Apollo 7: Rise of the Phoenix

After the tragic loss of the Apollo 1 crew on January 27, 1967, NASA’s goal to land a man on the Moon before the end of the decade almost looked unattainable. But over the succeeding months, NASA and its army of contractors pushed hard to determine the cause of the Apollo 1 accident, take whatever corrective actions were needed and get the Apollo program back on track. As 1967 and 1968 unfolded, NASA committed to an aggressive series of test flights but everything would need to go almost perfectly to reach the Moon before the end of 1969.

In this new plan, the “A” missions were to test the giant Saturn V Moon rocket for the first time. This goal was met with the unmanned Apollo 4 and 6 missions launched in November 1967 and April 1968, respectively. The goal of the “B” mission was to test the LM (Lunar Module) in Earth orbit which was accomplished by the unmanned Apollo 5 mission in January 1968. The next step was the “C” mission where the updated Apollo spacecraft was to be tested for the first time in Earth orbit with a crew on board. This task fell to the Apollo 7 mission. If Apollo were to reach the Moon on time, everything would need to go perfectly.

 

The New Spacecraft

During the early stages of the Apollo program, there were actually two versions of the Apollo spacecraft being built by its prime contractor, North American Rockwell (which, after decades of corporate mergers, is now part of Boeing). The first variant, designated Block I, was essentially a prototype meant for test flights near the Earth for the purpose of verifying the basic Apollo CSM (Command-Service Module) design. Lessons learned from constructing, testing and flying these versions were then to be incorporated into the improved Block II Apollo CSM which would include all of the systems required to support a flight to the Moon.

Following the Apollo 1 fire which killed its crew during a launch rehearsal for the first manned Block I mission (see “The Future Which Never Came: The Unflown Mission of Apollo 1”), a total of 1,800 changes in spacecraft design and procedures were made to the Block II CSM in order to improve crew safety and overall systems reliability. Among these changes was a new quick-opening crew hatch to replace the two-piece hatch design previously used. This new hatch was flight tested on the Block I CM-020 (Command Module number 020) used for the unmanned Apollo 6 mission launched on April 4, 1968 in the second test flight of the new Saturn V launch vehicle (see “Apollo 6: The Saturn V That Almost Failed”). Apollo 7 would be the first mission (manned or otherwise) to test the improved Block II CSM in space.

The Apollo CM (Command Module), which carried the astronauts during their mission as well as the recovery systems needed to return them safely to Earth, was conical in shape with a base diameter of 3.9 meters and a height of 3.2 meters. With a habitable volume of six cubic meters, the CM had about 140% more space for the three-man Apollo crew than NASA’s earlier two-man Gemini spacecraft. The SM (Service Module), which included all the systems and consumables needed to support the astronauts and their mission, was a cylinder with the same diameter. Its appearance was dominated by the 91-kilonewton Aerojet AJ10-137 engine of the Service Propulsion System (SPS) which would be used for all major propulsive maneuvers after the Saturn launch vehicle had finished its task. The SM also had a reaction control system (RCS) to be used for attitude control and smaller orbital maneuvers. Consisting of four “quads” of 440-newton engines evenly spaced around the middle of the SM, the RCS had its own propellant supply independent of the SPS. The total height of the CSM was 11 meters and the Block II version had a nominal mass of about 14.6 metric tons for early missions in low Earth orbit making it the most massive crewed spacecraft to fly up until that time beating the Soviet Soyuz 7K-OK by over a factor of two (see “The Avoidable Tragedy of Soyuz 1”). With a full load of propellant, consumables and other equipment needed for a lunar mission, the launch mass of the CSM swelled to almost 29 metric tons making it the most massive spacecraft design to fly beyond low Earth orbit.

The Apollo spacecraft was topped off by the launch escape system (LES) built by the Lockheed Propulsion Company (whose corporate parent is now part of Lockheed Martin). It consisted of a solid rocket motor assembly attached to the top of the CM by means of a truss framework with a total height of 9.9 meters and a mass of about 4,100 kilograms. It was designed to pull the CM and its crew to safety in case of an abort situation during the earliest phase of launch and would be jettisoned during the burn of the Saturn second stage when it was no longer needed. The LES included a lightweight boost protective cover (BPC) made of fiberglass and cork which protected the outer hull and windows of the CM during the early phases of ascent and when the LES was jettisoned.

