Artemis I – Flight Day 20: Orion Conducts Return Powered Flyby 

On Dec. 5, 2022, Orion completed the return powered flyby burn, committing the spacecraft to a Dec. 11 splashdown in the Pacific Ocean.

NASA’s Orion spacecraft is on course for its return to Earth on Sunday, Dec. 11. The spacecraft made its second and final close approach to the Moon at 10:43 a.m. CST Monday, Dec. 5, just before its return powered flyby burn, passing 80.6 miles above the lunar surface.  

The burn, which used the spacecraft’s main engine on the European-built service module, lasted 3 minutes, 27 seconds, and changed the velocity of the spacecraft by about 655 mph (961 feet per second). It was the final major engine maneuver of the flight test.  

“Orion is heading home! Today the team achieved another momentous accomplishment, flying Orion just 80 miles from the surface of the Moon. The lunar flyby enabled the spacecraft to harness the Moon’s gravity and slingshot it back toward Earth for splashdown,” said Administrator Bill Nelson. “When Orion re-enters Earth’s atmosphere in just a few days, it will come back hotter and faster than ever before – the ultimate test before we put astronauts on board. Next up, re-entry!” 

Several hours before the lunar flyby, the spacecraft performed a trajectory correction burn at 4:43 a.m. CST using the reaction control system thrusters on the service module. The burn lasted 20.1 seconds and changed the velocity of the spacecraft by 1.39 mph (2.04 feet per second). 

The mission management team convened and polled “go” to deploy recovery assets off the coast of California ahead of Orion’s splashdown on Dec. 11. As soon as Orion splashes down, a team of divers, engineers, and technicians will depart the ship on small boats and arrive at the capsule. Once there, they will secure it and prepare to tow it into the back of the ship, known as the well deck. The divers will attach a cable to pull the spacecraft into the ship, called the winch line, and up to four additional tending lines to attach points on the spacecraft. The winch will pull Orion into a specially designed cradle inside the ship’s well deck and the other lines will control the motion of the spacecraft. Once Orion is positioned above the cradle assembly, the well deck will be drained and Orion will be secured on the cradle. 

 “Last week, we completed our final rehearsal with the USS Portland, which will be our recovery ship for Artemis I,” said Melissa Jones, landing and recovery director, NASA’s Kennedy Space Center. “We had a great three days working with them to refine our procedures and integrate our teams so we can meet the objectives of recovering the Orion spacecraft.” 

Orion has used approximately 8,050 pounds of propellant during Artemis I, which is 180 pounds less than expected prelaunch. There are 2,075 pounds of margin available over what was planned for the mission, a 165-pound increase. 

As of 5:29 p.m. CST on Dec. 5, Orion was traveling 244,629 miles from Earth and 16,581 miles from the Moon, cruising at 668 mph. 

NASA Television and the agency’s website will resume live coverage of Orion’s journey at 9 a.m. Tuesday. 

As Orion leaves the lunar sphere of influence for the final time, watch NASA astronaut Thomas Marshburn read the children’s book Goodnight Moon from space during his expedition aboard the International Space Station as part of a collaboration with Crayola Education to bring stories and the unique teachings of space to life with art and creativity. 

Images are sent down to Earth, and uploaded to NASA’s Johnson Space Center Flickr account and Image and Video Library. When bandwidth allows, views of the mission will be available in real-time via video stream. 

Artemis I – Flight Day 19: Orion Prepares for Close Lunar Flyby, Teams Examining Power Conditioning Issue

art001e002003 (Dec. 4, 2022) On the 19th day of the Artemis I mission, Orion captures Earth from a camera mounted on one of its solar arrays as the spacecraft prepares for the return powered flyby of the Moon on Dec. 5, when it will pass approximately 79 miles above the lunar surface.

Orion performed the second return trajectory correction burn on Sunday, Dec. 4, at 10:43 a.m. CST, using the auxiliary thrusters and increasing the spacecraft’s velocity by 1.16 mph (1.71 feet per second).  

