An interstellar ark
is a conceptual space vehicle
that some have speculated could be used to traverse the distances between stars. The concept was first developed by Dr. Gregory Matloff
, who argues that such a vehicle may be the most economically feasible method of traveling such distances.
An interstellar ark might be a generation ship or a sleeper ship.
Considerations for generation-ship proposals
Such a ship would have to be large, and the only adequate technology likely to be available (even assuming the most favorable economic and political factors) soon enough to make plans is the Orion concept of propulsion by nuclear pulses. The largest spacecraft design analyzed in the Orion project had a 400m diameter and weighed approximately 8 million tons. It could be large enough to host a city of 100,000 or more people.
The purely engineering issues concern building, in space, a physically self-sufficient craft. In light of the multiple generations that it could take to reach even our nearest neighboring star systems such as Proxima Centauri, further issues of the viability of such interstellar arks include:
- the possibility of humans drastically evolving in directions unacceptable to the sponsors
- the minimum population required to maintain in isolation a culture acceptable to the sponsors; this could include such aspects as
- ability to maintain and operate the ship
- ability to accomplish the purpose (planetary colonization, research, building new interstellar arks) contemplated
- sharing the values of the sponsors (which are not likely to be empirically demonstrated to be viable beyond the home planet).
Considerations for sleeper-ship proposals
A sleeper type crewed starship would probably be propelled by a Daedalus
type fusion microexplosion nuclear pulse propulsion
system, that may allow it to obtain an interstellar cruising velocity of up to 10% of the velocity of light
At the present time, cryopreservation
and other forms of "cold sleep" lasting decades or longer are only theoretical possibilities, as it is currently impossible to reverse the process of cryopreservation. These possibilities are suggested by the short-term hibernation of certain mammalian species. Hypothermia and hibernation can greatly reduce the amount of food, water, and oxygen required to keep a human (or animal) alive while in stasis (suspended animation
Developing the medical technology that is required to achieve a "sleeper" type starship may theoretically be an achievable goal for late in the 21st century, depending on funding and laboratory experiments.
The appeal of these methods rests on hopes of:
- reducing ship mass by eliminating the equipment needed by an active ship-city population (without cold-sleep-maintaining and -reversing equipment of comparable mass), and/or
- avoiding the need for an acceptable ark-adapted culture.
Both Orion type thermonuclear pulse drive starships, and Daedalus type thermonuclear pulse drive starships could be built and launched towards nearby stars within a 10 light-year radius of the solar system later in the 21st century, if there was sufficient funding and political will to do this.
The ark has also been proposed as a potential habitat to preserve civilization and knowledge in the event of a global (or solar system wide) catastrophe.
- A group of three large arks served as the homes and battleships of the space-faring Thraki race in William C. Dietz's Legion of the Damned series.
- The concept of an interstellar ark was used humorously in the cult sci-fi classic The Hitchhiker's Guide to the Galaxy, in the form of the B-Ark of the Golgafrincham Ark Fleet, filled to capacity with cryosleeping advertising executives, management consultants, independent filmmakers, and other "undesirables" whom the Golgafrinchams wanted to expel. Hitchhiker's Guide author Douglas Adams had first proposed these plot elements for a TV special that was to have featured Ringo Starr, but the show was never produced.
- The Starlost is about a generation ship lost in space, whose inhabitants had forgotten that they were on a ship.
- In the PC game Outpost series, an interstellar ark named Conestoga was used to evacuate a population of humans from the impending destruction of Earth.
- The PC game Alien Legacy features "seedships", used to spread mankind due to an interstellar war that might wipe out the Earth.
- The Botany Bay was a sleeper ship used by Khan in the Star Trek episode Space Seed.
- Centauri Princess - arguably the first true-to-life rendition of a cylindrical interstellar ark peopled with humans, depicted in the sci-fi novel series First Ark to Alpha Centauri.