On Thursday, the United States returned to the lunar surface for the first time in over 50 after a commercially built spacecraft named Odysseus made a nail-biting touchdown near the moon's south pole. The spacecraft's 73-minute descent from the orbit became nail-biting following a last-minute navigation sensor malfunction. As the world hailed the feat, the American space agency NASA called it “a giant leap forward”. However, none of it would have happened without some fast work from engineers on the ground and a major save from NASA's payload.

According to CNN, before descent, Intuitive Machines which developed the Odysseus lunar lander informed that some of the crucial pieces of lander's navigation equipment were not working. However, NASA already had an experimental instrument on board that could be swapped to make up for the malfunctioning pieces of equipment. Hence, NASA's instrument managed to help the lander make a touch-down near the south side of the moon successfully. The instrument is called Navigation Doppler Lidar (NDL) which helped engineers bypass Odysseus' broken pieces and land using two lasers that are part of NDL's payload. 

How NDL helped in the operation 

According to the IM-1 presser, the NDL enhances the capabilities of space vehicles to execute precision navigation and eventually contribute to ensuring controlled soft landings. “The NDL is a LIDAR-based (Light Detection and Ranging) sensor composed of an optical head with three small telescopes and a box with electronics and photonics. NDL uses lasers to provide extremely precise velocity and range (distance to the ground) sensing during the descent and landing of the lander,” the Intuitive Machine said in a statement. “This instrument operates on the same principles of radar, similar to a police radar detector, but uses pulses of light from a laser instead of radio waves and with very high accuracy. This will enhance the capabilities of space vehicles to execute precision navigation and controlled soft landings,” the body furthered.

 After detecting the malfunction, the body reported that NDL helped in troubleshooting communication. “After troubleshooting communications, flight controllers have confirmed Odysseus is upright and starting to send data. Right now, we are working to downlink the first images from the lunar surface,” Intuitive Machines wrote on X, formally known as Twitter.