11 June 2016

Could the Space Voyages in the Film and Novel "2001: A Space Odyssey" Really Happen? (Part 1)

An advanced LANTR moon shuttle departs low-Earth orbit. Image credit: Pat Rawlings/NASA
The film and novel 2001: A Space Odyssey changed my life. I know, that sounds overwrought, but it's true. I was six years old in April 1968, when the classic collaboration between science fiction author Arthur C. Clarke and film director Stanley Kubrick hit movie screens around the world. By that point in my young life, I had been reading for three years. I knew that I liked science - especially geology - so a "science fiction" film sounded intriguing.

By the time the movie drew to a close, I had become a spaceflight fan and a science fiction buff. I remain so afflicted today. (I expect that the existence of this blog makes the "spaceflight fan" part kind of obvious.)

The film 2001 is enigmatic, with mostly banal dialog and an ending that left many who saw it in its first run feeling confused and even cheated. Clarke's novel fills in gaps, but its narrative differs from the cinematic narrative. For example, in the movie 2001, Jupiter is the spaceship Discovery's destination; in the book 2001, the natural wonders of the Saturn system as understood in 1968 are used to good effect. None of this ambiguity troubled me; in fact, the mysteries stoked my young imagination.

Arthur C. Clarke (left) and Stanley Kubrick on the Aries-1B moon shuttle passenger cabin set. Image credit: The Stanley Kubrick Archives
This background explains why a pair of technical papers caught my attention as the year 2001 approached and passed. Nuclear propulsion engineers at NASA's Lewis Research Center (now Glenn Research Center) in Cleveland, Ohio, authored both papers. They described ways that the piloted spaceflight capabilities portrayed in the film and book 2001 might be made reality using technology and techniques that are either already in existence or are plausibly foreseeable.

In the first paper, first published in 1997 and subsequently lightly revised, Stanley Borowski and Leonard Dudzinski looked at how a 24-hour voyage to a lunar surface base might be accomplished using Nuclear Thermal Rocket (NTR) propulsion and liquid oxygen (LOX) mined from the moon. For comparison, Apollo spacecraft needed more than three days to travel from Cape Kennedy to lunar orbit.

The second paper is much more ambitious, but also more speculative. It offers a design and operational scenario for a nuclear-fusion-propulsion spacecraft named Discovery II which could reach Jupiter orbit in just four months and Saturn orbit in seven. I will discuss it in my next post.

The film and book 2001 both begin with a band of man-apes who are having a tough time of it. They grub in the dust for bits of vegetation beside competing quadruped herbivores and huddle together at night listening to screeching big cats, for whom they make easy prey.

The book focuses on a hominid named Moonwatcher. Some time after an intellect-boosting encounter with an alien black monolith, he grasps the related concepts of tool-use and hunting. Soon his entire band wields bone clubs. They hunt the unsuspecting herbivores, drive off the big cats, and make war on a technologically backward rival band.

After murdering the rival band's leader, Moonwatcher of the film 2001 hurls his club triumphantly at the sky, where it becomes an Earth-orbiting satellite bearing nuclear warheads. In a heartbeat we leap over three million years of human evolution and technology advancement.

A more hopeful sign of advanced technology appears - a gleaming white space plane in Pan American Airlines livery. On board is Dr. Heywood Floyd, a high-level bureaucrat on a mission for the United States Astronautics Agency (USAA). National security, the novel 2001 explains, requires that he fly with only a pilot, co-pilot, and stewardess for company.

USAA is evidently a NASA successor organization. One can speculate that, in the 2001 timeline, a well-funded NASA worked with large commercial entities and handed off certain of its roles as, with NASA aid, those commercial entities succeeded in proving themselves capable of providing necessary spaceflight services. Along the way, NASA handed off aeronautical research (the first "A" in the acronym NASA) and became more focused on advanced spaceflight development and scientific exploration. This prompted a name change.

The Pan Am space plane deposits Floyd at a wheel-shaped artificial-gravity international space station. It is the fifth in a series, so is called Space Station V. There Floyd confronts members of a rival band - a group of Soviet scientists on their way home from the moon - and transfers to a near-spherical Aries-1B moon shuttle to begin his journey to the U.S. moon base in 150-mile-wide Clavius crater.

