08 March 2015

McDonnell Douglas Phase B Space Station (1970)

Image credit: MDAC/NASA
In the autumn of 1966, NASA asked President Lyndon Baines Johnson's Bureau of the Budget (BOB) for $100 million in Fiscal Year (FY) 1968 to begin Phase B contractor studies of Earth-orbital space stations. With the Apollo Program's culmination drawing near, the U.S. civilian space agency was eager to establish post-Apollo goals, and topping its wish-list was a space station - an Earth-orbiting laboratory for testing the effects on men and machines of long-term exposure to space conditions and for performing scientific and technological experiments and Earth and space observations.

NASA had performed internal Phase A space station studies almost since it opened its doors in October 1958. If NASA had had its way, a space station would have preceded Apollo's reach for the moon. President John F. Kennedy's May 1961 call for a man on the moon ahead of the Russians and before the end of the 1960s had, however, preempted space station development. The FY 1968 funding request was in some sense a plea to restore NASA's program to the traditional station/moon/Mars progression spaceflight thinkers had promoted since the 1920s.

The BOB turned down NASA's request: then, in January 1967, the Apollo 1 fire profoundly altered the space policy environment. NASA came under increased scrutiny and funding for post-Apollo space goals became even more elusive. Congress dealt the only approved post-Apollo manned program - the Apollo Applications Program (AAP), which would reapply Apollo lunar mission hardware to new goals, including a series of Earth-orbiting laboratories based on spent Saturn IB S-IVB rocket stages - a nearly half-billion dollar funding cut in August 1967.

NASA recovered from the fire - in November 1967, the successful first flight of the three-stage Saturn V moon rocket did much to restore confidence - but funding for post-Apollo programs was still not forthcoming. When NASA Administrator James Webb, who had led the agency from Apollo's beginning, announced in September 1968 that he would step down, he told journalists that he left NASA "well prepared. . .to carry out missions that have been approved." He added, however, that "[w]hat we have not been able to do under pressures on the budget has been to fund new missions."

After he stepped down, Webb's new deputy, Thomas Paine, became acting NASA Administrator. Webb, whose earliest Federal government experience dated to 1932, had deftly piloted NASA through Washington's political shoals; Paine, by contrast, has just seven months of experience in government service when he took over as NASA boss. Paine displayed his inexperience almost immediately by pressing President Johnson for a space station decision in the final weeks of his Administration. Johnson deferred the decision to the next President.

Soon after President Richard M. Nixon's January 1969 inauguration, Democrat Paine submitted his resignation as was customary. Republican Nixon, however, surprised everyone by keeping him on and appointing him as Webb's formal replacement. Paine then made another space station pitch. He apparently hoped that Apollo Program successes would induce the new President to give NASA a blank check for future projects.

5 March 1969: standing in front of a bust of U.S. rocket pioneer Robert Goddard, President Richard Nixon (left) announces that he has appointed Thomas Paine (center) to be NASA Administrator as Vice President Spiro Agnew looks on. The Senate would confirm Paine on 20 March. Image credit: NASA
Though the Apollo 8 Command and Service Module (CSM) had triumphantly orbited the moon and returned its three-man crew safely to Earth less than a month before his inauguration, Nixon refused to commit to new NASA programs. Instead, he postponed any decision on NASA's future direction at least until after the newly appointed Space Task Group (STG) completed its report in September 1969. Paine was a voting member of the STG, which was chaired by Vice President Spiro Agnew.

It is widely assumed today that Nixon kept Paine on in case Apollo failed. In the event that the first moon landing ended in grief, he wanted a holdover from the Democratic Johnson Administration upon whom he could hang the blame. At the time, however, even as savvy an aerospace trade publication as Aviation Week & Space Technology assumed that Nixon was impressed with Paine's abilities. Nixon, it must be said, was less impressed with the talents of the people with whom he surrounded himself than he was with their obedience.

