The First Time Anyone Shaved in Space

(With apologies to Roberta Flack, 1969)

I recently spent an entertaining hour and a half at a “wet shave meet-up” speaking about NASA space biomedical research in general and shaving in space in particular.

That sentence begs at least two separate explanations.

First, a wet shave meet-up is not a variation on Sir Arthur Conan Doyle’s “The Red-Headed League.” I didn't know it but wet-shave meet-ups are a national phenomenon where aficionados, enthusiasts and artisans can buy, sell and discuss blades, brushes, sharpeners, etc. It sounds a little crazy but there is actually a community of wet shaving aficionados who enjoy shaving with a razor and related tools as opposed to an electric razor. “Wet Shave Meet Ups” is a resource page (1) put together by Doug Smythe and Matthew Broderick to keep the community informed. Individual meet ups are organized by people in the community when and where the spirit moves them.  The “mother ship” of meet ups was held April 23 in Pasadena, California: “Big Shave West” (see it at “The Heart of Shaving: Big Shave West 2”) (2).  It had about 250 men and women in attendance, including manufacturers, YouTube “celebrities” and just-plain-fans from all parts of the globe.

I didn’t go to Pasadena, California, or even Pasadena, Texas. The Space City Meet where I spoke was organized by Adam Lindberg, artisan soapmaker for Stubble Trouble in Houston, a local meet-up at Rosewater, a new bar here in Clear Lake, Texas, co-owned by Pasha Morshedi, a colleague at NASA, and coincidentally where Adam is a bartender. There were about 30 wet shaving fans in attendance from as far away as Boston, along with manufacturers of small batch shaving products. It was organized by Gail Wells, the US brand manager for Edwin Jagger, an English company (3). She asked me to speak about shaving and grooming in space, and anything else of interest to the group.

This talk was arranged through the Johnson Space Center Speakers Bureau (4) so I had planned to give my usual 60-plus slide presentation on NASA’s Human Research Program and our work on resolving the risks to astronauts on future deep-space exploration missions, with a few interstitial slides on the history of shaving in spaceflight. Technical problems spared the attendees my full presentation, but luckily the shaving part could be retrieved. Being a NASA scientist, I use PowerPoint for all my presentations. The figures in this article are most of the charts I used at the meet up. Their text reveals the maturation of my approach to this topic.

Second, and contrary to my wife’s expressed disbelief, there is actually at least 30 minutes’ worth of presentation material on the topic of shaving in spaceflight.  

I was substituting for Neal Pellis who wasn’t available, but leaped at the excuse to explore this little appreciated aspect of everyday life in human spaceflight.

When I said “yes,” I already knew a few facts (remember: I'm a space geek): the first in-flight shaving was done on Apollo 10; Frank Borman requested an electric razor be waiting for him on the recovery helicopter after Apollo 8; some of the Skylab astronauts grew bushy beards while in orbit. But I had about three weeks to do some more research, so the first thing I did was contact some astronauts I know and ask them about wet shaving in flight. They responded almost apologetically that they used the electric shaver but without the vacuum attachment that featured in early designs. Instead, they just shaved near the inlet of the air conditioning system and let the spacecraft’s filters catch their whiskers.

If you are old like me, you remember the bearded faces of pioneering astronauts, beaming but exhausted, on the aircraft carrier after splashdown. In particular, the men on NASA’s second, third and fourth Gemini missions in 1965 extended our experience base of manned spaceflight stepwise to four, then eight and finally 14 days (figures 1), demonstrating that astronauts could come through the planned duration of the upcoming Apollo lunar landing missions with no debilitating physical effects. (The longest of seven previous American flights was 34 hours and the average was just under eight and a half hours.) Their beards confirmed what we already understood: that they had returned from the frontier, at no small risk to their lives and health, and had pushed back the boundary of the unknown just a little bit farther in man’s conquest of space, and in particular, America’s race to beat the Soviet Union to the moon.

Figure 1. Unshaven astronauts after early Gemini spaceflights. (Credits: NASA.)

