About this video

• Video Title: Earth to Mars in 10 Days
• Channel: Real Engineering
• Speakers: [Not specified in transcript]
• Duration: 00:26:20

Overview

This video explores the ambitious "Project Orion," a concept from the 1950s and 60s that proposed using nuclear explosions to propel spacecraft. It details the engineering challenges, the scientific breakthroughs that made it feasible, and the political and bureaucratic hurdles that ultimately led to its cancellation. The video also touches upon modern advancements that could potentially revive the concept of nuclear pulse propulsion for interplanetary travel.

Key takeaways

• Nuclear Pulse Propulsion (Project Orion): The video details the engineering of Project Orion, a spacecraft designed to be propelled by detonating nuclear bombs behind it. This method promised unprecedented thrust and efficiency.
• Engineering Challenges and Solutions: Key challenges included designing components that could withstand nuclear blasts (addressed by graphite coatings and specialized materials), managing the immense forces with advanced suspension systems (using gas bags and pistons), and safely storing and delivering "pulse units" (miniaturized nuclear devices).
• Technological Hurdles: The project faced issues like the difficulty of creating small, efficient nuclear devices for propulsion, the need for a robust suspension system to absorb shock, and the political unacceptability of launching nuclear materials from Earth.
• The Demise of Project Orion: The project was ultimately canceled due to its association with nuclear weapons, the formation of NASA which shied away from nuclear propulsion, and the signing of the Partial Nuclear Test Ban Treaty, which prohibited high-altitude and space-based nuclear detonations.
• Modern Revival Potential: Recent advancements in microfision, magnetic nozzles, and superconducting capacitors, along with computer simulations, have renewed interest in nuclear pulse propulsion. Modern concepts focus on vacuum-only operation and orbital assembly to address safety and political concerns.

The key technological advancements that could make a modern version of nuclear pulse propulsion feasible include:

• Microfision: The ability to ignite much smaller amounts of fissile material without using explosives, achieved through magnetic compression by external electric fields.
• Magnetic Nozzles: These can catch and redirect the superheated vapor created by microfision, acting as a more efficient and compact system than the original Orion's pusher plate. They can also extract energy from the exhaust to recharge capacitors.
• Supercapacitors: Used to deliver the massive electrical current needed for magnetic compression in microfision.
• Advanced Material Science: Allowing for lighter spacecraft components than originally estimated.
• Improved Suspension Systems: More refined systems to handle the pulses more smoothly and reduce the risk of misfires.

The engineers behind Project Orion planned to protect the spacecraft and its occupants through a multi-stage system:

1. Pusher Plate: A large, robust steel disc (26 meters in diameter) faced the nuclear detonations. It was coated in oil, which acted as a sacrificial layer to absorb the initial impact of the hypervelocity tungsten gases from the pulse units.
2. Gas Bag: Behind the pusher plate was a large gas bag. When the plate was violently slammed backward by the nuclear explosion's energy, the gas bag would compress, significantly reducing the acceleration experienced by the main spacecraft structure. This reduced the force from thousands of Gs to a few hundred Gs.
3. Suspension System: A long (27 meters) suspension arm containing springs and hydraulic pistons further absorbed and smoothed out the shock. This system was designed to convert the violent, rapid pushes into a more manageable average acceleration of about 1.25g, comparable to driving on a country road.
4. Shutter: After each pulse unit detonated and propelled the pusher plate, a shutter would close behind it to protect the pulse unit delivery system from the ensuing plasma.

These elements combined were intended to create a ride that, while still experiencing pulsed thrust, was survivable for both the structure and any potential crew.

The title "Earth to Mars in 10 Days" refers to the potential capability of a highly advanced, future iteration of nuclear pulse propulsion, specifically a concept like the "Mini Mag Orion."

The video explains that such a craft, utilizing microfision and magnetic nozzles, could achieve an exhaust velocity 40 times better than any chemical rocket and a delta V on the order of 150 km/s. This level of performance, the video suggests, is theoretically enough to reach Mars in approximately 10 days.

Whether it is "really possible" is still a matter of speculation and future technological development. The video presents this as a theoretical performance metric for a highly optimized, advanced nuclear pulse propulsion system that has not yet been fully realized or tested at scale. The challenges to achieving this, as discussed in the video, are significant, including the need for substantial funding, further technological breakthroughs, and overcoming regulatory and political obstacles.