Aries-1B moon shuttle. Image credit: Turner Entertainment/Metro Goldwyn Mayer
In the book 2001, the 30-passenger moon shuttle's "low-thrust plasma jet" propulsion system operates for "more than 15 minutes" to begin the 25-hour voyage to the moon. Floyd, alone on board with a pilot, co-pilot, steward, stewardess, and two engineers, hears the "whistling" of the "electrified" plasma jets. He feels the acceleration they impart to the moon shuttle as a "mild" pressure pushing him down into his seat.

In their 1997 paper, Borowski and Dudzinski dubbed their moon shuttle propulsion system LANTR, which stands for "LOX-Augmented Nuclear Thermal Rocket." They envisioned that LANTR propulsion would form a critical component of a cislunar transportation infrastructure that ultimately would include multiple interdependent vehicles and a Lunar Oxygen (LUNOX) mining and refining base near the Apollo 17 landing site at Taurus-Littrow on the southeast edge of Mare Serenitatis.

LUNOX, the NASA Lewis nuclear propulsion engineers explained, was likely to become the first large-scale space commodity. The "orange soil" Apollo 17 explorer Harrison Schmitt kicked up on the flank of Shorty Crater - which, it turns out, occurs at many places on the moon - would, they estimated, make a rich feedstock for LUNOX refining: every 25 tons of the volcanic glass-rich stuff collected and processed would yield a ton of LUNOX. For comparison, about 327 tons of more typical lunar surface material would need to be mined and refined to produce a ton of LUNOX.

The LANTR architecture would evolve over time from a NASA Lewis Nuclear Thermal Rocket (NTR) architecture developed for the abortive Space Exploration Initiative (1989-1993) of President George H. W. Bush. It would not at first use LUNOX, reach the moon in a day, or include reusable vehicles.

Borowski and Dudzinski sought to reduce the cost of their Earth-to-low-Earth-orbit (LEO) launches by exploiting then-existing Space Shuttle hardware and facilities. A pair of Shuttle-Derived Launch Vehicles (for example, Shuttle-C), each capable of placing a 66-ton payload into 407-kilometer-high LEO, would suffice to launch an expendable "two-tank" NTR stage, expendable piloted lunar spacecraft, and cargo.

Shuttle-C in its most basic form: an expendable cargo canister with a two-engine Shuttle boat-tail replaces the Space Shuttle Orbiter. Image credit: NASA
The first Shuttle-C's payload, the 24-meter-long "core stage," would comprise a pair of NTR engines, attitude control and docking systems, and a 7.6-meter-diameter, 17.5-meter-long insulated, meteoroid-shielded tank with 49.3 tons of cryogenic liquid hydrogen (LH2) inside. The engines would serve as both electricity generators and rocket motors. Because they would have two roles, or "modes," Borowski and Dudzinski dubbed them Bimodal Nuclear Thermal Rocket (BNTR) engines.

The BNTR engine's basic design would resemble that of NTR engines going back to the 1950s. LH2 would serve double duty as nuclear-fission reactor coolant and rocket propellant. After passing through and cooling the reactor, the hydrogen, now hot and gaseous, would vent into space through a bell-shaped nozzle to produce thrust.

The second Shuttle-C payload would comprise a 4.6-meter-diameter, nine-meter-long tank with nine tons of LH2, an adapter for linking with the core stage, and a conical crew capsule with four astronauts on board. It would also include a second spacecraft: a 44-ton LH2/LOX chemical-propulsion Lunar Landing Vehicle (LLV) with a five-ton crew cabin and nine tons of cargo bound for the lunar surface.

The two Shuttle-C payloads would dock in LEO, forming what Borowski and Dudzinski called a Lunar Transfer Vehicle (LTV). With the LLV attached, it would measure 46 meters in length. Its twin BNTR engines would heat and expel LH2 for 47.5 minutes to place the LTV/LLV combination on course for an Earth-moon voyage lasting 84 hours.

At the end of this cislunar journey, the BNTR engines would fire a second time so that the moon's gravity could capture the LTV/LLV combination into 300-kilometer-high orbit. The crew would board the LLV and descend to the lunar surface with their nine tons of cargo, which would include equipment for mining, refining, and storing LUNOX, as well as scientific gear and lunar base components.

