Everything Everywhere Daily: History, Science, Geography & More - Project Orion

Starting point is 00:00:00 In the years immediately following the end of the Second World War, several of the scientists who took part in the Manhattan Project had an explosive idea. They wondered if we could harness the incredible power of atomic bombs and put them to use for peaceful purposes. In particular, what if we could use atomic bombs to literally blast ships into space? This idea went further than you probably think it did. Learn more about Project Orion and the quite serious idea of blasting ships into space on this episode, of everything everywhere daily. What if your perceptions about the past were wrong? ThruLine is a podcast that takes you back in time

Starting point is 00:00:51 to uncover the parts of the story that may have gone unnoticed. It effectively turned day into night. And how it shaped the world now. Time travel with us every week on the ThruLine podcast from NPR. There are different types of crazy ideas. There are plausible crazy ideas. and implausible crazy ideas. In a previous episode, I talked about a project which was conceived called Atlantropa, which proposed damning the entire Mediterranean Sea in two different places,

Starting point is 00:01:27 as well as flooding much of Central Africa to create an inland system of waterways. Atlantropa is what I would call an implausible crazy idea. Assuming it could be accomplished would require an enormous amount of the world's productive capacity, and upon completion, it would have destroyed enormous ecosystems on both land and sea. Atlantropa was nothing more than an idea hatched by someone who never really sat down and did the math to see how it would work. The topic of this episode is not quite the same as the Atlantropa episode. Project Orion was, by all accounts, a crazy idea.

Starting point is 00:02:01 However, unlike Atlantropa, some very smart people sat down and did the math and came to the conclusion that it could actually work. Whether or not it would have been a good idea is a completely different story. The story starts in the aftermath of World War II and the Manhattan Project, which created the world's first atomic bomb. Many of the scientists who had worked on the bomb were horrified at the destructive potential of the device that they had created and were looking for peaceful uses for it. In particular, one physicist from Los Alamos and a key member of the Manhattan Project

Starting point is 00:02:32 was Stanislaw Ulam. Stanislaw Ulam was one of the giants of 20th century physics and mathematics. Not only did he help create the hydrogen bomb, but he also developed ideas of cellular automation and Monte Carlo simulations that are used in computing. In 1946, Ulam realized that the enormous forces unleashed in an atomic blast could potentially be used to propel an object into space. In a previous episode, I talked about Operation Plumbab, which was a series of atomic tests that were conducted in Nevada in the late 1950s.

Starting point is 00:03:05 One of these tests involved an underground detonation of a nuclear device. The device was placed down a deep borehole, which was then covered by a steel cap that was welded in place. The detonation sent the force of the blast, straight up the borehole, and blew off the cap at speeds six times greater than the escape velocity required to leave the Earth. Some people think that that steel cover may have been the first thing humans ever launched into space, assuming that it survived the flight through the atmosphere. That method of using an atomic bomb to launch something into space was not what Ulam was thinking. He was thinking of dropping bombs behind a vehicle, which would then be detonated to propel the vehicle into space. And it wouldn't just be one bomb either, but a series of bombs that would be ejected behind a ship to keep propelling it. The idea was called nuclear pulse propulsion.

Starting point is 00:03:58 In the few seconds since I've mentioned this, there's a good chance you may have come up with several objections as to why this wouldn't work, or at least why it wouldn't be a good idea. and I assure you those were addressed and I will get to them in a bit. In 1947, with the assistance of Frederick Rhinis, who later went on to win the Nobel Prize in physics, Ulam did the calculations and found that the idea was plausible. He and Rhinis published his result in an internal memorandum. The idea didn't die. In 1955, Ulam wrote a more extensive classified paper on the subject detailing just how such a system would work. The idea floated around for years, and in 1958 it was picked up by,

Starting point is 00:04:37 the physicist Ted Taylor who worked for General Atomics, which was a subsidiary of the defense contractor General Dynamic. Taylor convinced another major physicist, Freeman Dyson, who worked at the Institute for Advanced Study in Princeton, to come and work on the project for a year. It was given the name Project Orion, and DARPA, the Defense Advanced Research Projects Agency, agreed to fund it for the tune of $1 million per year. The fact that the Soviet Union had just put Sputnik in orbit a few months earlier certainly didn't hurt. Taylor, Dyson, and the team on Project Orion had to think about how to turn this from a theoretical idea into something that could actually work. One of the first realizations they had was that, at least from an energy and thrust standpoint, a nuclear explosion wasn't any different than a chemical explosion.