The launch vehicle for the Apollo missions destined for Earth orbit was the Saturn IB. The Saturn IB was a substantially improved version of the Saturn I originally developed by the team led by famed rocket engineer Wernher von Braun based at NASA’s Marshall Space Flight Center in Huntsville, Alabama. The first stage of this new launch vehicle, built by Chrysler and designated S-IB, was an updated version of the S-I stage successfully flown ten times between 1960 and 1965 during the Saturn I test flight program (see “The Last Launch of the Saturn I”). Like the S-I stage, the S-IB structure consisted of a set of eight 1.8-meter in diameter tanks holding LOX and RP-1 derived from the proven Redstone rocket clustered around a single 2.7-meter LOX tank adapted from the Jupiter rocket. A new set of eight swept-back fins as well as a host of other changes to the hardware and fabrication of the S-IB made it 9,000 kilograms lighter than the older S-I. The S-IB was powered by eight improved Rocketdyne H-1 engines whose total thrust at launch was increased from 6,683 to 7,120 kilonewtons.

By far the biggest change to create the Saturn IB was to the second stage designated S-IVB and built by the Douglas Aircraft Company. Instead of six Pratt & Whitney RL-10 engines which produced a total of 400 kilonewtons of thrust on the original S-IV stage used by the Saturn I, the new and larger S-IVB stage employed a single Rocketdyne J-2 engine to produce 890 kilonewtons of thrust using the same high energy propellant combination of liquid hydrogen and LOX used on the S-IV. The S-IVB stage also included a pair of auxiliary propulsion system (APS) modules which provided roll control during the burn of the J-2 as well as attitude control while coasting in orbit. The stage was topped off by the Instrument Unit (IU) which controlled both stages of the launch vehicle. In addition to carrying the CSM or LM into Earth orbit for initial test flights, the first launches also allowed flight testing of the nearly identical version of the S-IVB stage that was employed as the third stage of the Saturn V which would send Apollo to the Moon.

A tapered spacecraft launch adapter (SLA) consisting of four panels connected the S-IVB stage to the Apollo CSM. During flights of the Saturn V, the LM would also be housed inside this adapter beneath the SM. The Saturn IB, without the payload, was 43.2 meters tall and initially was capable of placing about 17 metric tons into low Earth orbit. The total height of the Apollo-Saturn IB was 68.3 meters and it had a typical lift off mass of 598 metric tons. Since its first flight on February 26, 1966 when it launched the Block I CSM-009 on the unmanned Apollo AS-201 mission (see “The First Flight of the Apollo-Saturn IB”), the Saturn IB had flown successfully a total of four times including, most recently, the Apollo 5 mission launched on January 22, 1968 for an unmanned test of the LM in low Earth orbit (see “Apollo 5: The First Flight of the Lunar Module”).

 

Plans for the Apollo 7 Mission

The primary crew for the Apollo 7 mission consisted of US Navy Captain Walter M. Schirra, Jr. as the Commander, USAF Major Donn F. Eisele as the Command Module Pilot and civilian Walter Cunningham as the Lunar Module Pilot (although there was no LM on this mission, the LMP still had duties for other aspects of the flight). Wally Schirra, a US Naval Academy graduate who served as a jet fighter pilot in the Korean War, was one of the original seven Mercury astronauts chosen by NASA in 1959 (see “Project Mercury: Choosing the Astronauts & Their Machine“). He had flown on the six-orbit Sigma 7 mission in October 1962 and was the command pilot of the Gemini 6 mission in December 1965 (see the Gemini 6 page). With a total of 34½ hours of spaceflight experience, the 45 year old Schirra would be the first person to fly into space three times. Donn Eisele, 38 years of age, was also a graduate of the US Naval Academy and a USAF test pilot with a MS in astronautics before being chosen as part of NASA’s third group of astronauts in October 1963. The 36 year old Walt Cunningham started his flying career as a Marine pilot and received advanced degrees in physics after leaving active service to work for the Rand Corporation on problems involving Earth’s magnetosphere. A Major in the Marine reserves, Cunningham was part of NASA’s third group of astronauts and, like Eisele, was making his first spaceflight. The backup crew for the Apollo 7 mission were veteran Gemini astronauts Tom Stafford, John Young and Gene Cernan.

The crew of Apollo 7 originally had been chosen in 1966 to fly the second Block I CSM mission initially designated AS-205. On November 15, 1966, NASA officials cancelled the second Block I test flight, informally called “Apollo 2”, after it was found to be redundant. A new “Apollo 2” mission, officially designated AS-205/208, would instead test the first Block II Apollo. The crew would also rendezvous with a LM launched on a separate Saturn IB rocket to perform the first manned test of this key piece of Apollo hardware.