Shortly after acquiring signal with the Deep Space Network’s Canberra ground station at 12:41 a.m. CST, Orion experienced an issue with a power conditioning distribution unit (PCDU), in which four of the latching current limiters responsible for downstream power were switched off. These lower-level switches connect to the propulsion and heater subsystems. Teams confirmed the system was healthy and successfully repowered the downstream components. There was no interruption of power to any critical systems, and there were no adverse effects to Orion’s navigation or communication systems. 

Teams are examining whether a potential contributor to this issue is related to a power configuration test implemented by the flight teams to investigate previous instances in which one of eight units opened without a command. The umbilical was successfully commanded closed each time and there was no loss of power flowing to avionics on the spacecraft.  

The spacecraft obtained additional data using its optical navigation system, which is a sensitive camera to take images of the Moon and Earth to help orient the spacecraft by looking at the size and position of the celestial bodies in the images. Engineers also continue to work plans to accomplish several additional test objectives during Orion’s journey back to Earth. A host of test objectives provide information to engineers about how Orion operates in space, allowing them opportunities to validate performance models and learn as much as possible about the spacecraft. 

In preparation for Orion’s return to Earth, the team from NASA’s Exploration Ground Systems Program and the U.S. Navy, who will recover Orion from the Pacific Ocean, completed its final training day at sea, using a mock capsule in the water for divers and small boats to practice open water recovery procedures. 

On Monday, Dec. 5, Orion will make its closest approach to the Moon, flying 79.2 miles above the lunar surface. It will perform the return powered flyby burn at 10:43 a.m. CST, which will last about 3 minutes and 27 seconds, changing the velocity of the spacecraft by approximately 655 mph (961 feet per second). The return powered flyby is the last large maneuver of the mission, with only smaller trajectory corrections to target Earth remaining. 

Live coverage of the close lunar flyby and burn will begin at 8 a.m. CST on NASA TV, the agency’s website, and the NASA app. During the coverage, lighting will be different than it was during Orion’s initial close lunar flyby on Nov. 21. The spacecraft will lose communications with Earth for approximately 31 minutes beginning at 10:40 a.m. CST, as it flies behind the far side of the Moon. 

At 4 p.m. CST on Dec. 5, NASA leaders will discuss the results of the return powered flyby burn and the deployment of recovery assets to sea ahead of Orion’s splashdown on Dec. 11. Live coverage will be available on all NASA channels. 

Just after 4:30 p.m. CST on Dec. 4, Orion was traveling 222,213 miles from Earth and 23,873 miles from the Moon, cruising at 3,076 mph. 

Images from the mission are available on NASA’s Johnson Space Center Flickr account and Image and Video Library. When bandwidth allows, live views from Orion are available in real-time. 

Artemis I – Flight Day 18: Orion Re-enters Lunar Sphere of Influence

art001e001933 (Dec. 2, 2022) A camera mounted on one of Orion’s four solar arrays captured this image of the Moon on flight day 17 of the 25.5-day Artemis I mission from a distance of more than 222,000 miles from Earth. Orion has exited the distant lunar orbit and is heading for a Dec. 11 splashdown in the Pacific Ocean.

Orion re-entered the lunar sphere of influence at 4:45 p.m. CST Saturday, Dec. 3, making the Moon the main gravitational force acting on the spacecraft. Entry into the lunar sphere of entry occurred when the spacecraft was about 39,993 miles from the lunar surface. It will exit the lunar sphere of influence for a final time on Tuesday, Dec. 6, one day after the return powered flyby about 79 miles above the lunar surface. 

On Flight Day 18, engineers also performed a development flight test objective that changed the minimum jet firing time for the reaction control thrusters over a period of 24 hours. This test objective is designed to exercise the reaction control system jets in a pre-planned sequence to model jet thruster firings that will be incorporated into the crewed Artemis II mission. 