The first astronauts were all males, all white and all military or former military qualified jet pilots (civilians without military experience and pilot qualifications were not selected as NASA astronauts until 1965), and they personified America’s image of the clean-cut hero. Intentional facial hair was not in vogue among such men in the early 1960s, and a few years later, shaggy beards would be a defining feature of the exact opposite of these men: “hippies.”

The early astronauts didn’t shave in space because they couldn’t, not because they didn’t want to. It wasn’t considered a priority in a program that was just trying to prove that man and machine could function long enough to get to the moon and back. By 1964, however, electric shavers were in development for future longer flights (figure 2A, right picture) that included a cumbersome vacuum hose to collect the cut whiskers (5) so they would not be a health hazard or contaminate the electronics (figure 2B), but they were not yet ready to fly (6).  Wet shaving was unthinkable: free-floating water droplets were considered anathema by engineers who remembered the problems caused to spacecraft electronics by Gordon Cooper’s body moisture during his 34-hour Mercury flight just two years earlier.

Figure 2. Early and later attempts at mechanical razors for shaving in space. (Credits: Historic Images and unknown manufacturer; Cunningham Collection.)

Figure 2B. A simulated space station mission in the 1960s established the justification of both the electric shaver and the vacuum attachment. (Credit: NASA in "Living in Space, NF-27, April 1969.)

There was no lack of desire to shave. Setting aside matters of comfort and hygiene, some astronauts also were sensitive about appearances. Jim McDivitt on the four-day Gemini 4 and Jim Lovell on the 14-day Gemini 7 had grown unmistakable beards. Frank Borman, also on Gemini 7, hinted at his uneasiness in comparison when he wrote in his biography that “Lovell had a full beard and I looked like a skid row bum recovering from a week-long binge.” (6) When Borman he flew with Lovell again, this time on Apollo 8, he made sure there was an electric razor waiting for him in the recovery helicopter (7)--which apparently only he used (figure 3).

Figure 4. Borman was able to shave aboard the helicopter after Apollo 8 but not after Gemini 7 (Credits: NASA.)

The breakthrough came in May 1969 aboard Apollo 10, the last mission before the lunar landing. First John Young, then Tom Stafford and Gene Cernan, homeward bound and taking advantage of the hot water available on the Apollo command module (9) advised Mission Control they were performing scientific experiment “Sierra-Hotel-Alfa-Victor-Echo” (figure 4). This transparent code-name was their light-hearted effort to let friends and family but not the press know that, thanks to brushless shaving cream and a safety razor, they would emerge from their spacecraft clean shaven after their eight-day mission. But the difference was noticeable in their last color TV broadcast before splashdown, so the secret was out.

According to Chris Spain’s website, “Space Flown Artifacts" (10)

Despite the original concerns it was found that using brushless shaving cream and safety razors there was actually no problem with loose whiskers. The process of shaving was still far from easy - most crews reported that the razors quickly became clogged with used shaving cream and whiskers and were almost impossible to clean out in the absence of running water.

The brushless shaving creams used by the astronauts were regular commercial products and the crews were apparently free to choose the brand they wanted to carry with them on a particular flight.

Figure 4. SHAVE experiment on Apollo 10. (Credits: NASA.)

(I wish I had found Chris’s article before my presentation to the wet shave meet up—wonder if I can get a do-over?)

Once it was established as an option, wet shaving even allowed Mike Collins on Apollo 11 to express himself creatively (figure 5).

Figure 5. Michael Collins before, during and after Apollo 11. (Credits: NASA.)

The preflight press information kits for the pre-shaving Apollos 7, 8 and 9 and the post-shaving Apollos 10, 11, 12, 13, 14 and 16 (10) shows they all list the personal hygiene items carried on each spacecraft: toothbrushes and toothpaste, tissues, solid waste collection bags and urine collection devices. However, none of them lists any devices for either wet or dry shaving, not even on those missions where shaving was known to occur. The relevant text was obviously copied from one press kit to the next, but it is hard to understand why such intimate activities as tooth-brushing, urination and defecation were acknowledged publicly but shaving was not.