In early December 1966, NASA reassigned the original Apollo 1 backup crew to the new “Apollo 2” mission and substituted the primary crew of the now cancelled second Block I mission as the new backup crew for Apollo 1. Schirra had pushed for the cancellation of the second Block I mission with the hope of commanding the new AS-205/208 mission and was less than pleased with the reassignment as the backup crew to the Apollo 1 mission. After the loss of the Apollo 1 crew, Schirra, Eisele and Cunningham became the primary crew of what would be the first test flight of the new Block II CSM.

The hardware assigned to the Apollo 7 mission consisted of Apollo CSM-101 and the Saturn IB designated SA-205. Launch would take place from Launch Complex 34 (LC-34) which had supported the earlier AS-201 and AS-202 unmanned test flights as well as the Apollo 1 mission. The SA-205 rocket would place the 14,692-kilogram CSM-101 into an initial 228 by 284-kilometer orbit after 10½ minutes of powered flight. For the first three hours in orbit, CSM-101 would remain attached to the S-IVB-205 second stage much as a Moon-bound Apollo would do prior to trans-lunar injection in order to test the combined S-IVB/CSM in low Earth orbit. After separation of the CSM, the crew would perform a station keeping exercise with the spent S-IVB-205 stage for about an hour before performing a separation burn using the SM’s RCS.

On the second day of the Apollo 7 mission, the first of eight planned SPS burns would be performed to rendezvous with S-IVB-205 to simulate the procedure to rescue a disabled LM after it had left the lunar surface. By this point, the S-IVB stage would have exhausted its batteries and the propellant of its APS leaving the stage as a tumbling, inert object. The rest of the mission would concentrate on evaluating the performance of the new Block II spacecraft in orbit to validate the systems and procedures required for a lunar mission. In order to achieve as many objectives as possible, the more important tasks would be performed early in the mission in case the planned 11-day mission had to be cut short for some reason.

In addition to all of the tests of Apollo’s systems, a total of five experiments were also planned for the mission. The S005 Synoptic Terrain Photography and the S006 Synoptic Weather Photography were broadly similar to the S-5 and S-6 experiments performed during most of the Gemini missions and would complement these earlier efforts. A modified Hasselblad model 500C 70 mm still camera fitted with an 80 mm lens would be used with a variety of film types and filters to perform these experiments. Also carried on the Apollo 7 mission were a pair of Maurer 16 mm sequence cameras fitted with either an 18 mm or a 5 mm wide angle lens to take photographs at a rate of one to 24 frames per second to record key parts of the mission. For the first time on a crewed American spaceflight, a television camera was also carried. This unit was a two-kilogram RCA black and white television camera operating at ten frames per second which could be fitted with lenses which provided either a wide angle 160° or narrow 9° field of view. Live telecasts up to about ten minutes in length were possible daily during overpasses of the tracking stations at Corpus Christi, Texas or Merritt Island, Florida which were equipped to convert the transmissions into an NTSC-compatible, 30 frames per second format used for American television at that time.

Also included on this mission were three medical experiments: the M006 Bone Demineralization (which was similar to the M-6 experiment flown earlier during the Gemini 4, 5 and 7 long-duration missions), M011 Blood Studies and M023 Lower Body Negative Pressure investigations. None of these experiments involved any special equipment to be carried during the Apollo 7 mission but instead would rely on pre- and post-flight examinations of the crew performed on the ground.

For this mission, the crew would wear the new A7-series Apollo space suits. The A7L suits were ten kilograms heavier than the 15-kilogram suits worn earlier by the ill-fated Apollo 1 crew. In addition to being more flexible and comfortable to wear, the suits were designed to protect the wearer from flames more effectively. Unlike most of the earlier manned American missions, the crew would only wear these suits during launch and the first few hours of the mission and again during reentry. Experience during the 14-day Gemini 7 mission in December 1965 (see the Gemini 7 page) where one or both astronauts were allowed to remove their space suits for long periods of time had shown that the astronauts were much more comfortable and performed better when they removed their bulky suits. During most of this 11-day mission (the longest crewed spaceflight since Gemini 7), the Apollo 7 crew would wear Teflon fabric coveralls over their one-piece constant wear garments which were similar to long johns.

