"Without Hiatus": The Apollo Applications Program in June 1966

Raw material for a post-Apollo space program. Image credit: NASA.
Elsewhere in this blog, I have described how Apollo began in 1959 as a mainly Earth-orbital program (see "More Information" at the bottom of this post). As originally conceived, Apollo included a Mission Module that could serve as a small laboratory in Earth orbit. NASA anticipated that Apollo spacecraft would ferry astronauts, experiments, and supplies to a temporary Earth-orbital laboratory before the end of the 1960s decade; an Apollo spacecraft might also fly around the Moon without stopping in lunar orbit (that is, perform a circumlunar flight). After 1970, a new program would build on experience gained through Apollo, leading to either a permanent Space Station or a piloted lunar landing and voyages to the planets.

President John F. Kennedy's call for a man on the Moon by 1970 (25 May 1961) made Apollo the U.S. lunar landing program. Aware that Kennedy was not enthusiastic about space for its own sake, NASA Administrator James Webb was careful not to assume a national commitment to spaceflight beyond the Apollo lunar program.

Even as NASA came to terms with the Moon goal, however, it sought to keep alive the Space Station option. In April 1963, for example, the space agency tasked Apollo Command and Service Module (CSM) contractor North American Aviation with a study of how the CSM might serve as a Space Station crew rotation and logistics resupply vehicle. Some believed that, if Apollo accomplished a piloted Moon landing in 1967, then NASA might shift to the Space Station track in 1968.

In early 1964, new President Lyndon Baines Johnson called on NASA to declare its plans for U.S. piloted spaceflight after Apollo reached the Moon. In response, Webb formed the internal ad hoc Future Programs Task Group.

In January 1965, the Task Group submitted a report that favored a post-Apollo program built upon a technological foundation of Apollo CSM and Lunar Module (LM) spacecraft and Saturn IB and Saturn V rockets. The Task Group had drawn upon the expertise of Bellcomm, NASA's Apollo planning contractor, which that same month submitted a plan for 55 Saturn-launched Apollo test missions, Apollo lunar missions, post-Apollo lunar and Earth-orbital missions, and Voyager robotic Mars/Venus missions.

Image credit: NASA.
Image credit: NASA.
Image credit: NASA.
The Johnson White House accepted NASA's Apollo-based post-Apollo concept; the NASA Headquarters Office of Manned Space Flight (OMSF) then established the Saturn-Apollo Applications (SAA) Program Office in August 1965. A month later, SAA named the post-Apollo program the Apollo Applications Program (AAP).

Congress did not warm to AAP despite its promise to explore space for the benefit of people on Earth. The forces that would truncate the Apollo Program — for example, the human and fiscal cost of war in Indochina — were building. Though President Johnson went to bat for AAP in Fiscal Year (FY) 1966, he concurred when Congress requested a postponement in major funding for the program. Congressional leaders promised that, if possible, the funding delay would be made up in FY 1967 and subsequent years.

In June 1966, the SAA Program Office described in a memorandum dispatched to officials at the Manned Spacecraft Center (MSC), Marshall Space Flight Center (MSFC), and Kennedy Space Center (KSC) an AAP which, it said, would "continue without hiatus an active and productive post Apollo Program of manned space flight and. . .exploit for useful purposes. . .the capabilities of the Saturn Apollo System." The memorandum — a snapshot of a program undergoing rapid, chaotic change in response to funding challenges — explained that the plan it outlined was based on proposals NASA had submitted to President Johnson's Bureau of the Budget a month earlier.

AAP objectives fell into two basic areas. The first, Long-Duration Flights, would "measure the effects on men and on manned systems of space flights of increasing duration" and permit NASA to "acquire operational experience with increasingly longer manned space flights" so that it could "establish the basic capabilities required for any of the projected next generation of manned space flight goals (earth orbital space station, lunar station, or manned planetary exploration)."