The crew would spend 45 days on the moon living out of the LLV. They would then pilot the LLV back to lunar orbit, transfer to the LTV capsule, cast off the spent LLV, and fire the BNTR engine pair to depart lunar orbit for an 84-hour journey to Earth.

Near Earth, the crew capsule would detach from the LTV and reenter the atmosphere directly. The remainder of the LTV would swing by Earth and fire its BNTR engines briefly to boost itself into a Sun-centered disposal orbit. In total, the LTV BNTR engines would operate for 61.4 minutes during a 54-day round-trip lunar mission.

Borowski and Dudzinski described one-way cargo missions based on their piloted architecture. Twenty-five tons of additional cargo would replace the crew cabin and propellants for boosting the LLV back to lunar orbit, bringing total cargo delivered to the moon's surface to 34 tons.

LUNOX production would ramp up with each successive expendable LTV/LLV lunar mission. In lockstep with the increasing supply of LUNOX, NASA would upgrade the cislunar transportation system, so that, after an unspecified number of flights, it would evolve into Borowski and Dudzinski's reusable LANTR architecture. The LANTR architecture would, they explained, support routine weekly 24-hour Earth-moon "commuter" flights.

By then, LUNOX production would amount to 10,878 tons per year. Of this, reusable Earth-bound LANTR LTVs would use 4888 tons, while reusable LLVs for transporting LUNOX, crews, and cargoes between the LUNOX surface base and a lunar orbit propellant depot would expend 5990 tons.

The NASA Lewis engineers assumed that 11 solar-powered, teleoperated LUNOX plants operating 35% of the time (70% of each two-week lunar daylight period) could each strip-mine and refine 25,000 tons of orange soil to produce about 1000 tons of LUNOX per year. They estimated that the orange soil area near the Apollo 17 landing site might yield up to 700 million tons of LUNOX; that is, enough to support weekly 24-hour commuter flights for the next 60,000 years.

LANTR would see the basic all-LH2 BNTR engine augmented with a system for introducing LOX into the supersonic hot hydrogen exhaust flow "downstream" of the reactor. The LOX would enable the hydrogen to burn much as it does in a conventional LOX/LH2 chemical rocket engine, dramatically increasing LANTR thrust. This, Borowski and Dudzinski wrote, would offer "big engine" performance from "smaller, more affordable, easier to test NTR engines."

To trim development cost, the LANTR LTV would structurally closely resemble the all-LH2 LTV already described. At 7.5 meters long, the LANTR LTV's forward section would measure 1.5 meters shorter than its all-LH2 counterpart. The aft section, the core stage, would be outwardly identical to its all-LH2 predecessor. As with the all-LH2 LTV, a pair of Shuttle-Cs would launch the fore and aft sections of the LANTR LTV, which would then rendezvous and dock automatically in LEO.

The LANTR LTV would then dock automatically with a propellant depot in LEO. There it would fill its large tank with 45.5 tons of LH2 and its small tank with 112.3 tons of LOX, which is much denser than LH2. The propellant depot's LOX and LH2 would all be produced on Earth and boosted into LEO on Shuttle-derived launch vehicles.

Meanwhile, a Space Shuttle or a next-generation reusable piloted spacecraft would deliver to the International Space Station (ISS) 20 passengers bound for the LUNOX production base on the moon. Accommodations on board the ISS are, of course, not spacious, so the new arrivals would immediately move into a 15-ton, 4.6-meter-diameter, eight-meter-long cylindrical Passenger Transport Module (PTM) docked with the station. Even in its most advanced form, Borowski and Dudzinski wrote, their Earth-moon transportation system would be "spartan" compared with Heywood Floyd's moon shuttle; it would, for example, not employ stewards.

The 20 moon voyagers would remain inside the PTM throughout their 24-hour Earth-moon journey, so would see little change in their immediate surroundings from the time they boarded it until they entered the lunar surface base. The PTM would, nevertheless, interface with three vehicles besides the ISS during each lunar flight.

As the time for LEO departure approached, the PTM would undock from the ISS and move away using its chemical-propellant attitude-control thrusters. It would rendezvous with a LANTR LTV standing by near the LEO propellant depot at a "safe distance" from the ISS: that is, far enough away that radiation from its BNTR engines could neither harm the ISS crew nor reflect off ISS structure and harm the astronauts in the PTM. The PTM would approach and dock tail-first with the LANTR LTV, forming a 195.6-ton LANTR "commuter shuttle."

