is a fictional mysterious extraterrestrial vessel that is the subject and setting of the science fiction novel Rendezvous with Rama
by Arthur C. Clarke
, and the later sequel trilogy by Clarke and Gentry Lee
: Rama II
, Garden of Rama
, and Rama Revealed
. It exists in a fictional future timeline of our own world. Rama is essentially a dark, featureless metallic cylinder, but is distinguished by its size: 54 km
long and 20 km in diameter. If the cylinder was unfolded, the internal area would be 50 km long and 60 km wide. Although it qualifies as a vessel, carrying an advanced propulsion system capable of interstellar travel, it is better described as a mobile "worldlet." The cylinder is mostly hollow; Rama's rotation around its long axis creates the illusion of gravity
on the inner surface of the shell, in the style of an O'Neill cylinder
, however the Coriolis effect
produces odd effects when objects are not in contact with the hull. Rama is, for all intents and purposes, an artificial world, with a usable landscape, capable of supporting life.
Rendezvous with Rama (Phase I)
Name and Discovery
Rama was first encountered by humans in the year 2131, when it entered the solar system
at a speed and heading that would have taken it on a slingshot
course around the sun and back into the void. At first, it was mistaken for a giant asteroid; it was first detected by SPACEGUARD
, an automated radar net designed to warn Earth of potential impact threats. Its first name, thus, was a database code: "31/439
" ("according to the year [2131 CE] and order of its discovery"). As it traveled closer to perihelion
, it was brought to the attention of humans due to its abnormalities in shape and heading. Still believing it to be an asteroid, astronomers gave 31/439 a proper name, due to its size, according to the tradition of christening celestial objects after random mythological figures. 31/439 became Rama
named after the Hindu deity Rama
After much speculation over the following months, telescope observation and unmanned probes confirmed that Rama was an artificial construct, and, if indirectly, first contact with extraterrestrial life. It was intercepted and explored by the crew of the Solar Survey ship Endeavour, under Commander William Norton. Endeavour departed after a three-week mission, and Rama, apparently indifferent to the life forms it encountered, refueled using the matter and energy of the sun, conducted several minor course corrections, and exited the solar system as predicted.
|| Interior |
|| ~54 km
|| ~50 km |
|| ~20 km
|| ~16 km |
| Surface Area
|| ~4000 km2
|| ~3000 km2 |
|| ~17000 km3
|| ~10000 km3 |
|| ~1016 kg
(The distances are approximate, since they appear to vary throughout the book.)
- Propulsion. Rama's maximum acceleration is 0.02g, or 0.1962 m/s², using an unknown form of reactionless drive, which seems to operate by generating a field around Rama that negates the inertia of the mass that it captures. Whatever the nature of its engineering, Rama could freely control its velocity, rotation and heading.
- Power. Rama can refuel by absorbing energy and material en masse directly from a star. When traveling between stars, virtually all of its systems and mechanics are shut down, and it effectively becomes a dead relic; its temperature reaches nearly absolute zero. Whether it can merely store energy or generate it, most likely via nuclear fusion like the suns it siphons, is unknown. The most likely source of both Rama's power and propulsion seems to be the Horns.
- Defense. Passive. Rama's hull, except around the Cylindrical Sea and the North Pole (see below), is at least 2 km thick, completely solid (according to seismic tests), and composed of an unidentified alloy that could withstand direct radiation from Sol up to a radius of 5 million km. Rama could also activate a "cocoon" of perfectly reflective material, in which it passed nearly adjacent to the sun unharmed.
- Offense. Rama has displayed zero hostile capability of any kind.
Most of the following names and terms were chosen arbitrarily by the crew of the Endeavour
The fore end of Rama's axis, in the direction of its acceleration, is called North. The aft end is South. These points make up the navigational system used inside Rama.
- North Pole: The bow of Rama is designed around three airlocks.
- South Pole: The stern of Rama is where the engines are located.
- The Cylindrical Sea: An artificial body of water that divides Rama's internal space between northern and southern hemicylinders.
- New York: A mysterious clustering of tall buildings on an island in the middle of the Cylindrical Sea.
- The Horns: A regular grouping of spires at the South Pole, within Rama. Exactly at the Pole is the Big Horn, and arranged in a hexagonal pattern around this are six other spires, each shorter and with a smaller diameter. The Horns seem to be used in Rama's enigmatic system of propulsion.