LONDON–The British built lander, Beagle 2, was supposed to reach the surface of Mars and start transmitting on Christmas Day, 2003. Instead, the craft went dark, mystifying the European Space Agency scientists who sent it.

After several months, the lander was declared lost or destroyed. On Friday, after 12 years, the ESA reported that the Beagle 2 had been found thanks to research based on images captured by NASA’s Mars Reconnaissance Orbiter.

Alfred McEwen, chief investigator of the project, said the orbiter’s high-resolution camera had been used to search for all of the landers that have tried to reach the Martian surface.

The photos show the Beagle 2 landed safely but only partially deployed. Because of this, it did not have enough active solar panels to transmit.

As a target, Mars remains elusive. Russia has greenlit 18 Mars launches since the 1960s with a success rate of just 14 percent. American launches have fared better but still suffer from a 30 percent rate of failure.

When a launch is successful it can usually transmit r radio signals back to Earth. McEwen notes that the case of the Beagle 2 is the only exception.

“This the first time we found one that didn’t send a signal after it landed,” he said. “If the landing sequence works correctly, the probe sends a radio signal, and you can use that to pinpoint where it is coming from, even if it broadcasts only very briefly. But in the case of Beagle 2, we didn’t get anything. All we had to go by was the target landing area.”

United Kingdom Space Agency chief executive, David Parker, said the discovery showed its landing procedures worked. Experts hailed the mission as a partial success though no information about Mars was acquired.

E.S.A.’s Mars Express launched the orbiter in 2003. It was released from its mother ship and was supposed to land six days later, but communications were never established.

“To be frank, I had all but given up hope of ever knowing what happened to Beagle 2,” said Professor Mark Sims of the University of Leicester, who worked on the project.

ESA scientists see the discovery as a vindication of over a decade of work