Live coverage is underway on NASA Television, the agency’s website, and the NASA app for Orion’s distant retrograde orbit insertion burn as a part of the Artemis I mission. The burn is planned for 4:52 p.m. EST. Orion will fire the orbital maneuvering system engine on its European service module to propel the spacecraft into an orbit over 40,000 miles above the surface of the Moon. The distant retrograde orbit provides a highly stable destination where little fuel is required to stay while engineers put Orion’s systems to the test in a deep space environment far from Earth.
The orbital maneuvering system engine on the European Service Module is the main engine that provides the primary propulsion for Orion’s major in-space maneuvers. The engine provides 6,000 pounds of thrust and is equipped to steer the spacecraft.Orion’s European Service Module is provided by ESA (European Space Agency) with contributions from 10 European countries and the United States, including Germany, Italy, Switzerland, France, Belgium, Sweden, Denmark, Norway, Spain, and the Netherlands.
Earlier in the day on flight day 10 of the 25.5-day mission, engineers continued planned testing with the star tracker in a variety of orientations in deep space as part of one of several flight test objectives.
Orion is currently traveling over 237,000 miles from Earth and over 57,000 miles from the Moon, cruising at about 2,300 miles per hour.
Orion is now about one day away from entering into a distant retrograde orbit around the Moon. The orbit is “distant” in the sense that it’s at a high altitude approximately 50,000 miles from the surface of the Moon. Due to the distance, the orbit is so large that it will take the spacecraft six days to complete half of a revolution around the Moon before exiting the orbit for the return journey back to Earth.
During the last day in the transit to distant retrograde orbit, flight controllers performed a third in a series of planned star tracker development flight tests relative to the Sun, with a fourth planned for tomorrow. Star trackers are a navigation tool that measure the positions of stars to help the spacecraft determine its orientation. In the first three flight days, engineers evaluated initial data to understand star tracker readings correlated to thruster firings.
The spacecraft completed its sixth outbound trajectory correction burn at 3:52 p.m. CST, firing the European Service Module’s auxiliary engines for 17 seconds to propel the spacecraft at 8.9 feet per second. This is the final trajectory correction before entering distant retrograde orbit. When in lunar orbit, Orion will perform three orbital maintenance burns to keep the spacecraft on course.
Overnight, engineers will begin a 24-hour test of the reaction control system engines to evaluate engine performance for standard and non-standard thruster configurations. This test will provide data to inform procedures and ensure that the reaction control thrusters can control Orion’s orientation in an alternate configuration if there is an issue with the primary configuration.
Just after 1:42 p.m. CST on Nov. 24, Orion was traveling 222,993 miles from Earth and 55,819 miles from the Moon, cruising at 2,610 miles per hour.
NASA Television coverage of the distant retrograde orbit insertion burn, scheduled for 4:30 p.m. EST on Friday, Nov. 25. The burn is scheduled to take place at 4:52 p.m.
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.
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.
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. CST for 47 minutes while reconfiguring the communication link between Orion and Deep Space Network overnight. The reconfiguration has been conducted successfully several times in the last few days, and the team is investigating the cause of the loss of signal. The team resolved the issue with a reconfiguration on the ground side. Engineers are examining data from the event to help determine what happened, and the command and data handling officer will be downlinking data recorded onboard Orion during the outage to include in that assessment. There was no impact to Orion, and the spacecraft remains in a healthy configuration.
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.
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.
On its sixth day into the Artemis I mission, Orion successfully completed its fourth orbital trajectory correction burn using the auxiliary engines at 1:44 a.m. CST ahead the first of two maneuvers required 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 with the first using the large orbital maneuvering system engine, the second using the small reaction control system thrusters, and the third using the medium-sized auxiliary engines.
Orion completed the outbound powered flyby at 6:44 a.m., passing about 81 miles above the surface at 6:57 a.m. The spacecraft speed increased from 2,128 mph before the burn to 5,102 mph after the burn. Shortly after the outbound flyby burn, the space craft passed about 1,400 miles above the Apollo 11 landing site at Tranquility Base at 7:37 a.m. Orion later flew over the Apollo 14 site at about 6,000 miles in altitude and then over the Apollo 12 site at an altitude of about 7,700 miles
“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, Artemis I mission manager, in a Nov. 21 briefing at Johnson Space Center.
Orion will enter distant retrograde orbit beyond the Moon on Friday, Nov. 25 with the second maneuver, 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.
Orion will travel about 57,287 miles beyond the Moon at its farthest point from the Moon on Nov. 25, pass the record set by Apollo 13 for the farthest distance traveled by a spacecraft designed for humans at 248,655 miles from Earth on Saturday, Nov. 26, and reach its maximum distance from Earth of 268,552 miles Monday, Nov. 28.
As of Monday, Nov. 21, a total of about 3,700 pounds of propellant has been used, about 75 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 200 pounds from prelaunch expected values.
Just after 2:45 p.m. CST on Nov. 21, Orion had traveled 216,842 miles from Earth and was 13,444 miles from the Moon, cruising at 3,489 miles per hour.
