Glenn Reynolds, the purveyor of Instapundit, used his weekly column in USA Today to use the occasion of the end of Cassini’s mission to Saturn to wonder if we could have sent a crewed spacecraft to Saturn in 1970. Because of a little-known military project called Orion (not to be confused with the current deep spacecraft project), the idea was not entirely frivolous.

How would Orion have worked?

The Orion project spanned from the late 1950s to the early 1960s. The idea was that the explosive force of nuclear bombs could be used to propel a spacecraft at speeds sufficient to make a three-year round trip to the Saturn system practical.

The spacecraft would be enormous and roomy, weighing about 4,000 tons. The original project showed that the concept was feasible, but it was dropped after the signing of the Nuclear Test Ban Treaty. The military, besides, did not see much use for what would have amounted to space going battleships with crews more than 100 people with enough supplies to sustain them.

Could Orion be built today?

Technically, given resources and political support, an Orion spacecraft could be constructed using 21st Century technology. The bombs used for propulsion would be designed to focus their explosive power and thus limit the fallout and EMP effects. Nevertheless, an Orion would have to be launched from a remote location.

Alternatively, the spacecraft could be assembled far enough away in space to avoid damaging the satellite infrastructure (say on the far side of the moon.)

The objection to building a modern Orion would be political. Protests have been held when probes like the Cassini were launched with plutonium used as fuel for RTG power systems.

Imagine the prospect of taking enough fissile material for thousands of miniature nuclear bombs, even if they were not set off in the atmosphere. The protests and the lawsuits would tie up the project for years, even if some fancy legal footwork could be executed to get around the Test Ban Treaty.

Reynolds suggests that some other country that is less finicky when it comes to environmental and other niceties might become the first to launch an Orion, say China or even India.

Maybe that might happen. Maybe it won’t.

Likely just the desire to get to someplace like Mars or Saturn quickly will be insufficient to revive the Orion program. The one catalyst that might make Nuclear Bomb propelled spacecraft a reality would be an impending planetary catastrophe, say an asteroid or comet on a collision course with Earth. Then the need to get to some place in space quickly and in force would override the objections to Orion.