丁香园AV

Synopsis

1969 was a monumental year for humanity, as it marked our first steps on another celestial body: the Moon. Over the course of 3 years and 5 months, 12 men visited the lunar surface for no more than 3 days at a time. Now, more than 50 years later, we intend to return to the Moon - this time to stay.  The Apollo programme was never intended to facilitate long-term human presence on the Moon. Artemis, on the other hand, aims to develop the necessary components to promote human colonies and research stations on the surface of, and in orbit around, the Moon. While Apollo and Artemis are far too complex to explore in their entirety, in this talk I intend to draw attention to a seemingly trivial - yet crucial - aspect of each programme: what does a journey to the Moon actually look like? More precisely, how does each programme navigate the space between low Earth orbit and the lunar surface, and why should one orbital path be more favourable than another? Key topics include Hohmann transfers, direct ascent, lunar orbit rendezvous, free-return trajectories, and near-rectilinear halo orbits.