Starting point is 00:05:24 It was just bigger. The first challenge was, how do you develop such a vehicle? Vehicles designed for spaceflight usually have to be small and lightweight to save on fuel. And here I'll reference my episode on the rocket equation. Such a small spacecraft would literally be ripped apart in a nuclear blast. So, for starters, the vehicle would have to be large and well built. Instead of lightweight metals like aluminum or titanium, it would probably have to be built from heavier materials such as iron and steel.

Starting point is 00:05:53 To this extent, it would have to be built more like a battleship than an airplane. The vehicle would have to have a very broad flat surface that became known as a pusher plate. The pusher plate would be the surface that the blast from the explosion would push. against to propel the vehicle. However, it wasn't as simple as just having a very broad surface to push against. Nuclear explosions are, well, nuclear explosions. There will be some amount of damage done to the pusher plate from the high temperatures. So it would have to be designed to degrade to a certain extent. Similar to how a heat shield is designed to degrade when a spaceship re-enters the atmosphere. Finally, the thrust provided by the bomb would be an enormous jolt to the

Starting point is 00:06:35 vehicle and anyone inside it. would have to be some sort of shock absorber to even out the jolts that came from the explosions. They originally considered an airbag system, but realized even the slightest flaw in the explosions could rupture the bag and destroy the vehicle. They eventually settled on a dual system of springs and gas pistons. The issue of the size of the shock from each bomb also had to be considered. The type of explosions used would need to be smaller bombs, not the enormous megaton hydrogen bombs. These would be much smaller than the bombs that were used in Hiroshima or Nagasaki. These would be smaller explosions under one kiloton.

Starting point is 00:07:10 The bombs would have to be ejected out the back of the vehicle through a hole in the pusher plate. However, small explosions means you need more of them in order to get an equivalent amount of thrust. It was calculated that the optimal place to detonate the bomb would be 20 to 30 meters beyond the pusher plate at a rate of one explosion every 1.1 seconds. The total number of explosions required to launch some of the largest designs approach 800. 800 nuclear bombs detonating one after another about one second apart. To put that into perspective, there have only been 520 atmospheric nuclear explosions conducted in human history. The total amount of thrust generated by this system would have been significantly greater

Starting point is 00:07:58 than that generated from chemical rockets. There were big plans floated by the Orion team for the type of missions that were possible. They felt that they could do a round-trip mission to Mars that could be completed in just four months. The motto of the Project Orion team in the late 50s was Mars by 1965, Saturn by 1970. And mind you, this was before any human being had ever been put into space. A proposed landing on Mars would require even more explosions to slow down and land the craft, as well as to launch it off the surface of the planet again. Many of the team members for Project Orion were so optimistic that they were planning to take their families on trips with them. All of this planning was theoretical.

Starting point is 00:08:42 No one had ever propelled anything using pulse propulsion, aka explosions before, even using conventional explosives. So in 1959, they set out to do just that. They conducted a test to see if they could, in fact, launched something using a series of rapid conventional explosives. And? And it worked. Sort of. The model of the vehicle they built managed to reach an altitude of 100 meters or 300 feet, and you can find videos of this test on YouTube that have been declassified. The biggest problem with the test was stability. You can't really steer an explosion. The model did go up, but it did so in a very awkward fashion. It was very easy to see how one blast

Starting point is 00:09:27 that went the wrong way could easily tip it in the wrong direction and have it crash into the ground. Despite the strong belief in the program by the Orion team, the idea never really caught on anywhere else. DARPA eventually pulled funding and Project Orion eventually sought funding from the military. The military, of course, wanted military applications for Project Orion. The Air Force envisioned Orion launching a massive platform that could sit in space, filled with nuclear warheads that could be dropped anywhere on the planet at a moment's notice. They basically wanted to make a Death Star. The Marines envisioned a system that could transport hundreds of troops around the world in just 30 minutes.

