Comment by dylan604
4 days ago
Artemis II won't fly by the moon until Day 6, but it only took Apollo 8 to Day 4 to get to the moon. Looking at the wiki for Apollo 8, it shows the moon was 218k miles at launch while they said the moon is currently 240k, so it still looks like Apollo was moving faster than Artemis.
Apollo put a lot more burden on the Service Module than Artemis plans to put on the Orion. Apollo put the CSM/LM into a low lunar orbit while Artemis plans to put Orion into a high lunar orbit and make the Starship carry a lot more delta-V to land from a much higher velocity (and then accelerate back up to that velocity when coming back).
On top of that there weren’t really solar panels in the 1960s so the Service Module had to carry tons of chemicals to produce electricity, as well as extra fuel for all of that weight. As a result it was massively overbuilt compared to anything we’d try today and even so had to take an expedited flight path to the moon of 3 days in order to conserve operational lifetime. Artemis does not have nearly as severe constraints on either the Orion or the future Starship and so can afford to take a more fuel efficient 5 day coast up to the Moon and make the design tradeoffs on Orion that that entails.
Admittedly, I let this launch sneak up on me, and I just haven't paid attention to the flight details. Thanks
My understanding is Artemis II orbits earth for 23.5 hours before heading to the moon while Apollo 8 did so for under 3 hours, so that accounts for some of the difference.
That would account for some of it. I was surprised the TLI burn wasn't until tomorrow, but I guess we didn't get the Apollo 2-7 tests of the system either, so maybe those are getting compressed into the additional time in earth orbit before TLI???
It's kind of said that we are having to do all of this repeated work just to get to where we've already been even if we are doing it on a much more accelerated schedule.