The commuter shuttle would climb away from LEO quickly (image at top of post). Acceleration to 24-hour Earth-moon transfer velocity would need only 21.2 minutes, or less than half the duration of the all-LH2 LTV burn required to achieve an 84-hour Earth-moon transfer.

During the climb away from LEO, the 20 passengers would, like Dr. Floyd in the book 2001, feel only a "mild" pressure - to be exact, 0.23 Earth gravities of acceleration at BNTR start-up, when the commuter shuttle was fully loaded with propellants, and 0.46 gravities just before BNTR engine shutdown, when about half its propellants had been expended.

Twenty-four hours after LEO departure, the BNTR engines would fire again to slow the commuter shuttle so that the moon's gravity could capture it into lunar orbit. It would rendezvous with a lunar-orbit propellant depot containing LH2 brought from Earth and LUNOX.

The PTM would undock from the commuter shuttle and link up with a waiting lunar surface-based reusable LLV, the second vehicle with which it would interface during its trip to the moon. The skeletal four-engine LLV would weigh 10.9 tons without propellants or cargo and 59.5 tons loaded with 33.6 tons of propellants and the 15-ton PTM.

In lunar orbital night: at the end of a 24-hour Earth-moon crossing, the PTM (lower left) has separated from the LANTR LTV (lower right) near the moon-orbiting propellant depot (barely visible above the LANTR LTV). A reusable LLV now moves into position to grapple the PTM and begin descent to the LUNOX production base on the moon's surface. Image credit: Pat Rawlings/NASA

The LLV would descend to the LUNOX base on four plumes of flaming Earth hydrogen and LUNOX. After touchdown, a wheeled flatbed - the third vehicle with which the passenger module would interface - would move into position beneath the PTM and detach it from the overhead LLV framework. The PTM/flatbed combination would then roll over the lunar surface from the landing field to an airlock leading into a surface habitat. After linkup with the habitat, the 20 passengers would exit the PTM to begin their duties on the moon.

In addition to moving passengers and cargo between Earth and moon and back again, the LANTR architecture would, as already indicated, move LUNOX and Earth-produced LH2. Four times per week a reusable tanker module with an empty weight of five tons loaded with 25 tons of LUNOX would ride a flatbed to a waiting automated LLV and then ascend to the moon-orbiting propellant depot. After pumping its LUNOX cargo into the propellant depot's tanks, it would return to the LUNOX base.

Welcome to the moon: in the lower right corner, a PTM rides a six-wheeled flatbed to an airlock leading into a large inflatable lunar surface habitat. Meanwhile, at upper center-right, a tanker LLV lifts off on a mission to transport LUNOX to the lunar-orbital propellant depot. Image credit: Pat Rawlings/NASA 
Borowski and Dudzinski assumed a fleet of four LANTR LTVs. Each would carry out 13 Earth-moon round-trips per year, for a total of 52 commuter flights (that is, one per week). Each LANTR LTV would in its BNTR engines hold enough fissile material to permit 44 Earth-moon round-trips, giving it an operational lifetime of 3.3 years.

A LANTR LTV near end-of-life would perform a one-way all-cargo mission before disposal into a Sun-centered orbit. One-way cargo would include Earth-produced LH2 for the propellant depot in lunar orbit. With about 23 tons of surplus LH2 in its "core stage" tank, a one-way LOX load of only 66 tons, and a potential cargo weight of about 80 tons, the LANTR LTV might deliver more than 100 tons of LH2 to lunar orbit during its final mission.

When Borowski and Dudzinski wrote their paper in 1997, existence of lunar polar ice in permanently shadowed craters, first predicted in 1961, remained uncertain. Data from a 1994 joint experiment using the Clementine lunar orbiter and NASA's Deep Space Network antennas had hinted strongly at the existence of hydrogen at the poles, but alternate explanations for the hydrogen signal existed, and an experiment using the giant Arecibo radio telescope in Puerto Rico could find no trace of lunar hydrogen.