The test used the reaction control system (RCS) thrusters, built by ArianeGroup, on the European Service Module. All firings of RCS thrusters during the flight test to date have used those on the service module. Another set of 12 RCS thrusters, built by Aerojet Rocketdyne, are located on the crew module.  

While the crew module thrusters will be tested a few days before Orion’s splashdown on Earth, their primary role takes place in the final hour before splashdown in the Pacific Ocean. After the crew module and service module separate the crew module’s RCS thrusters will be used to ensure the spacecraft is properly oriented for re-entry, with its heat shield pointed forward, and stable during descent under parachutes. 

Orion will be out of communication with NASA’s Deep Space Network for about 4.5 hours from 7:40 p.m. to 12:00 a.m. while network teams reconfigure ground stations. The flight control team has adjusted the activity timeline, and there is no impact to the mission’s trajectory. Automated commands will guide the spacecraft during this period, and Orion will reacquire signal as it passes within range of the Canberra ground station. 

Just after 4:30 p.m. on Dec. 3, Orion was traveling 221,630 miles from Earth and 40,086 miles from the Moon, cruising at 2,777 miles per hour. 

Images from the mission are available on NASA’s Johnson Space Center Flickr account and Image and Video Library. When bandwidth allows, live views from Orion are available in real-time. 

Artemis I – Flight Day 17: Orion Fine-tunes Trajectory, Downlinks Data, Continues Test Objectives

art001e001859 (Dec. 1, 2022) 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 imagery of the Earth and the Moon at different phases and distances, providing an enhanced body of data to certify its effectiveness under different lighting conditions as a way to help orient the spacecraft on future missions with crew.

After departing distant retrograde orbit the afternoon of Thursday, Dec. 1, Orion completed a planned trajectory correction burn to fine-tune its course toward the Moon. The five-second burn occurred at 9:54 p.m. CST Thursday, and changed the spacecraft’s velocity by about 0.3 mph or less than half a foot per second. 

Dec. 2, teams collected additional images with Orion’s optical navigation camera and downlinked a wide variety of data files to the ground, including data from the Hybrid Electronic Radiation Assessor, or HERA. The radiation detector measures charged particles that pass through its sensors. Measurements from HERA and several other radiation-related sensors and experiments aboard Artemis I will help NASA better understand the space radiation environment future crews will experience and develop effective protections. On crewed missions, HERA will be part of the spacecraft’s caution and warning system and will sound a warning in the case of a solar energetic particle event, notifying the crew to take shelter. NASA is also testing a similar HERA unit aboard the International Space Station.   

Orion carries other experiments to gather data on radiation, including several radiation area monitors about the size of a matchbox that record the total radiation dose during the mission, dosimeters provided by ESA (European Space Agency) mounted inside the cabin to collect radiation data with time stamps to allow scientists to assess dose rates during various mission phases, and three “purposeful passengers” collecting additional information on what crews will experience during future missions. Four space biology investigations, collectively called Biology Experiement-1, are examining the impact of deep space radiation on seeds, fungi, yeast, and algae.  

Orion will reenter the lunar sphere of influence on Saturday, Dec. 3, making the Moon the main gravitational force acting on the spacecraft. It will exit the lunar sphere of influence for a final time on Tuesday, Dec. 6, one day after its return powered flyby about 79 miles above the lunar surface. 

A total of about 7,940 pounds of propellant has been used, which is about 150 pounds less that the amount expected before launch. Approximately 2,040 pounds of margin is available beyond what flight controllers plan to use for the remainder of the mission, which is nearly 130 pounds more than expected amounts before launch. About 97 gigabytes of data have been sent to the ground by the spacecraft.  

Just after 1 p.m. CST on Dec. 2, Orion was traveling 229,812 miles from Earth and 50,516 miles from the Moon, cruising at 2,512 miles per hour. 