A better place to check is the Apollo stowage lists, but Mr. Spain noted,

The Apollo Stowage Lists make no mention of the shaving equipment carried by the crews, but we do know that Apollo 11 Command Module Pilot Mike Collins used Old Spice brushless shaving cream on that flight as it is now part of the Smithsonian collection [along with his Gillette Techmatic safety razor (figure 6)]. We also know that a tube of K-34 Gillette brushless shave cream was used by the crew of Apollo 12, as this was given by them to Support Crew member Paul Weitz as a memento after the flight. On Apollo 13 we know that they used a shaving cream by Mennen, as this is mentioned in the technical debriefing.

Figure 6. Razor and brushless shaving cream used by Mike Collins on Apollo 11. (Credit: Smithsonian Institution.)

However, a wind-up mechanical razor was available by the time Apollo 14 flew in early 1971. It was even featured in a well-acted in-flight skit in which Alan Shepard shaved with it (12) then appeared to order his reluctant crewmate Ed Mitchell to do likewise (figure 7). (I made figure 7 from YouTube via a screen capture but cannot now find the video again.)  Their razor looked very much like the unflown prototype intended for the Skylab space station in 1973 (see figure 2A, left side) except with a black body.

Mr. Spain observed that:

[a]lthough safety razors were found to work reasonably well in a weightless environment the evaluation of mechanical razors for use in space continued. These efforts led to the adoption of a wind-up mechanical design made from acrylic which was used for the first time on Apollo 14 with reasonable success.

On Apollo 16 Ken Mattingly used a mechanical razor and found it worked well if used frequently. If used on two day old stubble however, he reported that it felt like the whiskers were being pulled out rather than cut. His crewmates apparently used Wilkinson safety razors when they had to shave, but found the same problem with clogging blades as earlier crews.

Figure 7. Ed Mitchell tried but failed to resist an order from Al Shepard to shave during Apollo 14. After the flight, Mitchell grew a beard which h kept for the rest of his life. (Credit: NASA.)

Thus, with both a wet and a dry option available, the difference was like night and day. All previous crews were scruffy if not shaggy, and all subsequent crews looked more “kempt” (figure 9)…except for Apollo 13, who did not shave before splashdown, lacking both the warm water and the inclination to do so while they struggled with their crippled spacecraft.

Figure 9. Astronauts after splashdown on Apollo 7, 8 and 9 before inflight shaving became possible and with Apollos 10-17 after on-board shaving became possible. (Credits: NASA.)

In fact, according to Chris Spain, Apollo 10 was not the first to carry wet-shaving equipment, only the first to use it:

[t]he first long duration Gemini spaceflights [Gemini 4, 5 and 7] brought the issue of shaving in space to the fore. The main concern was to ensure that loose whiskers would not end up floating into critical flight instrumentation, but early experiments with electric shavers fitted with simple vacuum attachments were a failure.

On Gemini [presumably after Gemini 7] through Apollo, the crews were issued with Gillette Techmatic safety razors but they apparently went unused until the flight of Apollo 10.

Unfortunately, this is hard to square with Borman’s request for an electric shaver in the helicopter: why didn’t he just shave in flight instead? Presumably, any razor and cream that flew on Gemini was manifested only after its longest-duration mission, Borman and Lovell’s Gemini 7, or Borman would have shaved during that flight as well. Unless, that is, he didn’t relish cold-water shaving: Gemini did not provide hot water.

At the risk of contradicting Chris Spain (whose web article did not give a source for the presence of inflight shaving paraphernalia prior to Apollo 10), it only makes sense to me that the Apollo 10 astronauts were the first to shave in spaceflight because they were the first to be equipped to shave in spaceflight.  Apollos 7, 8 and 9 also had hot water, plus lots of relatively idle hours toward the ends of those missions. Admittedly, it would have been more tedious to shave a week-old beard under those conditions, but not impossible.

Wet shaving has continued to be a part of subsequent missions, programs and eras (figure 9), as demonstrated by Joe Engle on STS-2 in 1981 and Mike Mullane on STS 41-D in 1984. I don’t know how the post-Apollo practitioners solved the problem of clogged razors, however, in the absence of freely-running water.