Robotic spacecraft have since confirmed that a large quantity of water ice exists at the moon's poles - in the billions of tons. Provided that mining equipment can be designed to operate in the very cold, very dark environment of the permanently shadowed craters, the existence of water ice means that both oxygen and hydrogen await us on the moon in potentially easily processed form.

In theory, water ice-rich feedstock need only be heated to separate out the water, which would then be split into hydrogen and oxygen using electrolysis. Though this would seem to render Borowski and Dudzinski's LUNOX mining scenario irrelevant, their LANTR-based transportation system could burn LOX and LH2 derived from lunar polar ice as easily as it could Earth LH2 and LUNOX.

Early drafts of the 2001: A Space Odyssey screenplay - there were many - are replete with informative dialog. Though actors spoke some of the dialog during filming, most was replaced with classical music and sound effects in the final film.

In a late 1965/early 1966 draft of the script, the Aries-1B moon shuttle pilot and co-pilot speculate about the purpose of Heywood Floyd's unprecedented one-passenger lunar flight. The pilot remarks that the moon shuttle will return to Earth orbit without passengers because Clavius Base is under quarantine. Only Floyd will be permitted to leave the moon shuttle and no one at the base will be permitted to board it.

The co-pilot notes that moon shuttle tickets cost $10,000 one-way, so Floyd's mission will cost USAA and U.S. taxpayers about $600,000. Alas, Borowski and Dudzinski provided no estimate of the cost of reaching the moon using their infrastructure.

In the book 2001, Floyd disembarks from the Aries-1B and stops for a glass of lunar sherry - made from moon-grown algae - in the Clavius Base Administrator's office. He then attends a briefing in which he hears the latest news about the find that justified his secretive single-passenger moon flight. A black monolith found beneath the floor of Tycho crater has, he learns, nothing to do with the Chinese expedition of 1998. It was, geologists from Clavius Base have determined, deliberately buried three million years ago. It is thus the first evidence of intelligent life off the Earth.

After a moonbus ride across the rugged southern Lunar Highlands to Tycho, Floyd witnesses the beginning of a slow lunar dawn. He dons an advanced space suit - it takes only a few minutes and barely restricts his movements - then descends into the pit excavated around the monolith. Meanwhile, the Sun rises slowly over the lip of the excavation, shining its light on the monolith for the first time in three million years.

In the film 2001, Floyd joins other bureaucrats for a group photo in front of the monolith. Set against the brooding monolith, which seems to soak up all light, this very human ritual is so mundane as to be comical. As the photographer gestures repeatedly for them to move closer together - a critical part of the group-photo ritual - the monolith interrupts by emitting a powerful electronic scream.

Floyd and the others stumble around in pain and confusion as their suit radios receive the signal and blast it into their helmets. Only later do they realize that, by exposing the monolith to the Sun, they have tripped an ancient alarm.


"2001: A Space Odyssey" Revisited - The Feasibility of 24 Hour Commuter Flights to the Moon Using NTR Propulsion with LUNOX Afterburners," AIAA-97-2956, Stanley Borowski and Leonard Dudzinski; paper presented at the 33rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit in Seattle, Washington, 6-9 July 1997

"2001: A Space Odyssey" Revisited - The Feasibility of 24 Hour Commuter Flights to the Moon Using NTR Propulsion with LUNOX Afterburners, NASA/TM-1998-208830/REV2, Stanley Borowski and Leonard Dudzinski, NASA Glenn Research Center, June 2003

Kubrick, Stanley, and Arthur C. Clarke, 2001: A Space Odyssey, directed by Stanley Kubrick, Metro Goldwyn Mayer, April 1968

2001: A Space Odyssey, Screenplay by Stanley Kubrick and Arthur C. Clarke, pp. b35-b36a, 12/1965

2001: A Space Odyssey, Arthur C. Clarke, New York: New American Library, October 1999

The Making of Stanley Kubrick's 2001: A Space Odyssey, Piers Bizony, Taschen, 2014, p. 58-59

2001Italia.it: A Blog Devoted to 2001: A Space Odyssey, Simone Odino (accessed 12 June 2016)

More Information

The Last Days of the Nuclear Shuttle (1971)

Think Big: A 1970 Flight Schedule for NASA's 1969 Integrated Program Plan

Space Station Gemini (1962)

Making Propellants from Martian Air (1978)