What is Artemis doing now? – Episode 4 – Sciencetimes

Flight Day 16: The Orion probe finally begins its journey to Earth

The Orion capsule finally leaves its distant lunar retrograde orbit and begins preparing to return home. The Artemis mission team started to leave the lunar retrograde orbit at 3:53 (CST) on December 1, the 16th day of the mission, performing a injection correction for 1 minute and 45 seconds.

The Orion capsule, which has been calibrated by using the main engine of the European service module, is flying for a close flight to the moon at a speed of about 0.14 km per second. (The part that changes from gray to blue arrows in the orbit picture) Therefore, the next injection correction to be performed will occur on December 5th, when the lunar flyby is performed. (When starting to leave the moon to head to Earth among the blue arrows in the orbit picture)

After successfully completing jet calibration, the Artemis team proceeded with thermal testing of the eighth and final planned stellar tracker. In addition, an additional trajectory correction injection to fine-tune the Orion probe’s path (using auxiliary thrusters) is scheduled for 5 seconds at 9:53 p.m.

Mission Day 16 On December 1, at 4:30 p.m. EST, the Orion capsule is 382,380 km from Earth and 85,134 km from the Moon, and is cruising at 3,701 km/h.

On December 1, 2022, on day 16 of the flight, one of the cameras mounted on the solar arrays of the Orion capsule captured the moon as it prepared to leave a distant retrograde orbit © Artemis 1/NASA

Flight Day 17: Orion Probe Refines Trajectory, Downlinks Data and Continues Testing

On December 2nd, the 17th day of the mission, he is busy with his journey to the moon again. The trajectory correction injection performed the day before was successfully completed, and now the Orion capsule, which has changed to a speed of 0.15 m/s, is about to fly again using gravity to the moon.

One of the photos downlinked on December 2nd, the Orion probe took this lunar image on day 16 of its mission the day before. The Orion probe’s optical navigation camera took images of the Earth and the Moon at different phases and distances. This can help orient the spacecraft. © Artemis 1/NASA

On December 2, the Artemis team collected additional images with the Orion capsule’s optical navigation camera, while downlinking various data files to the ground, including Hybrid Electronic Radiation Assessor (HERA) data. . So far, about 97 GB of data has been transmitted over the ground.

The HERA radiation detector and other in-cabin dosimeters manufactured by the European Space Agency (ESA) measured charged particles passing through the sensor, and these measurements are the same as those measured by future crews in Artemis. When participating in missions, it will help to better understand the space radiation environment and develop effective protective devices. In addition, when an incident involving solar energy particles, such as a solar wind, occurs, an alarm can be sounded to inform the crew that they must evacuate. NASA is also conducting tests similar to the HERA device on the International Space Station.

Reaction control thrusters mounted vertically on the European service module © ESA, NASA

Meanwhile, Biology Experiment-1, which investigates the effects of deep space radiation on seeds, molds, yeasts or algae, is also in progress.

The Orion probe will use the lunar gravity to re-enter the moon’s sphere of influence on Saturday, December 3. On December 5th, it will begin to leave the moon through a lunar flyby, and on Tuesday, December 6th, it will start to leave the moon’s sphere of influence for the last time at about 127 km above the lunar surface.

To date, a total of about 3,601 kg of propellant has been used, about 68 kg less than the amount expected before launch. Excluding the fuel used for the rest of the mission, about 925 kg of fuel will remain, which is approximately 58 kg more than the pre-launch projected fuel.

Mission Day 17 On December 2, 1:00 PM Central Time, the Orion probe is cruising at 4,042 km/h at a distance of 369,846 km from Earth and 81,297 km from the Moon.

Flight Day 18: Orion Probe Reenters Moon’s Sphere of Gravity

On the 18th day of the mission, on December 2, 2022, at 4:45 pm (US Central Time), the Orion probe entered the lunar sphere of influence again when it was about 64,362 km away from the lunar surface. This is in order for the probe to use the moon’s gravity on December 6 to obtain power to return to Earth. The Orion capsule is scheduled to fly low at approximately 127 km above the moon and escape from the moon’s influence in one day.

A camera mounted on one of the Orion probe’s four solar panels re-photographed the Moon from a distance of more than 357,274 kilometers from Earth. © Artemis 1/NASA

Artemis team engineers also performed a development flight test goal of changing the minimum jet launch time for the reaction control thruster over the course of 24 hours that day. The above test was a preplanned test to model the jet thruster launch vehicle for inclusion in the Artemis 2 mission, and was designed to run a reaction control system (RCS) jet built by the European Service Module’s Ariane Group.

In addition to the crew module, there is another set of 12 RCS thrusters built by Aerojet Rocketdyne of Lampoldshausen, Germany, which will be tested days before the Orion probe lands on Earth, most importantly before landing on the Pacific coast of San Diego. done a few hours ago. Tests will include whether the probe can properly orient itself upon reentry to Earth, whether the heat shield is forward facing, and whether it is stable while descending under a parachute.

On the 18th day of the mission, the Orion probe loses communication with NASA’s deep space network for about 4 hours and 30 minutes from 7:40 pm (CST). By 12:00 a.m. the next day, while the network team is realigning the ground station, the flight control team is rescheduling the activity, which will not affect the mission trajectory. This is because automated algorithms are guiding the spacecraft during this period, after which the Orion probe will communicate again through the Canberra ground station.

Australian ground station Canberra © NASA

Mission Day 18 At 1:00 PM Central Time on December 3, the Orion probe is cruising at 4,469 km/h at a distance of 356,678 km from Earth and 64,512 km from the Moon.

Artemis, what are your plans for the future?

On Monday, December 5, at 9:00 a.m. EST, the Orion probe will begin a flyby using lunar gravity. After about two and a half hours (estimated time 11:43), the probe is scheduled to accelerate to depart for Earth.

On December 11, the probe begins entering Earth’s atmosphere and attempts a landing. The splashdown is scheduled to begin at 12:40 PM EST on Sunday, December 11th, after which the Orion capsule will be retrieved.

Artemis 1 Mission Related Photos Browse – Johnson Space Center Flickr

Where is the Orion capsule from the Artemis 1 mission now? – Check real-time tracking