the Orion Spacecraft, the Earth and the Moon are seen from a camera as the Artemis II crew and spacecraft travel farther into Space, on Monday. (AP/PTI)The four astronauts of NASA’s Artemis II mission on Monday (April 6) travelled 252,756 miles (406,771 kilometers) away from Earth. The Orion spacecraft, in setting the new record, swung around the far side of the Moon.The record before this was the 4,00,171 km travelled by Apollo-13 in 1970, though in that case, the mission had to deviate farther than its intended path due to a malfunction.For Artemis II, the distance was part of the plan, but setting this record is not the mission’s main objective. The distance is a function of the path Artemis II is following to fulfill its goals.What was the Artemis II flight path?The first crewed lunar mission since December 1972, Artemis II is not a landing mission. Instead, it is a highly regulated flyby designed to test the limits of the Orion spacecraft. While earlier missions like Apollo 8 followed a circular lunar orbit—dictating that the crew fire their engines to maintain a fixed distance from the lunar surface—the Orion spacecraft is flying an elliptical “free-return trajectory.” This path relies on the Moon’s gravity to naturally slingshot the spacecraft back toward Earth.How does the ‘free-return trajectory’ work?Prioritising crew safety and fuel efficiency, this free-return trajectory is executed in two distinct phases:The High Earth Orbit (HEO): Initially, rather than aiming directly for the Moon, Orion pushed into an elliptical path around Earth, stretching outward to roughly 74,000 km. This afforded the crew a 42-hour window to conduct critical checks on the environmental control and life support systems (ECLSS). Should any system have failed here, the spacecraft remained within Earth’s gravitational pull, allowing an abort and splashdown within hours.The Translunar Slingshot: Once cleared for deep space, Orion was pushed toward the Moon by the European Service Module, aiming for a precise point roughly 10,300 km beyond the lunar far side. This allowed the Moon’s gravity to act as a tether, catching the spacecraft and whipping it around the far side directly back toward Earth’s atmosphere.What makes this flight plan attractive?Story continues below this adThis looping, figure-eight route acts as an uncompromised, passive safety mechanism. It ensures that in the event of an engine failure, the crew does not find itself stranded in deep space.Additionally, this route is exceptionally fuel-efficient. Entering a circular lunar orbit requires a massive, fuel-heavy deceleration burn to get caught in the Moon’s gravity, followed days later by an equally massive acceleration burn to break free. Orion’s utilisation of gravity to change direction conserves critical propellant.This lighter fuel requirement reduced the overall mass the Space Launch System (SLS) rocket had to lift off the pad, while ensuring the spacecraft retained a reserve of propellant for potential emergencies.What next for the Artemis programme?The primary agenda of Artemis II is to prove that the Orion spacecraft—and its European Service Module—can safely sustain human life in the harsh radiation and isolation of deep space. The 10-day mission’s goal was to rigorously verify that the vehicle had the capacity to reach the same distances as the uncrewed Artemis-I while preserving the life of crew members.Story continues below this adOrion’s safe return will provide NASA with a wealth of telemetry and life-support data to analyse before optimising it for subsequent journeys. Promising a long-awaited return to the Moon, the missions are part of NASA’s vision to develop its ‘Moon Base’.