Paine chose not to await the outcome of the STG's deliberations. In January-February 1969, he oversaw creation within NASA of a Space Station Task Force, a Space Station Steering Group, and an independent Space Station Review Group. These bodies prepared a Phase B Space Station Study Statement of Work (SOW), which NASA released to industry on 19 April 1969.

The SOW solicited proposals to study a 12-man Space Station, the design of which would eventually serve as a building block for a 100-man Earth-orbital Space Base. The 12-man Station was to reach orbit on a Saturn V rocket in 1975 and to remain in operation for 10 years.

Of the contractor effort expended in the Phase B study, 60% was to be devoted to the 12-man Space Station, 15% to its future role as part of the 100-man Space Base, 15% to an interim logistics spacecraft for delivering early crews and supplies to the 12-man Space Station, and 10% to 12-man Space Station interfaces with an advanced logistics system (specifically, a fully reusable Space Shuttle, design to be determined).

Grumman, North American Rockwell (NAR), and McDonnell Douglas Aerospace Company (MDAC) submitted proposals in response to the SOW. On 22 July 1969 - two days after the successful Apollo 11 moon landing - NASA awarded to NAR and MDAC Phase B Space Station study contracts worth $2.9 million each. This was a far cry from the $100 million Webb had sought in late 1966 to fund Phase B Space Station studies.

Phase B study work began formally in September 1969, though the contractors had begun to put together subcontractor teams and to spend their own money on the study even before NASA issued its SOW. The MDAC and NAR Phase B study teams each included more than 30 subcontractors. NAR and MDAC were eager to move forward at their own expense because they expected that the eventual Phase C/D Space Station development contract would be extremely lucrative.

Image credit: NASA
NASA's Manned Spacecraft Center (MSC) in Houston managed the NAR Phase B study, while Marshall Space Flight Center (MSFC) in Huntsville, Alabama, managed MDAC's work. This division of labor reflected pre-existing center/contractor relationships. MSC managed NAR's contract to manufacture Apollo CSMs, while MSFC managed MDAC's contract to build the 6.6-meter-diameter S-IVB-based AAP Orbital Workshop.

AAP was renamed the Skylab Program in February 1970. The new name reflected AAP's abandonment of all missions not related to the S-IVB-based Orbital Workshop. The two planned Skylab Orbital Workshops were designated Skylab A and Skylab B.

In early June 1970, as the Phase B study effort neared its planned conclusion, NASA and European Space Research Organization (ESRO) officials met in Paris to discuss future cooperation in space with emphasis on the Space Station. Paine and ESRO Director General Hermann Bondi chaired the meeting, during which NAR and MDAC representatives presented briefings on their Phase B study results.

The U.S. Department of State had come out cautiously in favor of NASA's proposed Space Station/Space Shuttle Program in March 1969 because it expected that it would open up opportunities for international cooperation. With that in mind, NASA had invited foreign representatives to participate in Phase B Station study quarterly reviews. The Paris meeting gave ESRO an opportunity to return the favor and to confirm its desire to participate in a NASA-led Space Station Program.

C. J. Dorrenbacher, MDAC's Vice President for Advance Systems and Technology, began his presentation by drawing links between his company's 12-man Space Station design and Skylab A, which he said was scheduled to launch during 1972. The Skylab Program, he told the Paris meeting, would see NASA piloted spaceflight evolve from "cockpit to ship accommodations." He explained that Skylab would contain "many systems that are prototypes of those to be used on the Space Station," and added that "experience in the operation, maintenance, and habitability of [Skylab] will significantly extend our knowledge and, thus, our confidence in the Space Station Program."

