World Ship Studies
In some recent studies I have been looking at World Ships. These are massive vessels 10 to the power of 11 to 10 to the power of 12 tons travelling at 1,500 km/s (0.5%c) to reach the nearest stars in 1,000 years or less. They carry 1 million people at the start of the journey and allow for growth of that population.
The design concepts were to be propelled by 1,024 engines based on inertial confinement fusion (ICF) systems and this requires a staggering 170 TJ driver energy assuming an optimistic 25% wall plug efficiency of any lasers. ICF works on the principle of many laser beams hitting a fusion fuel target and leading to a symmetrical implosion and compression of a central hot spot region that leads to thermonuclear ignition and energy gain. The individual pellets in the design are 230 grams each of TN fuel along with 2.43 kg/shot of expellant propellant for thrust augmentation, all detonated at 100 Hz pulse frequency.
The first paper was published and examines population demographics, power supply requirements for the habitats and spin gravity to contain the atmosphere and regolith. It focussed on the issue of the sort of demographic population one would need in such a large vessel and how this links to the demographic models used on Earth within our individual nation state economies. The issue of demographics would be a critical one for a world ship that was operating over many centuries and many generations of people.
The humans that left Earth at launch would never see the new target home world. The humans that arrived at the target home world would never have seen Earth. The ones that are a part of the majority of the journey would never have seen either other than on computer screens and perhaps through large on-board telescopes.
The second paper focused on the propulsion system to be adopted and went into some detail on the calculations. These studies were based on earlier papers from Bond/Martin in 1984 which utilised external nuclear pulse propulsion and seeks to advance concepts to the next stage. Its not easy to push such a large vessel and requires a thrust of 978 GN.
It also gave a form of design review discuss on the many issues that would need to be worked on if such a project was to be taken to the next level of fidelity. It is the hope of this author that indeed others would one day pick up the design studies and continue them further forward.
The concept of a world ship is a rather romantic one carrying millions of people at a time on a journey to the distant worlds. In reality this may not be the manner in which the stars are settled by future humans. There are other routes such as sending banks of embryos, the transport of information through some quantum entangled states of matter, or even the development of faster than light drives. However, it is always fun to first see what the bottom line engineering requirements are likely to be.
K. F. Long, Population Demographics & Other Issues for the Massive Ra World Ship Model - Part 1, JBIS, 76(11), 262 - 272, 2024.
K. F. Long, Inertial Confinement Fusion Propulsion for the Massive Ra World Ship Model - Part 2, JBIS, Submitted, February 2024.
