Ascension is inspired by the real-life Project Orion that existed under the administration of President John F. Kennedy. The show sets up an alternate version of reality in which, in 1963, President Kennedy and the U.S. government, fearing the Cold War will become hot and lead to the destruction of the Earth, decided to launch a covert space mission. They sent 600 men, women and children into space on a century-long voyage aboard the USS Ascension, a massive, self-sustaining generation ship. Their mission is to colonize Proxima Centauri, assuring the survival of the human race. Nearly 50 years into the journey (i.e. in the present), as they approach the point of no return, the mysterious murder of a young woman — the first homicide since their departure — causes the ship’s crew to question the true nature of their mission.
It is an original science fiction mystery drama that takes places in an alternate present aboard a generation ship, and will consist of 6 one hour-long episodes.
It was inspired by the Orion military project under JFK. Levens pointed out that Kennedy squashed the development of Orion soon after Bay of Pigs as the military began equipping the spaceship with weapons. He was terrified that they were turning it into a Death Star”. About the starship he said that “it feels like a cruise ship. Essentially the ship is like a time capsule, another civilization that continued for 50 years parallel to our civilization.” Blum added that “the people on the ship, only some of their children, but most of their grandchildren, are the only people who are going to arrive at this new world. A lot of the people who started on this ship have died. It’s their children, their children’s children, who are going to get to where they’re going. And there are a lot of conflicts going on. Should they turn around and go back to Earth, which they’ve lost touch with? So they have no idea of what Earth even looks like now. Should they continue? Also there’s been a murder on the ship, which never happened before. So that’s kind of what starts it”
Technical aspects of Interplanetary and Interstellar Project Orion Designs
Dyson retained the concept of large nuclear explosions. Dyson moved away from the use of fission bombs and considered the use of one megaton deuterium fusion explosions instead. His conclusions were simple: the debris velocity of fusion explosions was probably in the 3000–30,000 km/s range and the reflecting geometry of Orion’s hemispherical pusher plate would reduce that range to 750–15,000 km/s.
To estimate the upper and lower limits of what could be done using contemporary technology (in 1968), Dyson considered two starship designs. The more conservative energy limited pusher plate design simply had to absorb all the thermal energy of each impinging explosion (4×10^15 joules, half of which would be absorbed by the pusher plate) without melting. Dyson estimated that if the exposed surface consisted of copper with a thickness of 1 mm, then the diameter and mass of the hemispherical pusher plate would have to be 20 kilometers and 5 million metric tons, respectively. 100 seconds would be required to allow the copper to radiatively cool before the next explosion. It would then take on the order of 1000 years for the energy-limited heat sink Orion design to reach Alpha Centauri.
In order to improve on this performance while reducing size and cost, Dyson also considered an alternative momentum limited pusher plate design where an ablation coating of the exposed surface is substituted to get rid of the excess heat. The limitation is then set by the capacity of shock absorbers to transfer momentum from the impulsively accelerated pusher plate to the smoothly accelerated vehicle. Dyson calculated that the properties of available materials limited the velocity transferred by each explosion to ~30 meters per second independent of the size and nature of the explosion. If the vehicle is to be accelerated at 1 Earth gravity (9.81 m/s2) with this velocity transfer, then the pulse rate is one explosion every three seconds.
The TV show is going with the fusion bomb momentum limited version. They are going for about 4% of lightspeed to go to Proxima Centauri in 100 years.
Later studies indicate that the top cruise velocity that can theoretically be achieved by a Teller-Ulam thermonuclear unit powered Orion starship, assuming no fuel is saved for slowing back down, is about 8% to 10% of the speed of light (0.08-0.1c). An atomic (fission) Orion can achieve perhaps 3%-5% of the speed of light. A nuclear pulse drive starship powered by Fusion-antimatter catalyzed nuclear pulse propulsion units would be similarly in the 10% range and pure Matter-antimatter annihilation rockets would be theoretically capable of obtaining a velocity between 50% to 80% of the speed of light. In each case saving fuel for slowing down halves the max. speed. The concept of using a magnetic sail to decelerate the spacecraft as it approaches its destination has been discussed as an alternative to using propellant, this would allow the ship to travel near the maximum theoretical velocity.
At 0.1c, Orion thermonuclear starships would require a flight time of at least 44 years to reach Alpha Centauri, not counting time needed to reach that speed (about 36 days at constant acceleration of 1g or 9.8 m/s2). At 0.1c, an Orion starship would require 100 years to travel 10 light years.
SOURCES – Wikipedia, Syfy, Dyson paper, Youtube