The unmanned spacecraft Helios 2 approached within 43.5 million km 27million miles of the Sun, carrying both US and West German instrumentation, on April 16, 1976 (? Highest velocity).

Due for launch in 2015, NASA’s Solar Probe+ will attempt to study the Sun from as close as 6.2 million km (3.9 million miles), from within the Sun’s outer atmosphere or corona. Travelling at 200 km/sec (125 miles/sec), the spacecraft will have to survive temperatures of up to 1,420 C (2,600 F).