Fastest Spacecraft

Calculating the speed of a spacecraft is a lot harder than simply pulling out your stopwatch. You have to account for the many possible frames of reference, two popular ones being the Earth and the Sun. While the fastest launch speed was achieved by New Horizons (currently en route to Pluto) at 36,000 mph (58,000 km/h), the fastest interstellar spacecraft is Voyager 1 which is moving away from the sun at 38,500 mph (62,000 km/h).