Helios probes

The Helios deep space probes were launched in the mid 1970s by the Federal Republic of Germany and NASA, using US Air Force launch vehicles.

There were two in the series, Helios I and Helios II. They were launched into heliocentric orbit to study solar processes. They set a speed record for the fastest man-made objects ever at 252,792 km/h (70.2 km/s). They also set the record for the closest approach to the Sun, at approximately 45 million kilometers, slightly inside the orbit of Mercury. The Helios 2 was sent into orbit 13 months after the launch of the Helios 1. Both probes orbited around the Sun in an ellipse, with their farthest distance from the Sun being almost 1 AU and their closest distance to the Sun at 0.3 AU. The Helios space probes completed their primary missions by the early 1980s, but they continued to send data up to 1985. Presently, these probes are no longer functional, but they still remain in their elliptical orbit around the Sun.

The name Helios has also been used for a NASA experimental aircraft, the Helios Prototype, and for a series of French military photo-reconnaissance satellites, Helios 1B and Helios 2A.

External links

* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1974-097A Helios 1 - NSSDC Master Catalog]
* [http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=1976-003A Helios 2 - NSSDC Master Catalog]
* [http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Helios_01 Helios 1 Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
* [http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Helios_02 Helios 2 Mission Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]