One year ago, NASA’s Orion spacecraft concluded its maiden voyage around the Moon, a journey of 1.4 million miles ending with a gentle splashdown in the Pacific Ocean. Artemis I was a resounding success for NASA’s ambitious lunar exploration program, marking the first flight of the Space Launch System rocket, and carrying the most capable Orion spacecraft to date. Yet even as the capsule lay cradled in the well deck of the USS Portland, after more than 25 days away from Earth, its journey was far from complete. With Artemis II on the horizon, Orion’s career as humanity’s next deep space crew vehicle is just beginning. This first crewed mission of the Artemis program will see Orion fly equipped with numerous upgrades, and lay the foundation for its groundbreaking, long-term reuse campaign.
The Orion spacecraft, today a cornerstone of the Artemis program, has a long and winding history. Originally intended to serve as the Crew Exploration Vehicle for NASA’s defunct Constellation program, the vehicle was temporarily shelved as priorities realigned. Under the Obama administration, Orion was resurrected first as a crew transportation system for the International Space Station, before finally being reinstated as a deep space exploration vehicle. Though it began life as a domestic product built by Lockheed Martin, Orion has come to embody the international aspirations of the Artemis program, with its service module built by Airbus Defense and Space on contract with the European Space Agency. On Artemis I, the Orion spacecraft proudly bore the insignias of both NASA and ESA.
The Orion spacecraft comprises three main components. The cone-shaped Crew Module provides habitable space for four astronauts during Artemis missions, a command center for the vehicle, and protection during reentry into the Earth’s atmosphere, as well as parachutes and recovery systems for a safe splashdown on Earth. The cylindrical Service Module provides power, propulsion, and life support supplies, and sports four large, robotically actuated solar panels. Finally, a Launch Abort System tower shields the Crew Module during launch, and contains high-power rockets that can pull the spacecraft away from the SLS rocket in the event of an emergency.
Artemis I marked the first integrated flight test of all three components on a lunar mission, with each component performing as intended. However, the Orion spacecraft on this flight, consisting of Crew Module CM-002 and European Service Module ESM-1, was only an interim version of the vehicle, and was not fully outfitted as it will be for future missions. The spacecraft’s life support systems included partial control of the atmosphere in the Crew Module, as well as the potable water supply which will serve future astronauts. Notably, the spacecraft did not feature an air revitalization system, which is used to refresh the breathable air in the cabin. Most crew equipment, such as controls and displays, were also absent on this flight, and the Crew Module only contained one seat (occupied by a well-instrumented mannequin). Additionally, the spacecraft did not include a docking system for connecting to other spacecraft, and its Launch Abort System was not completely active.
Artemis II will feature a more completely outfitted Orion spacecraft, composed of CM-003 and ESM-2. As Orion’s first crewed flight, the vehicle will necessarily include the complete suite of life support systems required to keep its four astronauts happy and healthy during their ten-day mission. This includes full pressure control and air revitalization systems for the cabin, fire detection and suppression systems, and a toilet for waste management. All of the spacecraft’s controls, displays, and seats will be present, as will an exercise device for the crew to demonstrate during their flight. Although docking hardware will not be included until Artemis III, the crew of Artemis II will practice maneuvering Orion in close proximity to the SLS upper stage after separation. Additionally, the Launch Abort System for Artemis II will be fully active and ready to protect the crew at a moment’s notice during ascent.
The upgrades to the Artemis II Orion spacecraft will also demonstrate a critical capability for the program: reuse. The production line for the Orion Crew Module is intended to utilize two kinds of reuse, described as either “light” or “heavy.” Light reuse involves removing the avionics, life support, and crew systems from one spacecraft and installing them into a future vehicle to save on production costs. Heavy reuse, meanwhile, would make use of the whole, intact pressure vessel – the sealed compartment where astronauts can live and breathe – along with all of its interior components. NASA plans from 2020 indicate that heavy reuse includes the components targeted by light reuse. Light reuse is expected to be performed more frequently, with Lockheed Martin planning to use each set of spacecraft systems on up to 5 flights. Heavy reuse, meanwhile, is expected to only be possible once for a given spacecraft, allowing them to fly twice before continuing on the light reuse pathway.
The Artemis II spacecraft represents a special case. A few components from the Artemis I vehicle will be reused for Artemis II, mainly including avionics and power systems, such as sensors and antennas. Because very few life support and crew systems were present on the Artemis I spacecraft, this does not meet the full criteria for “light” reuse, but it nevertheless demonstrates an important capability for future missions. Notably, however, that reuse caused the schedules of these two flights to be deeply intertwined. Delays to the Artemis II mission were primarily due to its reliance on components from the similarly-delayed Artemis I. To mitigate this issue, future reuse will only occur for missions which do not immediately follow one another, and Artemis III will use a new vehicle. Meanwhile, with Orion’s recovery at the end of Artemis I last year, the reuse process could finally begin, putting Artemis II on the path to flight.
This past November, the integrated Orion spacecraft for Artemis II was successfully powered on for the first time, representing a major milestone towards its highly-anticipated flight. Equipped with flight-proven avionics, the Artemis II spacecraft will carry the first humans to the moon since 1972: Commander Reid Wiseman, Pilot Victor Glover, and Mission Specialists Christina Koch and Jeremy Hansen. And yet, even the safe return of these brave explorers to Earth will not mark the end of the journey for this vehicle. Components from CM-003 are expected to fly several times over again, helping a new generation of astronauts to explore well into the next decade.