—Walt Whitman, 1819-1892
As a species, we experienced something amazing this past week. The realization we have a starship--an honest to goodness starship--the first man-made craft confirmed to have ventured into the unknown depths of interstellar space.
|Image courtesy of NASA|
But Voyager 1, and its sister ship, Voyager 2, have been flying through space for over 36 years and though largely forgotten until this major milestone brought them back to light, they've made history in a number of ways.
- The Voyager mission was conceived in 1960 as a Planetary Grand Tour, using Jupiter's gravity as a slingshot to send the crafts on to Saturn, Uranus and Neptune. The slingshot effect was later named gravity assist.
- Voyager I and 2 were originally to be named Mariner 11 and 12, however budget cuts forced a scale-back of the primary mission. Later referred to as the Mariner Jupiter-Saturn Probes, they were eventually renamed Voyager I and 2.
- Voyager 2 was actually launched before Voyager 1, on August 20, 1977. Voyager I was launched on September 5, 1977.
- Both crafts carry the famous Golden Record containing sounds of Earth--including human voices in several languages, insects, frogs, rain, whalesong, volcanoes, and symphonies. They contain the famous greeting "Hello from the children of planet Earth" recorded by Carl Sagan's young son, and a schematic of how to play the record in addition to a depiction of Earth's location in relation to several pulsars.
- Voyager I entered the asteroid belt on December 10, 1977. Nine days later, on December 19, Voyager I overtook Voyager 2.
Image courtesy of Wikipedia
- Voyager I's primary mission ended on November 2, 1980, after exploring Jupiter in 1979 and Saturn in 1980. It was the first probe to provide detailed images of the two gas giants and their many moons. (Go HERE and scroll down the page to see an amazing time lapse video of Voyager 1's approach to Jupiter on the right sidebar.)
- Differences between photos of the Jovian moon Europa taken in 1979 resulted in scientists theorizing that Europa may have a 30 mile deep liquid water ocean interior, below 19 miles of ice.
- The Voyager probes discovered volcanic activity on Jupiter's moon Io that had not been discovered by the earlier Pioneer probes.
- After Voyager 2 observed a thick atmospheric haze over the Saturn moon Titan, Voyager 1 was diverted for a closer fly-by. Its trajectory later carrying it out of the ecliptic plane of the solar system and ending its Grand Tour which originally would have taken it by Pluto after observing Saturn.
- Voyager 2 continued on to explore Uranus in 1986 and Neptune in 1989, the only probe to have done so.
- On February 14, 1990, Voyager 1 took the famous solar system "Family Portrait"--a mosaic of 60 frames taken from 6 billion miles out--and showing six planets--Jupiter, Earth, Venus, Saturn, Uranus and Neptune--as well as our Sun. The famous image of Earth became known as the "Pale Blue Dot" and inspired Carl Sagan's book Pale Blue Dot: A Vision of the Human Future in Space. The photos were taken at 40.11 AU and 32 degrees above the ecliptic plane of the solar system.
- Voyager I overtook the earlier Pioneer 10 craft on February 17, 1998 at a distance of about 69.4 AUs. (An AU, or Astronomical Unit, is the distance between Earth and the Sun.) Pioneer 10 was launched 5-1/2 years earlier in March 1972 and was traveling outbound at approximately 28,000 mph. The last detectable signal received from Pioneer 10 was on January 23, 2003. It was well beyond 80 AU at the time.
|Photo courtesy of Wikipedia|
- Voyager 2 reached a distance of 100 AU on November 12, 2012, only the third craft to have reached this point in the wake of Voyager 1 (at 122 AU) and Pioneer 10 (at 107 AU). However, only the two Voyager craft are still communicating with Earth.
- Although Voyager I was confirmed to have crossed the heliosphere on September 12, 2013, it required over a year to determine that the craft had actually made the transition on August 25, 2012. It took over 35 years to reach interstellar space traveling at a speed of about 38,110 miles per hour.
- Voyager I's radio signals (which travel at the speed of light in space) reach Earth in only about 17 hours 23 minutes.
- Voyager 1 and 2 are expected to run out of power sometime between 2025-2030--over 48 years after their launches--but a shutdown of the science instruments will take place in 2020.
The Voyager probes have given humankind major breakthroughs in the understanding of our world, our solar system, and our universe. As a Science Fiction/Romance writer, I owe these pioneers of space exploration a debt of gratitude. So many of their discoveries and imagery have provided the backbone of research and the spark of inspiration for my work.
On Friday, an invitation was extended to the public to send a message to Voyager 1 via @NASAVoyager using the hashtag #MessagetoVoyager. I was happy to add my tweet to the many other greetings and well wishes aimed at Voyager I:
Thank you for taking us places where only our imagination could have ventured before. #MessageToVoyager @NASAVoyager #SFRBrigade
— Laurie A. Green (@SFRLaurie) September 13, 2013