The MIR

Pioneer 4 was the first U.S. spacecraft to escape the Earth. It was launched on March 3, 1959 and passed the Moon at a distance of 60,000 km (37,300 mi). It was tracked to 655,000 km before its batteries were depleted at about 84 hours. Pioneer 3 was the same kind of craft. It was launched on Dec 6, 1958 and reached an altitude of 101,367 km but failed to escape the Earth's gravity. It reentered the atmosphere after 38 hrs. The Geiger-Mueller counters aboard Pioneers 3 and 4 discovered and mapped the second Van Allen radiation belt around the Earth.