Cross-section of MDAC's Phase B 12-man Space Station in launch configuration. Black triangular structures located midway along the Station's length are twin Isotope/Brayton nuclear power units. Image credit: MDAC/NASA
Like Skylab, MDAC's Space Station would leave Earth on top of a two-stage Saturn V. Designated INT-21, the rocket would comprise S-IC and S-II stages measuring 9.2 meters in diameter. This established the maximum diameter of MDAC's Space Station. The S-II second stage would inject the bullet-shaped 34-meter-long Station into a 456-kilometer-high circular orbit inclined 55° relative to Earth's equator. Its labors completed, the S-II stage would then detach and deorbit itself over a remote ocean area.

Dorrenbacher explained that MDAC's Station would comprise two main modules: the two-deck, roughly conical artificial-gravity module at its front end and the four-deck, drum-shaped core module. The 15-meter-long core module would be divided into two independent sections, each with a research deck and a living deck. The artificial-gravity module would also include research and living decks. Each of the three sections would have an independent life-support system and could house the entire Station crew in an emergency. The artificial-gravity and core modules would also each include a conical unpressurized module. On the artificial-gravity module, this would be called the equipment module; on the core module, it would be called the power and equipment module.

Soon after reaching orbit, MDAC's Station would discard a streamlined nose cone covering its front docking port. A "telescoping spoke" linking the artificial-gravity and core modules would then extend to separate the two modules by a few meters. This would expose the core module power and equipment module, enabling four large radio dish antennas to deploy and exposing waste heat radiators for the Station's twin Isotope/Brayton (I/B) nuclear power units. The I/B units, which would each produce 10 kilowatts of electricity, would be designed to jettison from the Station in an emergency and safely reenter Earth's atmosphere.

By the time of the Paris briefings, NASA had pushed back the planned launch of the 12-man Space Station from 1975 to 1977. Though the move was inspired by increasingly disheartening NASA budget projections, space agency officials hoped that the two-year slip would also help to ensure that the Space Shuttle would be ready to deliver astronauts, supplies, equipment, and experiment modules to the orbiting Station, eliminating any need to pay for an interim logistics vehicle. For its study, MDAC assumed a Shuttle consisting of a piloted winged Booster and a piloted winged Orbiter with a 4.6-by-18.3-meter cargo bay.

Cross-section of MDAC's Crew/Cargo Module. Image credit: MDAC/NASA
A Crew/Cargo Module maneuvers from the payload bay of a visiting Space Shuttle Orbiter to an axial docking port on MDAC's Phase B Space Station. Image credit: MDAC/NASA
Flight controllers on Earth would remotely check out the Station's vital systems. If it checked out as habitable, then 24 hours after it reached orbit its first 12 residents would lift off from Cape Kennedy on board a Shuttle Orbiter. Eight hours later, their Orbiter would rendezvous with the Station and open its cargo bay doors. The Station crew would depart the cargo bay inside an 18,000-kilogram Crew/Cargo Module (CCM).

MDAC's CCM, an independent spacecraft larger than the Apollo CSM, resembled designs for drum-shaped cargo spacecraft and small station modules based on Gemini spacecraft hardware which McDonnell Aircraft had put forward as early as 1962. McDonnell had manufactured the Gemini spacecraft, 10 of which carried two-man crews into Earth orbit in 1965-1966, before the company's April 1967 merger with Douglas Aircraft created MDAC. Probably MDAC viewed the 12-man CCM as a way of salvaging its Gemini-based designs or of saving time and effort during its Phase B study by partially reusing old designs.

The CCM would deploy four side-mounted engine modules and maneuver to a docking at the Station's aft port on the core module. The astronauts would then enter the Station through the port's 1.5-meter hatch (the standard Station hatch size) and begin checking out its systems. If initial Station manning came off without a hitch, the Orbiter, which would remain close by the Station but would not dock, would commence its return to Earth about 25 hours after the CCM bearing the first Station crew left its cargo bay.

A Shuttle Orbiter would deliver a CCM to MDAC's Station every 90 days with a new crew and supplies. Of the CCM's mass, about 13,000 kilograms would comprise cargo. After a new CCM docked at a side port carrying a new crew, the astronauts already on board the Station would board their CCM, undock, maneuver to the waiting Orbiter, and enter its cargo bay. The Orbiter would then hinge shut its cargo bay doors and return to Earth.

