mph (8 kph). The propulsion module of Chandrayaan-3 will stay in orbit around the moon, remaining in communication with the rover and the lander.
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“Landing will be on August 23 or 24, as we want the landing to happen when the sun rises on the moon, so we get 14 to 15 days to work,” he said. “If landing cannot happen on these two dates, we’ll wait for another month and land in September.”
Saturn V - payload to LEO: 141,136 kg
Cost per launch: $185 million in 1969–1971 dollars ($1.23 billion in 2019 value)
LVM3 - payload to LEO: 10,000 kg
Cost per launch: $63 million
Also, the time factor is much more important in crewed missions. Not just because of consumables like oxygen, water, food (and energy), but to keep the exposure to radiation at an acceptable level. Video 1 & video 2 about how they dealt with that on the Apollo missions.
The first comet I saw was in 2007: the McNaught Comet, which was amazing. And I happened to be working at a remote site in Australia, where a 1 km walk could give you a decent dark sky, and a 10 km drive gave you a perfectly dark sky. So I went for a drive just before sunset, and watched the slim crescent moon and the huge comet tail which seemed to cover at least 25 degrees of sky. No need for even binoculars - it was too huge, and definitely bright enough against that sky.
It was magnificent, and I thought “So that’s what comets are like. Cool.” I had no idea how lucky I had been.
I have this nice pair of binoculars. It is very good. I can see the surface of the Moon, Jupiter and 4 of its moons, Omega Centauri and other interesting objects. The problem it is huge and heavy. If I had skills I could make a mount like this one.
From the team which found it, this would only be the second (after this one) ultralong period magnetar (if that’s what it is).
Dr Hurley-Walker—O’Doherty’s honours supervisor—said the first object took us by surprise.
“We were stumped,” she said. “So we started searching for similar objects to find out if it was an isolated event or just the tip of the iceberg.”
Between July and September 2022, the team scanned the skies using the MWA telescope.
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“It showed up in observations by the Giant Metrewave Radio Telescope (GMRT) in India, and the Very Large Array (VLA) in the USA had observations dating as far back as 1988,” she said.
“That was quite an incredible moment for me. I was five years old when our telescopes first recorded pulses from this object, but no one noticed it, and it stayed hidden in the data for 33 years.
“They missed it because they hadn’t expected to find anything like it.”
The devil’s in the details; those emergency hyperspace route-side services only cover such short distances. You have to make the arrangements yourself if you don’t want to end up at Peli Motto’s.