The mission was planned to end on the 164^th revolution with a splashdown about 261 hours after launch in the western Atlantic Ocean 370 kilometers south-southwest of Bermuda. The designated recovery ship for this landing zone was the aircraft carrier USS Essex commissioned in 1942 and just eight months from its final decommissioning. Because of the weight of the Apollo CM, only the derricks on larger ships like the USS Essex were capable of lifting the five metric ton spacecraft out of the water following splashdown.

 

Preparations for Launch

The first major piece of hardware for the Apollo 7 mission to arrive at Cape Kennedy (which reverted to its original name of Cape Canaveral in 1973) was the S-IB-5 first stage of the Saturn IB SA-205 launch vehicle on March 28, 1968. This was followed by the S-IVB-205 second stage on April 7 and the IU on April 11. The S-IB-5 stage was then erected on the pad at LC-34 a year after the SA-204 launch vehicle, which was to have been used on the Apollo 1 mission, had been removed following its reassignment to support the Apollo 5 unmanned LM test flight at LC-37. The S-IVB-205 stage was added to the stack on April 16 to begin preparations for launch.

Because of the advance state of development of the Saturn IB following four successful flights, SA-205 was instrumented to return only 720 measurements of launch vehicle performance compared to 1,225 measurements made by the earlier SA-204 flight. After problems were encountered with the J-2 engines during the Apollo 6 test flight of the Saturn V SA-502, modifications were made to the liquid hydrogen line to S-IVB-205’s J-2 engine’s augmented spark igniter (ASI) to avoid fuel leak issues which plagued the Apollo 6 mission.

While SA-205 was being prepared at LC-34, delays in the delivery of the CSM-101 spacecraft pushed out the planned launch date of the Apollo 7 mission. The CM and SM completed their individual and combined systems checks at North American Rockwell on March 18, 1968 and finally finished their integrated systems checks six weeks later. CSM-101 was shipped from North American’s Downey, California facility on May 29 and arrived at the Cape the next day to begin the long process of prelaunch tests and systems checks there. With only 13 discrepancies noted in pre-delivery acceptance reviews (all of which were resolved before final shipment), CSM-101 was as “clean” as any ship yet delivered by a NASA contractor. Schirra had suggested that the CSM be given the call sign “Phoenix” after the bird in Greek mythology which rose from the ashes of its predecessor, but this was quickly rejected by program managers.

With the combined systems checks completed on June 19, CSM-101 was moved to KSC’s high altitude chamber to begin tests under low pressure conditions. After unmanned test runs, Schirra, Eisele and Cunningham spent several hours inside of CSM-101 putting their new spacecraft through its paces with an outside pressure equivalent to an altitude of 69 kilometers. The backup crew then followed for another round of tests with CSM-101 finally removed from the high-altitude chamber on July 29. CSM-101 was then mated with its spacecraft launch adapter, SLA-5, and subsequently moved to LC-34. After more integrated systems checks, CSM was electrically mated to SA-205 on August 20.

With overall space vehicle testing completed on September 4, 1968, launch crews moved forward to a successful countdown demonstration test (CDDT) on September 13. Eight days later, SA-205/CSM-101 completed its flight readiness test clearing the way for a launch on October 11.

 

Getting the Mission Off the Ground

The countdown for Apollo 7 started at the T-101 hour mark at 3:00 PM EDT on October 6, 1968 with a launch window extending from 11:00 AM to 3:00 PM on October 11. A total of three planned holds were included in the countdown to allow for any problems to be addressed as they were encountered: a six-hour hold at the T-72 hour mark and a three-hour hold at T-33 hours. The third hold at the T-6 hour mark allowed a six-hour rest period for the launch crews before the fast paced events of the terminal countdown phase.

The Apollo 7 crew were woken up early on the morning of Friday, October 11 for their launch day physicals followed by breakfast with NASA officials. Schirra, Eisele and Cunningham then donned their new A7L spacesuits that they would wear during their ride into orbit. After the crew left the Manned Spacecraft Operations Building, they proceeded to LC-34 and entered the CM at 8:35 AM EDT as the countdown hit T-2 hours, 27 minutes. The countdown proceeded smoothly until the T-10 minute mark when the chill down of the S-IVB stage’s J-2 engine thrust chamber jacket started. The temperature was dropping more slowly than expected prompting a hold at the T-6 minute, 15 second mark to ensure proper chill down. After 2 minutes and 45 seconds, the countdown resumed at 10:56:30 AM EDT. Liftoff took place at 11:02:45 AM EDT (15:02:45 GMT) and Apollo 7 was on its way. While not fully appreciated at the time, this would prove to be the last launch from LC-34 which would be mothballed less than three months later.

