Discovery launching an EVA pod
|First appearance||2001: A Space Odyssey|
|Auxiliary craft||EVA Pods|
|Propulsion||Cavradyne Plasma Propulsion Engines|
United States Spacecraft Discovery One is a fictional spaceship that appears in The Space Odyssey series, including the motion pictures 2001: A Space Odyssey and 2010: Odyssey Two. Discovery One is a nuclear-powered interplanetary spaceship operated in part by the HAL 9000 (Heuristic ALgorithmic computer) artificial intelligence.
This spaceship is founded on solidly conceived, yet unrealized science. One major concession was made in her appearance for the purpose of reducing confusion, and this was to eliminate the huge cooling "wings" which would be needed to radiate the heat produced by her hypothetical thermonuclear propulsion system. The producer and director Stanley Kubrick thought that the audiences might interpret the wings as meaning that the spacecraft was intended to fly through an atmosphere.
The Discovery One was named after Captain Robert Scott's sailing ship RRS Discovery, which was launched in 1901. Writer Arthur C. Clarke used to visit this ship when she was moored in London. She shares her name with a real spacecraft, the Space Shuttle Discovery (OV-103).
In the novel 2001: A Space Odyssey, the Discovery One is described as being about 460 feet (140 m) long (the 2010 movie mentions 250 feet) and powered by "Cavradyne" gaseous core nuclear reactor engines. 275 feet (84 meters) of tankage and structure separate the spherical part of the spaceship where the crew quarters, the computer, flight controls, small auxiliary craft, and instrumentation are located. In the crew's centrifuge, the crewmen would have enjoyed Moon-like gravitational conditions. This would be where they spend most of their time, and where the three hibernating astronauts rested in their compartments. The piloting, navigation, and other occasional tasks could take place in the zero-gravity command module.
Other sections of the crewmen's sphere would include the pod bay, where three one-man repair and inspection craft would be kept, and the spaceship's primary HAL 9000 mainframe computer with its level-upon-level of memory storage and digital processing units. Because of her lack of aerodynamic design and her immense size, the Discovery One would be assembled in and launched from orbit around the Earth. As described in the novel, the Discovery One was originally intended to survey the Jovian system, but her space mission was lengthened to go all the way to Saturn to investigate the destination of the signal from the black monolith at the crater Tycho. As a result, her space mission became a one-way spaceflight to Saturn and its moon Iapetus. After investigating alien artifacts at Saturn and Iapetus, the preliminary plan is for all five members of her crew to enter suspended animation for an indefinite period of time. Eventually, it is hoped that a much larger and more powerful spaceship, Discovery Two, would be built so that it would fly from the Earth to Iapetus, rescue the five astronauts, and then make the long voyage home with everyone in hibernation.
Cavradyne Engines 
According to the book, the ship's propulsion controls would be designed with the assistance of General Electric's Valley Forge Space Technology Center and the UK Atomic Energy Authority. These controls were located in the command module. A Honeywell nuclear reactor control panel displayed information on such parameters as turbine, compressor, heat exchanger, secondary circulatory, and radiator liquid helium storage, generator and recuperator performance, and pressures and temperatures at various stations. Precise readings could be obtained instantaneously on the control screen, if desired, as well as past performance and predicted future performance.
The fictional Cavradyne engines were based on research into gaseous core nuclear reactors and high-temperature ionized gases. The theory was presumed to have shown that gaseous uranium-235 could be made critical in a cavity reactor only several feet or meters in diameter if the uranium atomic density were kept high, and if temperatures were maintained at a minimum of 20,000 °F (11,400 K). At first, progress was slow because of such early unsolved problems as how to reduce vortex turbulence in order to achieve high separation ratios, and how to achieve adequate wall cooling in the face of the thermal radiation from the high-temperature plasma. In the Cavradyne system, the temperature of the reactor was not directly limited by the capabilities of solid materials, since the central cavity was surrounded by a thick graphite wall that moderates the neutrons, reflecting most of them back into the cavity. Wall cooling would be ensured by circulating the hydrogen propellant prior to its being heated. Fissionable fuel energy was said to be transferred to the propellant by radiation through a specially designed rigid—and coolable—container, similar to the way in which fission energy was transferred to hydrogen propellant in the NERVA design.
