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6 Mission-critical info for UST professionals Platform one NASA is developing a laser-based technology to help autonomous spacecraft land more accurately; it is also being adapted for cars (writes Nick Flaherty). The Safe and Precise Landing – Integrated Capabilities Evolution (Splice) project is working on a variation of Lidar that detects the movement and velocity of distant objects, as well as the spacecraft’s own motion relative to the ground, such as speed, pitch, roll and altitude. The technique, called Navigation Doppler Lidar (NDL), uses laser light frequencies 1000 times higher than current Lidar sensors, coupled with a global shutter flash system. A flash Lidar acquires data across a pixel array, using a single laser pulse to generate the entire map. This allows for much faster results. It also significantly reduces the computational load, because all the data is received at the same moment and in the same physical location, so no velocity calculations are necessary. “Higher frequency translates to more precise data and potentially more efficient and compact sensors,” said Farzin Amzajerdian, principal investigator at NASA’s Langley Research Center. “The velocity or speed is obtained by using the Doppler effect.” The frequency of the returned laser light shifts when it bounces off the ground as the spacecraft approaches it. This gives the spacecraft precise data to verify exactly how quickly it’s moving towards the ground and at what angle. The system will travel to the Moon on several commercial landers as part of the Artemis programme involving NASA and other space agencies. Space vehicles Safer landings in a flash October/November 2020 | Unmanned Systems Technology Electro-optics lead Aram Gragossian (left) and integration lead Jake Follman configure the Splice electronics at NASA’s Langley Research Center