The S-IB-5 stage operated nearly flawlessly shutting down the last of its eight H-1 engines at an altitude of 60.5 kilometers 144.3 seconds after launch just one second later than planned. The now spent first stage was cut loose with the ascent continuing under the power of the single J-2 engine of the S-IVB-205 stage. The S-IB-5 stage then tumbled to Earth impacting the Atlantic about 491 kilometers downrange 960 seconds after launch. After a nearly flawless performance, the S-IVB stage finally shutdown at an altitude of 222.3 kilometers only two seconds later than planned at ten minutes, 16.76 seconds after launch. Apollo 7 was now in 227.9 by 282.1 kilometer orbit with an inclination of 31.6° – almost identical to the desired initial orbit.

After the nearly perfect ascent into orbit, the Apollo 7 crew began their tests with the combined S-IVB/CSM spacecraft in low Earth orbit. The first order of business was to safe the S-IVB-205 stage for orbital operations with a series of ventings of the stage’s propellant tanks. This activity helped to rid the spent stage of the estimated 731 kilograms of LOX and 1,135 kilograms of liquid hydrogen still left in the propellant tanks at the time of orbital insertion and keep tank pressures at a safe level.  Although it took a bit longer than originally planned, initial safing of the S-IVB-205 stage was completed at 17:33:02 GMT some two hours, 30 minutes and 17 seconds after launch during the mission’s second revolution. At 17:32:45 GMT, the crew took manual control of the combined S-IVB/CSM stack for a three-minute test of this mode of control. By the time CSM-101 separated from S-IVB-205 at 17:57:47 GMT, the venting of residual propellant in the second stage had raised the orbit of Apollo 7 to 227.8 by 315.2 kilometers.

After separation from the S-IVB stage, the SM RCS was used to stop and turn the CSM around to begin maneuvers meant to simulate the extraction of a LM from the S-IVB stage as would happen during an actual lunar mission. S-IVB-205 had been fitted with a T-shaped LM docking target to aid in this exercise while the stage’s APS kept the stage steady. While all four panels of the SLA had opened to 45°, a retention cable on one of the panels designed to keep them open had failed to retract fully allowing that panel to close slightly to a 25° position. In the future, all four panels would be jettisoned avoiding a repeat of the issue. Despite the minor problem, Apollo 7 was able to maneuver to within 1½ meters of S-IVB-205 before backing off to continue station keeping in an effort to assess the maneuverability of the CSM.

After about a half an hour near the S-IVB stage (which now had the COSPAR designation of 1968-089B), the SM RCS was fired for 16.3 seconds starting at 18:22:54 GMT to change the spacecraft’s velocity by 1.7 meters per second. This rendezvous phasing burn placed Apollo 7 into a slightly lower 231.1 by 306.0 kilometer orbit which allowed the CSM to start moving ahead of S-IVB-205 over the course of the next day in preparation for the rendezvous exercise during the second day of the mission. In the meantime, additional ventings of the S-IVB propellant tanks were conducted over the next two hours to ensure that the tank pressures were kept at a safe level for the next day’s activities.

In the meantime, the Apollo 7 crew acquainted themselves with their new home in orbit as they continued testing of the spacecraft. The crew adapted quickly to weightlessness and experienced no disorientation as they moved about inside the comparatively spacious CM. Walt Cunningham purposely attempted to induce vertigo or motion sickness by moving his head in all directions at rapid rates but experienced no problems. The crew did complain of some stiffness in their lower backs, but this was alleviated by exercise and hyperextension of their back muscles.

Not so easy to fix were the bad head cold symptoms that Wally Schirra had started to experience about an hour after launch. The microgravity environment and the pure oxygen atmosphere only made the symptoms worse since his sinuses could not drain properly, as they would back on the Earth, causing much discomfort and making it difficult to equalize pressure in his ears. Schirra likely picked up the cold during a hunting trip he took with Donn Eisele a few days before the mission. In order to avoid this problem in future flights, the crew would be quarantined in the days leading up to launch. Initially, Schirra took two aspirin to ease his symptoms and later took Actifed – a name brand prescription drug (at the time) containing the decongestant pseudoephedrine HCl and the antihistamine triprolidine HCl.