Follow along and track Orion via the Artemis Real-Time Orbit Website, or AROW, and watch live footage from the spacecraft. You can find the latest images from Orion on the Johnson Space Center Flickr account.
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 datawith 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.
Five days into the 25.5-day Artemis I mission, Orion continues on its trajectory toward the Moon. Flight controllers in the White Flight Control Room at NASA’s Johnson Space Center in Houston captured additional imagery of the Moon using the optical navigation camera. Gathering imagery of the Earth and the Moon at different phases and distances will provide an enhanced body of data to certify its effectiveness as a location determination aid for future missions under changing lighting conditions.
Orion completed its third outbound trajectory correction burn at 6:12 a.m. CST, firing the auxiliary thruster engines for a duration of 6 seconds at a rate of 3.39 feet per second to accelerate Orion and adjust the spacecraft’s path while en route to the Moon.The amount of speed change determines which of Orion’s service module engines – reaction control, auxiliary, or orbital maneuvering system – to use for a particular maneuver.
The spacecraft entered into the lunar sphere of influence at 1:09 p.m. CST, making the Moon, instead of Earth, the main gravitational force acting on the spacecraft. Overnight, Orion will conduct the fourth outbound trajectory correction burn in advance of the outbound powered flyby burn. Flight controllers will conduct the outbound powered flyby burn by firing the orbital maneuvering system engine for 2 minutes and 30 seconds to accelerate the spacecraft, harness the force from the Moon’s gravity, and direct it toward a distant retrograde orbit beyond the Moon.
The outbound powered flyby burn is the first of a pair of maneuvers required to enter a distant retrograde orbit around the Moon. NASA will cover the maneuver live starting at 7:15 a.m. EST on the agency’s website, NASA Television, and the NASA app. The outbound powered flyby will begin at 7:44 a.m., with Orion’s closest approach to the Moon targeted for 7:57 a.m., when it will pass about 80 miles above the lunar surface. Engineers expect to lose communication with the spacecraft as is passes behind the Moon for approximately 34 minutes starting at 7:26 a.m. The Goldstone ground station, part of NASA’s Deep Space Network, will acquire the spacecraft once it emerges from behind the Moon.
Mission managers currently have two active anomaly resolution teams. Anomaly resolution teams are a standard part of managing the mission by pulling together a team of technical experts to focus on a specific issue by examining data to understand the implications in a particular system. Activating a separate team for this work enables engineers and flight controllers to continue focusing on commanding and monitoring the spacecraft and assessing the progress of the flight test.
One team is currently looking at the star tracker system to understand a number of faults in the random access memory, which have been successfully recovered with power cycles. A second team is analyzing a few instances in which one of eight units located in the service module that provides solar array power to the crew module, called a power conditioning and distribution unit umbilical latching current limiter, 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. Both systems are currently functioning as required, and there are no mission impacts related to these efforts. Analyzing the data for these systems and understanding their behavior during an active flight test while the hardware is in the deep space environment will improve mission operations on Artemis I and future missions.
At 1:25 p.m. CST on Nov. 20, Orion had traveled 232,683 miles from Earth and was 39,501 miles from the Moon, cruising at 371 miles per hour. 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.
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.
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.
On the third day of its Artemis I journey, NASA’s uncrewed Orion spacecraft is now more than half way to the Moon.
“Today, we met to review the Orion spacecraft performance, and it is exceeding performance expectations.” said Mike Sarafin, Artemis I mission manager.
Friday, flight controllers used Orion’s cameras to inspect the crew module thermal protection system and European Service Module, the first of two planned external evaluations for the spacecraft. Teams conducted this survey early in the mission to provide detailed images of the spacecraft’s external surfaces after it has flown through the portion of Earth’s orbit where the majority of space debris resides. The second inspection is required during the return phase to assess the overall condition of the spacecraft several days before re-entry. During both inspections, the Integrated Communications Officer, or INCO, commands cameras on the four solar array wings to take still images of the entire spacecraft, allowing experts to pinpoint any micrometeoroid or orbital debris strikes. The team in mission control at NASA’s Johnson Space Center in Houston will review the imagery following the survey.
Over the past few days, a team assessed anomalous star tracker data that correlated with thruster firings. 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. Teams now understand the readings and there are no operational changes.
NASA also has received updates from teams associated with the 10 CubeSats that were delivered to space on a ring attached to the Space Launch System rocket’s upper stage. All 10 CubeSats were successfully deployed via timer from the adapter. The CubeSats’ individual missions are separate from Artemis I. The small satellites, each about the size of a shoebox, are inherently high-risk, high-reward and the teams are in various stages of mission operations or troubleshooting in some cases.
NASA hosted a briefing Friday previewing Orion’s arrival to the lunar sphere of influence. To follow the mission real-time, you can track Orion during its mission around the Moon and back, and check the NASA TV schedule for updates on the next televised events. The first episode of Artemis All Access is now available as a recap of the first three days of the mission with a look ahead to what’s coming next, and the latest imagery and videos can be found on the Johnson Space Center Flickr.