Central tunnel of the MDAC Phase B Space Station core module. The CCM docking port is located at the bottom of the bottom, adjacent to Level 1. Image credit: MDAC/NASA
MDAC Phase B Space Station core module. Image credit: MDAC/NASA
The hatch through which the first astronauts would enter their new home would lead into the core module's "central tunnel." Besides forming the main "artery" linking the core module's four pressurized decks, the three-meter-diameter cylindrical tunnel would provide emergency living quarters for the entire 12-man crew, a 180-day supply of emergency food, a passageway for ducts and conduits, radiation-shielded photographic film storage, and space suit storage. MDAC thus opted for a "fall-back" shelter where the crew could await rescue in place of a separate Space Station lifeboat that could evacuate the crew in the event of trouble while a Shuttle Orbiter was not present.

At the forward end of the core module tunnel, a hatch would open into a cylindrical airlock at the center of the core module's unpressurized power and equipment module. A hatch in the airlock wall would open into the power and equipment module, which would contain liquid and gas storage tanks, the twin I/B power units and their waste heat radiators, power conditioning and distribution systems, and storage for equipment and supplies able to tolerate vacuum.

A hatch in the airlock ceiling would open into the telescoping spoke linking the core module with the artificial-gravity module. The spoke would link to a hatch leading into the artificial-gravity module's central tunnel, which would provide access to the artificial-gravity module's two decks.

A hatch at the forward end of the tunnel would open into a cylindrical airlock at the center of the artificial-gravity module's unpressurized equipment module. A hatch in the airlock's side would provide access to unpressurized storage, gas and liquid storage tanks, and small thrusters and propellant tanks. The equipment compartment would also include a place for eventual installation of a third I/B power unit. A 1.5-meter hatch in the airlock ceiling would provide access to the MDAC Station's exterior and serve as the Station's front docking port.

Artificial-gravity module. Image credit: MDAC/NASA
Dorrenbacher told the Paris meeting that the Station's first crew would almost immediately begin a 30-day artificial-gravity experiment. This would entail extending the telescoping spoke to its maximum length. Six crew members would take up residence in the artificial-gravity module, while "some" would occupy a small "zero-gravity cab" inside the spoke at the Station's center of gravity.

The astronauts would then ignite the small thrusters in the artificial-gravity module's equipment module to set the Station spinning end over end at a rate of four rotations per minute. This would produce acceleration which the crew would feel as gravity.

On deck 1 of the core module, 19.2 meters from the center of gravity, the astronauts would feel acceleration equivalent to 0.35 Earth gravities. On the artificial-gravity module's living deck (Deck 6), 39.3 meters from the center of gravity, the astronauts would feel 0.7 Earth gravities.

During the artificial-gravity experiment: MDAC Phase B station with docked CCM (left) and extended artificial-gravity module (right). Image credit: MDAC/NASA
After a month of artificial-gravity experimentation, the astronauts would halt the Station's rotation using the small thrusters to restore it to a zero-gravity condition. The artificial-gravity module thrusters would carry enough propellants to permit up to four similar experiments.

Dorrenbacher described the 12-man Space Station as "a research facility to accommodate all experiment disciplines. . .a general-purpose laboratory." It would include three lab decks. Deck 2 would at launch from Earth be dedicated to the study of living things in weightlessness. It would include the Station's medical dispensary and isolation ward. Deck 4 would serve both scientific support and engineering experimentation roles. It would include a drum-shaped experiment and test isolation facility, a mechanical lab, an electronics/electrical lab, a hard-data processing facility, an optics facility, and a small experiment airlock. Deck 5 would include a centrifuge with a pair of cabs large enough to accommodate men and experiments.

