30 October 2015

An Alternate Station/Shuttle Evolution: The Spirit of '76 (1970)

North American Rockwell concept of a fully resuable Space Shuttle. Image credit: NASA
NASA Administrator Thomas Paine was optimistic that national enthusiasm for Apollo 11, the first piloted lunar landing, would translate into national support for an expansive future NASA program. He viewed a 12-person Space Station served by a reusable Space Shuttle as the necessary first step toward such a future for the U.S. civilian space agency.

On 22 July 1969 - the day after Apollo 11 astronauts Neil Armstrong and Edwin Aldrin lifted off from the moon in the Ascent Stage of the Lunar Module Eagle - NASA awarded Phase B Space Station study contracts to McDonnell Douglas Aerospace Company (MDAC) and North American Rockwell (NAR). Each contractor led a team of subcontractors, so in all as many as 30 aerospace companies were involved in executing the Phase B studies. Marshall Space Flight Center in Huntsville, Alabama, directed the MDAC contract and the Manned Spacecraft Center in Houston, Texas, directed NAR.

I described the MDAC study in considerable detail in a March post (see the links at the bottom of this post). NAR's 12-person Space Station was, like the MDAC Station, meant to reach low-Earth orbit atop a two-stage Saturn V rocket in 1975 and operate for up to 10 years. The barrel-shaped 33-foot-diameter, 50-foot-tall Station would be ready for staffing as soon as it deployed automatically in 270-nautical-mile-high orbit.

Plan drawing of North American Rockwell's Phase B Space Station. Image credit: North American Rockwell/NASA/David S. F. Portree
The Phase B Station would comprise four pressurized living decks. Deck 1 would include a galley and a wardroom with recreation equipment and seating for 12, a sickbay with space medicine research equipment, two "neuter" docking units, and two observation portholes set into one of the round docking port hatches. Deck 2 would include individual staterooms for six astronauts (a large cabin with an office for the Station Commander and smaller cabins for crew members), a personal hygiene compartment including a full-body shower, and the Primary Control Center (PCC).

Deck 3 would resemble Deck 2, except that its large stateroom would be set aside for the Chief Science Investigator and a repair shop would replace the PCC. Deck 4, the laboratory deck, would include experiment equipment for eight major scientific disciplines, an airlock with an extendable boom for exposing experiments to space, a small backup control center, and two docking units.

Image credit: North American Rockwell/NASA
Image credit: North American Rockwell/NASA
Image credit: North American Rockwell/NASA
Image credit: North American Rockwell/NASA
To enhance crew safety, Decks 1/2 and Decks 3/4 would comprise a pair of independent, redundant living volumes. If a fire broke out and burned out of control on Deck 4, for example, the Station crew would evacuate to the Deck 1/2 volume through an "inter-volume airlock" adjacent to the repair shop on Deck 3. They would seal off the damaged volume and call for help from Earth.

Upper and lower equipment bays atop Deck 4 and below Deck 1, respectively, would each contain a conical "tunnel" airlock, a pressurized "torus" ring for storing supplies and spare parts, and an section open to vacuum containing spherical storage tanks for life-support gases and liquids. The equipment bays would also house propellant tanks supplying the Phase B Station's attitude-control thrusters. Spacewalking astronauts would leave the station through the lower tunnel. Rectangular openings in the Deck 1 floor and the Deck 4 ceiling would enable astronauts to enter the storage rings.

Image credit: North American Rockwell/NASA
Image credit: North American Rockwell/NASA
NASA envisioned that the Phase B Space Station design would, with minimal modifications, serve as a "building block" module for advanced space projects. Multiple modules might, for example, be stacked and clustered to form a 100-man Earth-orbiting Space Base. A single module - perhaps cut down to two decks - might serve as a lunar-orbital Space Station or Mars spacecraft crew module.

After considering Brayton-isotope and nuclear-reactor power systems, NAR settled on solar power for its Phase B station. The company explained its decision by noting that a Brayton-isotope power source would provide adequate electricity for the 12-person Station but could not be scaled up to serve a Space Base; by the same token, a reactor capable of supplying a Space Base would be too large and complex to efficiently power a 12-person Station.

A cylindrical "power boom" would carry four rolled-up advanced-design steerable solar arrays. A total of 10,000 square feet of solar cells would generate 25 kilowatts of electricity. The rotating boom would reach space attached to a port atop the upper equipment bay. The upper bay's conical tunnel would lead through a hatch into the hollow power boom.

