It made history as India's first unmanned lunar spacecraft. Then it vanished.
Nearly a decade later, NASA has located two unmanned spacecraft orbiting the moon, including India's Chandrayaan-1, which went quiet in 2009.
Scientists used a new ground radar to locate the spacecraft -- one active and one dormant -- orbiting the moon, NASA said Thursday.
"We have been able to detect NASA's Lunar Reconnaissance Orbiter [LRO] and the Indian Space Research Organization's Chandrayaan-1 spacecraft in lunar orbit with ground-based radar," said Marina Brozovic, a radar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.
"Finding LRO was relatively easy, as we were working with the mission's navigators and had precise orbit data where it was located."
The Chandrayaan-1 was more of a challenge because the last contact with the spacecraft was in August 2009.
Chandrayaan-1 spacecraft is small -- about half the size of a smart car -- making its detection even more noteworthy.
While interplanetary radar has been used to see small asteroids several million miles from Earth, researchers were unsure it could detect an even smaller object as far away as the moon.
Such objects are especially a challenge to find because the moon is filled with regions with high gravitational pull that can drastically change a spacecraft's orbit.
The new technology is crucial to future moon missions.
Optical telescopes cannot search for small objects because of the bright glare of the moon.