Deck 2: the life sciences laboratory. Image credit: MDAC/NASA
Image credit: MDAC/NASA
Based on NASA input, MDAC defined eight experiment disciplines for its Phase B Station. These were astronomy, space physics, space biology, Earth survey, aerospace medicine, space manufacturing, engineering/operations, and advanced technology. Not all disciplines could be accommodated simultaneously; for example, the artificial-gravity experiment series would preclude experiments that would need a stable platform and weightlessness.

Dorrenbacher then provided a rough schedule of the Station's experiment programs. Biomedical experimentation would begin with the arrival of of the first crew and continue without pause throughout the Station's planned 10-year lifetime, as would "man-system integration" experiments. In general, early research not associated with the artificial-gravity experiment series would focus on Station operations and habitability. "Component test" experiments would end in early 1978, "maintenance and logistic" experiments would conclude in late 1978, and "occupancy and space living," "contamination," and "exposure" research would end in mid-1979.

CCMs would deliver new experiment apparatus to replace and augment that launched with the Station, Dorrenbacher told the Paris meeting. Disused experiment hardware and other unwanted equipment and furnishings would be packed into CCMs for return to Earth. He suggested that, following the conclusion of artificial-gravity experiments in late 1978, furnishings on Deck 6 should be returned to Earth in CCMs so that it could be converted into a physics & chemistry laboratory using new apparatus delivered in CCMs.

By then, the first Attached Modules (AMs) and Free-Flying Modules (FFMs) would arrive at MDAC's Station in Shuttle Orbiter cargo bays. One AM, devoted to Ultraviolet (UV) Stellar Astronomy, would dock with a port on the core module's side linking it to Deck 4. Another AM, devoted to Earth Surveys, would dock either at Deck 4's second port or at a port on Deck 2. Two FFMs, devoted respectively to Solar Astronomy and High-Energy Stellar Astronomy, would dock with the Station's front port on the artificial-gravity module when they needed servicing; for example, after they had expended their photographic film. AMs would rely on the Station for electrical power, while FFMs would each sport a pair of electricity-generating solar arrays.

Image credit: MDAC/NASA
CCMs, meanwhile, would deliver non-human biology experiment subjects beginning in early 1979. They would transport to the Station small vertebrates such as rats and invertebrates such as fruit flies. Vascular plants would first reach the Station later that same year.

Also in late 1979, the general Stellar Astronomy FFM would arrive near the Station. MDAC envisioned that UV Stellar Astronomy and High-Energy Stellar Astronomy would conclude at the beginning of 1981, while Solar Astronomy, general Stellar Astronomy, and small vertebrate, invertebrate, and plant studies would continue until the Station reached its planned end-of-life in 1987. Biomedical centrifuge and fluid physics AMs would arrive in late 1981, with the former remaining with the Station until end-of-life and the latter departing in late 1985. Small Vertebrates Centrifuge and Infrared Stellar AMs would arrive in late 1982 and remain docked until Station end-of-life.

Late 1983 would see arrival of the Remote Maneuvering Satellite (RMS), which would take up residence in a "hangar" in the airlock at the Station's front port. Dorrenbacher called the RMS a "subsatellite," but did not otherwise describe its role. RMS operations would cease in late 1986.

Also in late 1983, the X-Ray Telescope FFM and advanced particle and plasma physics experiment apparatus would arrive. The X-Ray Telescope FFM would operate through Station end-of-life. Some advanced physics experiments would cease in early 1985; all would end by late 1986. Late 1985 would see the arrival of materials science experiment apparatus and the Cosmic-Ray Physics FFM, both of which would remain in operation through Station end-of-life.

Dorrenbacher described how the vast quantity of data Station experiments generated would reach Earth. MDAC estimated that 9070 kilograms of magnetic tape, microfilm, exposed photographic and X-ray film, and photographic plates would need to be returned to Earth each year. The Station's four large dish antennas would enable continuous two-way television communication through ground stations or through relay satellites so that Station and Earth researchers could work together continuously in real time. The antennas would be capable of transmitting up to a trillion bits (one terabyte) of data to Earth each day.