The major technical challenge of the Phase B Station was, NAR explained, its anticipated long lifetime in orbit. The company invoked detailed on-board subsystems monitoring, subsystems designed for maintainability, easy subsystems accessibility, and a large on-board stockpile of spare parts as solutions to the Station lifetime problem.

Astronauts would reach NAR's orbiting Station on board fully reusable Space Shuttle Orbiters. The Shuttle's mission would be to economically change out Station crews, replenish supplies, and deliver scientific equipment and other cargo. Most of the many Shuttle designs under study by mid-1970 comprised a winged piloted Booster and a winged piloted Orbiter; the latter would include a cylindrical payload bay that could be opened to space.

The payload bay would be sized to transport standardized cylindrical modules. Most commonly carried would be the cargo/crew transfer module; other modules would arrive at the Station's five ports outfitted as specialized laboratories, instrument carriers, or free-flyers.

Upon achieving orbit, the Orbiter crew would open the payload bay doors and activate a mechanism that would pivot the module it carried onto a neuter docking port on the Orbiter crew cabin roof. The Orbiter would then dock with the Station using the neuter docking unit on the other end of the module. Astronauts would enter and depart the Station through the module. When time came to leave the Station, the Orbiter would undock from the module, leaving it attached to the Station, or would undock the module from the Station and pivot it back into the payload bay for return to Earth.

A Space Shuttle Orbiter docks with the NAR Phase B Space Station using a module deployed from its payload bay and linked to the docking port atop its crew cabin. Image credit: North American Rockwell
On 28 July 1970, a little more than a year after NASA awarded the Phase B Station contracts, Administrator Paine resigned effective 15 September. The next day (29 July), NASA instructed MDAC and NAR to examine Stations that could be launched in pieces in Space Shuttle Orbiter payload bays and assembled in space. This marked the continuation of a gradual shift toward a "phased" Station/Shuttle Program.

The phased approach, a response to deep cuts in NASA funding, would postpone Station development until late in the Shuttle development phase, when Shuttle development costs would wind down, or until after the first few Shuttle orbital flights. In either case, the Shuttle would begin operational flights before it began to launch Space Station modules into orbit.

Shortly after the 29 July directive, NAR engineers offered an alternative to the Shuttle-first phased approach. In a brief presentation titled "Spirit of '76," they proposed that NASA postpone Shuttle development and instead in 1976 launch a prototype Phase B Station on a two-stage Saturn V.

The Station-first phased approach was, they argued, superior to the Shuttle-first phased approach because the Shuttle would demand a much greater technological leap than would the Station. This meant that it might hit development roadblocks that would increase its estimated cost and delay its first launch (as indeed did happen). In addition, the Spirit of '76 Station could better address the emerging post-Apollo space priorities of President Richard Nixon. These included international space cooperation and direct benefits to people on Earth.

NAR's Spirit of '76 Station was outwardly very similar to NAR's Phase B Station. Differences included less advanced, smaller solar arrays capable of generating 20 kilowatts of electricity and docking ports of the Apollo passive drogue design. The Spirit of '76 Station would support a smaller crew complement (normally six astronauts - nine during crew rotation) and have a rated lifetime of 72 man-months instead of 10 calendar years. The latter attribute would largely eliminate the technical challenges of building for a long lifetime in orbit.

Like the Phase B Station, the Spirit of '76 Station would circle the Earth in an orbit inclined 55° relative to the equator, causing it to overfly nearly all inhabited regions. Earth observations, NAR claimed, would yield improved weather forecasts that would save the U.S. $2.5 billion per year (how this figure was calculated was not explained). Spirit of '76 crews would also "patrol" for storms, research "weather modification," seek geothermal energy sources and "new sources of dwindling resources," watch out for crop diseases and water pollution, predict earthquakes, and improve "sea food production."

Besides Earth observations, the Spirit of '76 astronauts would conduct "aerospace medicine" experiments. In keeping with the goal of benefits for people on Earth, many of these would aim to discover the healing potential of the "benign space environment" and seek new and improved "medical diagnostic and treatment techniques." Other experiments would assess and develop countermeasures for spaceflight effects on humans.

