PIONEER 11 SPACECRAFT, STUDYING JUPITER & SATURN

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon.

Joseph loves astronomy and they have been talking about Pioneer 11, the robotic space probe launched by NASA on a day like today in 1973.

Pioneer 11, also known as Pioneer G, is a 260-kilogram robotic space probe launched by NASA on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, solar winds, and cosmic rays.

It was the first probe to encounter Saturn, the second to fly through the asteroid belt, and the second to fly by Jupiter. Later, Pioneer 11 became the second of five artificial objects to achieve an escape velocity allowing it to leave the Solar System.

Due to power constraints and the vast distance to the probe, the last routine contact with the spacecraft was on September 30, 1995, and the last good engineering data was received on November 24, 1995.

Approved in February 1969, Pioneer 11 and its twin probe, Pioneer 10, were the first to be designed for exploring the outer Solar System. 

More information: NASA

Yielding to multiple proposals throughout the 1960s, early mission objectives were defined as:

-Explore the interplanetary medium beyond the orbit of Mars.

-Investigate the nature of the asteroid belt from the scientific standpoint and assess the belt's possible hazard to missions to the outer planets.

-Explore the environment of Jupiter.

Subsequent planning for an encounter with Saturn added many more goals:

-Map the magnetic field of Saturn and determine its intensity, direction, and structure.

-Determine how many electrons and protons of various energies are distributed along the trajectory of the spacecraft through the Saturn system.

-Map the interaction of the Saturn system with the solar wind.

-Measure the temperature of Saturn's atmosphere and that of Titan, the largest satellite of Saturn.

-Determine the structure of the upper atmosphere of Saturn where molecules are expected to be electrically charged and form an ionosphere.

-Map the thermal structure of Saturn's atmosphere by infrared observations coupled with radio occultation data.

-Obtain spin-scan images of the Saturnian system in two colors during the encounter sequence and polarimetry measurements of the planet.

-Probe the ring system and the atmosphere of Saturn with S-band radio occultation.

-Determine more precisely the masses of Saturn and its larger satellites by accurate observations of the effects of their gravitational fields on the motion of the spacecraft.

-As a precursor to the Mariner Jupiter/Saturn mission, verify the environment of the ring plane to find out where it may be safely crossed by the Mariner spacecraft without serious damage.

Pioneer 11 was built by TRW and managed as part of the Pioneer program by NASA Ames Research Center. A backup unit, Pioneer H, is currently on display in the Milestones of Flight exhibit at the National Air and Space Museum in Washington, D.C. Many elements of the mission proved to be critical in the planning of the Voyager program.

Pioneer 10 and 11 both carry a gold-anodized aluminum plaque in the event that either spacecraft is ever found by intelligent lifeforms from other planetary systems.

The plaques feature the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft.

More information: NASA

 The vision of NASA is to reveal the unknown
for the benefit of all humankind.

Victor J. Glover