By Joey Roulette and Steve Gorman
CAPE CANAVERAL, Fla. (Reuters) – NASA’s next-generation colossal rocket prepared for its long-awaited first launch on Monday on a six-week uncrewed test flight around the moon and back, marking the first mission of the space agency’s Artemis program, successor of Apollo.
The 32-story, two-stage Space Launch System (SLS) rocket and Orion crew capsule were scheduled to lift off from the Kennedy Space Center in Cape Canaveral, Florida, during a two-hour launch window that opened at 8:33 a.m. . EDT (1233 GMT).
SLS-Orion’s maiden voyage, a mission named Artemis I, is intended to put the 5.75 million-pound vehicle through a rigorous demonstration flight, pushing its design limits before NASA deems it reliable enough to carry astronauts.
Billed as the world’s most powerful, complex rocket, the SLS represents the largest new vertical launch system the US space agency has built since the Saturn V that flew during the Apollo moon program in the 1960s and 70s.
The spacecraft was slowly moved to historic Launch Pad 39B earlier this month after weeks of final preparations and ground tests. Last week, NASA officials completed their flight readiness review, declaring that all systems were “launch ready.”
One issue cited by NASA officials last week as a possible holdup for Monday’s launch would be any sign during rocket fueling that a recently repaired hydrogen line component could not hold.
If the countdown clock stops for any reason, NASA has set September 2 and September 5 as backup launch dates.
Barring last-minute technical difficulties or adverse weather conditions, Monday’s countdown should end with the rocket’s four R-25 main engines and two solid rocket boosters firing to produce 8.8 million pounds of thrust, about 15% more thrust than produced by the Saturn V, sending the spacecraft streaking skyward.
About 90 minutes after launch, the rocket’s upper stage will push Orion out of Earth orbit en route for a 42-day flight that will bring it within 60 miles of the Moon’s surface before traveling 40,000 miles (64,374 km) beyond the moon and back to Earth. The capsule is expected to launch into the Pacific on October 10.
Although there will be no humans, Orion will carry a simulated crew of three – one male and two female mannequins – equipped with sensors to measure radiation levels and other stresses that real astronauts will experience.
A top goal of the mission is to test the durability of Orion’s heat shield during reentry as it slams into Earth’s atmosphere at 24,500 miles (39,429 km) per hour, or 32 times the speed of sound, on its return from lunar orbit. – much faster than the more common re-entries of astronaut capsules returning from low Earth orbit.
“That’s our highest priority to accomplish,” chief flight manager Rick LaBrode said of demonstrating the heat shield’s ability to withstand reentry friction, which is expected to raise temperatures outside the capsule to nearly 5,000 degrees Fahrenheit. (2,760 Celsius). “This will keep the capsule together and save the astronauts.”
RETURN TO THE MOON
NASA’s Artemis program – named after the goddess who was Apollo’s twin sister in ancient Greek mythology – aims to return astronauts to the surface of the Moon as early as 2025 and establish a long-term lunar colony as a stepping stone for even more ambitious future journeys by sending humans to Mars.
More than a decade in development with years of delays and billions of dollars in budget overruns, the SLS-Orion spacecraft has so far cost NASA at least $37 billion, including design, construction, testing and ground facilities.
NASA chief Bill Nelson defended the Artemis program as a boon to space exploration and an “economic engine,” noting that in 2019 alone, for example, it generated $14 billion in trade and supported 70,000 U.S. jobs.
Among the program’s biggest financial beneficiaries are the SLS and Orion prime contractors – Boeing Co and Lockheed Martin Corp, respectively.
Twelve astronauts walked on the moon during six manned Apollo missions that landed from 1969 to 1972, the only space flights that have yet to place humans on the lunar surface.
If successful, Artemis I would pave the way for a first crewed SLS-Orion mission, a round-trip flight around the moon called Artemis II, as early as 2024, followed a year or more later by a Artemis III on the lunar surface.
Artemis III involves a much higher degree or complexity by integrating SLS-Orion with a series of spacecraft to be built and flown by Elon Musk’s SpaceX launch company.
These include SpaceX’s own heavy-duty lunar launch and landing vehicle, which is still under development, as well as several components that remain to be built – an orbital fuel depot and space tankers to fill it. Even the new moonwalking suits remain to be designed.
NASA’s Office of the Inspector General last year said the first Artemis III lunar landing was more likely to occur two to three years later than the agency’s target date of late 2025.
(Reporting by Joey Roulette and Steve Gorman; Editing by Daniel Wallis)