On its sixth day into the Artemis I mission, Orion and the European Service Module completed their fourth orbital trajectory correction burn using the auxiliary engines at 08:44 CET (07:44 GMT) ahead the first of two manoeuvres to enter a distant retrograde orbit around the Moon.

The first three trajectory correction burns provided an opportunity to fire all three thruster types on Orion, the first firing (on flight day one) used the large orbital manoeuvring system engine OMS-E, the second (on flight day two) used the European reaction control system thrusters, and the third (on flight day five) used the medium-sized auxiliary engines.

Artist’s impression of Orion showing the engines on the European Service Module. The main engine is at the bottom, surrounded by the auxilliary engines and the reaction control thrusters are visible on the side. Credits: NASA
Tranquility base seen by ESA’s Smart-1 spacecraft

A key moment for the mission Orion’s outbound powered flyby that occurred at 13:44 CET (12:44 GMT) on 22 November, passing just under 130 km above the surface at 13:57 CET (12:57 GMT). The spacecraft’s speed increased from 3424 km/h before the burn to 8211 km/h after the burn. Shortly after the outbound flyby, Orion passed about 2250 km above the Apollo 11 landing site at Tranquility Base at 14:37 CET (13:37 GMT).

During a 34-minute period Orion and the European Service Module flew behind the Moon and communications was lost, as expected. Orion re-acquired signal with NASA’s Deep Space Network at 13:59 CET (12:59 GMT). The European Service Module had initiated the orbital powered flyby on cue, firing the large main engine for 149.5 seconds to accelerate the spacecraft at a rate of more than 933 km/h. It used 800 kg of MON oxidiser and 500 kg of MMH fuel to execute the burn.

“The mission continues to proceed as we had planned, and the ground systems, our operations teams, and the Orion spacecraft continue to exceed expectations, and we continue to learn along the way about this new, deep-space spacecraft,” said Mike Sarafin, NASA’s Artemis I mission manager.

Artemis I mission overview. Lunar flyby starts at 01:10

Far from the Moon

Orion will enter a so-called distant retrograde orbit beyond the Moon on 25 November with the second orbital manoeuvre, called the distant retrograde orbit insertion burn. The orbit is “distant” in the sense that it’s at a high altitude from the surface of the Moon, and it’s “retrograde” because Orion will travel around the Moon opposite the direction the Moon travels around Earth. This orbit provides a highly stable orbit where little fuel is required to stay for an extended trip in deep space to put Orion’s systems to the test in an extreme environment far from Earth. 

Artemis I orbital overview

Orion will travel about 92194 km at its farthest point from the Moon on 25 November, passing the record set by Apollo 13 for the farthest distance travelled by a spacecraft designed for humans, as on 26 November Orion and the European Service Module will be over 400 000 km from Earth and reach its maximum distance from Earth of 432192 km on 28 November.

Fuel report

On 21 November the European Service Module had used 1685 kg of propellant 34 kg less than expected values. There is now a 958 kg propellant margin for Artemis I, an increase of 91 kg more than calculated before launch.

Just after 19:45 CET (18:45 GMT) on 21 November, Orion has travelled 348973 km from Earth and was 21636 km from the Moon, cruising at 5615 miles per hour.