Images from the mission are available on NASA’s Johnson Space Center Flickr account and Image and Video Library. When bandwidth allows, live views from Orion are available in real-time. 

Artemis I – Flight Day 15: Team Polls “Go” For Distant Retrograde Orbit Departure

art001e000669 (Nov. 27, 2022) On flight day 12 of the 25.5-day Artemis I mission, a camera on the tip of one of Orion’s solar arrays captured the Moon as Orion travels in distant retrograde orbit around the Moon.

The Artemis I mission management team met today to review the overall status of the flight test and polled “go” for Orion to depart from its distant retrograde orbit, where it has been since Nov. 25. Orion will conduct a burn to depart the orbit at 3:53 p.m. CST Thurs., Dec. 1 and begin its trek back toward Earth.  

“We are continuing to collect flight test data and buy down risk for crewed flight,” said Mike Sarafin, Artemis mission manager. “We continue to learn how the system is performing, where our margins are, and how to operate and work with the vehicle as an integrated team.” 

On Flight Day 15, Orion also performed a planned orbit maintenance burn to maintain the spacecraft’s trajectory and decrease its velocity ahead of its Thursday departure from a distant lunar orbit. During the burn, Orion used six of its auxiliary thrusters on the European Service module to fire for 95 seconds. The burn was initially planned for a shorter duration but was lengthened as part of the team’s effort to add test objectives to the mission. The 95-second burn provided additional data to characterize the thrusters and the radiative heating on the spacecraft’s solar array wings to help inform Orion’s operational constraints. All previous thruster burns were 17 seconds or less.  

Orion’s European-built service module has provided the propulsive capabilities to adjust the spacecraft’s course in space via its 33 engines of various types, and serves as Orion’s powerhouse, supplying it will electricity, thermal control, and air and water for future crews, in addition to propulsion. Artemis I is the first time NASA is using a European-built system as a critical element to power an American spacecraft. Provided by ESA (European Space Agency) and its partner Airbus Defence and Space, the service module extends NASA’s international cooperation from the International Space Station into deep space exploration.  

NASA is continuing to extend its relationships with its international partners to explore the Moon under Artemis. The agency’s Gateway, a multi-purpose outpost in development to orbit the Moon that will provide essential support for long-term lunar exploration, includes contributions from ESA as well as the Canadian Space Agency and the Japan Aerospace Exploration Agency. Agencywide, NASA has more than 600 active international agreements with organizations and space agencies around the world. 

Teams also elected to add four additional test objectives to Orion’s return trip to Earth to gather additional data on the spacecraft’s capabilities. Two will evaluate whether opening and closing a valve the pressure control assembly affects a slow leak rate in that system; a third will demonstrate Orion’s ability to perform attitude maneuvers at the rate that will be necessary for a test on Artemis II; and the fourth will test its capability to fly in a three degree of freedom attitude control mode, as opposed to the six degree of freedom mode it typically flies in.

Prior to today’s orbital maintenance burn, a total of 5,681 pounds of propellant had been used, 203 pounds less than values expected before launch. Some 2,004 pounds of margin is available beyond what is planned for use during the mission, a 94-pound increase above prelaunch expected values. 

Just after 4 p.m. CST on Nov. 30, Orion was traveling 253,079 miles from Earth and 50,901 miles from the Moon, cruising at 2,052 mph. 

Coverage of the distant retrograde orbit departure burn will begin Thursday at 3:30 p.m. CST, with the burn scheduled to occur at 3:53 p.m. Watch live on NASA TV, the agency’s website, and the NASA app. 

View the latest imagery of the Moon, Earth, and Orion on NASA’s Johnson Space Center Flickr account and Image and Video Library. When bandwidth allows, views of the mission are available in real-time. 

Artemis I — Flight Day 13: Orion Goes the (Max) Distance

(Nov. 28, 2022) On flight day 13, Orion reached its maximum distance from Earth during the Artemis I mission when it was 268,563 miles away from our home planet. Orion has now traveled farther than any other spacecraft built for humans.