The Station's impressive experiment capability would demand careful management of crew time. MDAC assumed that Station crews would work around the clock, with six men on duty and six off duty at all times. Each crew would include eight scientist-engineers and four Station flight-crew crewmembers. Two flight-crew and four scientist-engineers would work during each 12-hour shift.

One scientist-engineer would serve as principal scientist. He would work closely with the flight-crew commander, who would have responsibility for the safety of the entire crew, to ensure that science interests were taken into account during Station operations.

Two scientist-engineers would serve as principal investigator representatives. They would use the Station's considerable communications capabilities to work directly with scientists on Earth.

Image credit: MDAC/NASA
Off-duty Station crewmembers would spend most of their time on the living decks (Decks 1, 3, and - during the artificial-gravity experiment series - 6). There, Dorrenbacher explained, they would have at their disposal private staterooms with 4.6 meters of floor space for "relaxation, recreation, study, and meditation." Each living deck would include six staterooms, which together would take up about half the deck's volume. Staterooms would each include a small viewport for watching the Earth go by, a folding bunk, a desk, and storage cabinets for personal belongings.

When not in their staterooms, off-duty crewmembers could hang out in their living deck's multipurpose wardroom, which would include portable dining tables with zero-gravity restraints in place of conventional chairs. Dorrenbacher told the Paris meeting that the wardoom could be "quickly and easily" converted into a gym, theater, meeting room, or recreation room.

Image credit: MDAC/NASA
Visible in the wardroom are three large observation windows, an exercise device to simulate weightlifting, zero-gravity "seats" both stowed (left) and in use, a round 1.5-meter hatch to which CCMs can dock (right), and a visiting Vulcan scientist. Image credit: MDAC/NASA
Cabinets in the galley, adjacent to the wardroom, would be kept stocked with enough food for 90 days. Crew-members could choose to serve themselves or could take it in turns to prepare meal trays for their crew-mates. Food would be "selected for maximum palatability with various degrees of wet or even fresh foods."

The three living decks would each include a hygiene facility. Apparently configured for men only, these would include a toilet, two urinals, two hand-washing units, a shower, a clothes-washing machine, and a clothes-dryer. Hygiene facilities would be located next to water-recycling life-support machinery on each living deck.

MDAC proposed a novel approach to station orbit maintenance. Some processed waste water would be electrolyzed (split into oxygen and hydrogen using electricity) and the hydrogen used to fuel low-thrust resistojets on the Station's hull. MDAC calculated that water delivered to the Station in food would be sufficient to maintain its orbital altitude.

MDAC placed core module control consoles on the living decks adjacent to the wardrooms. The artificial-gravity module would include an identical control console on Deck 5. The primary control console - the Station's "bridge" - would be located on Deck 3. The control consoles on Decks 1 and 5 would serve as backups for the Deck 3 primary console, and would also support experiments; they might, for example, be used to monitor data arriving from the FFMs.

Dorrenbacher then described an arbitrarily selected moment in the MDAC Phase B Station's 10-year career to illustrate possible activities of on-duty and off-duty crew-members. At 2030 hours Greenwich Mean Time on 26 March 1985, the flight-crew commander would be at work conducting safety checks on space suits stored in the core module central tunnel. The shift's other on-duty flight-crew astronaut would, meanwhile, sample the Deck 1 water system to ensure that it contained no harmful bacteria.

Two of the on-duty scientist-engineers would work in the Deck 2 labs and two elsewhere. The physician would analyze crew blood and urine samples in the biomedical lab, while the psychologist would analyze data on "crew skill retention in extended zero gravity" in the man/system integration lab. The geologist/photo-optical engineer, meanwhile, would install and align sensors in the Earth Survey AM docked to Deck 2, and the astronomer/systems engineer would monitor data from the X-Ray Telescope FFM at the secondary control console on Deck 5.

