By James T. McKenna
NASA’s latest Moon rocket blasted off from Florida’s Kennedy Space Center at 1:47 a.m. today on a planned 25-and-a-half-day mission to prove the space agency remembers, after a half century, how to fly astronauts to the Earth’s natural satellite and bring them home safely.
The Space Launch System (SLS) journey on the uncrewed Artemis 1 mission came just shy of 50 years after a mammoth Saturn V sent three astronauts to the Moon on December 1972’s Apollo 17. That was the last U.S. lunar mission. Artemis 1 is to reach the Moon on November 21 and spend a week in a distant retrograde orbit around it that will carry the crew capsule 40,000 miles (64,374 kilometers) beyond it.
The mission’s main objectives are fundamental. One is to show that the heat shield on the rocket’s crew capsule can survive re-entry through the Earth’s atmosphere after a lunar flight. Another is to demonstrate the performance of NASA’s operations and facilities throughout all phases of a Moon mission. A third is to ensure that the space agency can recover the crew capsule after splashdown. NASA wants to prove it can return a lunar crew safely to Earth.
The Artemis program is a series of increasingly complex missions aimed at establishing a permanent human presence on the Moon and enabling missions beyond it to Mars. They would be highlighted by Artemis 3’s lunar landing of astronauts (including the first woman and first person of color), which is targeted for 2025. In Greek mythology, Artemis was the twin sister of Apollo and the goddess of (among other things) the Moon. Boeing is NASA’s main contractor for the SLS, which is intended to power the initial Artemis missions.
“Today we got to witness the world’s most powerful rocket take the Earth by its edges and shake the wicked out of it, and it was quite a sight,” NASA Artemis Mission Manager Mike Sarafin said a few hours after the launch, drawing on the Bible’s Book of Job.
Artemis 1’s launch came on the third try. Previous opportunities in August, September and this month were delayed by propellant leaks and hurricanes. During the latest effort, the launch team overcame several issues, including a liquid hydrogen fuel line leak and a communications failure in the system the U.S. Space Force would use to destroy the rocket if a problem occurred in flight.
Once the 8.8-million-pound-thrust (3,9144-kilonewton) rocket lifted off into high clouds of the night sky, the flight went smoothly. After about 2 minutes 12 seconds, the SLS’s two 177-foot-tall (53.9-meter) Northrop Grumman solid rocket boosters burned out and separated from the 322-foot-tall (98.3-meter) main rocket to fall back to the Atlantic. (By comparison, the 363-foot-tall, or 111-meter tall, Saturn V generated 7.6 million pounds, or 33806.5 kilonewtons, of thrust at liftoff.) The launch abort tower jettisoned 3.5 minutes after liftoff.
About 87 minutes after liftoff, the SLS’s interim cryogenic propulsion (or upper) stage ignited its lone, 24,750-pound-thrust (110-kilonewton) Aerojet Rocketdyne RL10 engine for 18 minutes. With that long, “trans-lunar injection” burn, the United Launch Alliance upper stage accelerated the crew capsule to 22,500 mph and pushed it beyond 247,000 miles from Earth. Ten minutes later, the upper stage separated from the Lockheed Martin-built Orion capsule, setting it on a 268,553-mile (432,194-kilometer) cruise to the Moon. Orion’s service module, which provides the capsule’s propulsion, life support and other critical systems, is provided by the European Space Agency and lead contractor Airbus.
“The spacecraft is Moon-bound,” launch commentator Leah Cheshier said from Houston’s Johnson Space Center (JSC). The Artemis 1 flight team took control of the rocket as soon as it cleared the launch tower in Florida.
Orion, which is designed for a crew of four, carries only one seat on this flight: the commander’s seat, in which rests a male-bodied mannequin in a spacesuit with two sensors to record space radiation’s effects on a human body. Other sensors in the seat will capture acceleration and vibration data.
At the location of the rear seats are two mannequin torsos, one female and one male, which simulate human tissue and organs. Dubbed “phantoms” and named Helga and Zohar, these will record radiation levels during the mission and evaluate a radiation-protection vest. Acceleration forces on the unvested mannequin also will be measured, particularly during splashdown in the Pacific off San Diego, California. NASA also is measuring the environment in the crew cabin throughout the flight.
In the hours after the upper stage separated, 10 small satellites deployed from it on missions to pursue a host of science and space research objectives. These were CubeSats, products of a NASA program to foster low-cost, innovative work in space. CubeSats weigh no more than 30 pounds (13.6 kilograms) and must be able to fold into a volume about the size of a large shoebox. They also must not require power from their host spacecraft.
Most of the Artemis CubeSats aim to support that program’s goal of a permanent human presence on the Moon, characterizing the lunar surface, soil and radiation environment and searching for water and hydrogen there. One will carry a 2.2-pound (1-kilogram) “nano-lander” to assess lunar soil mechanics. Others will test innovative propulsion and trajectory techniques using low-energy maneuvers, iodine thrusters and water jets. One will scout out near-Earth asteroids. Another will study cool plasma in the Earth’s magnetosphere. Yet another will study the Sun’s radiation, solar winds and other solar events. Lastly, one will use yeast to assess whether space radiation might break down an astronaut’s DNA.
The SLS is not a new launch vehicle. Congress required NASA to reuse as much hardware as possible. So, the four Aerojet Rocketdyne RS-25 engines that powered the SLS’ core stage are refurbished and upgraded space shuttle main engines that each generate 416,300 pounds (1,852 kilonewtons). They are rated to operate at 109 percent during the rocket’s ascent. The four engines collectively flew on 25 space shuttle missions before today’s launch. One flew on 12 shuttle launches.
The vehicle’s solid rocket boosters are also refurbished and upgraded from shuttle operations, with new nozzles and avionics. With a fifth segment added to each, they are the most powerful solid boosters ever flown, according to NASA.
The Orion service module’s single engine is a refurbished shuttle Orbital Maneuvering System engine provided by NASA.
The interim cryogenic propulsion stage is based on the cryogenic second stage of the United Launch Alliance’s Delta IV rocket.
NASA Administrator Bill Nelson, asked why it’s a priority to land the first woman and first person of color on the Moon, said: “It’s reflective of us. It’s reflective of America. Our national motto is the Latin ‘E pluribus unum. Out of many, one.’ So, our astronaut corps reflects that.”
As does much of NASA’s workforce, said Emily Nelson, NASA’s chief flight director at JSC and a successor to space agency legends like Christopher Kraft, Glynn Lunney and Gene Krantz.
“If you see the photos and imagery from the last time we were went to the Moon, the diversity of the people who had the opportunity to contribute was maybe not quite where it is today. I think that’s a point of pride, but it’s in no way surprising because I think we’ve all grown in that direction.” She added: “It’s really exciting for my generation and for the Artemis generation to get the opportunity to go to the Moon and beyond.”