Artemis

The crew module of NASA’s Orion spacecraft has successfully separated from its service module at 11:00 a.m. CST in preparation for the crew module’s return to Earth. The service module will burn up harmlessly in Earth’s atmosphere upon re-entry over the Pacific Ocean. The Artemis I trajectory is designed to ensure any remaining parts do not pose a hazard to land, people, or shipping lanes.

Next, the crew module will perform a skip entry technique, dipping into the upper part of Earth’s atmosphere and using that atmosphere, along with the lift of the capsule, to skip back out of the atmosphere, then reenter for final descent under parachutes and splash down. This technique enables the spacecraft to accurately and consistently splash down at the selected landing site for Artemis missions regardless of when and where they return from the Moon. During re-entry, the enormous heat generated as Orion encounters the atmosphere turns the air surrounding the capsule into plasma, which will briefly disrupt communications with the spacecraft.

Below are the upcoming re-entry milestones in CST:

11:20:14 p.m. – Crew Module Entry Interface
11:35:28 p.m. – Altitude 40,000 feet
11:36:02 p.m. – Forward Bay Cover Chute Deploy
11:36:06 p.m. – Drogue Chute Deploy
11:37:26 p.m. – Main Chute Deploy
11:39:41 p.m. – Splashdown

Earth’s atmosphere initially will slow the spacecraft to 325 mph, then the parachutes will slow Orion to a safe splashdown speed of 20 mph or less as it descends through Earth’s atmosphere. Parachute deployment begins at an altitude of about five miles with three small parachutes pulling the forward bay covers away. Once the forward bay cover separates, two drogue parachutes will slow and stabilize the crew module for main parachute deployment. At an altitude of 9,500 feet and a spacecraft speed of 130 mph, three pilot parachutes will lift and deploy the main parachutes to slow Orion to a landing speed that ensures astronaut safety for crewed missions.

When Orion splashes down, the crew module uprighting system, also known as CMUS, deploys a series of five bright-orange helium-filled bags on the top of the capsule to upright the capsule in the event it stabilizes upside down. The system will deploy regardless of the landing position of the capsule, and it takes less than four minutes to upright the capsule if needed. The capsule must be upright for crew module communication systems to operate correctly and to help protect the health of the crew members inside on future missions.

Teams in Mission Control Houston conducted spacecraft system checks ahead of Orion’s planned splashdown on Dec. 11, while the Exploration Ground Systems recovery team made its way toward the landing area off the Baja Coast near Guadalupe Island.

Flight controllers activated the crew module reaction control system heater and conducted a hot-fire test for each thruster as planned. The five pulses for each thruster lasted 75 milliseconds each, and were conducted in opposing pairs to minimize attitude changes during the test. Thrust for the crew module propulsion system is generated from 12 monopropellant MR-104G engines. These engines are a variant of MR-104 thrusters, which have been used in other NASA spacecraft, including the interplanetary Voyagers 1 and 2.

Approximately 12,100 pounds of propellant have been used, which is 240 pounds less than estimated prelaunch, and leaves a margin of 2,230 pounds over what is planned for use, 324 pounds more than prelaunch expectations.

On its way back to Earth, Orion will pass through a period of intense radiation as it travels through the Van Allen Belts that contain space radiation trapped around Earth by the planet’s magnetosphere. Outside the protection of Earth’s magnetic field, the deep space radiation environment includes energetic particles produced by the Sun during solar flares as well as particles from cosmic rays that come from outside the galaxy.

Orion was designed from the start to ensure reliability of essential spacecraft systems during potential radiation events and can become a makeshift storm shelter when crew members use shielding materials to form a barrier against solar energetic particles.

For the uncrewed Artemis I mission, Orion is carrying several instruments and experiments to better understand the environment future crews will experience and provide valuable information for engineers developing additional protective measures. There are active sensors connected to power that can send readings to Earth during the flight, as well as passive detectors that require no power source to collect radiation dose information that will be analyzed after the flight.

Commander Moonikin Campos is equipped with two radiation sensors, as well as a sensor under the headrest and another behind the seat to record acceleration and vibration throughout the mission. The seat is positioned in a recumbent, or laid-back, position with elevated feet, which will help maintain blood flow to the head for crew members on future missions during ascent and entry. The position also reduces the chance of injury by allowing the head and feet to be held securely during launch and landing, and by distributing forces across the entire torso during high acceleration and deceleration periods, such as splashdown.

