NASA’s most powerful rocket is nearly ready to send an uncrewed Orion capsule on a 42-day journey to the Moon and back, but this deceptively straightforward plan involves a ton of moving parts—including a harrowing 5,000-degree reentry through Earth’s atmosphere. Here’s what you can expect from this historic mission, called Artemis 1, as NASA officially ushers in the Artemis era.
When will NASA’s SLS launch?
NASA’s Space Launch System (SLS) is scheduled to depart the Vehicle Assembly Building at Kennedy Space Center in Florida on August 18 to begin its short trek to Launch Complex 39B. Should all go according to plan, SLS, along with an uncrewed Orion capsule placed atop, will launch on August 29 during a two-hour window that starts at 8:33 a.m. ET. Backup windows are also in place for September 2 and September 5.
The inaugural launch will send the $20.4 billion Orion on a 42-day journey to the Moon and back, in a mission that will require the capsule to travel a total distance of 1.3 million miles (2.1 million kilometers). Orion will enter into a lunar orbit and hang out for a few weeks before returning home. Splashdown in the Pacific Ocean is expected on October 10—assuming Orion survives reentry. Its heat shield will have to endure temperatures reaching 5,000 degrees Fahrenheit (2,760 degrees Celsius), as Orion is expected to hit the atmosphere at speeds reaching 25,000 miles per hour (40,000 kilometers per hour).
What’s the purpose of the Artemis 1 mission?
Artemis 1 is a test mission. It’ll be the first integrated trial of SLS and Orion, the latter of which was sent to space on a trial mission in 2014. As for SLS, this will be its first launch.
“This is a mission that truly will do what hasn’t been done and learn what isn’t known,” Mike Sarafin, Artemis 1 mission manager at NASA, said in a statement. “It will blaze a trail that people will follow on the next Orion flight, pushing the edges of the envelope to prepare for that mission.”
Sarafin is referring to Artemis 2, in which a crewed Orion capsule will attempt the same mission. Both Artemis 1 and 2 are precursor missions for the real deal, Artemis 3, in which NASA will attempt to land a man and woman on the lunar surface. Artemis 2 is currently scheduled for late 2024, while Artemis 3 could happen in the following year. The Artemis program as a whole is NASA’s effort to return humans to the lunar environment, but unlike Apollo, these missions are designed to keep us there. To that end, NASA and its international partners are planning to build a lunar space station, called Gateway, to support activities both on and around the Moon.
Artemis seeks a sustainable and permanent return to the Moon, but in reality it’s about something far grander. “Our sights are not set on the Moon,” Reid Wiseman, chief astronaut at NASA Johnson, told reporters at a briefing on August 5. “Our sights are clearly set on Mars.” Indeed, the technologies and experiences gained during Artemis will prepare NASA and its partners for crewed treks to the Red Planet, which could happen in the late 2030s or early 2040s. For all this to happen, however, NASA needs Artemis 1 to succeed.
What is the role of SLS in Artemis 1?
A core technology for the Artemis program is the $23.8 billion Space Launch System, which NASA administrator Bill Nelson described as the “only rocket that can take humans to the Moon.” Blasting off with 8.8 million pounds of thrust, it’s the most powerful rocket ever built. The super heavy-lift launch vehicle will be more powerful than the Apollo-era Saturn V (7.5 million pounds of thrust), the system that launched the Space Shuttle (7.8 million pounds of thrust), and SpaceX’s Falcon Heavy (5 million pounds of thrust). SpaceX’s upcoming Starship, however, will blow it out of the water with 17 million pounds of thrust at first launch. For Artemis 1, SLS’s job will be to deliver Orion to Earth orbit, from where the capsule can commence on its journey to the Moon.