The second emphasis area, Spaceflight Experiments, would emphasize space life sciences, astronomy, space physics, advanced lunar exploration, and space technology applications and development. AAP lunar exploration would support objectives proposed at the July 1965 meeting of space scientists in Falmouth, Massachusetts. The Falmouth meeting was one of a series of important lunar science planning meetings that began with the interdisciplinary Iowa City meeting in 1962.

At the time the SAA Program Office circulated its memo, the first Apollo lunar landing attempt was expected in late 1967 or early 1968. NASA, the memo explained, had ordered from its contractors 21 CSMs, 15 LMs, 12 Saturn IBs, and 15 Saturn Vs for delivery between 1966 and 1970. Most were intended for ground and flight tests.

The SAA Program Office assumed that four Saturn IBs (designated AS-209 through AS-212), six Saturn Vs (AS-510 through AS-515), and their associated CSM and LM spacecraft would remain unused after the first successful piloted Moon landing, and that these would immediately become available for AAP missions. Basic Apollo CSM and LM spacecraft would be modified to achieve new goals by the installation of "overlay kits."

Building upon these assumptions, the June 1966 memo described two possible AAP Program schedules. The Case I schedule assumed that no Saturn-Apollo hardware beyond that ordered for the Moon program would become available before late 1968 and that only enough AAP missions would be flown to accomplish minimal AAP goals. Case I missions would not necessarily serve as a bridge for linking Apollo lunar missions with a new piloted program in the mid-to-late 1970s. Even with these limitations, the SAA Program Office envisioned that Case I would see 21 Saturn IB and 16 Saturn V launches in the AAP by the end of 1973.

The more ambitious Case II schedule would see "an early extensive utilization of Saturn Apollo capabilities, with an earlier focus on a post-Apollo national space objective (such as a prototype of a space station or a planetary mission module)." Case II would see 26 Saturn IB and 17 Saturn V rockets launched from KSC before the end of 1975.

Both the Case I and Case II schedules would begin in 1968 with missions AS-209, AS-210, AS-211, and AS-212. AS-209 and AS-210, concurrent 14-day Earth-orbital life sciences/crew training missions launched on Saturn IB rockets, would kick off AAP. Their CSMs would dock for crew transfer and an orbital rescue test.

AAP spent-stage Workshop comprising (left to right) a Saturn IB rocket S-IVB stage, a drum-shaped Spent Stage Experiment Support Module (SSESM), and a docked Apollo Command and Service Module (CSM) spacecraft. Image credit: NASA.
The third 1968 AAP mission, AS-211, would see the launch of the first AAP spent-stage Workshop. The crew would detach their CSM from the Saturn IB S-IVB second stage that propelled it into Earth orbit, then would turn and dock with a Spent Stage Experiment Support Module (SSESM) mounted on the front of the stage.

In addition to docking ports, the SSESM would include solar panels for making electricity, an airlock for spacewalks, experiment equipment, and tanks of gaseous oxygen for purging and filling the S-IVB's 20-foot-diameter hydrogen tank so that it could serve as a habitable volume. The astronauts would conduct biomedical and astronomy/space physics experiments on board the CSM and inside the SSESM and hydrogen tank for from 28 to 56 days.

AAP missions in 1968/1969 would re-fly experiment apparatus first flown on short-duration (no more than 2 weeks) Earth-orbital Apollo Moon program test flights in 1966/1967. These would, the memorandum stated, include experiments in particles and fields, ion wake physics, X-ray astronomy, and UV spectroscopy. At the time the SAA Program Office wrote its memorandum, the first of these test flights, dubbed AS-204, was scheduled for liftoff in late 1966 with Mercury/Gemini veteran Gus Grissom, Gemini veteran and first U.S. spacewalker Ed White, and rookie astronaut Roger Chaffee on board.

Three Pegasus satellites were launched to gather data on the the meteoroid environment of low-Earth orbit. Pegasus 3, with a wingspan of 29 meters, included meteoroid-capture panels designed for retrieval by Gemini or Apollo astronauts; it would, however, not receive visitors before it reentered the atmosphere in August 1969. Image credit: NASA. 
The final 1968 AAP mission, AS-212, would see a CSM deliver supplies to the AS-211 spent-stage Workshop. It would then rendezvous with Pegasus 3, a 1.45-metric-ton satellite that was launched atop a Saturn I rocket on 30 July 1965. The AS-212 crew would spacewalk to retrieve meteoroid-capture and thermal coating test panels mounted on the satellite.

