This image shows a depiction of a solar sail, and in particular of the sail used by the Japanese IKAROS mission. The idea of a thin, light, large-area surface has traditionally been based off of “sailing” on particles and radiation emitted by the Sun. However, a similar concept would leverage a highly reflective surface to reflect directed laser light 180 degrees from the surface, enabling direct propulsion and large, continuous accelerations, with the goal of completing an interstellar journey. (Credit: Andrzej Mirecki/Wikimedia Commons)

Ask Ethan: Could the ‘Breakthrough Starshot’ project even survive its planned journey?

With advanced laser technology and an appropriate sail, we could accelerate objects to ~20% the speed of light. But would they survive?

For all of human history, embarking upon an interstellar journey has been a seemingly unreachable dream, made practically impossible by the enormous distances separating our Sun from any of our stellar neighbors. Even with the most powerful rocket technology ever developed, it would take tens of thousands of years to journey to the nearest star outside of our Solar System. Even the fastest, farthest spacecraft ever launched from Earth — like the Voyager, Pioneer, and New Horizons missions — only move at a few tens of kilometers-per-second on their way out of the Solar System, meaning a journey of a few light-years will take a thousand human lifetimes to complete.

But recently, a clever idea that leverages recent developments in laser technology has hoped to change all of that: . By accelerating a “laser sail” to appreciable fractions of the speed of light, they hope to send an attached micro-spacecraft to interstellar destinations in decades, not millennia. But would those proposed spacecrafts survive the journey? That’s what…