NASA’s uncrewed Orion spacecraft reached the farthest distance from Earth it will travel during the Artemis I mission — 268,563 miles from our home planet — just after 3 p.m. CST. The spacecraft also captured imagery of Earth and the Moon together throughout the day, including of the Moon appearing to eclipse Earth. 

Reaching the halfway point of the mission on Flight Day 13 of a 25.5 day mission, the spacecraft remains in healthy condition as it continues its journey in distant retrograde orbit, an approximately six-day leg of its larger mission thousands of miles beyond the Moon.  

“Because of the unbelievable can-do spirit, Artemis I has had extraordinary success and has completed a series of history making events,” said NASA Administrator Bill Nelson. “It’s incredible just how smoothly this mission has gone, but this is a test. That’s what we do – we test it and we stress it.” 

Engineers had originally planned an orbital maintenance burn today but determined it was not necessary because of Orion’s already precise trajectory in distant retrograde orbit. Based on Orion’s performance, managers are examining adding seven additional test objectives to further characterize the spacecraft’s thermal environment and propulsion system to reduce risk before flying future missions with crew. To date, flight controllers have accomplished or are in the process of completing 37.5% of the test objectives associated with the mission, with many remaining objectives set to be evaluated during entry, descent, splashdown, and recovery. 

NASA’s Exploration Ground Systems team and the U.S. Navy are beginning initial operations for recovery of Orion when it splashes down in the Pacific Ocean. The team will deploy Tuesday for training at sea before return to shore to make final preparations ahead of splashdown. 

Managers also closed out today a team formed earlier in the mission to investigate readings associated with the spacecraft’s star trackers after determining the hardware is performing as expected and initially suspect readings are a byproduct of the flight environment.   

Flight controllers also have completed 9 of 19 translational burns and exercised the three types of engines on Orion – the main engine, auxiliary thrusters, and reaction control system thrusters. Approximately 5,640 pounds of propellants have been used, which is about 150 pounds fewer than prelaunch expected values. More than 2,000 pounds of margin remain available beyond what teams plan to use for the mission, an increase of more than 120 pounds from prelaunch expected values. So far, teams have already sent more than 2,000 files from the spacecraft to Earth. 

Just before 8 p.m. EST, Orion was 268,457 miles from Earth and 43,138 miles from the Moon, cruising at 1,679 miles per hour.

To follow the mission real-time, you can track Orion during its mission around the Moon and back and watch live imagery from the spacecraft. Check the NASA TV schedule for updates on the next televised events. The latest imagery and videos can be found on the Johnson Space Center Flickr. 

Artemis I – Flight Day Eight: Orion Exits the Lunar Sphere Of Influence

(Nov. 22, 2022) Flight Day 7, Orion’s Optical Navigation camera captured the far side of the Moon, as the spacecraft orbited 81.1 miles above the surface, heading for a Distant Retrograde Orbit. Orion uses the optical navigation camera to capture imagery of the Earth and the Moon at different phases and distances, providing an enhanced body of data to certify its effectiveness under different lighting conditions as a way to help orient the spacecraft on future missions with crew.

On the eighth day of its mission, Orion continues to travel farther away from the Moon as it prepares to enter a distant retrograde orbit. 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.  

Orion exited the gravitational sphere of influence of the Moon Tuesday, Nov. 22, at 9:49 p.m. CST at a lunar altitude of 39,993 miles. The spacecraft will reach its farthest distance from the Moon Friday, Nov 25, just before performing the next major burn to enter the orbit. The distant retrograde orbit insertion burn is the second in a pair of maneuvers required to propel Orion into the highly stable orbit that requires minimal fuel consumption while traveling around the Moon.   