The Case I AAP schedule had the disadvantage of not permitting continuous rocket and spacecraft production and launch operations between AS-212 and the missions that would follow it. This, the memorandum explained, meant that Saturn-Apollo production and operations would be required to "phase down" during 1969-1970 and build up again in 1971. Case I missions after AS-212 would occur from three to nine months later than in Case II. The SAA Program Office favored and thus provided more details for the Case II schedule than for Case I. For this reason, from here on this post focuses exclusively on Case II.

The first of four 1969 AAP missions, AS-213, would be a near-duplicate of the AS-211 Workshop mission. On the second 1969 mission, AS-214, a CSM and the first LM-derived Apollo Telescope Mount (ATM) would carry out a 14-day solar astronomy mission. The ATM would reach orbit within the Spacecraft LM Adapter (SLA), the tapered shroud that linked the CSM with the top of the S-IVB rocket stage. AAP flights in 1968-1970 would occur during solar maximum, when activity on the Sun would peak, so in general their astronomy programs would emphasize solar observations. The AS-214 CSM would then undock from the ATM and dock with the AS-213 spent-stage Workshop to provide resupply and crew rotation.

In the June 1966 memorandum, the SAA Program Office assumed that LM-derived ATMs, labs, and carriers would launch with and operate while docked with piloted CSMs. As 1966 progressed, however, AAP planning increasingly emphasized ATM, lab, and carrier dockings with spent-stage Workshops. Such dockings would enable NASA to build up capable interim space stations and gain experience with in-space assembly of multi-modular spacecraft.

AS-214 would include the first Apollo Telescope Mount (ATM). Two astronauts would operate the ATM from the LM Ascent Stage; astronomical instruments would fill the stripped-out LM Descent Stage. Image credit: NASA.
The proposed AAP Laser Communications lab was not specifically mentioned as a payload in the June 1966 AAP program plan, though its design was typical of proposed LM-derived AAP labs. Image credit: Perkin Elmer.
The proposed AAP Optics Lab as it would appear stowed for launch in the SLA. Note that experiment equipment (mainly telescopes) and a square "platform" with attachment points at its corners for linking to the SLA completely replace the Descent Stage. Image credit: NASA.
The third 1969 mission, AS-215, was envisioned as a meteorology-oriented mission dubbed "Applications-A." It would probably have operated in an orbit steeply inclined relative to Earth's equator and employed an experiment/sensor carrier based on the LM design.

The AS-510 mission, the final 1969 AAP mission and the first AAP mission to launch on a Saturn V rocket, would place a CSM into geosynchronous Earth orbit (GEO) for communications, biomedicine, and Earth observation experiments. The rocket's S-IVB third stage, modified to permit two restarts, would ignite in low-Earth orbit to boost the CSM into an elliptical transfer orbit, then would fire again 5.5 hours later to circularize the CSM's orbit at the GEO altitude of 35,870 kilometers.

Five AAP Saturn IB missions would fly in 1970. These would include a 135-day stay on board a spent-stage Workshop in Earth orbit, two resupply visits to the spent-stage Workshop as part of other AAP missions, two solar ATM flights, a Biomed Lab mission, a fluids lab for studying weightless propellant behavior, the Applications-B Earth observation mission, and the introduction of an "Extended Capability CSM" for independent 45-day flights. Extended Capability CSM modifications would include long-life, high-capacity fuel cells for making electricity and water, an oxygen-nitrogen breathing mixture to replace Apollo's pure oxygen atmosphere (this was a concession to aerospace physicians, who worried about the health effects of breathing pure oxygen for long periods), and a long-life C-1 rocket engine in place of the Apollo CSM's Service Propulsion System main engine.

