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 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.  

Orion Begins Checkouts, Completes First Service Module Course Correction Burn

A view of Earth as seen from the Artemis I Orion capsule about 9 hours into flight on Nov. 16, 2022. (Image credit: NASA TV)

Following a successful launch on Wednesday, Nov. 16, NASA’s uncrewed Orion spacecraft is heading toward the Moon on a 25.5-day mission beyond the lunar surface. Orion lifted off atop the Space Launch System (SLS) rocket at 1:47 a.m. EST from Launch Complex 39B at NASA’s Kennedy Space Center in Florida. Engineers intend to learn as much as possible about Orion’s performance during the flight test and are focused on the primary objectives for the mission: demonstrating Orion’s heat shield at lunar return re-entry conditions, demonstrating operations and facilities during all mission phases, and retrieving the spacecraft after splashdown.

A view inside the Artemis I Orion capsule with a view of the manikin ‘passenger’ recording data on conditions for the future crew members. (Image credit: NASA TV)

Flight controllers in the Mission Control Center at NASA’s Johnson Space Center in Houston successfully completed the first outbound trajectory correction burn by the European-built service module’s main engine as planned at 9:32 a.m. The burn tested Orion’s main engine for the first time and adjusted the spacecraft’s course toward the Moon. Several additional course correction burns are planned on journey.

While Orion began its trek toward the lunar environment, 10 CubeSats deployed by timer from an adapter still attached to the SLS’s upper stage. Each CubeSat has different timelines for acquiring a signal with its mission operators.

Flight controllers performed a modal survey, a test to verify that the models and simulations used to design Orion’s solar array wings accurately reflect the motion that is occurring in flight. This was accomplished by firing Orion’s reaction control system thrusters and observing how the solar array wings react to that specific firing sequence. Engineers also calibrated the optical navigation system and gathered imagery using the spacecraft’s cameras. Orion is outfitted with multiple cameras used for various functions such as engineering as well as sharing the progress of the mission with the public.

Scheduled for Thursday is the second outbound trajectory burn using the auxiliary thrusters, which will be used for most trajectory correction burns.

Watch the launch broadcast replay below:

Watch the post-launch press conference.