At launch, the 322-foot-tall (98-meter) rocket will weigh nearly 6 million pounds. For Artemis 1, NASA will use the Block 1 variant of SLS, which features the core stage (equipped with four hydrogen-fueled RS-25D engines), a pair of five-segment solid rocket boosters attached to the side, and the Orion capsule on top. The Block 1 crew configuration will be capable of lifting over 27 tons to space. A key moment of the launch will happen at the 90-second mark, when SLS reaches max q—the point during a launch when rockets are exposed to the greatest aerodynamic stress.
The 177-foot-tall (54-meter) side boosters will fire for nearly three minutes, explained John Honeycutt, Space Launch System program manager at NASA’s Marshall Space Flight Center, during the August 3 press briefing. The boosters will then jettison from the core stage, fall into the Atlantic, and sink to the ocean floor. NASA will make no attempt to recover the boosters. The core stage will shut down roughly eight minutes after launch, but not before jettisoning the service module panels and launch abort system. The Orion crew capsule will then separate from the rocket while still attached to the cryogenic propulsion stage (ICPS) that will power the capsule to the Moon.
What happens when Orion reaches the Moon?
After Orion completes one full orbit of Earth and deploys its solar arrays, ICPS will assist with a perigee raise maneuver followed by a 20-minute trans-lunar injection, sending Orion on a trajectory that will allow it to be captured by the Moon’s gravity. Orion will separate from the ICPS roughly two hours after launch, after which time the ICPS will deploy 10 cubesats that are likewise headed to the Moon.
Orion, now on its own, will then get its power from a service module provided by the European Space Agency. The journey to the Moon will take around four days, during which time ground teams will carefully track the capsule’s performance. Once at its destination, the service module will perform a critical lunar gravity assist maneuver, allowing the craft to enter into a distant retrograde orbit. Orion’s closest approach will see the spacecraft come to within approximately 60 miles (97 km) of the lunar surface. We’ll get some incredible images of the Moon during that close flyby, in what is likely to be one of the highlights of the mission.
Parked in this elongated retrograde orbit, the capsule will travel some 40,000 miles (64,000 km) past the Moon—a distance that’s “30,000 miles (48,000 kilometers) farther than the previous record set during Apollo 13 and the farthest in space any spacecraft built for humans has flown,” according to NASA.
Orion will cruise behind the Moon, during which time communication with ground controllers will temporarily be lost (this will happen each time Orion ventures behind the Moon, as its orbit lies in the same plane as Earth and the Moon).
Will anything be inside Orion?
Artemis 1 doesn’t involve a human crew, but Orion won’t be empty. Riding inside will be three manikins, named Campos, Helga, and Zohar. Together, these fake crew members will demonstrate what actual astronauts will have to endure during similar missions.
NASA’s Campos will wear a standard Orion spacesuit and measure vibrations, g-forces, and radiation throughout the 42-day journey. On the topic of radiation, and unlike the International Space Station, Orion will travel beyond the protective boundary of the Van Allen Belts—conglomerations of high-energy particles positioned between the Earth and Moon. The Moonikin will be strapped to a new energy dampening system known as the Crew Impact Attenuation System.
Helga and Zohar—analogues of adult women—will take part in the MARE experiment designed by the German Aerospace Center. Zohar will be wearing an AstroRad radiation vest designed by Lockheed Martin and Israeli startup StemRad, while her companion, Helga, will not wear the vest and instead serve as the control.
Women are more vulnerable to the risks posed by space radiation, giving rise to the manikin experiments, as Bhavya Lal, associate administrator for technology, policy, and strategy at NASA, explained during the August 3 press briefing. In deep space, humans will be exposed to more energetic particles, including those coming from the Sun’s solar flares and from outside the galaxy. Radiation presents “a top environmental challenge beyond” low Earth orbit, Lal said, hence the importance of the manikin trio.
Does Artemis 1 involve other payloads?
Yes. As already mentioned, the Orion stage adapter will launch 10 cubesats shortly after launch. Each satellite will head to lunar orbit on its own, where they’ll conduct various science and technology missions.