Figure 9. Joe Engle (STS-2) and Mike Mullane (STS 41-D) wet-shaving in the Space Shuttle era. (Credits: NASA.)

Interestingly, the inability or even reluctance to shave was not just a feature of American spaceflights: no Russian cosmonauts shaved in space until 1974, five years after the Americans. My colleagues Anna Kussmaul and Yuri Smirnov of the Institute of Biomedical Problems of the Russian Academy of Sciences in Moscow told me about the history of shaving on their flights.

In 1966 the Russians were preparing a series of Voskhod missions to exceed the Americans’ recent accomplishments in Gemini, including the planned 18-day flight of Voskhod 3 to break the 14-day record of Borman and Lovell on Gemini 7 (13). (The longest previous Russian mission was five days, and the average of the eight was just over two days.) One record the Russians apparently did not intend to establish was the first shave in space: Voskhod 3 cosmonaut Boris Volynov asked his boss, Gen. Nikolai Kamanin, for permission not to shave in flight, so Kamanin ordered that no shavers be flown (14). (This was about two months before planned launch, but sometimes things get overlooked until too late.) Voskhod 3 and its follow-ons were cancelled a few months later and Volynov didn’t fly until an early next-generation Soyuz mission in 1969.

In 1970 the Soyuz 9 crew flew for 18 days, taking back the endurance record. In 1971 the Soyuz 11 crew lived and worked aboard the first space station, Salyut, for 24 days--and apparently did not shave (figure 10A). But their appearance may have impressed space managers because that same year the Ufa factory received an order to create the first electric shaver for spaceflight (15). Three missions later, the Soyuz 14 crew tested the Agidel-K electric shaver (figure 10B), with vacuum attachment (not shown), during their two-week stay on Salyut 3. The first confirmatory photo I could find shows the Soyuz 18 crew clean-shaven after their 63-day flight aboard Salyut 4 in 1975 (figure 10C).

I still don't know when the Russians adopted wet shaving in flight, but they do it today.

Figure 10A. Soviet cosmonauts on Salyut/Soyuz 11 before and during spaceflight in 1971. (Credit: TASS.)

Figure 10B. The Agidel-3 commercial version of the Agidel-K (for "cosmic") electric shaver used in spaceflight. (Credit: Ufa.)

Figure 10C. Obviously clean-shaven Soviet cosmonauts Pyotr Klimuk (left) and Vitaly Sevastyanov (right) shortly after their 63-day spaceflight on Salyut 4/Soyuz 18 in 1975. (Credit: TASS.)

As Chris Spain noted,

Despite the difficulties, which led many astronauts to let their beards grow for at least part of the missions, most reported that it felt very refreshing when they did manage to shave.

In the American space program, starting in 1965, new cadres of astronauts were selected who were not military pilots. The scientist astronauts of 1965 and 1967 including university professors with more relaxed and contemporary tastes in facial hair.

The first to launch and land with facial hair was Owen Garriott, whose mustache only got longer during his 59 days in orbit during the Skylab 2 mission in 1973 (figure 11). Many subsequent astronauts have sported mustaches throughout their spaceflight careers.

Figure 11. Owen Garriott and the first mustache to go into spaceflight. (Credits: NASA.)

The very next crew all launched clean-shaven, but during their 84-day Skylab 3 flight, Gerry Carr and Bill Pogue both grew substantial beards (figure 12), confident that they would not be mistaken for hippies.

Figure 12. Skylab 3 astronauts before and after 84-day spaceflight. (Credits: NASA.)