The Biomed Lab would be based on the Apollo LM or a "refurbished Command Module." The latter was envisioned as a used Command Module (CM) stripped of its heat shield, parachutes, and other systems, fitted out as a small pressurized laboratory, and launched a second time on a Saturn IB with a piloted CSM.

Four AAP Saturn V missions would fly in 1970, of which three would voyage to the Moon. These would be the first lunar missions since Apollo's end. The AS-511 Saturn V would launch a piloted mapping mission to lunar polar orbit. It would orbit for up to two weeks while the Moon rotated beneath it. This would enable the CSM to pass over nearly the entire lunar surface (and fly over half the surface in daylight).

The refurbished Command Module (CM) Lab came in dependent (upper left) and independent (lower right) forms. The "cruciform" was included in the design to provide attachment points linking the dependent CM Lab to the SLA. Image credit: North American Aviation.
Apollo CM pressure vessel. Image credit: NASA.
The AS-512 CSM would transport to lunar orbit an LM Shelter containing living quarters, supplies, and exploration gear (a small rover, a core drill, and an advanced sensor package). Once in orbit about the Moon, the LM Shelter would undock from the CSM and land automatically, then the piloted CSM would return to Earth. Less than three months later, the AS-513 Saturn V would launch an Extended Capability CSM and an LM Taxi to the Moon. The latter would land near the LM Shelter with two astronauts on board, including the first scientist-astronaut to reach the Moon. They would explore their landing site for 14 days.

The year 1970 would end with the AS-514 launch, which would place the first modified ("Mod") S-IVB Workshop into Earth orbit. The Mod S-IVB Workshop was a step up from the spent-stage Workshop; it would launch with no propellants in its tanks and its hydrogen tank outfitted with living quarters, supplies, and experiment gear. The four Saturn IB-launched AAP missions in 1971 would, the memorandum explained, support a one-year stay by a single crew on board the AS-514 Mod S-IVB Workshop.

In 1971, the AS-515 Saturn V would launch an Extended Capability CSM and an ATM on a 45-day mission to GEO to conduct stellar and solar astronomy, relativity, and space physics experiments. AS-516 (the first Saturn V built specifically for AAP) and AS-517 would launch an advanced lunar exploration mission similar to the AS-512/AS-513 pair, and AS-518 would launch a second Mod S-IVB Workshop.

The four Saturn IBs launched in 1972 (AS-225 through AS-228) would support stays on the second Mod S-IVB station. One of these missions would also test Command Module modifications meant to replace Apollo ocean splashdowns with cheaper land landings. Modifications would include steerable parachutes.

AS-512 in 1970 would deliver the LM Shelter to the lunar surface; AS-513 would see two astronauts arrive separately in an LM Taxi and live in the LM Shelter for 14 days. The LM Shelter would include a rover (shown stowed and in release position) and a core drill (shown deployed). This image dates from January 1965 but is applicable to the June 1966 AAP plan. Image credit: NASA.
Apollo CM with deployed parawing. Image credit: North American Aviation.
From 1972 through 1975, the memorandum explained, AAP missions would support a transition to an unspecified post-AAP piloted "follow-on program." NASA would increase its Saturn IB launch rate to six per year by 1973, and would continue to launch Saturn V rockets at a rate of four per year. The latter would launch four missions to GEO to conduct stellar astronomy, physics, and technology applications experiments (1972-1973), the automated Voyager Mars probes (1973), and a lunar mission similar to the AS-512/AS-513 pair each year through 1975. Two of the GEO missions would include ATMs. AS-520/AS-521 would launch the 1972 lunar mission pair and AS-525/AS-526 the 1973 pair.

The SAA Program Office envisioned that ATM missions might lead in late 1973 to an AAP astronomy mission featuring a reflecting telescope with a mirror measuring from 60 to 100 inches across. This, the memorandum explained, might serve to verify the mirror design ahead of its use in planned orbiting National Astronomical Observatories, sophisticated space telescopes expected to reach Earth orbit in the late 1970s.

