100-Year Starship: Project Orion revisited

Recently Pete Worden of NASA's Ames Research Center ignited a flaming poop-storm when he announced, among other things, that NASA and DARPA (Defense Advanced Research Projects Agency) had been allocated joint funding to study building a manned vessel which would take about 100 years to reach the nearest stars.

Almost immediately, commercial news outlets (notably Fox, but there were others) mangled this information into something incoherent and undecipherable, but definitely sinister.

Here's the actual (fairly innocuous) DARPA press release, in its entirety: 100-Year Starship

So let's unravel and debunk this mess. The first and most legitimate question that the media asked was, why DARPA? Answer number one is, DARPA gets funding easily. It's much easier to get project money earmarked through DARPA than through NASA or JPL. The second answer is that any vessel capable of getting to the nearest stars inside of a century can also get anywhere in the solar system Really Fast, and besides the obvious mundane applications for this, it could be our very best (and possibly only) hope of being able to intercept and deflect a large asteroid or comet from a collision with the earth. So, it legitimately counts as "defense", just not defense against a sentient enemy.

What is the "100-Year Starship"?

It is important to understand that when NASA talks about a 100-year starship, this is not new technology. In fact, the technology is older than the Mercury missions. That's not a typo: we had the ability to build a ship to the nearest stars four years before we launched Alan Shepard into space (and four years before the Soviet Union launched Yuri Gagarin into space, 23 days earlier than Shepard).

This was Project Orion. Orion was the brainchild of Stanislaw Ulam, Cornelius Everett and Freeman Dyson, although it is Dyson who will forever be credited as the father of this technology. Orion relied upon External Pulsed Plasma Propulsion (EPPP), also known as Nuclear Pulse Propulsion. EPPP is a nice and scientific way of saying, take a string of firecrackers and set them under an empty soup can and light them, and the soup can will fly all over the place; now we just need a really big soup can and a string of atomic bombs to light off under it. Instant starship, just add uranium.

The thing about Orion was, by virtue of being propelled by atomic bomb blasts, not only could the ship itself be big, it actually HAD to be big. Really big. As in, more internal space than a really good-sized container ship kind of big. Which, if you were going to be stuck in the thing for 90+ years, was probably for the best.

As originally envisioned and designed, Orion used a simple nuclear fission pulse, to attain a maximum speed of about 5% of the speed of light, or about 10,000 km/second. Compared to the Apollo or (now erstwhile) Constellation chemical rockets which maxed out at 12 km/second, or even solar sail technology which could theoretically attain 140 km/second, Orion seriously hauls ass.

At 10,000 km/second, Orion could travel from the earth to Jupiter and Europa in about 24 hours. From earth to Saturn, Enceladus and Titan would be about 30 hours. And yes, from earth to Alpha Centauri would take about 90 years.

If we had launched Orion in 1960 toward Alpha Centauri, it would be more than halfway there by now. All for about $24 billion, a little less than the combined cost of the Apollo missions.

Project Orion was canceled due to the Partial (nuclear) Test Ban Treaty of 1963. But the Cold War is over, and now (unlike in 1957) it is reasonable to conceive of building and launching such a vessel from orbit, rather than from the earth's surface, which has some serious problems. So, Orion is being quietly revisited. There are several newer versions of the Orion theme, such as the Gabriel Project, but the underlying technologies and principles are basically the same.

Here is the original (once Secret, now Unclassified thanks to FOIA) proposal for Project Orion, in its entirety. Project Orion 1957

Ad astra, babes.

UPDATE:

One of my Zenith Maritime Academy students recommended a book to me about Freeman Dyson and Project Orion and Dyson's son George, whose work with redesigning the Aleutian Baidarka was nearly as groundbreaking as his father's. It's called The Starship and the Canoe by Kenneth Brower. It looks like a very cool read. Thanks, Barton!