The first man to launch with a full beard was Paul Scully-Power, an Australian-born payload specialist (e.g., visiting astronaut). He and six crewmates spent eight days orbiting Earth aboard the Space Shuttle Challenger during the STS 41-G mission in October 1984. His experience is notable because he was under some pressure to shave before flight to ensure the face seal of his helmet would function correctly during an emergency. Instead, he demonstrated that it sealed adequately despite his beard (figure 13). Two more fully-bearded men have followed Scully-Power's example: payload specialist Loren Acton on STS 51-F/Spacelab-2 in 1985 and Reinhard Furrer, a German payload specialist on STS 51-A/Spacelab-D1 also in 1985). (American astronaut Ron McNair had a beard when he was selected as a NASA astronaut in 1978, but by the time he flew on STS 41-B in 1984, he was clean-shaven.) The problematic style of helmet was superseded after the first 25 Shuttle flights, and subsequent helmets were indifferent to beards, but I can recall no other fully bearded men who have flown in space since then.

Figure 13. Paul Scully-Power and crewmates on STS 41-G in 1984. (Credits: NASA.)

Today, both wet- and dry-shaving continue to find adherents aboard the International Space Station (figure 14), as demonstrated in 2000 by Yuri Gidzenko and Sergei Krikalev on the first ISS crew and Yuri Usachev on the second crew.

Figure 14: Russian cosmonauts Yuri Gidzenko and Sergei Krikalev (left) on the first ISS expedition and Yuri Usachev (right on the second ISS expedition. (Credits: NASA.)

Shaving is now a standard part of routine hygiene for astronauts and cosmonauts, a normal activity of daily living, as it will be as long as men fly in space, the foundation having been laid in this area, as in so many others, by their predecessors decades earlier.


(1) Wet Shave Meet Ups resource page, (accessed Aug. 14, 2016).

(2) "The Heart of Shaving: Big Shave West 2," (accessed Aug. 14, 2016).

(3) Edwin Jagger,

(4) To request me or other NASA employees a a speaker at your next event, please contact the NASA Johnson Space Center Speakers Bureau,

(5) “Living in Space,” NASA Facts, NF-27 (Revised 4/69).

(6) Borman, F., with R.J. Serling, Countdown, William Morrow and Co., New York, 1988, p. 219. Borman reported a value of $5,000 for the unsuccessful development effort, or $38,000 in 2016 (, which would probably have paid for only a very small developmental effort and no flight-qualified hardware.

(7) Borman, p. 149.

(8) Borman, p. 219.

(9) SM2A-03-Block II-(1) Apollo Operations Handbook, 15 April 1969, Systems Data, Sec. 2, Subsection 2.7, Environmental Control System (ECS), 2.7.1 Introduction, p. 2.7-5, (accessed Aug. 7, 2016).

(10) Spain, C., “Space Flown Artifacts,”, 2009 (accessed Aug. 6, 2016).

(11) Godwin, R., ed., The NASA Mission Reports series, Apogee Books, Toronto, 2000-2002.

(12) Framepool, Apollo 14 / NASA / Crew / Space Capsule / 1971, (accessed August 12, 2016).

(13) Siddiqi, A., Challenge to Apollo (SP-2000-4408), NASA, Washington, D.C., 2008, p. 522, (accessed Aug. 19, 2016).

(14) Kamanin, N., Hidden Space (Russian: Skritiy kosmos), diary entry for March 21, 1966, (accessed August 16, 2016).

(15) Space reliability, (accessed Aug. 16, 2016).



A Jones for MOL #12: The Retroactivity of MOL (The Conclusion)

Note: this post may not make much sense unless you have already read Part 1 (1).  Even then, I make no promises…

In Part 1, we considered the use of the overpowered Gemini retrorockets and the even more overpowered Gemini-B retrorockets for de-orbiting those spacecraft. Despite the obvious nature of their designations, it appears the retrorockets were sized for launch escape purposes, but were conveniently available for de-orbiting when the spacecraft made it safely to orbit. De-orbiting by use of the Gemini retros resulted in a faster return from orbit than the theoretical minimum capability provided by the Orbital Attitude and Maneuvering System thrusters would have provided, with the added advantage of depleting the explosive solid fuel rockets instead of letting them burn and explode during re-entry. 

The discussion and calculations in Part 1 assumed that the de-orbiting thrust was delivered exactly into the direction of travel, in what is the most efficient application of that thrust. However, in practice, the Gemini retro maneuver involved an element of pitch. If Gemini-B had ever flown it might also have involved an element of yaw.

