Before NASA can facilitate a major interplanetary expansion, it must do something that hasn’t been done in more than 53 years: successfully send astronauts to the Moon and back. The journey is unique because of its extreme distance, a quarter of a million miles from Earth. It was the farthest manned spaceflight that was not to the Moon Polar Dawna private flight on the SpaceX Dragon ship that carried current NASA Administrator Jared Isaacson and three others 1,370 km from Earth. The ISS orbits about 250 miles away.
“Deep space travel is inherently risky,” he says Paul Andersondeputy program manager of the Orion spacecraft at Lockheed Martin. “[In] in low Earth orbit, you’re a few hours away from home. From the moon, at best, you’re four days away from returning home.
The journey to the Moon will begin with the explosive launch of the SLS rocket, which will become the most powerful vehicle ever flown by humans, and only the second rocket to send humans to the Moon.
“As the rocket climbs, it follows its trajectory and makes adjustments based on signals received in flight,” says Boeing’s Quintero. “Everything must work in harmony, like in an orchestra.”
About two minutes after launch, the solid rockets that provide most of the liftoff thrust will be ejected. About six minutes later, the main engines will shut down and the main stage will separate and fall off. During the first two hours of flight, the SLS upper stage will perform two burns to raise the spacecraft’s orbit and then also separate.
Two days later, a European service module attached to Orion will trigger a critical engine combustion called translunar injection (TLI). This acceleration will send the spacecraft on its way to orbit the Moon and return to Earth with minor trajectory adjustments for the rest of the mission.
Although the Orion capsule outwardly resembles the Apollo command module, the technological capabilities of the space capsule have come a long way. Modern life support systems, GPS navigation, solar energy, and sophisticated computers are just some of the tools that did not exist during Apollo.
“We did the entire mission with Artemis I without a crew,” Anderson says. “Launched, orbited, burned up, orbited the moon, came back, flew in, descended and landed – all autonomously.”
Astronauts will continue to play a key role in piloting the spacecraft, especially during operations such as docking with another craft that will be necessary for a lunar landing. After separating from the SLS upper stage in space, the Artemis II crew will take the controls of the spacecraft to practice docking maneuvers with the spent part of the rocket before heading to the Moon.