After a nail-biting descent, the Odysseus spacecraft has landed near the lunar south pole and prepares to kick off a week of data gathering.
In a historic lunar accomplishment, the first private spacecraft to land successfully on the Moon touched down on 22 February. The spacecraft, named Odysseus and built by Intuitive Machines in Houston, Texas, also became the first US lunar lander since 1972, when the last crew of Apollo astronauts visited the Moon.
In the hours before landing, Odysseus produced some nail-biting moments, such as the malfunctioning of the laser rangefinders that were supposed to help guide the craft’s autonomous journey to the lunar surface. Mission engineers had to upload a software patch to enable it to use a secondary laser provided by NASA instead.
The exact state of the spacecraft remained unclear immediately after its landing, which occurred at 5:23 p.m. Houston time. But it did send a faint signal back to mission control in Houston, indicating that at least some portion of it had survived the touchdown. “Odysseus has found its new home,” said mission director Tim Crain as the control room burst into cheers.
Lunar landing
Regardless of how operational the spacecraft might be going forward, the landing provides a boost to efforts by commercial firms and the US government aiming to go to the Moon. NASA paid for a large proportion of the private mission and is counting on companies, such as Intuitive Machines, to help ferry equipment and scientific instruments to the Moon in preparation for sending astronauts there.
“The US has returned to the Moon,” said NASA administrator Bill Nelson in a video statement. “Today is a day that shows the power and promise of NASA’s commercial partnerships.”
On 23 February, the day after the landing, Intuitive Machines reported that “flight controllers are communicating and commanding the vehicle to download science data.” If Odysseus’s scientific payloads work as expected, they could collect data for up to seven days, until night falls at the landing site and there is no solar power left for them to use.
Five of the previous nine Moon landing attempts failed. This includes a mission sent last month by Astrobotic in Pittsburgh, Pennsylvania, that ran out of fuel within hours of launch because a valve malfunctioned. However, also last month, the Japanese space agency succeeded in landing its SLIM lander near Shioli crater, close to the Moon’s equator — albeit upside down.
Speedy traveler
Odysseus launched on 15 February from Cape Canaveral in Florida, and headed directly for the Moon. Along the way, it fired its engine several times to set itself on the correct trajectory and it transmitted images of Earth and the Moon. It entered lunar orbit on 21 February, initially circling 92 kilometers above the surface before making its landing attempt.
The spacecraft fired its engines to descend to a lower altitude, then moved into a series of autonomous manoeuvres in which it re-oriented itself and began assessing the craters and boulders underneath it. It navigated towards its intended landing site and fired its engines again to slow its descent, ultimately touching down on the surface.
The six-legged, phone-booth-sized spacecraft landed near the Malapert A crater, around 300 kilometers from the lunar south pole. NASA is interested in the Moon’s south pole because the region’s dirt and shadowy craters might contain ice that could provide fuel and other resources for future lunar explorers. Most lunar landers have visited the Moon’s equatorial regions; the only mission that has landed near the south pole is India’s Chandrayaan-3, which touched down last August.
Bargain missions
Odysseus is the second launch, after Astrobotic’s attempt, of NASA’s Commercial Lunar Payload Services (CLPS) programme, which aims to incentivize small aerospace companies to fly payloads for NASA and others to the Moon at low cost. NASA paid Intuitive Machines US$118 million to develop Odysseus, which is a fraction of the cost of a typical interplanetary mission.
“I’m very stoked that they pulled it off,” says Stephen Indyk, director of space systems at Honeybee Robotics in Greenbelt, Maryland, who was not associated with the mission. “It really adds validity to the whole CLPS programme.”
NASA has six payloads onboard Odysseus, including a set of cameras to study how rocket exhaust interacts with the lunar surface. The space agency wants to use CLPS flights to test technologies for its own missions to the Moon, including plans to send astronauts to the lunar south pole as soon as 2026. A second Intuitive Machines Moon mission is slated to carry an ice drill to the south polar region, perhaps by the end of this year.
Odysseus is the first craft to burn methane-based rocket fuel in space. Methane-based propellants are more efficient and environmentally friendlier than conventional rocket propellants, such as those that contain kerosene. But they can be difficult to work with because they need to remain at ultracold temperatures. Several other aerospace companies are planning to use methane fuels in the future.