The six off-duty crew-members, having just finished their late meal, would all be found on Deck 3. The operations director, a flight-crew crew-member, would take a shower in the hygiene facility while the physician, a scientist-engineer, would watch a videotaped television program in his stateroom before going to sleep.

The other off-duty crew would be in the wardroom. The station controller, a flight-crew astronaut, would compete against the astrophysicist, a scientist/engineer, in a simulated time-distance race on stationary exercise bikes. Nearby, the biologist and the electro-mechanical engineer, both scientist-engineers, would compete in a game of "computer football."

Dorrenbacher concluded his presentation by assuring Paine, Bondi, and the other NASA and ESRO officials that MDAC's 12-man Phase B Space Station would be a "low-cost, flexible, international research facility" built using known technology (that is, mostly adaptations and upgrades of Skylab hardware). Furthermore, its module designs would be readily adaptable to future NASA/ESRO joint missions; specifically, they could serve as building blocks making up the 100-man Space Base of the mid-to-late 1980s.

Conceptual art of 100-man Space Base in orbit over Australia and New Guinea. The two truss-work arms hold at their ends nuclear reactors and their rectangular waste heat radiators. A free-flying large space telescope orbits nearby. Image credit: NASA
As noted earlier, NASA had instructed MDAC to design its 12-man Station to be launched on a Saturn V. Dorrenbacher failed to mention in his briefing that NASA Administrator Paine had announced on 13 January 1970, six months before the Paris briefing, that Saturn V production and test facilities would be mothballed, and that the fifteenth and last Saturn V of the Apollo buy, previously assigned to the Apollo 20 moon mission, would instead launch Skylab A. He also neglected to mention that NASA had directed NAR and MDAC in early May to begin considering designs for Space Stations that could be assembled solely from modules launched in the Shuttle Orbiter's cargo bay.

On 30 June 1970, NASA extended the MDAC and NAR Phase B Saturn V-launched Station contracts for six months. A month later, two highly significant events took place: Paine resigned the post of NASA Administrator effective 15 September (28 July) and NASA formally directed MDAC and NAR to shift their attention to studying Shuttle-launched modular Station designs within the scope of the Phase B contract, which, as has been discussed, already included provisions for Shuttle-launched research modules (29 July).

Just before he stepped down, Paine announced that Saturn V production would be permanently halted. Soon after he departed, the Space Station groups he established drew up an SOW for a focused Phase B Extension study of a Shuttle-launched modular Station. NASA released the SOW on 16 November 1970. MDAC, NAR, and their respective subcontractors began Phase B Extension work on 1 February 1971.

NASA also moved to toe the line on the Nixon Administration's slowly emerging space policy. That policy gave lukewarm support to the Space Shuttle and left the Space Station it was meant to serve in limbo.

Aware that the Station enjoyed almost no support in the Nixon White House, NASA directed MDAC and NAR to study research modules that would operate attached to a Shuttle Orbiter. The modules would each carry a small team of scientists and enough expendables (for example, reactants for the Orbiter's electricity-generating fuel cells) to stretch the period of time the Orbiter could spend in space to 30 days. This became known as the "sortie lab" concept.

On 5 January 1972, NASA Administrator James Fletcher announced that President Nixon's FY 1973 NASA budget request included modest funds to begin development of a partially reusable Space Shuttle. Though little mention was made of a Space Station, the Phase B Extension studies lingered on until late in the year.

On 29 November 1972, Fletcher formally abolished NASA's Space Station Task Force and established the Sortie Lab Task Force. In August 1973, NASA and ESRO agreed that the latter should develop the Sortie Lab, which became known subsequently as Spacelab.

