Space, the final frontier

March 3rd 1972 was a day that passed by like any other for most people. yet it was a day that changed space exploration forever, altered our world view and shaped all future space missions more than any other day in history has so far ever done.


It was though, a day that was overshadowed by the Apollo missions, because Apollo 15 (launched 26th July 1971) was the first mission to take a lunar rover to the Moon with them, and the glow of that outstanding achievement outshone all others especially with Apollo 16 being eagerly anticipated and gearing up for launch on 16th April 1972. Not surprising then that the associated media overlooked the plucky little Pioneer 10 craft, whose launch date was nestled quietly and inconspicuously between those two missions just 6 weeks before Apollo 16 was due to launch.


That day, on the 3rd March, something the size of an old fashioned widescreen tv (well if you count all the booms and antennae the length would be about the length of a family sized car) was launched from Cape Canaveral on an Atlas-Centaur vehicle. It reached a speed of more than 30,000mph pretty soon after launch. This was the fastest speed that any spacecraft had ever attained.


11 hours later it reached the Moon.


12 weeks later it flew past Mars.


3 months later it reached the Asteroid Belt and began it's journey through the most populated with rocks place in the entire Solar System. Yet just to put that in perspective, over populated with its fair share of rocks it may be but the course that NASA had given the little Pioneer was to get no closer than five and a half million miles to one of those rocky bodies to ensure its safety as it passed through.


Pioneer 10 was the very first spacecraft to fly through the Asteroid Belt and through this 'gate to the outer planets'. It was the fastest vehicle that had at that time ever been made and it was speeding up. It was speeding up because the planet it was first heading for was giving it a huge gravitational welcome like no other planet in our Solar System can. Jupiter, its first destination after the Asteroid Belt, was pulling it in until little Pioneer was flying at around 80,000 mph.


It finally reached Jupiter or, as is more technically described, reached its closest approach on the 4th December 1973. Travelling at around just over 81,000 mph it passed by Jupiter around 81,000 miles above the top layer of clouds. Here is the first series of photos taken from Pioneer as it approached Jupiter. It actually began taking photos of Jupiter from the 6th November 1973, the first ever taken from so far out in space.

As it travelled 'behind' Jupiter, the planet became a crescent which gradually faded away back into the inky backcloth of sky as Pioneer left it behind forever.


In amongst all the many and varied sets of data Pioneer sent back to Earth was something extremely surprising. Even more surprising is that the vast majority of people still don't know.


Pioneer told us, that all the evidence from studying its magnetosphere leads to one conclusion, that Jupiter is not so much a gas giant, as a liquid giant! This was a totally unexpected and extraordinary discovery. Even more shocking is that this liquid is a type of liquid that does not exist on Earth, and we have no idea what it might look like! Astronomers are still getting their heads around that one! Perhaps that's why they are still referred to as the gas giants and not the liquid giants.


Pioneer achieved many firsts, first to go as fast as it did, first to pass through the Asteroid Belt, first to reach Jupiter, first to detect atoms of helium in the space between the planets, first to detect sodium and aluminium ions in the solar wind, first to confirm a long held theory that Jupiter had a heat source that was and is causing the great planet to emit more heat than it receives from the Sun, first to pass and travel further than the orbits of all the planets in our Solar System, and there were many more firsts which you can read up about on the NASA website, http://www.nasa.gov/centers/ames/missions/archive/pioneer.html


It  passed Jupiter, after taking hundreds of photos, and then went on to pass by the orbits of Saturn, Uranus, Neptune and Pluto (at that time still regarded as a planet) and became the first human made machine to head out into the great outdoors of the Solar System and reach for the Interstellar medium. Pioneer 10's mission officially came to a close on the 31st March 1997,  but NASA followed its progress for another 6 years as part of researching the technology for communicating with spacecraft and probes at great distances in preparation for future missions.


On 23rd January 2003, Pioneer metaphorically waved goodbye to us as NASA received its final detectable signal. We may not hear from it any more, but as far as we know it continues on it's way towards the Interstellar medium and then on towards the star Aldebaran, the eye of Taurus the Bull. It should only take a couple of million years or so to get there.


One more thing, when it does reach the Aldebaranians they'll know we sent it because bolted on to the Pioneer 10 (and 11)'s small frame is a small gold-coloured plaque with a nice picture of a man and a woman and of course a map of how to get to Earth in case, I imagine, they fancy a nice cuppa and a sandwich one day if they happen to be passing.