A crew is expected to experience two-and-a-half times the force of gravity during ascent and four times the force of gravity at two different points during the planned reentry profile. Engineers will compare Artemis I flight data with previous ground-based vibration tests with the same manikin, and human subjects, to correlate performance prior to Artemis II.

In addition to the sensors on the manikin and seat, Campos is wearing a first-generation Orion Crew Survival System pressure suit – a spacesuit astronauts will wear during launch, entry, and other dynamic phases of their missions. Even though it’s primarily designed for launch and reentry, the Orion suit can keep astronauts alive if Orion were to lose cabin pressure during the journey out to the Moon, while adjusting orbits in Gateway, or on the way back home. Astronauts could survive inside the suit for up to six days as they make their way back to Earth. The outer cover layer is orange to make crew members easily visible in the ocean should they ever need to exit Orion without the assistance of recovery personnel, and the suit is equipped with several features for fit and function.

Shortly before 2:30 p.m. CST on Dec. 9, Orion was traveling 171,500 miles from Earth and 214,200 miles from the Moon, cruising at 2,100 mph.

Watch the latest episode of Artemis All Access for a glimpse at the latest mission status and an inside look ahead of splashdown.

Live splashdown coverage will begin at 11 a.m. EST on Sunday, Dec. 11. Splashdown is scheduled at 12:39 p.m., and coverage will continue through Orion’s handover from Mission Control in Houston to Exploration Ground Systems recovery teams in the Pacific Ocean. Coverage will be live on NASA TV, the agency’s website, and the NASA app.

On flight day 23 of NASA’s Artemis I mission, the Orion spacecraft continues making the return trip to Earth, capturing photos and video along the way.

“At present, we are on track to have a fully successful mission with some bonus objectives that we’ve achieved along the way,” said Mike Sarafin, Artemis I mission manager. “On entry day, we will realize our priority one objective, which is to demonstrate the vehicle at lunar re-entry conditions, as well as our priority three objective, which is to retrieve the spacecraft.”

The mission management team met with the entry flight director and NASA recovery director as the planned splashdown of Orion Sunday, Dec. 11 is now about 72 hours away. They evaluated the weather and decided on a landing site in the Pacific Ocean near Guadalupe Island, south of the primary landing area. Watch the reentry preview briefing for more details.

Later tonight, flight controllers will conduct a final survey of Orion’s crew module and service module using cameras on each of the spacecraft’s four solar arrays. During the crew module inspection, flight controllers will be looking at the back shell made up of 1,300 thermal protection system tiles and will protect the spacecraft from the cold of space and the extreme heat of re-entry.

Just before re-entry, the crew module and service module will separate and only the crew module will return to Earth while the service module burns up in Earth’s atmosphere upon re-entry over the Pacific Ocean. The Artemis I trajectory is designed to ensure any remaining parts do not pose a hazard to land, people, or shipping lanes.

After separating from the service module, the crew module will prepare to perform a skip entry technique that enables the spacecraft to accurately and consistently splash down at the selected landing site. Orion will dip into the upper part of Earth’s atmosphere and use that atmosphere, along with the lift of the capsule, to skip back out of the atmosphere, then reenter for final descent under parachutes and splash down. This technique will allow a safe re-entry for future Artemis missions regardless of when and where they return from the Moon.

Earth’s atmosphere initially will slow the spacecraft to 325 mph, then the parachutes will slow Orion to a splashdown speed in about 10 minutes as it descends through Earth’s atmosphere. Parachute deployment begins at an altitude of about five miles with three small parachutes pulling the forward bay covers away. Once the forward bay cover separates, two drogue parachutes will slow and stabilize the crew module for main parachute deployment. At an altitude of 9,500 feet and a spacecraft speed of 130 mph, three pilot parachutes will lift and deploy the main parachutes. Those 116-foot-diameter parachutes of nylon broadcloth, or “silk,” will slow the Orion crew module to a splashdown speed of 20 mph or less.

The parachute system includes 11 parachutes made of 36,000 square feet of canopy material. The canopy is attached to the top of the spacecraft with more than 13 miles of Kevlar lines that are deployed in series using cannon-like mortars and pyrotechnic thrusters and bolt cutters. Learn more about Orion’s parachute system in the Artemis I reference guide.

NASA TV coverage of Artemis I’s return to Earth begins at 11 a.m. EST on Sunday, Dec. 11. The Orion spacecraft is scheduled to splash down in the Pacific Ocean at 12:40 p.m. near Guadalupe Island.

