“The oldest computer (not) on Earth.”

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Link here. I suspect that most of my readers will be able to guess what computer we are talking about, and even where it is located.



  • Alex

    What about the flight computer of Pioneer 10 and 11, which are even older?

  • Alex: Neither Pioneer spacecraft is operating any longer. Both Voyager spacecraft are, with the computers still doing their jobs.

  • Steve Earle

    As of 2003 Pioneer 10 was still operating but we lost contact due to distance and a weakening signal from the spacecraft, most likely due to the RTG power levels dropping. The Deep Space Network was not able to pick up it’s weaker transmitter signal.

    Considering that it was launched in 1972, it was yet another amazing achievement of engineering and design.

    When it was last contacted Pioneer 10 was still maintaining it’s spin-stabilized antenna orientation to Earth, so depending on the power level from its RTG, it’s possible it is still operating, we just aren’t able to talk to it……

    “…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.[49] 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.[50] NASA decided that the RTG units had probably fallen below the power threshold needed to operate the transmitter. Hence, no further attempts at contact were made.[51]…”

    And, unbelievably, there are even older space probes that may still be operating as well: Pioneer 6, 7, and 8 launched in 1965, 66 and 67 respectively:

    “….a successful telemetry contact with Pioneer 6 was made on December 8, 2000 to celebrate 35 years of continuous operation since launch. Its original design life expectancy was only 6 months.

    Although NASA described Pioneer 6 as “extant” as of 26 March 2007,[2] there has been no contact since December 8, 2000. At this time Pioneer 6 had operated for 12,758 days, making it the oldest operating space probe until it was surpassed by Voyager 2 on August 13, 2012.[3] It is also believed that contact is still possible with Pioneers 7 and 8.[citation needed] Only Pioneer 9 is definitely dead…..”

  • Steve Earle

    All of that begs the question of what exactly is a “computer”? How many logic circuits does it take before a set of switches becomes a computer?

    Again from Wikipedia’s Pioneer 10 page:

    “…Much of the computation for the mission was performed on Earth and transmitted to the spacecraft, where it was able to retain in memory up to five commands of the 222 possible entries by ground controllers. The spacecraft included two command decoders and a command distribution unit, a very limited form of processor, to direct operations on the spacecraft. This system required that mission operators prepare commands long in advance of transmitting them to the probe. A data storage unit was included to record up to 6,144 bytes of information gathered by the instruments. The digital telemetry unit was used to prepare the collected data in one of the thirteen possible formats before transmitting it back to Earth.[1]:38..”

  • Alex

    Steve Earle: Great, thank you for that detailed information.

  • wayne

    How about the “oldest computer on Earth?”


    ” ‘Decoding the Heavens’, the story of the Antikythera mechanism, the most stunning scientific artefact we have from antiquity, which was discovered in 1900 and led to 100 years of study to understand it.”

  • LocalFluff

    Looks like the Voyagers did quite some unfolding of beams and instruments and such Christmas Tree decorations in flight. It doesn’t seem to be as dangerous as it looks. Maybe because it is tangible, it is manageable.

    Steve Earle, great stuff!

  • Edward

    Steve Earle asked: “what exactly is a “computer”?”

    Good question. The Computer History Museum in Mountain View, California includes as examples of early computers not only the abacus:

    but Napier’s bones:

    An example of a mechanical computer is the Babbage Difference Engine:

    There was a time when people who did computations for a living were called computers.

    Early electronic computers were analog in nature, programmable through changing the circuitry, not by entering different program instructions.

    In these examples, logic circuits are different than those used in modern digital computers. The logic and operation is handled by human hands. The question is more complex that one might think.

    NASA needed a computer that was light enough to launch into space yet could solve complex problems. They hired universities and industry to develop the semiconductor based integrated circuit, which had already been studied and researched by a few universities. (Reference: chapter 5 of the book “Digital Apollo.”)

  • wayne

    Edward/Steve– good stuff!
    The Computer History Museum is way cool.

    A demo of Charles Babbage’s Difference Engine
    -this one is in Mountain View, way cool
    (a working specimen, made from original blueprints & they used machinery from that era.)

  • wodun

    You could change the question to, “The oldest computer not in the solar system?”

  • Edward

    The Babbage Difference Engine has moved from the museum to the owner’s possession. It was very nice of him to loan it to the museum for a couple of years or so.

    You’re right. Voyager has left the building!

  • Steve Earle

    Edward said:
    “…You’re right. Voyager has left the building!…”

    Depending on how you define the “building” there are 5 spacecraft/computers that have left the Solar System so far.

    Pioneers 10 and 11, Voyagers 1 and 2, and most recently New Horizons.

    My personal definition of “leaving the Solar System” is passing the orbit of the Ninth and last Planet, Pluto.

    That’s right, I said it. Nine Planets. The last of which is Pluto.

    They can take Pluto when they pry it from my cold dead fingers….. ;-)

    I know there’s all this talk of helio-this and helio-that, but to me the Sun and the 9 Planets (NINE DAMMIT!) are what make up the “System” :-)

    The fact that 5 human-built spacecraft have left the solar system within my lifetime is incredible.

    The fact that we are still talking to 3 of them (and if we had better antennas, we might still be talking to a 4th!) is even more amazing.

    Ancient Chinese Proverb (and Curse!): “May You Live in Interesting Times”

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