Beyond the Orbit of Pluto
The Voyager Space Probes Continue their Unprecedented Mission
The Voyager Space probes are two of the most imaginative and daring pieces of technology ever devised by the human race. Envisioned and designed by the National Aeronautics and Space Administration (NASA) and built by the Jet Propulsion Laboratory (JPL) in the late 1970s. These two spacecraft went on to magnificently fulfill their original missions and then to travel into the heretofore uncharted depths of interstellar space. It is an unparalleled achievement in the annals of space exploration.
The Space Probes
The Voyager space probes wer originally conceived as part of the Mariner space program that was designed to study the inner planets of Mercury, Venus and Mars. An enterprising young engineer at JPL, Gary Flandro, discovered that an upcoming, periodic alignment of the outer planets would allow the Voyager space probes to make a gravity-assisted tour of the outer planets.
In late August 1977, Voyager 2 was launched ahead of its sister ship. Its mission was to make a close flyby of both Uranus and Neptune. It reached Jupiter in 1979, Saturn in 1980, Uranus in 1986 and finally Neptune in 1989. Its mission completed, Voyager 2 was aimed and sent towards the edge of the solar system, the heliopause. For 34 years, Voyager 2 has remained in contact with the Deep Space Network and reliably relayed information from some of the furthest reaches traversed by man and his machines.
Two weeks later , in early September, 1977, Voyager 1 was sent aloft on a journey to Jupiter and Saturn. Like its sister ship, it was intended primarily for research within the solar system. Unlike Voyager 2, however, it was propelled at a much greater rate of speed. Once Voyager 1 had accomplished its primary mission, it was redirected towards the edges of our solar system and in the intervening decades has become the manmade object furthest from the sun. it will continue to be so for the foreseeable future.
Both spacecraft were specially designed to send back detailed and diverse images of the intended targets. While the instrumentation on board the craft included standard optical cameras, there were a host of other imaging and measuring devices. Crowded into the ¾ ton space craft were a radio pulse measurement system, an infrared interferometer, an ultraviolet spectrometer, a plasma spectrometer and (yes, this is a real scientific instrument ) a triaxial fluxgate magnetometer. There were also numerous passive receptors that would yield valuable information.
Though their power sources are titled as radioisotope thermal generators (RTG), the two spacecraft are, in essence, nuclear powered. The radioactive decay of the isotopes included at launch produce enough heat to generate 470 watts of power each for Voyager 1 and 2. While this is a seemingly inconsequential amount of power, the spacecraft need to do little more than broad cast its data after passive collection. The Deep Space network of receivers on Earth are sensitive enough to detect and record these transmissions. The RTGs of both space probes are expected to last until, at least, the year 2020.
One of the most fascinating aspects of the Voyager space probes is the message from humanity included on each of the spacecraft. A gold-plated record with audio and visual information has been included on each of the space craft. The renowned cosmologist and personality, Carl Sagan, chaired the committee to determine the contents that would be included on the record.
The contents included audio messages from then U.S. President Jimmy Carter and then U.N. Secretary general, Kurt Waldheim. It is unclear to all what the aliens will make of the contradictory messages sent by the unabashed appeaser and the former Nazi. In addition, various sounds of Earth were recoded and included greetings in 55 languages, the sounds of human babies crying and the songs of the humpback whale. Musical selections were also recorded and included pieces by Beethoven. Mozart, Stravinsky and Chuck Berry.
There is also visual information recoded in analog and digital form. The analog images feature a stylized representation of man as well as the hydrogen atom and a pictorial description of a record player. The final image is intended as a guide for the space faring species that discovers the record.
Where Are They Now?
The two Voyager space probes have been in transit for a little over 34 years. Their current speed is now a little over 16 kps or 36,000 miles per hour. While light travels at 300,000 kps, this is not Star Trek Voyager. For a more realistic perspective, the Apollo space craft traveled at approximately 25,000 mph on their trip to the moon. While this speed is a veritable rocket here on Earth, it is a mere pittance when it comes to interstellar travel. At its current speed, Voyager 1 will need another 75,000 years to reach the next star system.
Still, Voyager 1 is the furthest manmade object form the Earth. Currently, Voyager 1 is just over 11 billion miles (18 billion kilometers) from Earth; that’s 120 astronomical units (A.U.), the distance form the Earth to Sol. Bear in mind that man sent these two probes into outer space with the technology of the 1970s; modern cell phones have more computing power. Without a doubt, the two Voyager space probes are an amazing accomplishment that still yield important scientific results to this day.
The Aliens Finally Answer
One of the more obscure pieces of information available about the Voyager space probes is that intelligent, alien life, while never seen, has indeed been contacted. On April 1st, 2012, NASA indicated that first contact had been made with an alien civilization. A short burst of non-random, electronic signals were recorded at the Arecibo Observatory in Puerto Rico and then a lengthy message followed. The short message repeated at 30 second intervals but the longer message was sent only once. The greatest cryptologists in the world were enlisted to decipher the digital messages. They translated the short burst fairly easily. It simply read,
“Send more Chuck Berry. NOW!!”
The lengthier message was a description of the various destructions that they would visit upon the Earth if we failed to comply with their simple command. Since then, Chuck Berry recordings have been beamed continuously towards a nearby star in the Orion nebula. And so it goes.