The ship's centrifuge was a spinning band of deck, mounted inside the crew compartment. The centrifugal force created by its spin simulated the effects of gravity. It was the primary living and work area, featuring consoles, panels, screens, and devices. In the movie, there was Earth gravity in the centrifuge. At all other points on the ship, including the command bridge crew members used velcro shoes to attach themselves to the floor. There was an automated kitchen developed with the assistance of General Mills; a ship-to-Earth communications center; a complete medical section where the astronauts undergo regular automated checkups (results were displayed and recorded, and diagnosis of deficiencies given directly on a readout screen, and medicament or other treatment prescribed) an observatory, created with the help of astronomers at the Royal Greenwich Observatory; and a geophysical exploration module worked out with French engineers from the Paris-based Schlumberger Limited. The latter permitted a wide variety of surface and subsurface experimentation to take place on an alien body, such as an asteroid or a moon. Since subsurface structure could be extremely important in the spaceship's investigatory program in the Jovian system, a drill was incorporated into a remotely-controlled surface lander. Controls on the console included a depth selector, drilling rate selector, equipment calibration, recording and error analysis controls, and various screen and gauge indications of subsurface characteristics.
The Discovery is described as a very large ship that could be handled by only two astronauts (David Bowman and Frank Poole), along with the HAL 9000. In the book IBM predicted that computer development would have advanced to such an extent that the mission could be undertaken with all the astronauts placed in hibernation. It was said to be desired, however, that regular communications be maintained throughout the voyage between the pilot and copilot and mission control back on Earth. During communication, account was taken of the elapsed time for electromagnetic waves crossing space between the spaceship and the Earth. Naturally, this time would depend on the relative positions of the bodies in the Solar System at any given moment.
The Fate of the Discovery 
After the malfunction of HAL 9000, Bowman deactivates the malfunctioning computer and thus effectively isolates himself onboard Discovery. When the spacecraft arrives at Jupiter, it encounters TMA-1's considerably larger cousin, 'Big Brother', or 'TMA-2', at the L1 point between Jupiter and Io. Bowman leaves Discovery to examine the Monolith and is taken inside it. Discovery is left abandoned.
In the novel 2010: Odyssey Two, set nine years after the events of 2001: A Space Odyssey, a joint Soviet-US mission (including Heywood Floyd) travels to Jupiter aboard the spacecraft Alexei Leonov to investigate the mysteries surrounding the 2001 mission, believing that Discovery harbors many of the answers. Leonov docks with Discovery, reactivates the onboard systems, and stabilises its orbit around Io. Hal's creator, Dr. Chandra, is sent aboard to reactivate the HAL 9000 computer and ascertain any information he can regarding the previous mission.
Later on, an apparition of Dave Bowman appears, warning Floyd that Leonov must leave Jupiter within fifteen days. Floyd asks what will happen at that time, and Bowman replies, 'Something wonderful.' Floyd has difficulty convincing the rest of the crew, at first, but a dark spot on Jupiter begins to form and starts growing. HAL's telescope observations reveal that the “Great Black Spot” is in fact a vast population of monoliths, increasing at a geometric rate. (The film accelerates the pace, both shortening Bowman's deadline to two days and making the spot grow faster.)
Initially it was planned to inject Discovery on an Earth-bound trajectory (though it would not arrive for some years); however, when faced with Bowman's warning, the Leonov crew devises a plan to use Discovery as a 'booster rocket', enabling them to return to Earth ahead of schedule, but leaving Discovery in a wide orbit of Jupiter. The crew worries that Hal will have the same neuroses on discovering that he will be abandoned yet again, and Chandra must convince HAL that the human crew must leave.
Detaching itself from Discovery, Leonov makes a hasty exit from the Jupiter system, just in time to witness the swarm of Monoliths engulf Jupiter. Through a mechanism that the novel only partially explains, these monoliths increase Jupiter's density until the planet achieves nuclear fusion, becoming a small star.
As Leonov leaves Jupiter, Bowman instructs HAL to begin repeatedly broadcasting the message:
ALL THESE WORLDS ARE YOURS EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE.
USE THEM TOGETHER. USE THEM IN PEACE.