Starting point is 00:10:05 There is a problem with all of these ideas, and it's something I haven't mentioned yet that you've probably thought of already. Radiation and nuclear fallout. The atmospheric nuclear tests, which had already been conducted, were starting to show evidence all over the planet. High levels of strontium-90 were found in milk and were showing up in the teeth of babies. This led to increase public concern about atmospheric testing, which eventually, led to the partial nuclear test ban treaty of 1963. It banned the detonation of nuclear weapons in the atmosphere, in the sea, and in space. Dyson's initial calculations was that each Orion launch would kill up to 10 people from radioactive fallout. Moreover, Freeman Dyson also couldn't get around

Starting point is 00:10:48 the problem of radiation. Anyone inside of an Orion vehicle would be extremely close to every detonation, which would mean being exposed to high amounts of powerful gamma radiation. Given the proximity of the crew, they would receive a dose of about 700 rads of radiation for every detonation. A 1,000 rad dose is considered lethal. 700 rads would probably kill most people, if not cause very serious illness. Now multiply that times 800. It would require an enormous amount of radiation shielding. After the passage, of the test ban treaty. Interest in Project Orion vanished for obvious reasons. Despite the lack of interest in Project Orion, interest in nuclear pulse propulsion never completely disappeared. While it would

Starting point is 00:11:37 probably never be used to launch anything from the surface of the planet, it could be used in space to deflect an asteroid heading towards Earth. In fact, it could probably provide the best short-term solution if our planet should ever find itself on a collision course with a large object. There are also ideas for nuclear pulse propulsion that doesn't involve bombs. There are fusion-based systems that have been proposed that would just expel a small pellet behind a spaceship that could be hit with lasers to ignite a fusion reaction to achieve basically the same thing. And the idea of non-pulsed nuclear rockets is also not dead. And in fact, NASA is working on such a system right now that could be tested in space by the year 2025. If we ever wanted to send a very large spaceship to another star, a nuclear

Starting point is 00:12:22 pulse propulsion spacecraft might still be one of the best ways to do it. Project Orion was a crazy idea that wasn't nearly as crazy as you might think when you first hear it. A lot of very smart people did the math and came to the conclusion that it could work, at least in theory. It was a visionary concept that aimed to harness the power of nuclear explosions for spacecraft propulsion. Despite its innovative approach and technical ingenuity, it could never overcome its numerous environmental and safety concerns.

Starting point is 00:12:50 While the project's legacy persists as a testament to human imagination, like bringing back velociraptors, it probably falls firmly into the category of things that could be done, but perhaps shouldn't be done. The executive producer of Everything Everywhere Daily is Charles Daniel. The associate producers are Thor Thompson and Peter Bennett. Today's review comes from listener, Bruce, over on Apple Podcasts in the United States. They write, short and sweet.

Starting point is 00:13:20 Wow, excellently written, fabulous voice, and really well done altogether. I love factoid's and random interesting information to share with my colleagues and friends, so thank you. Well, thanks, Bruce. As I must constantly remind people, and I feel like I should do so again.

Starting point is 00:13:35 With great knowledge comes great responsibility. Use what you learn on this podcast for good instead of evil. Unless you want to make bets with your friends and take their money. That is acceptable. Remember, if you leave a review or send me a boostagram, you two can have it read on the show.

Everything Everywhere Daily: History, Science, Geography & More - Project Orion

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