We Are Living Carl Sagan’s Dream for Space Exploration
published during a waning crescent moon.
Carl Sagan's Dream

Carl Sagan.

My first remembered experience with space was when I was about six years old. This was in the early 60’s just after President Kennedy set a course to send humans to the moon. I followed all the space missions passionately, and I had done quite a bit of reading about space, but it wasn’t until my father bought me a small telescope that I directly experienced the thrill of it for myself.

In my mind’s eye, I can still see my first view of a planet beyond Earth.

I grew up in a tiny town of about 200 people far from any major city lights. At night, you could easily see the Milky Way with your unaided eye. You could make out the embedded dark lanes, where dust clouds obscured the starlight from the center of the galaxy. You could see thousands of stars—I once tried to count them! It’s actually very difficult to do.

At the time, I had no idea how to use a telescope. So I set it up in our backyard and looked at a bright yellow star that appeared a little unusual in that it wasn’t twinkling like the others. This first look through my new tiny telescope just happened, by chance, to be of the planet Saturn. Saturn is, of course, the giant gas planet with rings. It certainly appeared very small, but the image was very crisp, and the rings were clearly there. In my mind’s eye, I can still see my first view of a planet beyond Earth.

I was enthralled.

I knew that I would somehow be involved in astronomy for the rest of my life. I couldn’t image doing anything else! But I didn’t know at the time that you could actually get paid for it. It was a nice surprise in high school to learn that people do get paid to look through telescopes.

Carl Sagan's Dream

Credit: Michael J. Bennett

In all the history of mankind there will be only one generation which will be the first to explore the solar system…

As I got older, I did as most astronomers do and consumed Carl Sagan’s books. One of my favorites was The Cosmic Connection. I remember reading what I thought a bit corny at the time:

“In all the history of mankind there will be only one generation which will be the first to explore the solar system, one generation for which, in childhood the planets are distant and indistinct discs moving through the night, and for which in old age the planets are places, diverse new worlds in the course of exploration.”

It took me a long time to realize that not only was I a member of the generation he was thinking about but even more amazingly, I became a part of this space exploration effort. During my 40 years long career, I have worked with NASA’s missions to Mars, Jupiter (and its moons), Uranus, and Neptune (and its moon, Titan). More recently, I worked on the New Horizons flyby of Pluto last year and was a first-hand witness to the completion of NASA’s ambition of a robotic reconnaissance of all of the planets. I can still hardly believe that I was blessed to play small roles in these missions, which will be in the history books of the future.

Carl Sagan's Dream

NASA’s Solar System Exploration Map. Credit: NASA

“Surprised” is too weak of a word to describe our reaction to every spacecraft encounter with a planet, asteroid or comet I’m not sure there are words to adequately describe the sense of discovery that we’ve repeatedly felt as we’ve explored our planetary backyard in this grander universe. Perhaps we should have had a poet as a member of every space mission to better capture the intense thrill of discovery.

But we’ve also found that there are dangers as well as opportunities in space.

We’ve found a solar system rich beyond measure in liquid water, organic materials, and energy sources – all the ingredients we learn about in elementary school that are necessary for life as we know it. Three of Jupiter’s moons and two of Saturn’s have subsurface oceans of liquid water, larger in volume than all the oceans on Earth combined. Pluto has a rich layer of organic material coating much of its surface and likely has liquid water in its interior. The asteroid belt contains millions of times the amount of metals that have been mined on Earth in all of human history. Water and carbon-rich compounds are found there in vast abundances that could supply humanity’s needs for thousands or maybe millions of years.

But we’ve also found that there are dangers as well as opportunities in space. For instance, we’re still trying to understand the physiological changes in human bodies due low gravity. Scott Kelly’s yearlong stay in the International Space Station is one of our most important experiments testing how humans respond to the space environment. Medicine is currently being re-invented for humans in space.

There are other dangers as well. We sometimes see “shooting stars” (more properly known as meteors) in the night sky that are caused by grains of sand hitting the Earth’s upper atmosphere at speeds high enough to cause them to vaporize. There are much larger objects orbiting the sun as well. These we call asteroids; some are as large as Texas. Thousands of these cross the Earth’s orbit and will eventually collide with the Earth. One such asteroid measuring about 10 km in diameter hit the Earth 65 million years ago causing the dinosaurs to go extinct, as well as wiping out over 50% of all life on our planet. Another meteor, about the size of a small mountain, exploded in the Earth’s atmosphere and flattened hundreds of square miles in Tunguska, Siberia in 1908. We are due for another of these smaller impacts.

There is also weather in space. Typically, the solar wind is a benign, fast moving plasma streaming away from the sun. A small portion of this wind hits the Earth’s magnetosphere and is funneled into the Earth’s polar regions. When that happens, they produce the fantastically beautiful auroras. The strength of this wind is increased a million fold during solar storms. Some storms can be large enough to wipe out communication satellites. Intense solar storms can also disrupt power grids over much of the Earth. In space, astronauts that are in unshielded space capsules would be exposed to lethal levels of radiation. This is a problem that we must solve before humans go on multi-year missions in space.

Carl Sagan's Dream

But the biggest danger ahead of us when we talk about space exploration may be the one that humans take with us into this frontier. The military knows well that space is the ultimate “high ground” for battle. That is why the US, China, and Russia are developing space applications as fast as their technological sophistication and funding will allow. Battles will eventually be fought both in space and from space. The battles may be fought over who owns the vast resources in space, or it may be over ideology. But our guide of world history shows that battles and wars will happen wherever humans go.

Space exploration is one of the most inspiring frontiers for our current and next generation of scientists.

But there is no doubt that we have a stronger space exploration effort now than at any time since the Apollo program in the 1960s. Astronaut applications at NASA are at record levels, and commercial space pilots will soon be flying to the ISS, opening up a new era in the commercialization of manned space flight. Space exploration is one of the most inspiring frontiers for our current and next generation of scientists.

So what would Carl Sagan say now that we have fulfilled his vision for the first generation of space-faring humanity? Personally, I find it sad that we can’t ask him ourselves. Sagan had an unstoppable optimism about the future of humanity and the power of imagination. But if I try to imagine what he would say in response to all that we’ve recently accomplished, I think it would go something like this:

There will be only one generation in human history that will be the first to move human civilization into space, one generation that in childhood will know of cities on Earth, but when looking back from old age will see cities on the moon, Mars, and asteroids, and that will be able to watch as the space frontier moves outward beyond the planets toward the stars.

Those of you still in school and trying to decide upon a career are this next generation. You have the grand opportunity of watching these events occur in your lifetime. You have the even grander opportunity of helping make it happen.