Voyager 2 received commands in early November to switch to the backup set of thrusters that control the roll of the spacecraft. I keep close tabs on the Voyagers because, still operational, they constitute our first interstellar mission, headed beyond the heliosphere and still returning data. Launched in 1977, they’re an obvious example of long-term survival in space, an issue that will become increasingly visible as we plan for longer and deeper missions beyond our Solar System. We got word on November 5 that Voyager 2 has accepted the new commands.
Let’s talk about this first in terms of engineering. Behind the switch is the need to reduce operating power, for using the backup thruster pair that controls roll motion will let engineers turn off the heater that warms the fuel line to the primary thruster, saving about 12 watts of power. With Voyager 2’s power supply providing about 270 watts, finding savings like this can help the spacecraft remain operational. It’s remarkable to consider that the thrusters involved here have fired more than 318,000 times, while the backup pair has not yet been used in flight. Voyager 1 made a similar change in 2004 and is now using all three sets of its backup thrusters.
Sometimes when I read the relatively dry language of the status reports on Voyager my thoughts turn to ancient journeys that once defined out thinking. Pushing deep into the unknown evokes Homer to me, the journey of Odysseus and his crew on a ten year attempt to find their way home while running into all manner of mysteries, but of course there are mythic links to man’s innate urge to explore in many other cultures. Just making such connections seems like a romantic view of hard science, but why not? I just read Athena Andreadis’ short interview in SF Signal in which she talks about the uses of intuition in science, coupled with a ‘type of rigor and dedication usually associated with monastic orders.’ She goes on to liken scientists to wizards and ‘astrogators who never sleep,’ a direct nod to speculative fiction and its influence.
Andreadis knows all about hard science, of course. She’s a researcher in molecular neurobiology as well as being a cross-genre writer of considerable talent. We’re just coming off the Thanksgiving holiday here in the States and with the weekend approaching, I’m in a reflective mood anyway, so what Athena says about science has a fine resonance for me this morning, wrapping itself around the Voyager story and its interplay with the human need for journeying. Later in the interview, Charles Tan asked Andreadis whether the exploration of space was essential to the human future. The answer is a qualified yes, but one that takes into account our frequent over-estimation of our own destiny and the things we are capable of:
Space is inherently hostile to humans. People argue that humans have managed to overrun Earth and hence we can do the same beyond Earth, given advanced enough technology. However, we evolved here and even now, despite our technology, we are helpless before major planetary upheavals. The concept of going beyond our planet has a powerful hold on our imagination, for a good reason: we have a deep-rooted urge to explore, which is both a blessing and a curse. The challenges of crewed space expeditions are mind-boggling.
How true, and how often understated! But Andreadis believes in the attempt as part of that same urge for exploration that has seen ships embarking for ports unknown throughout our history:
Even so, I think it is indeed essential that we take to space at some point. Not for fortune or glory, but because we yearn for the next horizon. At the same time, we need to be deeply aware that we can never “conquer” space. The self-serving inanities of the Strong Anthropic Principle aside, triumphalism will avail us naught in a universe that is supremely indifferent to us and our aspirations.
In the poem ‘Mid-Journey,’ Andreadis writes in a way that calls up Homeric venturing and echoes (for me at least) Tennyson’s own Homeric reflections on getting older in ‘Ulysses’:
How plucked and gutted is our bright youth!
The gates of heaven stood open back then.
Now, fatigue and demons track our trail.
Within us and behind us, blood and darkness
And for those who loved us, ruins and flames.
Warmth and comfort are yokes for us.
We chose thorns, shoals and starlight.
We vowed ourselves irrevocably to battle.
We will die exiles, mercenaries to strangers,
Having seen and dreamed imperishable beauty.
You can hear the poem read aloud here. Stephen Pyne works nicely with the mythic nature of our spacecraft in his Voyager: Seeking Newer Worlds in the Third Great Age of Discovery (Viking, 2010), mindful of the need to relate what we do with science to the great themes of exploration as they have played themselves out in fact and in myth throughout history. We do well to remind ourselves, as Athena does, of both the rigor of science and the informed intuition that breeds the magic of discovery. I think about both, and about long voyages on wine-dark seas, when I imagine our Voyagers, still alive, being prepared for still deeper wanderings.