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inglor_czyesterday at 10:33 PM1 replyview on HN

"Artemis II never escaped Earth’s pull."

Hmm. Maximum speed attained by Artemis II when they left their initial orbit was about 11.1 km/s IIRC. While this is somewhat less than true escape velocity from Earth (11.2 km/s) and you are technically correct, it is also enough of a speed that if you fly away in any random direction (and not a carefully calculated one), perturbances from the Sun and other massive objects will probably prevent you from reaching any sort of stable orbit around the Earth, and you will start bouncing around the inner Solar System in an erratic way.

I certainly wouldn't like to model that trajectory for months or years.


Replies

SV_BubbleTimetoday at 2:31 AM

The sun’s pull on the ship at the outside limit at the moon, is obviously negligible compared to the pull of the Earth. This should be obvious, because otherwise the moon would have left long ago.

Why is this so difficult to understand? Honestly I think that misleading NASA graphic did a lot of damage.

You throw in acceleration, which I never mentioned and doesn’t matter. The Artemis II never left Earth’s gravitional pull, the original issue was effectively what if it missed - and the answer is no big deal.