NASA’s Mission Control Center at the agency’s Johnson Space Center in Houston unexpectedly lost data to and from the spacecraft at 12:09 a.m. for 47 minutes while reconfiguring the communication link between Orion and Deep Space Network. Teams have resolved the issue, and the spacecraft remains in a healthy configuration while engineers analyze data to determine the cause. 

While in transit to the distant retrograde orbit, engineers conducted the first part of the propellant tank slosh development flight test, called prop slosh, which is scheduled during quiescent, or less active, parts of the mission. The test calls for flight controllers to fire the reaction control system thrusters when propellant tanks are filled to different levels. Engineers measure the effect the propellant sloshing has on spacecraft trajectory and orientation as Orion moves through space. The test is performed after the outbound flyby burn and again after the return flyby burn to compare data at points in the mission with different levels of propellant onboard.  

Propellant motion, or slosh, in space is difficult to model on Earth because liquid propellant moves differently in tanks in space than on Earth due to the lack of gravity. The reaction control thrusters are located on the sides of the service module in six sets of four. These engines are in fixed positions and can be fired individually as needed to move the spacecraft in different directions or rotate it into any position. Each engine provides about 50 pounds of thrust. 

As of Wednesday, Nov. 23, a total of about 3,971 pounds of propellant has been used, about 147 pounds less than prelaunch expected values. There is more than 2,000 pounds of margin available over what is planned for use during the mission, an increase of about 74 pounds from prelaunch expected values.  

Just after 1 p.m. CST on Nov. 23, Orion was traveling about 212,437 miles from Earth and was more than 48,064 miles from the Moon, cruising at 2,837 miles per hour.    

To follow the mission real-time, you can track Orion during its mission around the Moon and back, view a live stream from Orion’s cameras, and find the latest imagery and videos on Flickr. The second episode of Artemis All Access is now available as a recap of the last few days of the mission with a look ahead to what’s coming next.  

Artemis I – Flight Day Seven: Orion to Test Search Acquire and Track Mode, Exit Lunar Sphere of Influence

The Orion spacecraft is now on its seventh day into the Artemis I mission, a flight test around the Moon, paving the way for astronauts to fly on future missions. At 12:02 a.m. CST, Orion completed the fifth outbound trajectory correction by firing the European service module’s auxiliary engines for 5.9 seconds, which changed Orion’s velocity by 3.2 feet per second.  

The R-4D-11 auxiliary engines are a variant of the flight proven R-4D engine, which was originally developed for the Apollo program and was employed on every mission to the Moon. The engines are positioned at the bottom of the service module in four sets of two, and each provide about 100 pounds of thrust. In total, Orion’s highly capable service module has 33 engines of various sizes and serves as the powerhouse for the spacecraft, providing propulsion capabilities that enable Orion to go around the Moon and back on its exploration missions.  

The team in the White Flight Control Room at NASA’s Johnson Space Center in Houston continued testing the spacecraft’s star trackers to determine their sensitivity to thermal variations as part of planned testing, and engineers used the optical navigation system to gather additional imagery of the Moon. The star trackers and optical navigation system are part of Orion’s advanced guidance, navigation, and control system, responsible for always knowing where the spacecraft is located in space, which way it’s pointed, and where it’s going. It even controls the propulsion system to keep the spacecraft on the correct path. The optical navigation can serve later in this mission and in future missions as a backup, ensuring a safe trip home should the spacecraft lose communications. 

Download this video in high-resolution.

Overnight, flight controllers will conduct the search acquire and track (SAT) mode developmental test objective. SAT mode is an algorithm intended to recover and maintain communications with Earth after loss of Orion’s navigation state, extended loss of communications with Earth, or after a temporary power loss that causes Orion to reboot hardware. To test the algorithm, flight controllers will command the spacecraft to enter SAT mode, and after about 15 minutes, restore normal communications. Testing SAT mode will give engineers confidence it can be relied upon as the final option to fix a loss of communications when crew are aboard. 