 

A Busy Second Day

As the Apollo 7 crew slept in shifts during their first night in orbit, the systems on S-IBV-205 began to shutdown as expected. By 03:25 GMT on October 12, the propellant in the APS units, which maintained the stage’s attitude, had been exhausted as was the battery which powered its navigation system. By about 11:00 GMT, the IU had lost all power save for the C-band transponder, which had its own battery, allowing ground controllers to track the stage for the balance of its stay in orbit. S-IVB-205 was now a passive target which began to tumble as residual gases in its propellant tanks continued to be vented.

Because the orbit of S-IVB-205 was decaying faster than expected, Apollo 7 would not be at its prescribed distance of 178.7 kilometers ahead of the spent stage at the start of the planned rendezvous exercise. A second unscheduled phasing maneuver using the RCS was started at 06:54:55 GMT. The 17.6-second burn changed the spacecraft velocity by 2.1 meters per second placing Apollo 7 into a 223.7 by 305.0 orbit which reestablished the desired conditions.

By the second day, Eisele and then Cunningham started experiencing head cold symptoms along with their Commander. The discomfort caused by the colds combined with multiple changes made on short notice to the already busy day’s activities took their toll on the mood of the crew. With the crew dealing with new tasks as they prepared for the first SPS burn of the mission as well as the first TV broadcast scheduled to start at 10:56 GMT, Schirra finally announced at 10:36 GMT: “The show is off! The television will be delayed without further discussion. We’ve not eaten. I’ve got a cold, and I refuse to foul up my time.” This was a prelude to the friction between the crew and ground controllers as the mission continued.

The SPS was fired for the first time during the mission starting at 17:27:40 GMT. This successful 9.36-second burn changed the spacecraft velocity by 62.2 meters per second placing Apollo 7 into 197.9 by 312.3 kilometer orbit. This corrective combination maneuver placed Apollo 7 into a higher orbit with a 15-kilometer altitude offset which allowed it to move above and behind S-IVB-205. A second 7.76-second SPS burn starting at 19:03:41 GMT took place when Apollo 7 was 148 kilometers behind and 14.4 kilometers below S-IVB-205. This placed Apollo 7 into a more circular 210.9 by 284.5 kilometer orbit for the final approach to their target. After three more firings of the RCS including a 708-second braking maneuver which changed the spacecraft velocity by 15 meters per second, Apollo 7 completed its rendezvous with S-IVB-205 at 20:58:28 GMT.

The Apollo 7 crew then spent the next 25 minutes in the vicinity of S-IVB-205 in a 226.2 by 298.2 kilometer orbit coming no closer than about 20 meters to the tumbling stage. While the retention cable finally pulled the last panel into place, the stage was tumbling too much to be safely approached any closer. Apollo 7 had now successfully completed another important mission objective by demonstrating that the CSM could rendezvous with a disabled LM in lunar orbit. The only major complaint from the crew was the lack of ranging information during the final braking maneuver – data they normally would have during a rendezvous with an actual LM. After the completion of the exercise, the RCS was fired for 5.4 seconds at 21:22:45 GMT for a posigrade maneuver to move Apollo 7 away from its target for the last time. With its part of the mission completed, S-IVB-205 finally fell from its decaying orbit over the Indian Ocean at about 09:30 GMT on October 18. In the meantime, the crew of Apollo 7 settled into their routine of testing the CSM’s many systems in orbit.

 

The Long Haul

By the beginning of the third day in orbit, Apollo 7 had already successfully completed 90% of its mission objectives. With Schirra and his crew committed to completing the full 11 days in orbit, a long series of systems tests in various configurations would dominate the crew’s schedule for the days to come. On the third day, a series of test with the navigation system’s sextant were performed. The receding S-IVB-205 was tracked via the sextant out to 593 kilometers. Later in the mission, the sextant was used for navigation exercises measuring the positions of stars relative to lunar surface features and the Earth’s horizon as would be done during the voyage to and back from the Moon. There were some issues spotting the indistinct nighttime horizon of the Earth and sunlit particles from a urine dump were mistaken for stars prompting a change in procedures in future Apollo missions.

On the fourth day, a series of three tests were performed using the CSM radar transponder which would be employed as the LM rendezvoused with the CSM after leaving the lunar surface. These exercises culminated with a test started at 19:29 GMT on October 14 where a ground radar located at the White Sands Missile Range in New Mexico acquired the transponder at a slant range of 722 kilometers and continued to track it out to 769 kilometers. The first live television broadcast from Apollo 7 took place earlier that day at 14:45 GMT. Despite their less than good moods, the crew put on a good show for viewers back at home opening their seven-minute telecast with a sign which read “From the lovely Apollo room high atop everything”. During this and the following six live telecasts over the next week, the astronauts gave viewers tours of their spacecraft, demonstrations of the effects of weightlessness and views out the windows of the Earth passing below. For the first time, American television viewers were offered a peek inside of an American spacecraft during a mission to watch history in the making.

