Thursday, September 06, 2007

Greetings From Earth

I’m terrible at remembering birthdays, either sending cards late or not at all. I knew it was coming up, and was an important one at that. Typically the usual everyday trivialities got in the way.

Hopefully enough people raised a glass and gave it the proper blessing: Happy 30th Birthday Voyager 1!

Launched from Cape Canaveral on September 5, 1977, aboard a Titan-Centaur rocket, Voyager’s primary mission was to conduct up-close studies of Jupiter and Saturn and their larger moons. It’s sister craft Voyager 2 – which had actually been launched two weeks earlier – would also take in the same two planets but then carry on to Uranus and Neptune.

Voyager 1 reached Jupiter in 1979, making its closest approach in early March and completing its encounter a month later. In November of 1980 it completed a flyby of Saturn and started the long journey out of the solar system.

Although Voyager 2 only followed four months behind in its survey of Jupiter, during which time the two craft sent back more that 33,000 photographs along with all the scientific data, it didn’t pass by Saturn until August 1981. Once complete, Voyager 2 used the planet’s enormous gravity fields to slingshot it on to the next stage of its Grand Tour.

In late January 1986, Voyager 2 came within 50,600 miles of the cloudtops of Uranus, radioing back images and scientific data on the planet’s rings, atmosphere and moons. Three years later and just over twelve years after its launch, Voyager 2 encountered Neptune in August of 1989.

After passing over the planet’s north pole at a distance of 3,000 miles it came within 25,000 miles of Triton. Neptune’s largest moon was the last solid body the tiny spacecraft had the opportunity to study before beginning its long journey out of the Solar System.

Once their primary missions were complete, in 1990 the Voyager Interstellar Mission began as the craft started their long through the outer environs of the solar system. On Valentine’s Day of that year the last Voyager image received was, aptly, a portrait of the solar system.

By February 17, 1998, Voyager 1 broke the record set by the earlier Pioneer 10 spacecraft to become the most-distant man-made object in space. In December 2004, the craft entered the solar system’s final frontier. Voyager 1 is currently 9.7 billion miles from the sun and still travelling at a speed of over 38,000 miles per hour, while Voyager 2 is 7.8 billion miles away.

Electrical power and propellant for the attitude control should be sufficient until 2020 by which time both craft will finally lose the ability to send back valuable data. Before then the craft are expected to cross the heliopause, the region where the Sun’s influence wanes, and interstellar space begins. After that they can both sit back and enjoy the ride.

What’s really amazing is that these two spacecraft, each made up of 65,000 individual parts, are still working at a time when more recent missions to chart our neighbouring planets have failed so spectacularly.

Ad astra per aspera. Not always. Belated Happy Birthday!


Post a Comment

<< Home