Orion will exit the lunar sphere of influence, or the gravitational pull of the Moon, at 10:31 p.m. CST and continue traveling toward distant retrograde orbit. The next live event will be NASA Television coverage of the distant retrograde orbit insertion burn, scheduled for 4:30 p.m. EST on Friday, Nov. 25. Shortly before entering the orbit, Orion will travel about 57,287 miles beyond the Moon at its farthest point from the lunar surface during the mission. View the Artemis I mission map to see Orion’s path in space.  

On Saturday, Nov. 26, Orion will pass the record set by Apollo 13 for the farthest distance traveled by a spacecraft designed for humans at 248,655 miles from Earth, and the spacecraft will reach its maximum distance from Earth of 268,552 miles Monday, Nov. 28.  

Just after 4 p.m. CST on Nov. 22, Orion was traveling over 208,000  miles from Earth and was over 36,000  miles from the Moon, cruising at over 3,000  miles per hour.   

Listen to a replay of the Twitter Spaces NASA hosted Tuesday, Nov. 22, with NASA Flight Director Gerry Griffin, Jim Geffre from Orion, Nijoud Merancy with the Artemis program and Jennifer Ross-Nazzal with the NASA history office to discuss the milestone. 

Learn more about Orion’s systems that were designed for deep space missions with astronauts. 

Orion Successfully Completes Lunar Flyby, Re-acquires Signal with Earth

Artemis I Earthrise

Orion re-acquired signal with NASA’s Deep Space Network, at 7:59 a.m. EST after successfully performing the outbound powered flyby burn at 7:44 a.m. EST with a firing of the orbital maneuvering system engine for 2 minutes and 30 seconds to accelerate the spacecraft at a rate of more than 580 mph. At the time of the burn, Orion was 328 miles above the Moon, travelling at 5,023 mph. Shortly after the burn, Orion passed 81 miles above the Moon, travelling at 5,102 mph. At the time of the lunar flyby, Orion was more than 230,000 miles from Earth.  

The outbound powered flyby burn is the first of two maneuvers required to enter the distant retrograde orbit around the Moon. The spacecraft will perform the distant retrograde orbit insertion burn Friday, Nov. 25, using the European Service Module. Orion will remain in this orbit for about a week to test spacecraft systems. The distant retrograde will take Orion 40,000 miles past the Moon before it returns to Earth. Orion’s greatest distance from the Earth will be Monday, Nov. 28 at 3:05 p.m. CST at more than 268,500 miles. Orion’s greatest distance from the Moon will be on Friday, Nov. 25 at 3:53 p.m. CST at more than 57,250 miles. 

The Deep Space Network, managed by NASA’s Jet Propulsion Laboratory in Southern California, handles communications for Artemis I beyond low-Earth orbit. This includes the mission’s trajectory corrections, powered flyby burns, and insertion into and departure from distant retrograde orbit, while the Near Space Network provides supplemental navigation data with assistance from the Near Space Network’s tracking and data relay satellite constellation. 

The Deep Space Network consists of three facilities spaced equidistant from each other – approximately 120 degrees apart in longitude – around the world. These sites are at Goldstone, near Barstow, California; near Madrid, Spain; and near Canberra, Australia. The strategic placement of these sites permits constant communication with spacecraft as our planet rotates – before a distant spacecraft sinks below the horizon at one site, another site can pick up the signal and carry on communicating. Orion initially regained signal with the Madrid ground station after the lunar flyby and then transitioned signal to the Goldstone station. 

NASA will host a news conference on NASA T V at 5 p.m. EST to discuss Orion’s outbound powered flyby burn and provide an update on post-launch assessments of the Space Launch System rocket and Exploration Ground Systems.  

Participants will include: 

  • Mike Sarafin, Artemis I mission manager  
  • Judd Frieling, NASA flight director  
  • Howard Hu, Orion Program manager 

NASA TV coverage of the distant retrograde orbit insertion burn will begin at 4:30 p.m. EST Friday, with the burn scheduled to occur at 4:52 p.m. 

