Exactly How Orion Re-entered Earth’s Atmosphere & Was Recovered
Orion has been traveling through space since November 16th when it was successfully launched on top of the Space Launch System. After breaking multiple records held previously by Apollo and completing a host of different tests, the spacecraft faced its biggest challenge yet this afternoon around 12:00 pm EST. Here Orion entered Earth’s atmosphere traveling around 25,000 mph or approximately 40,200 kph.
During the maneuver, the spacecraft performed a skip entry technique followed by extreme temperatures, speed, and various forces, just to name a few. Thankfully, the entire process was a major success and an important milestone for NASA as they work toward returning humans to the surface of the Moon. Here I will go more in-depth into today’s milestone, specific re-entry and splashdown details, what to expect in the future, and more.
Reentry, Splashdown, & Recovery
Just hours ago NASA tweeted saying, “Splashdown. After traveling 1.4 million miles through space, orbiting the Moon, and collecting data that will prepare us to send astronauts on future #Artemis missions, the @NASA_Orion spacecraft is home.” Over the last couple of days, the agency was very busy in preparation for this moment. For example, the fifth return trajectory correction burn occurred at 2:32 p.m. CST, Saturday, Dec. 10. During the burn the auxiliary engines fired for 8 seconds, accelerating the spacecraft by 3.4 mph (5 feet per second) to ensure Orion was on course for splashdown. Next, the sixth and final return trajectory correction burn occurred at 6:20 a.m. this morning. Similar to the previous burn, the auxiliary engines fired for 8 seconds, accelerating the spacecraft by .68 mph (.99 feet per second).
From here, the Orion spacecraft separated from its service module at 11:00 a.m. CST in preparation for the crew module’s return to Earth. The service module burned up harmlessly in Earth’s atmosphere upon re-entry over the Pacific Ocean. The Artemis I trajectory is designed to ensure any remaining parts don’t pose a hazard to land, people, or shipping lanes. Next, the crew module performed 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. 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.
As the capsule got closer, incredible views of the Earth were provided by onboard cameras. As Orion continued through the atmosphere, it was initially slowed to 325 mph. We then watched as drogue shutes were deployed before the three main parachutes. These slowed Orion to a safe splashdown speed of around 20 mph or 32 kph. Specifically, parachute deployment began at an altitude of about five miles with three small parachutes pulling the forward bay covers away. Once the forward bay cover separated, the two drogue parachutes slowed and stabilized the crew module for main parachute deployment. At an altitude of 9,500 feet or around 2895 meters and a spacecraft speed of 130 mph or 209 kpm, the three pilot parachutes lifted and deployed the main parachutes to slow Orion to a landing speed. Finally, from both cameras on board the spacecraft as well as various recovery ships, we watched the Orion Spacecraft successfully splash down right off the coast of Baja, California.
After splashing down, the crew module uprighting system, also known as CMUS, deployed 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. While this was not the case in this mission, the system deploys regardless of the landing position of the capsule, and it takes less than four minutes to upright the capsule if needed.
Finally, at the direction of the NASA recovery director, Navy divers and other team members in several inflatable boats approached the spacecraft. Once Orion was ready to be pulled into the ship’s well deck at the waterline, the divers attached a cable, called the winch line, and pulled the spacecraft into the ship with four additional tending lines to attach points on the crew module. The winch then pulled Orion into a specially designed cradle inside the ship’s well deck using the other lines to control the motion of the spacecraft. Once Orion was positioned above the cradle assembly, technicians drained the well deck and secured it on the cradle. Altogether this marked a major milestone for the agency and an important first step toward returning humans to the surface of the Moon.
What’s Next?
Now that we know more about today’s recovery, we can take a closer look at some of the overall mission results and what to expect in the future. In total Orion was in space for around 25 and a half days. During this period, NASA reported that the spacecraft performed much better than expected. So much so that the agency was able to complete a host of additional tests during its journey. Not to mention, approximately 12,100 pounds of propellant have been used, which is 240 pounds less than estimated prelaunch, which left a margin of 2,230 pounds over what was planned for use, 324 pounds more than prelaunch expectations.
Some especially important data that will be revealed in the coming days has to do with Orion’s passenger. While this was an uncrewed mission and no humans were on board, a manikin named Commander Moonikin Campos was. 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. 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 terms of the future Artemis missions, the completion of Artemis 1 is a major step and a promising sign as NASA already prepares for the next launches. For example, just yesterday NASA tweeted mentioning, “The @NASA_SLS core stage engine section for @NASA’s Artemis III mission has now arrived in the turn basin at @NASAKennedy.” This included a short video of the engine section arriving via water transport. With Artemis 1 a success, NASA now has the important job of gathering all the necessary data from this launch and applying it to Artemis II. The Artemis II flight test will be NASA’s first mission with crew and will pave the way to land humans on the Moon apart of Artemis III. Building on those early missions, NASA’s Artemis program will return humans to the Moon for long-term exploration and future missions to worlds beyond, including Mars. “The unique Artemis II mission profile will build upon the uncrewed Artemis I flight test by demonstrating a broad range of SLS and Orion capabilities needed on deep space missions,” said Mike Sarafin, Artemis mission manager. “This mission will prove Orion’s critical life support systems are ready to sustain our astronauts on longer duration missions ahead and allow the crew to practice operations essential to the success of Artemis III.”
The initial launch will be similar to Artemis I as SLS lofts Orion into space, and then jettisons the boosters, service module panels, and launch abort system, before the core stage engines shut down and the core stage separates from the upper stage and the spacecraft. With crew aboard this mission, Orion and the upper stage, called the interim cryogenic propulsion stage (ICPS), will then orbit Earth twice to ensure Orion’s systems are working as expected while still close to home. The spacecraft will first reach an initial orbit, flying in the shape of an ellipse, at an altitude of about 115 by 1,800 miles. The orbit will last a little over 90 minutes and will include the first firing of the ICPS to maintain Orion’s path. After the first orbit, the ICPS will raise Orion to a high-Earth orbit. This maneuver will enable the spacecraft to build up enough speed for the eventual push toward the Moon. The second, larger orbit will take approximately 42 hours with Orion flying in an ellipse between about 235 and 68,000 miles above Earth. For perspective, the International Space Station flies a nearly circular Earth orbit about 250 miles above our planet.
The Artemis II crew will travel 4,600 miles beyond the far side of the Moon. From this vantage point, they will be able to see the Earth and the Moon from Orion’s windows, with the Moon close in the foreground and the Earth nearly a quarter-million miles in the background. With a return trip of about four days, the mission is expected to last just over 10 days. Instead of requiring propulsion on the return, this fuel-efficient trajectory harnesses the Earth-Moon gravity field, ensuring that—after its trip around the far side of the Moon—Orion will be pulled back naturally by Earth’s gravity for the free return portion of the mission. All of which is NASA’s next big mission aiming for a launch in 2024.
Conclusion
Earlier today we watched a historic ending to the Artemis I mission. Orion managed to successfully enter the Earth’s atmosphere, perform the skip entry technique, and splashdown right off the coast of Baja, California. With this mission complete, NASA will now shift its focus to the recent mission data and the upcoming launch of humans with Artemis II and III. We will have to wait and see how it progresses and the impact it has on the space industry.
