Pioneer 11 Topics

• voyager probes
• voyager flybys
• miss pioneer
• uranus and neptune
• hydrogen atom
• ring particles
• threshold settings
• axis control
• mission planners
• extraterrestrial intelligences
• pioneer 10
• earth and sun
• faint ring
• sensor gain
• star sensor
• epimetheus
• mimas
• space probe
• true sense
• experience gained from

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Pioneer 11, Pioneer 11

Attitude position could be calculated from the reference direction to Earth and Sun, with the known direction to Canopus as backup. Pioneer 11's star sensor gain and threshold settings were modified, based on experience gained from the settings used on Pioneer 10. Three pairs of rocket thrusters provided spin-axis control (maintained at4.8 rpm) and change the spacecraft's velocity. The thrusters could be either fired steadily or pulsed, by command.

If there were faint ring particles that could damage a probe in that area, mission planners felt it was better to learn about it via Pioneer. Thus, Pioneer 11 was acting as a "pioneer" in a true sense of the word; if danger was detected, then the Voyager probes could be rerouted further away from the rings, but missing the opportunity to visit Uranus and Neptune in the process.

After the Voyager flybys, it became known that there are two similarly-sized moons (Epimetheus and Janus) in the same orbit, so there is some uncertainty about which one was the object of Pioneer's near-miss. Pioneer 11 encountered Janus on September 1, 1979 at 14:52 UTC at a distance of 2500 km and Mimas at 16:20 UTC the same day at 103000 km.

Barring incident, Pioneer 11 will pass near one of the stars in the constellation in about 4 million years.

However, Pioneer 11 was redirected to Saturn making its plaque somewhat out of date. If the space probe is ever found by extraterrestrial intelligences, this message is meant to provide information about the origin of the spacecraft. It includes a drawing depicting a man, a woman, the transition of a hydrogen atom, and the location of the Sun and Earth in the galaxy.

Source: Wikipedia > Pioneer 11