NASA’s Lunar IceCube satellite will use a spectrometer to study lunar ice, while the agency’s BioSentinel probe will carry yeast to measure the effect of radiation on living organisms over a long duration and beyond the protective Van Allen Belts. NASA says BioSentinel “will conduct the first study of the biological response to space radiation” outside of low Earth orbit in nearly 50 years. The remaining eight cubesats, each no larger than a suitcase, will perform equally important tasks in the lunar environment.
What will happen when Orion comes back to Earth?
After several weeks spent in lunar orbit, Orion will perform a return trajectory correction and head back home. “For its return trip to Earth, Orion will get another gravity assist from the Moon as it does a second close flyby, firing engines at precisely the right time to harness the Moon’s gravity and accelerate back toward Earth, setting itself on a trajectory to re-enter our planet’s atmosphere,” the space agency said.
The trek home will take four days. Once at Earth and just prior to reentry, Orion will jettison ESA’s service module. Moving at 6.8 miles per second (11 kilometers per second), the capsule will slam into our planet’s atmosphere, during which time it will set a record for the fastest reentry of a crew-rated space vehicle. Orion’s heat shield will have to take the brunt of this abuse, as Orion decelerates to speeds of 300 miles per hour (480 km/hr).
At the press briefing on August 3, Nelson said Orion will return from the Moon at Mach 32, but that a spacecraft returning from a future Mars mission is likely reach Mach 36—or a daunting 27,400 miles per hour (44,099 km/hr). “We’ve got a lot of testing to do,” he said, saying Orion is equipped with “the most advanced heat shield ever.” He reminded reporters that “this is a test flight—it’s just the beginning.”
A series of parachutes will slow the craft even further, allowing for a gentle splashdown in the Pacific Ocean off the coast of San Diego. The Navy, along with teams from NASA’s Exploration Ground Systems, will then inspect and recover the vehicle using small boats and the amphibious transport dock ship USS John P. Murtha.
As for the service module, it will burn up on reentry and “fall as dust” onto the Pacific Ocean, according to Philippe Deloo, Orion European Service Module program manager at ESA.
What are NASA’s key objectives for Artemis 1?
During the August 3 press briefing, Sarafin listed four key objectives for the debut Artemis mission.
First, the space agency needs to confirm that Orion’s heat shield will be capable of withstanding atmospheric reentry. As NASA says in its press kit, “no aerodynamic or aerothermal test facility can recreate the conditions the heat shield will experience returning at lunar return speeds.” Indeed, the expected heat, at 5,000 degrees Fahrenheit, is half the temperature of our Sun.
The space agency will also use Artemis 1 to demonstrate its operations and facilities throughout the entire mission, such as “NASA’s launch facilities and ground-based infrastructure, SLS operations, including separation events during ascent, Orion operations in space, and recovery procedures.”
A third and obvious objective will be to retrieve Orion after splashdown. NASA will return the spacecraft to Kennedy Space Center upon the conclusion of the mission, where it will be subject to a detailed inspection. Teams will “gather data and test the integrity of the vehicle” to better understand the “engineering uncertainties” involved, Sarafin said. Ground teams will also retrieve the troves of data that will be gathered during the flight, including the data gathered by the three manikins. Orion’s parachute system will also be retrieved and analyzed.
NASA’s fourth objective is to succeed with its side plans, such as certifying the capsule’s optical navigation system, deploying the 10 cubesats, and gathering imagery. At the August 5 briefing, Rick LaBrode, NASA’s lead Artemis 1 flight director, said NASA will make extra efforts at public outreach, with at least one media event or release scheduled for each day of the mission. LaBrode added that NASA will attempt to capture an Earthrise photo as Orion returns from the back side of the Moon, similar to the famous photos captured during the Apollo era.
It’s going to be an incredible 42-day journey, as NASA and partners embark on an entirely new chapter in the history of space exploration. It all starts—fingers crossed—on August 29.
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