Cutaway art of Spacelab pressurized module in Space Shuttle payload bay. Image credit: NASA

"NASA Plans Five-Year Fund Rise," W. Normyle, Aviation Week & Space Technology, 14 October 1968, pp. 16-17

"Pace of Post-Apollo Planning Rises," W. Normyle, Aviation Week & Space Technology, 3 February 1969, p. 16

"NASA Aims at 100-Man Station," W. Normyle, Aviation Week & Space Technology, 24 February 1969, pp. 16-17

"Against the Tide," Aviation Week & Space Technology, 17 March 1969, p. 15

"Shuttle Group Readies Proposal Requests," Aviation Week & Space Technology, 19 January 1970, pp. 17-18

Development and Use of a 12-Man Space Station, MDC G0583, C. Dorrenbacher, McDonnell Douglas Astronautics Company, Briefing to the European Space Research Organization on Space Station Plans and Programs in Paris, France, 3-5 June 1970

Astronautics and Aeronautics 1968, NASA SP-4010, pp. 212-213

Astronautics and Aeronautics 1970, NASA SP-4015, pp. 193-194

Space Stations: A Policy History, J. Logsdon, George Washington University, NASA Contract NAS9-16461, NASA Johnson Space Center, no date (1980), pp. I-16, II-1-5, II-8-10, II-13-15, II-18-33

More Information

Space Station Gemini (1962)

"A True Gateway": Robert Gilruth's June 1968 Space Station Presentation

Reviving & Reusing Skylab in the Shuttle Era: NASA Marshall's November 1977 Pitch to NASA Headquarters

The 1991 Plan to Turn Space Shuttle Columbia Into a Low-Cost Space Station


  1. Last time I posted, it didn't stick. I think I don't like blogspot like I did Wired. It is what it is.

    1. How much fuel or energy needed to spin for artificial gravity, for one of these designs?

    2. This is a big volume post, still re-reading it to glean all the possible decision tree alternatives which were discarded.

    3. My leaning is that long term space travel becomes more plausible once you fix the gravity issue. Do we yet know that bone mass reduction is caused by microgravity alone? What if we discover there's a radiation or other component to that physical decline? Some of the examples provided would have answered that question in the 1970s. That's what I find frustrating from our space policy. Alot of time has been wasted by ignoring the artificial gravity research opportunity.

    1. Hi Ben, are you trying to respond using an iPad? I find it difficult to interface with Blogger as well. It takes some persistance but it can be done. I blame Apple for this since they pick and choose what they like anout the internet, which makes some websites hard to deal with.

  2. Sorry about the comment problem. WIRED is undergoing changes and I'm pleased to be clear of all that. Here I can do what I want without being swamped with advertisements.

    The documents I have do not provide details on the artificial gravity system except to say that the station could be spun up and spun down four times in all. I have only a few documents out of the set that McDonnell Douglas prepared in the Phase B study; they produced something like 20 volumes, all specified by NASA MSFC in its Statement of Work. Imagine how enormous this post would be were I to obtain all those documents!

    My understanding is that bone loss varies a lot from individual to individual. Exercise and loading the bones also affect different people differently. Non-load-bearing bones lose mass, too, and it's hard to do anything about it. And then, upon return to gravity, the way the bones react varies, too. I don't think that there's a radiation or other component to bone loss, though I wouldn't claim expertise; I just don't know about any connection.

    Bone loss is only one factor related to microgravity - immune system suppression, changes in eye shape, muscle loss, etc. point to a need for some level of artificial gravity. In my private plan for NASA's future, the station after ISS is a variable-gravity station capable of long-term simulation of everything from lunar gravity to Earth gravity. It's also a prototype interplanetary spacecraft, and it can operate in weightlessness, too. Of course, my private plan is just that. I do believe, however, that a variable-gravity station is a logical next step if we plan to put people on other worlds for extended periods.


  3. This was such a great idea! Which makes it even sadder to think it was cancelled.

  4. Thanks for this post. I find this endlessly interesting especially to see how different aspects of the project were applied to ISS, Shuttle and the actual Skylab mission.

    Planning "big" allows for the smaller aspects to be separated out and applied elsewhere.

    Great stuff. Thanks for the effort.


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