The fourth day in orbit also saw the third of the eight firings of the all-important SPS. This third burn, which started at 18:50:45 GMT about 16 hours later than originally planned, lasted 9.1 seconds and changed the spacecraft’s velocity by 63.9 meters per second. This maneuver dropped the perigee of Apollo’s orbit to 165.8 kilometers and placed it over the northern hemisphere guaranteeing that the RCS could be used to deorbit Apollo 7 in case of a failure of the SPS. In the end, this backup plan was not needed as the SPS was put through its paces in a variety of control modes with burns as short as just half a second. The longest burn, the fifth which started at 12:02:45 GMT on October 18, lasted 66.95 seconds and changed the velocity of Apollo 7 by 515.5 meters per second. This burn allowed the accuracy of the propellant gauging system to be verified and changed the orbit to 165.0 by 452.3 kilometers – the highest apogee of the mission.

Friction with ground controllers and the crew continued through the mission. Sleep was one issue which especially irked the crew. While Apollo was a quieter spacecraft than Gemini, the need to have at least one crew member on watch at all times meant there was always activity taking place that could awaken crew members who were sleeping on staggered schedules starting as early as 4 PM or as late as 4 AM. While there were a pair of hammocks strung beneath the CM couches to allow the crew to stretch out, they were not popular and Walt Cunningham instead preferred to sleep in his couch on the far right side of the cabin. Despite Schirra’s request for an extra hour and a half of sleep for the crew, they were inadvertently woken up early on October 15 which irked the Commander who had been dealing with his head cold for four days now. Ultimately, mission control acknowledged their error and promised a ten hour sleep cycle for the next day. In order to minimize any sleep issues for the rest of the mission, Donn Eisele ultimately stood watch overnight while Schirra and Cunningham got some much needed sleep.

In addition to their second television broadcast, October 15 also saw the beginning of photography in support of the S005 Synoptic Terrain Photography and the S006 Synoptic Weather Photography experiments starting at 17:42 and 18:12 GMT, respectively. Over the course of the following days, a total of 500 photographs were taken in support of each experiment. Where possible, these observations were coordinated with aircraft photography taken by NASA Earth Resources Aircraft Mission 981 over selected sites in the southwestern US between October 14 and 22 using an instrumented Convair 240A. Because of problems steadying the camera during photography as well as the short time available to change film magazines, filters and exposure settings required for each category of targets, only about 200 of the S005 photographs were usable. Despite the problem, the collection of photographs met the experiment’s overall science objectives complementing the photographs taken earlier during the Gemini missions. For the S006 experiment, 300 photographs recorded 27 categories of weather phenomena including spectacular images of Hurricane Gladys in the Gulf of Mexico taken on October 17 and the eye of Typhoon Gloria on the 19^th. These images were far superior in resolution and quality than those routinely returned by the new ESSA-series of polar orbiting weather satellites which had entered operational service a couple of years earlier. Another 80 photographs taken in support of the S006 experiment also proved useful for studies in oceanography.

Among the important set of tests performed during the Apollo 7 mission involved the spacecraft’s thermal control system. These tests helped to verify the performance of the system validating it for use during lunar missions. Starting at 14:02 GMT on October 18 and again at 11:02 GMT on October 20, 50-minute long passive thermal control tests were successfully performed. In this mode, the CSM was placed into a slow roll to even out the effects of solar heating on the spacecraft exterior. Later popularly referred to as the “barbeque mode”, it would be used by the Apollo spacecraft during the cruise to and return from the Moon.

The power-producing fuel cells which generated electrical power for the CSM and drinking water for the crew also performed well during this initial manned Apollo mission. Numerous tests were performed to measure the stratification of the liquid hydrogen and LOX reactants used by the fuel cells verifying predictions of the conditions in their respective tanks in the SM. While adjustments were required to balance electrical loads and optimize their performance, the fuel cells worked much better with fewer problems than were encountered during the Gemini missions. By the end of the Apollo 7 mission, the new spacecraft had performed excellently despite the demanding test schedule.

