A half-century after the Apollo programme came to an end, NASA is still at least three years away from attempting to send men back to the moon's surface because much of the required technology is still in the design phase.
But with the inaugural flight of its next-generation megarocket, the Space Launch System (SLS), and the Orion crew capsule it is intended to transport on Monday in Florida, NASA hopes to make a significant advancement in its revived lunar aspirations.
The unmanned capsule will go around the moon and return to Earth on a six-week test voyage named Artemis I when the combined SLS-Orion spacecraft lifts off from Cape Canaveral's Kennedy Space Center.
After the mission's flight readiness assessment, NASA Associate Administrator Bob Cabana, a former space shuttle commander and pilot, said at a press conference late on Monday, "We are go for launch."
Before it is certified suitable to transport passengers, the voyage aims to put the SLS vehicle—which is thought to be the most complicated and potent rocketship in the world—through a rigorous stress test of its systems during an actual flight.
The SLS is the largest new vertical launch system NASA has created since the Saturn V rockets used in the 1960s and 1970s for the Apollo lunar mission.
The SLS-Orion spacecraft has so far cost NASA at least $37 billion, which includes design, building, testing, and ground facilities. Its development has taken more than ten years and has been plagued by years of delays and billion-dollar cost overruns. Bill Nelson, the administrator of NASA, has referred to the Artemis programme as a "economic engine," saying that it, for instance, supported 70,000 American jobs and generated $14 billion in revenue in 2019 alone.
The NASA budget has been progressively boosted by Congress to accommodate money for Artemis. The main SLS and Orion contractors, Boeing Co. and Lockheed Martin Corp., are among those who stand to gain the most financially.
The Artemis program of NASA seeks to send astronauts back to the moon as early as 2025 and to build a permanent lunar colony as a stepping stone to even more ambitious future missions transporting people to Mars. Artemis is named after the goddess, who was Apollo's twin sister in Greek mythology.
According to Lori Garver, who served as NASA's deputy administrator throughout the development of the rocket, "Even with this delay and higher money, it is improbable that NASA will be landing humans on the moon by 2025, but if all goes well, it might happen in the next few years."
The only spaceflights to date to land people on the moon were the six Apollo missions from 1969 to 1972, with twelve astronauts. They all traveled to the areas around the lunar equator.
The first woman and first person of color to step foot on the moon will be sent to one of the 13 prospective landing sites NASA disclosed last Friday around the lunar south pole.
The launch of the SLS-Orion is an essential first step. After weeks of last-minute preparations and ground trials, the 322-foot (98-meter) tall spaceship was carefully towed to Launch Pad 39B.
The four primary SLS engines and its solid rocket boosters are scheduled to fire at 8:33 a.m. EDT (12:33 GMT) on Monday, barring last-minute technical issues or poor weather. NASA has designated September 2 and September 5 as backup launch dates if the countdown is postponed past the two-hour window intended for liftoff.
Orion's thrusters are scheduled to fire after separation from the rocket's upper stage more than 2,300 miles (3,700 km) from Earth, setting the capsule on its outbound course and bringing it as close to the lunar surface as possible before traveling about 40,000 miles (64,400 km) beyond the moon and returning to Earth. The planned splashdown in the Pacific Ocean is scheduled for October 10.
A simulated crew of three—one male and two female mannequins—will be aboard Orion, and they will be equipped with sensors to gauge the radiation exposure that a crew of real astronauts would experience.
If Artemis I is successful, it might lead to the first crewed SLS-Orion mission, an out-and-back lunar voyage called Artemis II, as early as 2024.
With the integration of the SLS-Orion and spacecraft created and launched by businessman Elon Musk's firm SpaceX, Artemis III will be considerably more complicated. There are yet-to-be-built parts like an orbiting fuel store and space tankers, as well as SpaceX's heavy-duty Starship launch and lunar landing vehicle. Even brand-new moonwalking suits still need to be created.
Two astronauts would be transported to the moon's surface for over a week by a four-person Orion crew that would dock in orbit with a SpaceX lander.