I'm having trouble understanding the current orbit planned for NASA's Space Launch System's Exploration Mission 1. Is it possible to explain how the planned orbit works and what the maximum distance from the Earth, and the Moon will be?
The graphic below is from the NASA news item The Ins and Outs of NASA’s First Launch of SLS and Orion. The article says:
The outbound trip to the moon will take several days, during which time engineers will evaluate the spacecraft’s systems and, as needed, correct its trajectory. Orion will fly about 62 miles (100 km) above the surface of the moon, and then use the moon’s gravitational force to propel Orion into a new deep retrograde, or opposite, orbit about 40,000 miles (70,000 km) from the moon.
The spacecraft will stay in that orbit for approximately six days to collect data and allow mission controllers to assess the performance of the spacecraft. During this period, Orion will travel in a direction around the moon retrograde from the direction the moon travels around Earth.
For its return trip to Earth, Orion will do another close flyby that takes the spacecraft within about 60 miles of the moon’s surface, the spacecraft will use another precisely timed engine firing of the European-provided service module in conjunction with the moon’s gravity to accelerate back toward Earth. This maneuver will set the spacecraft on its trajectory back toward Earth...
What is a "new deep retrograde" orbit? How will it be new, deep, and differ from the early Apollo-era free-return orbits? Is it what is roughly suggested between
01:37 in the following video — also linked from the same NASA article, where the spacecraft is suddenly far from the moon, and the Earth and Moon appear similar size?
below: Apollo-era drawing of Circumlunar free return trajectory, from here.
below: EM-1 mission path, from here.