On a recent episode of the Clear + Vivid podcast, Alan Alda interviewed NASA engineer Les Johnson about his efforts to develop a solar sail that can take us to the stars. He is the Principal Investigator for the NEA Scout, which was launched into space during the Artemis I mission and is now heading towards a near-Earth asteroid via solar sails (see above).
During the interview, Mr. Johnson discussed the NEA Scout as well as his hopes for future human travel to the stars using solar sails, noting that while slow, the sails can outperform modern rocket engines in the long-run. He also pointed out that a solar sail may be able to get us to Proxima Centauri, the closest neighboring star, in hundreds of years versus the 70,000 years it will take the Voyager spacecraft to travel that same distance. I like how he puts such a mission in perspective, pointing out it took hundreds of years to build some of the great cathedrals.
Messrs. Alda and Johnson also discussed the ethics of space travel considering astronauts will be spending generations in space with many humans never seeing either the Earth or the destination in their lifetime. Mr. Johnson said space lasers may be another option for interstellar travel at some point in the future, reducing the travel time to Proxima Centauri to 40-50 years. Given the time spans, he said it may make sense to initially send robots into space first.
Finally, the podcast covered missions closer to Earth, such as mining asteroids for water and minerals, as well as 3D printing to create what we need in space. It sounded a lot like the situation in find in the science fiction TV series The Expanse.
Overall, it was a great conversation worth a few minutes of your day. Check it out.
Extra: Mr. Johnson is also the author of several books, including the co-authored Saving Proxima. Here is a quick summary of that tale:
2072. At the lunar farside radio observatory, an old-school radio broadcast is detected, similar to those broadcast on Earth in the 1940s, but in an unknown language, coming from an impossible source—Proxima Centauri. While the nations of Earth debate making first contact, they learn that the Proximans are facing an extinction-level disaster, forcing a decision: will Earth send a ship on a multiyear trip to render aid?
Interstellar travel is not easy, and by traveling at the speeds required to arrive before disaster strikes at Proxima, humans will learn firsthand the time-dilating effects of Einstein’s Special Relativity and be forced to ponder ultimate questions: What does it mean to be human? What will it take to share the stars with another form of life? What if I return younger than my own children? The answers are far from academic, for they may determine the fate of not one, but two, civilizations.