Light-Bearer: Construction Orbit Picture

Second in a series of images re-envisioning Larry Niven's short story “The Warriors.” See my first image in this sequence, linked below under "Related Images" for more details on this project.

This is my re-envisioned version of Niven’s Angel's Pencil, the completed interstellar colony slow-boat. I’ve modified the vessel extensively, to bring it’s appearance more in line with the conventions of theoretical Ram-ship design - hence the name Angel's Pencil is no longer appropriate, so I've renamed the spacecraft Light-Bearer – I've moved the landing-craft capture-and-docking deck back behind the life-system and brought the ram-field module to the bow – the idea of hanging your only landing craft out on the nose of a relativistic vehicle just seemed a rather dubious choice for the engineers to make.

The Bussard ramjet

Robert W. Bussard (August 11, 1928 – October 6, 2007) was an American physicist who worked primarily in nuclear fusion energy research. He was the recipient of the Schreiber-Spence Achievement Award for STAIF-2004. He was also a fellow of the International Academy of Astronautics and held a Ph.D. from Princeton University.

In 1960, Bussard conceived of the Bussard ramjet, an interstellar space drive powered by hydrogen fusion using hydrogen collected with a magnetic field from the interstellar gas. Due to the presence of high-energy particles throughout space, much of the interstellar hydrogen exists in an ionized state (H II regions) that can be manipulated by magnetic or electric fields. Bussard proposed to "scoop" up ionized hydrogen and funnel it into a fusion reactor, using the exhaust from the reactor as a rocket engine.

The Bussard ramjet, to all appearances, solves the mass-ratio problem for high velocity sub-relativistic interstellar flight, and the deadly-space-junk problem.

From Atomic Rockets: If your starship is moving fast enough, the widely scattered hydrogen atoms will hit your hull like cosmic rays, and damage both the ship and the crew. One can theoretically use magnetic or electrostatic fields to sweep the hydrogen atoms out of the way so the ship doesn't hit them.

And if you are gathering your propellant instead of carrying it along with you, your mass ratio becomes infinity. This means you could theoretically accelerate forever.

Accelerating at 1 g a Bussard ramjet could reach the center of the galaxy in a mere twenty years of proper time, and could theoretically circumnavigate the entire visible universe in less than a hundred years.

Only there is a problem:

Things started to unravel in 1978. T. A. Heppenheimer wrote an article in Journal of the British Interplanetary Society entitled "On the Infeasibility of Interstellar Ramjets." Heppenheimer applies radiative gas dynamics to ramjet design and proves that radiative losses (via bremsstrahlung and other similar synchrotron radiation-type mechanisms) from attempting to compress the ram flow for a fusion burn would exceed the fusion energy generated by nine orders of magnitude, that is, one billion times. The energy losses will probably show up as drag. This was confirmed by Dana Andrews and Robert Zubrin in 1989.

Recommended reading: See Winchell Chung’s Atomic Rockets page Bussard Ramjet.

Renaming the ship:

Etymology: the Greek word ἑωσφόρος (heōsphoros) is a proper noun, literally meaning “Bringer-of-dawn,” translated as an adjective the word means “Light-bearer.”

Light-Bearer lends the obvious thematic parallels out of mythology, most notably it evokes the Prometheus myth.

Allusions to the Prometheus myth seem particularly appropriate to ”The Warriors:” It can be argued that, in Niven’s story, Steve Weaver’s awakening to the rational requirement of self-preservation had far-reaching effects, weakening the hold the UN government had over mankind. In Niven’s known Space universe the UN’s social-engineers had, for hundreds of years, restricted access to historical records in order to obscure general knowledge of mankind’s past, using a mixture of mind-control techniques, drugs, and psychiatric manipulation to transform Man into a child-like, pliable, robot* – all of which ended with Steve Weavers choice to use the spacecraft's drive as a weapon during Man’s first encounter with the Kzinti.

Launching a relativistic spacecraft:

From LEO a temporary thruster-pack will boost the vehicle into lunar orbit where it will be fitted with a light-sail. Battery of lunar-based laser-cannon will then accelerate the vehicle out past the asteroid belt where asteroid-based Belter laser-cannon will add to the acceleration, these will continue to propel the craft year after year, with new cannon being constructed and added as the distance between the solar system and the spacecraft increases. The vehicle will be accelerated by the laser light till the vehicle reaches sufficient velocity for operation of its Bussard Ramjet.

* On a philosophical note I rather doubt that simply removing knowledge of violence would result in a more passive human (and I rather think the desire to attain this goal is questionable in itself) with or without extensive propaganda, mind-control, or psychiatric manipulation.

Related Images:

Relativistic Sky

Stalking Prey

Resources: Earth Backdrop courtesy NASA/JPL
The Warrior: Scorpio
Light-Bearer: Construction Orbit