May 27, 2018

045 - Pioneer 10: The Lost Traveller

49 minutes

Note: NASA was established in 1958 as opposed to 1959 as mentioned by Shankar.

Pioneer 10 (Pioneer F) was the first aircraft to give humans an insight into the planet Jupiter and its moons. It was the first mission to Jupiter. It was part of the Pioneer program, a series of United States unmanned space missions launched between 1958 and 1978.

Objectives:

Document Jupiter, its environment and its moon (mainly Europa, Callisto, Io, Ganymede) through photographs (Jovian System)

Study the solar wind, cosmic rays, heliosphere, and far reaches of the Solar System

Explore the atmosphere and radioactivity of the planet

Study the outer Solar System and heliosphere exploration

Study the asteroid belt

History

Gary Flandro, an aerospace engineer, conceived a mission to exploit a rare outer planets’ alignment.

The space probe was manufactured by TRW Inc. They were given a combined $380 million contract in 1970 to build Pioneer 10 and 11.

It took 25 million man-hours

As per a TRW engineer, “This spacecraft is guaranteed for two years of interplanetary flight. If any component fails within that warranty period, just return the spacecraft to our shop and we will repair it free of charge.”

Spacecraft and Design:

Six 76-centimetres long panels attached to a 36-centimetres bus to form a hexagonal structure. It could host eight to eleven instruments which were protected in a honeycomb aluminium structure. The orientation of the probe was controlled by the use of propellant (conical scanning). Aluminized mylar and kapton blankets (insulation coating) for passive thermal control. It carried 36 kilograms of liquid hydrazine monopropellant with a total launch mass of 260 kilograms.

It used four SNAP-19 radioisotope thermoelectric generators (RTGs) powered by plutonium-238. The spacecraft needed 100 Watts to power all the equipment. At launch, it provided a combined 155 W, and 140 W while in transit to Jupiter. By 2001, it became 65W leading to operation of only selected instruments.

Mission computation was largely performed on Earth with the commands transmitted to the spacecraft. It had a meagre capacity of 6,144 bytes, a limited form of a processor, two command decoders and one distributor which required ground control to prepare commands in advance.

Plaque:

Pioneer 10 contains a gold plaque which provides information about the origin of the spacecraft. Designed by Dr Carl Sagan and Dr Frank Drake, it was drawn by Linda Salzman Sagan. The plaque consists of diagrams of a man and a woman, completely nude. It also has the diagram showing the position of our solar system in the galaxy and the chemical information about hydrogen.

Scientific Instruments:

Infrared Radiometer - Evaluated heat output and cloud temperature from Jupiter

Quadri-spherical Plasma Analyzer - Detect particles of solar wind

Cosmic Ray Telescope (CRT) - Collect data on the composition and energy ranges of cosmic rays

Helium Vector Magnetometer (HVM) - Measured the interplanetary magnetic field, solar wind interaction with Jupiter’s magnetic field, and Jovian magnetic field.

Geiger Tube Telescope (GTT) - Survey the electrons and protons present in the radiation belts of Jupiter along the spacecraft’s path.

Trapped Radiation Detector (TRD) - To detect light emitted by particles

Imaging Photopolarimeter (IPP) - Build visual images of the planet by looking at it through red and blue lights.

Meteoroid Detectors

Charged Particle Instrument (CPI) - Detect cosmic rays

Asteroid/Meteoroid Detector (AMD)

Ultraviolet Photometer - Determine the quantity of hydrogen and helium in space and the atmosphere of Jupiter.

Dates:

Launched on March 2, 1972, 01:49:00 UTC from the Space Launch Complex 36A in Florida aboard an Atlas-Centaur launch vehicle.

Launch vehicle accelerated for 17 minutes reaching a speed of 51,682 km/h (32,114 mph).

Reached interplanetary space ninety minutes after launch

The initial spin rate of 30 rpm, reduced to 4.8 rpm after the extension of three booms.

Passed the Moon in eleven hours

Crosses the orbit of Mars on June 1972

Entered the asteroid belt on July 15, 1972 - left the inner solar system

Closed asteroid at 8.8 million kilometres with 307 Nike on December 2, 1972.

Left asteroid belt on February 15, 1973 (7 months) (first spacecraft)

Began photographing Jupiter on November 6, 1973, at 25 million kilometres range. (Total of about 500 photographs transmitted)

Closest approach to Jupiter - December 4, 1973, at 132,252 kilometres per hour

Crossed orbit of Saturn: 1976

Crossed orbit of Uranus: 1979

April 25, 1983: Crossed the orbit of Pluto

June 13, 1983: Crossed the orbit of Neptune

March 31, 1997: End of mission at 67 AU from the Sun

Last signal: January 23, 2003 - 12 billion kilometres away from the Earth.

Final attempt to contact Pioneer 10 made on the evening of March 4, 2006

Jupiter:

Pioneer 10 was able to help the scientists with the following:

It figured out that the magnetic field of Jupiter is inverted compared to that of the Earth.

Display real-time images of Jupiter back to earth (The broadcast received an Emmy award)

Images of the Red Spot which is being observed by humans for about two centuries. Believed to be in existence for over 350 years.

Study the amount of radiation dissipated by Jupiter. The radiation made the space probe send out false commands.

Io orbiting within a cloud of hydrogen which extends up to 805,000 kilometres.

Generated an infrared map of Jupiter which showed that it radiated more than the radiation it received from the Sun.

Miscellaneous Points:

Pioneer Anomaly - Acceleration towards the sun ((8.74±1.33)×10−10 m/s2). Resulting in 4000 km deficit per year.

To collect radiation environment information of Jupiter, the encounter trajectory was maximised. It could have damaged the space probe.

First to find helium presence in the interplanetary medium and sodium and aluminium presence in the solar winds

Size of the particle not more than 1mm. (not as bad as previously thought)

As of 2016, travels at 26,900 km/h, 10 billion miles (114.07 AU) away from the Earth.

Travels around 2.54 AU per year. (1 AU = 150 million kilometres)

If course unaffected, Pioneer 10 will reach Aldebaran in two million years

Additional Sources:

Pioneer story

17776

The Pioneer Plaque:

By Vectors by Oona Räisänen (Mysid); designed by Carl Sagan & Frank Drake; artwork by Linda Salzman Sagan - Vectorized in CorelDRAW from NASA image GPN-2000-001623, Public Domain, Link

Relative size of solar system:

Image: Wikipedia

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