 

The Return Home

As the highly successful Apollo 7 mission began to wind down, preparations were begun for the return home. On October 21, the SPS made its seventh burn starting at 14:08:57 GMT to adjust its orbit for retrofire the following day. The 7.7-second burn changed the spacecraft velocity by 67.1 meters per second placing Apollo 7 into a 163.9 by 425.6 kilometer orbit. In the final days before the return to Earth were being made, one last issue arose between mission control and the crew. While the mission plan called for the astronauts to don their spacesuits for the return the Earth, the crew was concerned about their ability to equalize pressure in their ears during descent because of their ongoing head colds. Ultimately the compromise was made for them to wear their A7L spacesuits but without the helmets and gloves on allowing them to more freedom to deal with the change in cabin pressure.

The final 11.79-second deorbit burn of the SPS started at 10:42:01 GMT on October 22 cutting the spacecraft velocity by 104.7 meters per second and ensuring that the trajectory of Apollo 7 intersected Earth’s atmosphere. About four minutes later, the CM and SM separated. The CM reached its entry interface at an altitude of 122 kilometers at a velocity of 7.877 kilometers per second at 10:56:11 GMT. Communications were blacked out for almost five minutes by the hot plasma enveloping the CM starting at 10:57:43 GMT. After experiencing a rather mild 3.3 g peak load during reentry, Apollo 7 deployed its drogue chutes at 11:06:08 GMT followed 50 seconds later by the trio of main parachutes. The Apollo 7 CM splashed down at 11:11:48 GMT (7:11:48 AM EDT) only 3.5 kilometers from its aim point in the Atlantic southwest of Bermuda and only 13 kilometers from the primary recovery ship, the USS Essex. The Apollo 7 mission had lasted 260 hours, 9 minutes and 3 seconds – the second longest manned spaceflight at that time.

Initially, the CM was in a stable “apex down” configuration as it bobbed in the ocean but righted itself after inflating flotation devices in its forward compartment. Schirra, Eisele and Cunningham were picked up by helicopter and were onboard the USS Essex less than an hour after splashdown. The CM was recovered by the carrier about an hour later. While there were issues with relations between ground controllers and the crew, all of the mission objectives were met with NASA officials rating Apollo 7 as a “101% success”. With this resoundingly successful maiden mission of the Block II Apollo spacecraft, the way was clear for the Apollo 8 mission to conduct the first manned test flight of the Saturn V rocket to send its crew to the Moon for the first time in history bringing the goal of a lunar landing one step closer (see “Apollo 8: Where No One Has Gone Before“).

After extensive debriefing and exams as well as a public relations tour, the crew members of the Apollo 7 mission went their separate ways. Wally Schirra had already made his decision to retire from the US Navy and NASA’s astronaut corps before the Apollo 7 mission. He officially left on July 1, 1969 after a decade of near constant training for his various space missions. Donn Eisele went on to serve as the backup Command Module Pilot for the Apollo 10 flight of May 1969 which was the final dress rehearsal for the Apollo 11 lunar landing. Eisele resigned from the Astronaut Office in 1970 and became technical assistant for manned spaceflight at the NASA Langley Research Center – a position he occupied until retiring from both NASA and the USAF in 1972. After the Apollo 7 mission, Walt Cunningham went on to head up the Skylab Branch of the Astronaut Office and left finally left NASA in 1971. None of the crew would fly in space again.

 

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Related Video

Here is a short NASA documentary entitled The Flight of Apollo 7.

 

 

Related Reading

“The Future That Never Came: The Unflown Mission of Apollo 1”, Drew Ex Machina, January 27, 2017 [Post]

“Apollo 8: Where No One Has Gone Before”, Drew Ex Machina, January 5, 2019 [Post]

 

General References

David Baker, The History of Manned Space Flight, Crown Publishers, 1981

Alan Lawrie, Saturn I/IB The Complete Manufacturing and Testing Records, Apogee Books, 2008

Richard W. Orloff and David M. Harland, Apollo: The Definitive Sourcebook, Springer-Praxis, 2006

Apollo 7 Press Kit, NASA Press Release 68-168K, October 6, 1968

Results of the Fifth Saturn IB Test Flight AS-205 (Apollo 7 Mission), MPR-SAT-FE-68-4, NASA Marshall Space Flight Center, January 25, 1969

Final Flight Evaluation Report Apollo 7 Mission, D2-117017-4 Rev A, NASA Office of Manned Space Flight, February 1969

Science Screening Report of the Apollo 7 Mission 70-Millimeter Photography and NASA Earth Resources Aircraft Mission 981 Photography, NASA TM X-58029, NASA Manned Spacecraft Center, June 1969