But if Mariner 10’s mission was historic, so was the Boeing-built spacecraft itself, which for the first time used the gravity of one world (Venus) to reach another (Mercury) and in doing so ...

Mariner 10 was the seventh successful launch in the Mariner series and the first spacecraft to use the gravitational pull of one planet (Venus) to reach another (Mercury). It was also the first probe ...

MESSENGER was the first spacecraft to orbit Mercury and the second spacecraft to study it up close after NASA's Mariner 10 flew by the planet in the 1970s. MESSENGER spent four years orbiting Mercury.