Learn more about distant retrograde orbit and NASA’s communication and navigation networks. See which antennas are communicating with Orion in real-time on Deep Space Network Now and track Orion via the Artemis Real-Time Orbit Website, or AROW. 

Artemis I – Flight Day Four: Testing WiFi Signals, Radiator System, GO for Outbound Powered Flyby

Orion snapped this high-resolution selfie in space with a camera mounted on its solar array wing during a routine external inspection of the spacecraft on the third day into the Artemis I mission.

On Saturday, Nov. 19, the Mission Management Team polled “go” for Orion’s outbound powered flyby past the Moon. NASA will cover the flyby live on NASA TV, the agency’s website, and the NASA app starting at 7:15 a.m. EST Monday, Nov. 21. The burn is planned for 7:44 a.m. Orion will lose communication with Earth as it passes behind the Moon from 7:25 a.m. through 7:59 a.m., making its closest approach of approximately 80 miles from the surface at 7:57 a.m. 

During flight day four, flight controllers moved each solar array to a different position to test the strength of the WiFi signal with the arrays in different configurations. The Integrated Communications Officer, or INCO, tested the WiFi transfer rate between the camera on the tip of the solar array panels and the camera controller. The goal was to determine the best position to most efficiently transfer imagery files. Teams learned that having multiple cameras on at once can impact the WiFi data rate, and therefore, future solar array wing file transfer activities will be accomplished from one solar array wing at a time to optimize transfer time. 

The Emergency, Environmental, and Consumables Manager, or EECOM, tested Orion’s radiator system. Two radiator loops on the spacecraft’s European Service Module help expel excess heat generated by different systems throughout the flight. Flight controllers are testing sensors that maintain the coolant flow in the radiator loops, switching between different modes of operation and monitoring performance. During speed mode, the coolant pumps operate at a constant rate. This is the primary mode used during Artemis I. Flow control mode adjusts the pump speed as needed to maintain a constant flow through the system. The flight test objective is to monitor system performance and the accuracy of flow sensors to characterize the stability of this mode of operation.  Each loop is monitored in flow control mode for 72 hours to provide sufficient data for use on future missions. 

In a white clean room, employees dressed in white observe The Orion crew and service module stack for Artemis I was lifted out of the Final Assembly and Test (FAST) cell. The Orion star trackers are highlighted about halfway up the spacecraft.
Star trackers are sensitive cameras that take pictures of the star field around Orion. By comparing the pictures to its built-in map of stars, the star tracker can determine which way Orion is oriented. The star trackers on Orion are located on the European Service Module on either side of the optical navigation camera. This Nov. 2019 photo was taken as the Orion crew and service module stack for Artemis I was lifted out of the Final Assembly and Test (FAST) cell.

As part of planned testing throughout the mission, the guidance, navigation, and control officer, also known as GNC, performed the first of several tests of the star trackers that support Orion’s navigation system. Star trackers are a navigation tool that measure the positions of stars to help the spacecraft determine its orientation. In previous flight days, engineers evaluated initial data to understand star tracker readings correlated to thruster firings.  

Engineers hope to characterize the alignment between the star trackers that are part of the guidance, navigation and control system and the Orion inertial measurements units, by exposing different areas of the spacecraft to the Sun and activating the star trackers in different thermal states.  

Just after 5:30 p.m. on Nov. 19, Orion had traveled 222,823 miles from Earth and was 79,011 miles from the Moon, cruising at 812 miles per hour. You can track Orion via the Artemis Real-Time Orbit Website, or AROW. 

Overnight, engineers in mission control will uplink large data files to Orion to better understand how much time it takes for the spacecraft to receive sizeable files. On flight day five, Orion will undergo its third planned outbound trajectory correction burn to maneuver the spacecraft and stay on course to the Moon. 

Learn more about the console positions in mission control and the additional test objectives planned throughout the mission.