Image of Telescopes
Aram Gragossian, Navigation Doppler Lidar electro-optics lead, prepares the instrument’s telescopes for the test. (Credits: NASA/David C. Bowman)

GPS is used every day to navigate on Earth. As NASA prepares to land humans on the Moon by 2024, new laser-based technology will safely and precisely navigate astronauts to their destination.

The Navigation Doppler Lidar (NDL) unit is comprised of a small electronics box connected by fiber optic cables to three telescopes that transmit a laser beam. The lasers are sent down towards the surface, and the reflection received back at the telescope is processed to determine what direction the spacecraft is moving, how far away the surface is, and how fast the vehicle is moving towards the surface.

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