Podcast: Solar Sailing to the Stars

Image (Credit): NEA Scout sail fully deployed. (NASA)

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.

Credit: Baen Publishers

A Day in Astronomy: The Birth of Carl Sagan

Image (Credit): Astrobiologist Carl Sagan. (Nautilus.us)

On this day in 1934, scientist and communicator Carl Edward Sagan was born in Brooklyn, NY. He was to become a great communicator of all things related to astronomy. He has played a key role over the years introducing millions to our place in the universe through his books, television series, speeches, and scientific work. His television series Cosmos was a milestone in educational television, bringing the stars and planets into everyone’s living room, while his books (Contact, Pale Blue Dot, The Dragons of Eden) continue to encourage the next generation of astronomers.

Dr. Sagan has a long resume, but I am most fascinated with his work to communicate with extraterrestrial life. He was a strong supporter of the Search for Extra-Terrestrial Intelligence (SETI) and worked with NASA to ensure our spacecraft were equipped with a record of human activity to educate other planetary civilizations, including the gold records placed on the Pioneer 10 and 11 space probes as well as the two Voyager space probes.

Years ago, the Smithsonian magazine had a good summary of Dr. Sagan’s life in the article “Why Carl Sagan is Truly Irreplaceable.” I recommend the article as a good way to get to know the man, though delving into his books is even better.

Credit: Ballantine Books

Extra: Carl Sagan was also the founder and first president of the Planetary Society. Visit this Planetary Society site, Ann Druyan wishes you a happy Sagan Day, for more on Dr. Sagan’s work.

RIP: Astronomer Frank Drake

Image (Credit): Photo of Frank Donald Drake. (SETI Institute)

We lost a grand mind last Friday with the death of astronomer Frank Drake at the age of 92 (1930 – 2022).

In addition to giving us the famous Drake Equation pertaining to the potential existence of extraterrestrial intelligence in our galaxy, he spent his life looking for signs that we are not alone and served as the president of the SETI Institute as well as director of the SETI Institute’s Carl Sagan Center for the Study of Life in the Universe. Among many other things, he also worked with Carl Sagan on the “Golden Record” placed in the Voyager spacecraft.

One thing that comes across from interviews is that he was a very hopeful man who did not tire easily. In an earlier interview with Space.com, he shared this unique view of our space neighbors:

That reminds me of something else. We have learned, in fact, that gravitational lensing works. If they [aliens] use their star as a gravitational lens, they get this free, gigantic, super-Arecibo free of charge. They are not only picking up our radio signals, but they have been seeing the bonfires of the ancient Egyptians. They can probably tell us more about ourselves than we know … they’ve been watching all these years.

You can watch Mr. Drake discuss gravitational lens and more in this earlier lecture on YouTube. You can also learn much more about Mr. Drake’s career and activities at FamousScientists.org.

Image (Credit): The Voyager Golden Record cover shown with its extraterrestrial instructions. (NASA/JPL)

Space Mission: A Trip to the Oort Cloud?

Image (Credit): Illustration of the Oort Cloud – not to scale. (Mikkel Juul Jense / Science Photo Library)

While NASA does not have any plans to send a specific missions to study the Oort Cloud, the most distant region in our solar system containing trillions of frozen objects, it has already sent five spacecraft in that direction. Two Voyager spacecraft, two Pioneer spacecraft, and the New Horizons spacecraft are all heading that way, but it is quite a distant.

For example, the Voyager spacecraft will not hit the Oort Cloud for another 300 years and will continue to travel through the cloud for another 30,000 years before escaping the solar system. As a result, all of these spacecraft will be dead as a rock before ever hitting that region and of no use to anyone back here, yet they will still carry messages from all of us to the stars. So in that sense, they still have a mission to perform should anyone be out there.

The Oort Cloud is still a theory since it has not been observed, but there is plenty evidence regarding its existence, including the comets that come into the center of our solar system from that region. The cloud itself is believed to be a sphere rather than on the same plane as the planets, so it forms a protective ring around the planets potentially becoming a hazard to any incoming or outgoing spacecraft. What this will mean for interstellar space travel, should that day come, is anyone’s guess at this point.

You can read more about the Oort Cloud here.

Videos: The Golden Record on the Voyager Spacecraft

Source: NASA.

Years ago, two spacecraft exited our solar system at about 35,000 miles per hour with a message to anyone who finds them detailing our location in the galaxy, the beauty of the Earth, and our culture in terms of warm wishes, music, and natural sounds. Crafted by Carl Sagan and others, the golden discs or records placed on Voyager I and II also contains instructions on how to read the material. And thanks to the site Open Culture, we can learn more about how one would unravel these instructions. It reminds me of Jodie Foster’s character in the movie Contact as she tried to interpret signals being received from afar. I recommend you check out the two videos that are part of the “How to Decode NASA’s Message to Aliens” page.

Source: Jodie Foster in Contact from Warner Bros. Pictures.