The new star, which Earth eventually dubs "Lucifer", destroys Discovery. HAL is transformed into the same kind of life form as David Bowman and becomes Bowman's companion.
Official Name: USSC Discovery One
USSA "Registration Number": XD-1
Overall Length: 140.1 m
Overall Beam: 16.7 m
Overall Draft: 17 m
Command Module Diameter: 16.5 m
Reactor Module Length: 32.2 m
Reactor Module Draft: 8.8 m
Mass: 5,440 tonnes
Life Support: (two men, out of hibernation): 90 months
Suspended Animation System: Meditech 712-R Hibernacula (3 Centrifuge, 5 Medical Level)
Pod Bay features: Three each Pod turntable Base, Extension motor, Extension Platform, Outer hull door, Space suit rack. Test bench with two LCD screens and HAL 9000 terminal. Two large emergency oxygen bottles. Nine small emergency oxygen bottles. Circuit Breaker Box. Manual control station with HAL 9000 terminal, Six LCD screens, and full control set.
Pod Bay Deck: Along with the Pod Bay, the Pod Bay Deck also features an emergency airlock, circuitry storage bay, two fresh water tanks, a maintenance equipment room, an emergency shelter and space suit rack, emergency batteries for the centrifuge and pod bay, and a zero-g toilet.
Living Module: Centrifuge, Magnetic-Drive type. 11.6 m. diameter. Rotation Rate 3 RPM. Living Module Control Stations: 12-screen HAL 9000 interface/ communications module, Nuclear reactor monitoring station, Remote probe control, Radar mapping station, climate control, and Revival Monitoring Station.
Living Module Habitation Features: Sanitary module, (Shower, Sink, Waste water recycling Control) Three Meditech 712-R Hibernacula, Sun-ray tanning station, Water closet (Head), Three Circuit breaker panels. One emergency space suit locker, Two spare part lockers, Three clothing lockers.
Command Deck: The Command Deck includes the cockpit, zero-g astronomy lab, zero-g sciences lab, two fresh water tanks, six-spacesuit recharge unit, a pre-launch personnel clearance area, the circuit breaker room, and a zero-g toilet. The Command Deck also includes all HAL 9000 related systems (see below).
HAL 9000 systems: Logic memory center, auxiliary power unit, computer climate regulation system, autonomic systems control center, and reactor control system.
Thrusters: Eight Mk 114 on command module. 720 kgf (7.1 kN) thrust each. Two forward and two aft of reactor module. Nine Mk 29 vernier thrusters; three clustered around each Cavradyne engine exhaust. 1,600 kgf (15.7 kN) thrust each. Eight mid-course correction thrusters (four on each TJI propulsion mount) Four emergency escape rockets at Command Module rear.
Central Communications Complex: Discovery One's central communications complex is mounted atop the seventh fuel module aft of the command section. The main audio-visual communications antenna measures 4.13 meters in diameter. Both telemetry antennas measure 1.26 meters across. The entire assembly can be swiveled 360 degrees and aimed upwards or downwards at any angle between 0 and 285 degrees.
Misc. Equipment: An emergency communications antenna, about half the size of the main antenna, is stored beneath the blow-away cover at the command module's top. Four probes (two atmospheric, two remote-controlled landers) and a telescope array are stored beneath the bottom blow-away cover.
Structural Support: Discovery One's reactor module is secured to the aftermost fuel module by four heavy-duty docking latches. Twelve reinforced coupling units along the spine provide additional support. The spine and reactor module are held in place by six docking latches at the intermodule adapter plate. The entire spine/reactor assembly can be jettisoned in an emergency by eight explosive separation bolts installed in the adapter plate. Finally, the entire Emergency Propulsion System (EPS) can be jettisoned using a ring of 16 explosive bolts installed in a ring around the forward section of the EPS. There is no re-docking capability for any assembly.
- David Bowman (Mission Commander)
- Frank Poole (Deputy Commander)
- Victor Kaminsky (Survey Team Leader) [Geophysicist in the novel]
- Jack Kimball (Geophysicist) [Peter Whitehead/Survey Team Leader in the novel]
- Charles Hunter (Astrophysicist)
- Arthur C Clarke "The Lost Worlds of 2001", Signet, 1972