Just before 6:00 p.m. CST on Dec. 8, Orion was traveling 207,200 miles from Earth and 180,400 miles from the Moon, cruising at 1,415 mph.

Images are available 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.

 

Orion continues its journey back to Earth on day 22 of the 25.5-day Artemis I mission with flight controllers and engineers continuing to test the spacecraft and its systems in preparation for future flights with humans aboard.

Engineers conducted the second part of the propellant tank slosh development flight test, called propellant slosh, which is scheduled during quiescent, or less active, parts of the mission. 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 test calls for flight controllers to fire the reaction control system thrusters when propellant tanks are filled to different levels. The reaction control thrusters used are located on the sides of the service module 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 Engineers measure the effect the propellant sloshing has on spacecraft trajectory and orientation as Orion moves through space.

The test was first performed after the outbound flyby burn, and now again after the return flyby burn, to compare data at points in the mission with different levels of propellant onboard. Approximately 12,060 pounds of propellant has been used, which is 215 pounds less than estimated prelaunch, and leaves a margin of 2,185 pounds over what is planned for use, 275 pounds more than prelaunch expectations. The first prop slosh test objective was completed on day eight of the mission as it prepared to enter the distant retrograde orbit.

A few key milestones for Orion remain, including the entry system check outs and propulsion system leak checks on mission days 24 and 25, respectively.

Orion will travel at around 25,000 mph while reentering Earth’s atmosphere, testing the world’s largest ablative heat shield by reaching temperatures up to 5,000 degrees Fahrenheit – approximately half the heat of the sun. The heat shield is located at the bottom of the Orion capsule, measuring 16.5 feet in diameter, and sheds intense heat away from the crew module as Orion returns to Earth. The outer surface of the heat shield is made of 186 billets, or blocks, of an ablative material called Avcoat, a reformulated version of the material used on the Apollo capsules. During descent, the Avcoat ablates, or burns off in a controlled fashion, transporting heat away from Orion. Learn more about Orion’s heat shield in the Artemis I reference guide.

On Thursday, Dec. 8 at 5 p.m. EST, NASA will host a briefing to preview Orion’s return scheduled for Sunday, Dec. 11 and to discuss how the recovery teams are preparing for entry and splashdown. The briefing will be live on NASA TV, the agency’s website, and the NASA app.

Watch the latest episode of Artemis All Access for a look back at recent mission accomplishments and a preview of splashdown, including parachute information.

Just after 3 p.m. CST on Dec. 7, Orion was traveling 234,100 miles from Earth and 127,700 miles from the Moon, cruising at 820 miles per hour.

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.

 

 

Orion exited the lunar sphere of gravitational influence Tuesday, Dec. 6, at 1:29 a.m. CST for the last time on the Artemis I mission less than a day after completing the return powered flyby burn that put the spacecraft on course for splashdown Sunday, Dec. 11. Earth’s force of gravity is now the primary gravitational force acting on the spacecraft. 

Orion successfully performed the fourth return trajectory correction burn at 4:43 a.m. using the reaction control system thrusters. The burn lasted 5.7 seconds and changed the velocity of the spacecraft by 0.6 feet per second.

Flight controllers used Orion’s cameras to inspect the crew module thermal protection system and European Service Module, the second of three planned external spacecraft inspections. Teams conducted this survey early in the mission to provide detailed images of the spacecraft’s external surfaces after it had flown through the portion of Earth’s orbit containing the majority of space debris, and teams reported no concerns after reviewing the imagery. This second inspection during the return phase is being used to assess the overall condition of the spacecraft several days before re-entry.  

During both inspections, the Integrated Communications Officer, or INCO, commanded cameras on the four solar array wings to take a series of still images. Engineers and flight controllers at NASA’s Johnson Space Center in Houston will review the imagery over the coming days. A final photographic survey will be conducted Friday as Orion continues its journey home. 

Teams responsible for recovering Orion after its splashdown are continuing preparations ahead of the Dec. 11 splashdown off the coast of California. The mission management team will determine the landing site location Thursday, Dec. 8. Listen to NASA’s Artemis I recovery director, Melissa Jones, talk about what it takes to fetch the Orion spacecraft from the Pacific Ocean at the end of the mission on “Houston We Have a Podcast.” 

Just after 5:30 p.m. on Dec. 6 , Orion was traveling 244,000 miles from Earth and about 79,000 miles from the Moon, cruising at 500 miles per hour. 

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.