The Spirit of '76 presentation bears no date, but its projected 1970s NASA flight schedule indicates that it was prepared in August 1970 - that is, after NASA directed the Phase B contractors to study Shuttle-launched Stations (29 July) but before Paine canceled two Apollo missions (2 September). It has Apollo 18, the final piloted moon mission, leaving Earth in the second quarter of 1974. For reasons not immediately clear, Apollo 19 is not shown on the NAR schedule. As it turned out, Apollo 17 was the last piloted lunar flight; it flew in December 1972.

NAR expected that the Skylab Program, precursor to the Spirit of '76 Program, would take place between Apollo 17 and Apollo 18. The Orbital Workshop, a converted Saturn S-IVB rocket stage, would reach Earth orbit in the last quarter of 1972, and the last of its three crews would return to Earth in mid-1973. In reality, Skylab did not reach orbit until May 1973 and its last crew did not return to Earth until February 1974.

After no NASA piloted flights in 1975, the Spirit of '76 Station would reach Earth orbit early the following year. As its name implies, it would be staffed during the U.S. Bicentennial festivities on 4 July 1976. The orbiting Station would stand as a "source of national pride" as the United States celebrated its 200th birthday.

Unlike Skylab, which would operate unstaffed between crews, the Spirit of '76 Station would be staffed continuously after its first crew arrived early in the second quarter of 1976. Four consecutive three-person crews would launch to the Station for overlapping six-month stays.

Apollo 7 Saturn IB rocket lifts off. Visible below the silver-and-white Command and Service Module (CSM) is the tapered Spacecraft Launch Adapter (SLA). Image credit: NASA
This artist concept from 1966 shows a CSM turning end-over-end to dock with and extract an Apollo Lunar Module (LM) from the top of a spent S-IVB stage. Note the four partially open SLA segments; these would protect the LM during ascent through Earth's atmosphere. NAR envisioned that Spirit of '76 Cargo Modules would also ride to orbit within the SLA attached to the top of an S-IVB stage. Image credit: NASA
In the absence of a Shuttle Orbiter, NAR invoked two-stage Saturn IB rockets and modified Apollo Command and Service Module (CSM) spacecraft as its Spirit of '76 crew transports. Cargo would reach the Station inside modules carried within the tapered Saturn Launch Adapter (SLA) which linked the CSM to the top of the Saturn IB S-IVB second stage.

After CSM separation, the SLA's four petal-like segments would fold open, exposing a Cargo Module with an Apollo drogue docking unit on top. The CSM, which carried an active probe docking unit on its nose, would link up with the drogue unit and detach the Cargo Module from the top of the S-IVB stage. The crew would then ignite the CSM's Service Propulsion System main engine to begin maneuvering to Station altitude. They would dock with the Spirit of '76 Station using an Apollo probe unit on the bottom end of the Cargo Module. All four crews would arrive at the Spirit of '76 Station with a Cargo Module. At least one Cargo Module would be outfitted as a instrument carrier: after docking with the Station it would deploy cameras, a radar, and other sensors for Earth observations.

The second crew would arrive three months after the first crew arrived, increasing the Spirit of '76 crew complement to six. Three months later, at the end of their six-month stay in space, the first crew would depart and the third crew would replace them. The fourth crew would replace the second crew three months after that; then, having completed their six-month stint, the third crew would return to Earth three months later, leaving the three astronauts of the fourth crew to finish up the planned experiment program and mothball the Station. Late in the third quarter of 1977 they would undock in their CSM, reenter, and splash down, ending the Spirit of '76 Program.

NAR offered two funding models for the Spirit of '76 Station. Both would require a $2.3-billion Spirit of '76 Station, four Cargo Modules at a cost of $9 million each, and $220 million for experiments.

The first funding model, with a cost of $2.8 billion spread over six years, assumed use of re-purposed or leftover Apollo and Skylab rockets and spacecraft. It would see the CSMs built for Apollo 18 (designated 114) and Apollo 19 (115) diverted from the lunar program. Along with the Skylab backup/rescue CSM (119) and 115A, which was committed to no program, they would be converted into Spirit of '76 Station ferries. Ending Apollo with Apollo 17 would free up two Saturn V rockets (514 and 515, the last remaining of the original Apollo Program buy), one of which would launch the Spirit of '76 Station (the other, presumably, would launch Skylab). The four CSMs would reach Earth orbit on the last remaining Saturn IBs (designated 209, 210, 211, and 212).

