ODYSSEUS MAKES EPIC LUNAR JOURNEY, BREAKS LEG, PHONES HOME
The historic lander is the first commercial mission to make a soft landing on the Moon.
On Feb. 22, the lunar lander Odysseus touched down softly — if somewhat awkwardly — on the Moon, becoming the first Americanmade craft to land there since 1972. It also became the first non-governmental craft to ever do so, after previous private attempts had failed.
It wasn’t a flawless landing. As Odysseus — about 14 feet (4.3 meters) tall and weighing roughly 1,488 pounds (675 kilograms) — neared the lunar surface, instead of hovering stably before touching down, it was still drifting slowly. When its feet touched down, they skidded across the Moon’s surface, snapping one of the craft’s six landing gear legs. As the engine shut off, Odysseus gently toppled partially over, coming to rest at about a 30° angle from upright.
Despite the tumble, the lander was able to generate power from its solar panels, allowing all its payloads to collect and return data. However, the awkward landing altered the mission because the craft’s solar panels could not aim directly at the Sun. The lander was scheduled to collect data for as long as 10 days but instead was put into hibernation after six days as lunar night approached.
Odysseus was not designed to survive the cold night, but Intuitive Machines hoped that as the Sun rose overhead three weeks later, enough light would reach its solar panels to wake it up. Flight controllers started listening for a signal on March 20, but after three days of radio silence, the team called time on Odysseus and declared its mission had ended.
SOUTHERN LANDING
Odysseus carried six payloads for commercial companies and another six under contract for NASA. Several of NASA’s payloads were intended to test navigation and landing technology that will be used for the agency’s Artemis program, which will return astronauts to the Moon. “All of the data that can be used for Artemis will be used for Artemis,” said NASA’s Sue Lederer during a press conference Feb. 28.
Odysseus landed about 185 miles (300 kilometers) from the Moon’s south pole,
near a crater named Malapert A. The area is part of the rugged polar highlands, the same region Artemis landings will target.
Due to a wiring error, Odysseus was forced to fly its touchdown without its built-in laser rangefinders, a key navigation instrument. Engineers delayed the landing to put together a last-minute hack, rerouting data from the laserranging tools on one of the science payloads. However, Intuitive Machines revealed that the patch didn’t work; in the scramble, engineers missed a flag in the code to tell the navigation algorithm the data were valid.
As a result, the lander came to rest about 0.9 mile (1.5 km) outside of its intended landing zone, at a higher elevation than expected, and on a 12° slope within a small crater. These factors contributed to its slightly clumsy touchdown.
Still, for Intuitive Machines, the fact that the craft managed to land softly using only data from its cameras and internal motion sensors is a feat in itself. “It’s the first time anybody’s flown this algorithm, and it exceeded expectations because we live to tell about it,” said Tim Crain, the company’s chief technology officer.
TECHNOLOGY DEMONSTRATIONS
The NASA payloads included a variety of tests and demonstrations, including landing technologies (involved in the failed laser rangefinder patch), tracking the lander’s fuel in zero gravity, and other navigation and communication tools.
One instrument was designed to observe how the landing engine exhaust interacts with the lunar surface and its sharp, abrasive dust. Unfortunately a hardware failure prevented it from collecting data during the descent and landing, but controllers were able to later fix this and make observations from the landing site.
In another spaceflight first, Odysseus’ engine runs on a mixture of liquid methane and liquid oxygen. These propellants must be stored at very low temperatures, as even in space, heat from the Sun or spacecraft exhaust can cause them to boil off. Such cryogenic fuels are expected to play a key long-term role in the Artemis program.
The lunar lander also brought a payload to study radio emissions from objects like the Sun, Jupiter, and Earth. This is an early first step toward a longheld dream of astronomers: placing a radio telescope on the Moon’s farside, shielded from interference from Earth.
The landing is the second mission of NASA’s Commercial Lunar Payload Services (CLPS) initiative, which contracts commercial companies to deliver tools and technology to the Moon.
The first CLPS mission, the Peregrine lander built by the U.S. company Astrobiotic, failed to reach the Moon and burned up in Earth’s atmosphere in January.