Orion’s solar arrays split the gap between Earth and the Moon on the 14th flight day of the Artemis I mission in this image captured by a camera at the tip of one of the spacecraft’s four solar arrays. Credit: NASA
After exiting distant retrograde orbit on the afternoon of Thursday, December 1, Orion completed a planned trajectory correction burn to adjust its course toward the Moon. The five-second burn (see video below) occurred Thursday at 9:54 p.m. CST and changed the spacecraft’s speed by about 0.3 mph, or less than half a foot per second.
On Artemis I flight day 17 (Friday, December 2), the teams collected additional images with Orion’s optical navigation camera and linked a variety of ground data files. This included downloading data from the Hybrid Electronic Radiation Evaluator, or HERA. The radiation detector measures charged particles that pass through its sensors.
Measurements from HERA and other radiation-related sensors and experiments aboard Artemis I will help NASA better understand the space radiation environment that future crews will experience and develop effective protections. On manned missions, HERA will be part of the spacecraft’s caution and warning system and will sound a warning in the event of a solar energy particle event, notifying the crew to take shelter. NASA is also testing a similar HERA unit aboard the International Space Station (ISS).
Orion carries other experiments to collect radiation data, including several matchbox-sized radiation area monitors that record the total radiation dose during the mission, dosimeters provided by the ESA (European Space Agency) mounted inside the cabin to collect radiation data over time. stamps to allow scientists to assess dose rates during various phases of the mission, and three “purpose passengers” who collect additional information about what the crews will experience during future missions. Four space biology investigations, collectively called Biology Experiment-1, are examining the impact of deep space radiation on seeds, fungi, yeast and algae.
Orion will re-enter the lunar sphere of influence on Saturday, December 3, making the Moon the main gravitational force acting on the spacecraft. It will exit the lunar sphere of influence for the last time on Tuesday, Dec. 6, a day after its return powered flyby about 79 miles (127 km) above the lunar surface.
Orion’s Optical Navigation Camera captured this image of the Moon on Flight Day 16 of the Artemis I mission. Orion uses the Optical Navigation Camera to capture images of Earth and the Moon at different phases and distances, providing a enhanced data set to certify its effectiveness in different lighting conditions as a way to help guide the spacecraft on future crewed missions. Credit: NASA
A total of about 7,940 pounds of propellant was used, which is about 150 pounds less than the amount planned before launch. About 2,040 pounds of margin is available beyond what flight controllers plan to use for the rest of the mission, which is nearly 130 pounds more than the amounts planned before launch. About 97 gigabytes of data have been sent to Earth by the spacecraft.
Shortly after 1 pm CST on December 2, Orion was traveling 229,812 miles (369,847 km) from Earth and 50,516 miles (81,298 km) from the Moon, cruising at 2,512 miles per hour (4,043 km/h).