Tuesday, July 11, 2023

In the Light of Other Suns

The Eighth Interstellar Symposium, entitled "In the Light of Other Suns" is underway this week at my alma mater, McGill University, in Montreal, Quebec.  Hosted by the Interstellar Research Group and Professor Andrew Higgins, the space conference includes studies of various challenges associated with interstellar flight... and there are many!

Last night, I was fortunate enough to be in a sold out auditorium for a panel discussion amongst experts with varying backgrounds.  The six hundred in attendance sat attentively as a wide range of questions were addressed, from "How much might the transit depicted in Avatar 2 cost?" to "Is it ethical to have a child on a planet that is not Earth, virtually guaranteeing that they will never set foot on their species' origin planet?"  The answer to the former is on the order of petadollars (billions of billions of dollars), and the answer to the second is "We don't know."

The experts have no illusions that people will be travelling to Alpha Centauri in the coming decades.  They anticipate microsatellites being propelled at relativistic speeds (>0.1c) to take pictures of exoplanets in that timeframe.  Starships with people might be a hundred years away.  So, why are distinguished professors studying them today?

The economic answer is that long term projects overcome incremental hurdles that enable spinoff technologies in the present.  But there are so many more reasons, like the plain fact that we are an aspirational species.  NASA technologist Les Johnson, irked by the question of economic returns associated with interstellar flight, posited that humans wanting to know things is reason enough (a comment that elicited enthusiastic applause).

Current engineering studies examine photonic propulsion and the highly reflective surfaces required to reach dizzying speeds.  Others look at the stability of a tiny satellite's trajectory while being bombarded with photons or collisions with space dust when moving at some fraction of c.

I was expecting to hear more about Breakthrough Starshot, the aforementioned mission to snap photos of exoplanets and send them back to Earth.  It seems that the interstellar community is becoming less focused on this one particular mission, instead looking at energy propulsion in a broader sense.  The possibility of a one month transit to Mars was discussed; the spaceship would use a 1g acceleration for the first half of the trip (lasers pushing it from Earth) followed by a 1g deceleration during the second half (lasers pushing it from Mars).  So ya, it would require laser arrays deployed on the Martian surface, but don't worry, studies have looked into the feasibility of that too.

Is it a space symposium for dreamers?  Absolutely.  But power to them (the photonic kind).  A technical engineering conference that can fill a large auditorium is doing something right.