On Cassini, Voyager and the Rest
And so now the Cassini spacecraft has ended its mission and I have been very pleased over the years to see it succeeding so thoroughly. A follower and proponent of the exploration of space from birth, I feel that this year in particular is worth reflection.
Having been born in the same year as the launch of the Voyager 1 and 2 spacecraft 40 years ago, I grew up with their journey through the solar system in the 1980s. I recall anticipating Voyager 2’s arrivals at Uranus and Neptune in 1986 and 1989 and watching as new astronomy books thereafter included pictures of these planets and their moons where previous books could only rely on artists’ conceptions and poor telescopic images. Now these probes are far beyond Pluto and are setting out into interstellar space; though they are still functional it is likely that their radioisotope generators will wind down to inoperability before 2030. Then the spacecraft that truly opened up the outer solar system and gave us the perspective of our world as a pale blue dot in the Cosmos will be silent, though they each carry perhaps one of the most enlightened and hopeful artifacts we have ever produced – the golden records crammed with music, sounds, greetings and pictures from Earth. Their importance lies not as much in the slight possibility that they will be found by an alien intelligence, or even our own descendants in a distant future, but that we were hopeful enough about our future to do it and that something meaningful of Humanity has escaped not just the confines of Earth but the empire of the Sun. Billions of years from now when things here are utterly different than they are today, those two records will likely be much the same as they were when launched. In fact, not only are the two Voyager spacecraft headed beyond the solar system, but the earlier Pioneer 10 and 11 spacecraft (each with a modest plaque illustrating something of the creators of the probes and where they came from) and the New Horizons probe (which recently flew past Pluto) join them. But for myself, feeling a sort of kinship, I seem to accompany the Voyager probes in our mutual explorations of the Cosmos.
I recall reading about the Cassini spacecraft, then under construction, in the early 1990s and in 1994, at a chance meeting with a science journalist, asking if it was still in development, always afraid of a cancellation. When the spacecraft was launched in 1997 I was in my first year of university and I remember bringing it up at a birthday shindig to which I had been invited, as it coincided with the individual’s very birthday. Such news met with a lukewarm reception, but then at that early date the probe could just as easily have fallen into the ocean on launch or failed en route. When, after its long journey, Cassini arrived at Saturn in 2004 I was a high school teacher and I kept my students informed of the discoveries being made, especially when the Huygens lander which had hitched a ride to Saturn on Cassini’s underbelly parachuted to the surface of the moon Titan. Titan, a moon bigger than our own with an atmosphere thicker than Earth’s, a surface filled with primordial organic chemicals, covered in lakes of methane and dunes made up of grains of ice. A world where, were we to land there, our habitats would not need to pressurized, merely heated above the ambient temperature of -180 °C as we explored an environment perhaps similar in many ways to the early pre-biotic Earth. So now 20 years after its launch, after a successful survey of Saturn’s domain, running low on fuel, Cassini has been dispatched into the clouds of Saturn and incinerated as its cousin, the spacecraft Galileo, had been at Jupiter and for the same reason – to prevent the possible contamination of nearby moons with bacteria from Earth.
With the long term survival and prosperity of Humanity in continued and heightened peril, it is always tempting for some to suggest that such endeavors as the Voyager and Cassini missions are not worth the cost. Although these spacecraft have validated the techniques of interplanetary travel, returned a wealth of scientific information, captured the imaginations of millions, given us a new perspective on our place in the universe and quantitatively allowed us to compare these other worlds to our own, thus improving the understanding of our own home, let us put this aside for the moment. The cost of these missions is a pittance compared to our expenditures on military matters which directly threaten our survival and to the amount of money hoarded by the wealthiest members of our society. However, those who would write off space exploration as superfluous hardly then claim that nuclear warfare or extreme wealth inequality are necessary. Perhaps these are seen as the unfortunate features of a world order that cannot be imagined any other way, whereas not exploring space is as easy as not funding it. Nevertheless, I am ultimately optimistic about our future.
What also makes 2017 such an auspicious year in terms of space anniversaries is that come this October 4th it will have been 60 years since the first satellite (Sputnik I) was launched and one could say that the Space Age began. At that time my parents, who were then only married 2 years, went outside like many to see whether they could spot a glint of light off of what was our first toe into the waters beyond Earth as it went beeping overhead.