As mentioned above, NASA began AAP amid increasing fiscal pressures. After pushing off a formal start to AAP as requested by Congress in FY 1966, President Johnson submitted a $5.01 billion NASA budget for FY 1967, of which $270 million was meant to fund AAP. Congress slashed the FY 1967 AAP budget to $83 million.

Observers of the U.S. space program were surprised when President Johnson went to bat for AAP again the following year. He requested that NASA's FY 1968 budget total $5.1 billion, with $455 million allotted to AAP. On 27 January 1967, the day after NASA OMSF director George Mueller briefed the press corps on the planned rapid ramp-up in AAP development, fire broke out inside the AS-204 Apollo CSM crew cabin during a test on the launch pad. Fed by the CSM's pure oxygen atmosphere, it immediately became an inferno. A poorly designed hatch trapped astronauts Grissom, White, and Chaffee inside, so they perished.

After the fire, NASA came under close scrutiny and was found wanting. Congress could not "punish" the agency by cutting the Apollo Program budget — to do so would have endangered achievement of President Kennedy's goal of a man on the Moon by 1970 — but it could express its displeasure by cutting programs meant to give NASA a post-Apollo future. The agency's FY 1968 appropriation was slashed to $4.59 billion, with AAP receiving only $122 million.

Under President Richard Nixon, NASA's budget slide accelerated. The Saturn rocket production lines were placed on standby in January 1970. At the same time, AAP became the Skylab Program. NASA Administrator Thomas Paine, who saw Skylab as a step toward a late 1970s 50-to-100-man Earth-orbiting Space Base, cancelled the Apollo 20 Moon mission so that its Saturn V (AS-513) could launch Skylab, a Saturn IB S-IVB-derived Orbital Workshop (OWS) resembling the AAP Mod S-IVB Workshop. Two years later, in January 1972, Nixon called for new-start funding for the Space Shuttle, which became NASA's main post-Apollo piloted program.

Work toward using Saturn-Apollo hardware in post-Apollo missions continued, though on a much-reduced scale. Apollo 17 (December 1972) saw the sixth and last piloted Moon landing of the 20th century and the last flight of the LM. NASA designated its Saturn V SA-512. On 14 May 1973, SA-513, the last Saturn V to fly, launched Skylab. An ATM for solar studies — the design of which was not based on the LM — reached orbit permanently attached to the OWS, and the Multiple Docking Adapter (MDA) replaced the SSESM. Three Saturn IBs (SA-206 through SA-208) launched three-man crews to Skylab in Apollo CSMs. The final Skylab crew splashed down on 8 February 1974, after 84 days in space.

The SA-210 Saturn IB, the last Saturn rocket to fly, launched the last Apollo CSM to fly. Its July 1975 mission to dock with a Soviet Soyuz spacecraft in low-Earth orbit brought the Apollo era to a close.


"Saturn/Apollo Applications Program Summary Description," memorandum with attachments, MLD/Deputy Director (Steven S. Levenson for John H. Disher), Saturn/Apollo Applications, NASA Headquarters, to George M. Low, Manned Spacecraft Center, Leland F. Belew, Marshall Space Flight Center, and Robert C. Hock, John F. Kennedy Space Center, 13 June 1966.

More Information

A Forgotten Rocket: The Saturn IB

Space Station Resupply: The 1963 Plan to Turn the Apollo Spacecraft Into a Space Freighter

Apollo Extension System Flight Mission Assignment Plan (1965)

"Assuming That Everything Goes Perfectly Well in the Apollo Program. . ." (1967)

The First Voyager (1967)

"Still Under Active Consideration": Five Proposed Earth-Orbital Apollo Missions for the 1970s (1971)


  1. An excellent & informative article, thank you very much.

  2. Hi, Kerrin - so sorry I haven't been responsive of late. Had some health issues, but I think keeping the blog alive is a big part of staying healthy. Anyway, thanks for your kind encouragement. dsfp

  3. This is great, David! Keep up the good work and best wishes to you in the new year.


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