NASA has a lot to celebrate today. On the one year anniversary of the NASA New Horizons fly-by of Pluto-Charon (technically that was July 15), NASA’s Juno is not just flying by Jupiter, but entering Jovian orbit. As the Juno spacecraft enters orbit, it will become the third-fastest man-made object with a velocity of 25 miles per second (40 kilometers per second or Mach 117).
The fastest man-made objects in history happen to be the Helios satellites that orbited the Sun at 70 km/s (Mach 204) in the mid-1970s, and, my favorite, a manhole cover that was inadvertently launched into the air at 72 km/s (Mach 210) by a nuclear explosion test that went awry in the New Mexico desert in 1957. The New Mexico nuclear manhole cover and five objects made by NASA are the only man-made macrosystems to surpass earth’s escape velocity of 11 kilometers per second.