Friday, March 02, 2018

Happy Birthday, Pioneer 10!

Pioneer 10 was launched March 2, 1972. Shown, artist rendering of Pioneer 10 flyby of Jupiter. Image credit, NASA.

March 2 marks a birthday, of sorts, for NASA's Pioneer 10 mission. On this day in 1972, the spacecraft was launched on the first mission to the planet Jupiter.

Originally designated Pioneer F, the spacecraft weighed 258 kilograms (569 pounds), completed the first mission to the planet Jupiter and, later, became the first of five artificial objects to achieve the escape velocity that will allow them to leave the Solar System. The project was conducted by the NASA Ames Research Center in California, and the space probe was manufactured by TRW Inc.

The spacecraft was launched on March 2, 1972 by an Atlas-Centaur expendable vehicle from Launch Complex 36A at Cape Canaveral, Florida. Between July 15, 1972, and February 15, 1973, it became the first spacecraft to traverse the asteroid belt. Photography of Jupiter began November 6, 1973, at a range of 25,000,000 kilometers (16,000,000 mi), and a total of about 500 images were transmitted. The closest approach to the planet was on December 4, 1973, at a range of 132,252 kilometers (82,178 mi). During the mission, the on-board instruments were used to study the asteroid belt, the environment around Jupiter, the solar wind, cosmic rays, and eventually the far reaches of the Solar System and heliosphere.

Pioneer 10 crossed the orbit of Saturn in 1976 and the orbit of Uranus in 1979. On June 13, 1983, the craft crossed the orbit of Neptune, the outermost planet, and so became the first human-made object to leave the proximity of the major planets of the Solar System. The mission came to an official end on March 31, 1997, when it had reached a distance of 67 AU from the Sun, though the spacecraft was still able to transmit coherent data after this date.

After March 31, 1997, Pioneer 10's weak signal continued to be tracked by the Deep Space Network to aid the training of flight controllers in the process of acquiring deep space radio signals. There was an Advanced Concepts study applying chaos theory to extract coherent data from the fading signal.

The last successful reception of telemetry was received from Pioneer 10 on April 27, 2002; subsequent signals were barely strong enough to detect, and provided no usable data. The final, very weak signal from Pioneer 10 was received on January 23, 2003 when it was 12 billion kilometers (80 AU) from Earth. Further attempts to contact the spacecraft were unsuccessful. A final attempt was made on the evening of March 4, 2006, the last time the antenna would be correctly aligned with Earth. No response was received from Pioneer 10. NASA decided that the RTG units (the spacecraft's power generators) had probably fallen below the power threshold needed to operate the transmitter. Hence, no further attempts at contact were made.

To learn more about Pioneer 10 and the NASA Pioneer missions, visit these sites.

NASA Pioneer Missions

Web Archive of the NASA Pioneer Mission Home Page


Wednesday, February 28, 2018

Phoenix Mars Lander Is a Bit Dusty

The above animation "blinks" between two images: One taken May 25, 2008, the other taken December 21, 2017. Both show the landing site for NASA's Phoenix Mars Lander. The later image shows the result of dust layering. Image credit: NASA/JPL-Caltech/Univ. of Arizona

A late 2017 image of NASA's Phoenix Mars mission, which landed nearly a decade ago in the norther regions of Mars, shows that dust has covered some marks of the landing.

The Phoenix lander itself, plus its back shell and parachute, are still visible in the image taken December 21, 2017, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. But an animated-blink comparison with an image from about two months after the May 25, 2008, landing shows that patches of ground that had been darkened by removal of dust during landing events have become coated with dust again.

In August 2008, Phoenix completed its three-month mission studying Martian ice, soil and atmosphere. The lander worked for two additional months before reduced sunlight caused energy to become insufficient to keep the lander functioning. The solar-powered robot was not designed to survive through the dark and cold conditions of a Martian arctic winter.

Both images in the animation were taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The one with three patches of darker ground -- where landing events removed dust -- was taken on July 20, 2008. The one with a more even coating of pale dust throughout the area was taken on December 21, 2017. Both image cover an area roughly 300 meters wide at 68 degrees north latitude, 234 degrees east longitude.

The University of Arizona, Tucson, led the Phoenix mission and also operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, managed the Phoenix Mars Lander Project and manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington. Lockheed Martin Space, Denver, built both the Phoenix and Mars Reconnaissance Orbiter spacecraft.

For more information on the Phoenix Mars Lander, the Mars Reconnaissance Orbiter mission and NASA's Mars exploration program, check out these site.