NAR's other Spirit of '76 funding model, with a total cost of $3.1 billion, would see lunar missions continue through Apollo 19 in the fourth quarter of 1974. NASA would buy two new CSMs (120 and 121) and convert 119 and 115A for the Spirit of '76 program. To trim costs, 120 and 121, which would launch the third and fourth crews, might include the 119 and 115A Command Modules; NAR envisioned refurbishing them after they returned the first and second crews to Earth. A new two-stage Saturn V (516) for launching the Spirit of '76 Station would cost $260 million including launch operations.

Artist concept of Space Shuttle Orbiter with Saturn V S-IC first stage. Image credit: NASA
If all of its many technological challenges could be met successfully, the first Space Shuttle would soar into orbit in the first quarter of 1978. Early in its career, it would take the form of a reusable Orbiter launched atop an expendable Saturn V S-IC first stage. NAR suggested that the Spirit of '76 Station might be revived and become a destination for Shuttle Orbiters during this period. Through phased development, NASA would soon replace the S-IC stage with a reusable winged Booster, then a Shuttle-launched modular station would be assembled in Earth orbit sometime in the 1980s.

Ironically, Rockwell International - formerly North American Rockwell - became the Space Shuttle prime contractor. The company that argued that a Space Station should be developed first because Space Shuttle development would be fraught with technical challenges thus became responsible for tackling the challenges of building the Shuttle.

Sources

"Spirit of '76," North American Rockwell Space Division, undated presentation (August 1970)

Space Station Program, North American Rockwell Space DivisionBriefing to the European Space Research Organization on Space Station Plans and Programs in Paris, France, 3-5 June 1970

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

McDonnell Douglas Phase B Space Station (1970)

Where to Launch and Land the Space Shuttle? (1971-1972)

A Forgotten Rocket - The Saturn IB

Apollo's End: NASA Cancels Apollo 15 & Apollo 19 to Save Station/Shuttle (1970)

7 comments:

  1. Wow, extremely interesting stuff. You know, I'm writting a pretty big alternate history of the space program - you can read it here.
    http://www.alternatehistory.com/discussion/showthread.php?t=366697
    The divergence with our universe happens late 1971 - when Caspar Weinberger OMB delete funding for the shuttle - nothing happens on January 5, 1972.

    Your stuff (like this one) is an excellent source of inspiration for me. I'd like to adapt some part of it, Do you allow me to do so ?

    ReplyDelete
  2. Thank you for your kind words. This is history, so it's meant to inform. I only ask that if you use my blog as a source, you link back to the post(s) you use, perhaps as part of a footnote. That way everybody wins.

    1400 pages - that's enormous. Has anyone written an alternate history quite that big before?

    dsfp

    ReplyDelete
    Replies
    1. I've been working on it since February 2008. I take an immense amount of pleasure and fun doing all the research through the web and adapting my findings into the story fabric. Only recently did it evolved into a coherent thing.
      You'll be surprised to read that, at the forum where I'm posting http://www.alternatehistory.com/discussion there are stories even **bigger** than mine, spreading over hundreds of pages of comments. I'm just beginning !
      This year I've reach a point where I want to share that big thing with other people. Hence I've started posting at the AH.com forum.

      Delete
  3. Although not related to this post I should mention that while reading the Wired Beyond Apollo post about SDI and the military use of the Moon and asteroids yesterday I noticed an inaccuracy, the Clementine mission being referred to as the first mission to the Moon since the Soviet Luna 24 mission in 1976, while in reality the Japanese Hiten probe, launched in 1990 and deliberately crashed on the Moon in 1993 was the first, an inaccuracy that should be corrected when the particular post gets reposted here.

    ReplyDelete
  4. Glad you caught that - wish it had been caught sooner because these days I cannot access my WIRED posts to make changes. If I re-post that here I will indeed correct it. Thank you for pointing out my careless error.

    I swear, nowadays it seems that I have to check every detail before I post. Not sure if it's my advancing old age, being too busy, or the proliferation of small lunar and planetary spacecraft and reapplication of spacecraft for extended missions under new or partly new names. Probably a bit of all three!

    Thanks again -

    dsfp

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  5. This post (12 man space station, completely reusable shuttle, continuing Saturn V use), this...this is the future those of us who grew up in the 60's and 70's were supposed to have.

    ReplyDelete
  6. And the cost would have been less than we paid to do it the wrong way.

    dsfp

    ReplyDelete

I like hearing from my readers. No rules except the obvious ones - please keep it civil and on topic.