First, note that NASA oriented its Gemini spacecraft slightly nose-down (“pitch down”) during retrofire, apparently to help the command pilot maintain the proper attitude by keeping the Earth’s horizon at the top edge of his forward-looking window.  I have calculated that the nose-down pitch angle for manned Gemini in four cases was about 21 degrees. This angle allowed the pilots to confirm visually that their retro attitude was correct: in those early years of the space age it was not unheard of for spacecraft to have significant errors in the direction they were pointed for retrofire. The nose-down pitch presumably allowed them to confirm that the flow of the earth’s surface past the Gemini’s nose was the same on the left and right sides, and thus that they were correctly oriented “blunt-end forward” (yes, that is what they called it; it even had an acronym: “BEF”) so the retrothrust slowed them down and they fell out of orbit. 

Nose-down pitch of 21 degrees at retrofire would deliver less effective thrust directly opposite the orbital motion, thus extending the travel time in the de-orbit arc. However, the downward component of the thrust would have “pushed” the orbit lower, making it more elliptical and shortening the time and distance traveled to entry interface. A purely downward push would have produced a new low point, or perigee, about ¼ of the way around the Earth, and a new high point, or apogee, about half an orbit after that. 

My math skills only allow me to calculate simple orbit changes from thrusting directly forward or backward. I might be able to struggle through the calculations for a purely upward or downward maneuver. But the combination of the two is beyond me. Luckily, I was able to enlist Ryan Whitley of NASA JSC to mathematically model an inclusive set of Gemini and Gemini-B de-orbit cases. Along the way he helped me understand my own questions better.

I will present the results from the case of a circular orbit at 344 kilometers (186 nautical miles, 214 statute miles), but we also modeled elliptical orbits of 344 by 148 km. (186 x 80 n.mi., 214 x 92 st. mi.) and 256 by 144 km. (138 x 78 n. mi., 159 x 90 st. mi.). The circular orbit provides the most challenging scenario; the elliptical orbits represent likely reconnaissance orbits early and late in the 30-day mission whose intentionally-low perigees are already very close to the threshold for atmospheric entry.

The Gemini de-orbit maneuvers combining retrograde thrust and nose-down pitch produced a terminal orbit designed to intersect the atmosphere—and thus initiate re-entry—at its low point about ¼ of the way around the globe. This orbit had a slightly flattened angle of entry into the atmosphere and slightly increased the entry velocity compared to the nose-horizontal case (see Table 1).

Table 1. Effects of Nose-down Pitch and Yaw on Gemini Descent Orbit Characteristics

Second, there is a simple solution to the problem (if it really is a problem) of Gemini-B having 50% more retrorocket thrust than Gemini: waste the excess thrust. 

By trigonometry, aiming the Gemini-B sideways (this is called “yaw”) by 48 degrees—that is, just over halfway between parallel to its direction of travel and perpendicular to its direction of travel—before its six retrograde rockets fired would still have produced the same orbital deceleration as Gemini would have achieved by firing its four retro rockets directly backwards. Achieving the same atmosphere re-entry velocity and flight path angle (the angle of intersection with the atmosphere) as Gemini had would keep re-entry thermal loads within the qualification limits validated during testing. Those limits were validated by Gemini spacecraft #2 in two separate suborbital flights, first for NASA’s Gemini program in January 1965 and then for the Air Force’s Gemini-B development program in November 1966.

There is no reason the Gemini-B/MOL flights would not have continued the practice of nose-down pitch established during NASA’s ten manned Gemini missions, to provide the same assurance. Assuming deorbiting was to take place on the southbound leg (called the descending node) of a polar orbit, Ryan’s model showed that aiming the Gemini-B’s 50% excess retrograde thrust to one side or the other with a yaw of 132 degrees (which is 48 degrees less than the usual 180 degrees of yaw, that is, aiming directly backwards to the direction of flight) while maintaining Gemini’s 21-degree nose-down pitch would have produced a re-entry essentially identical to a typical Gemini re-entry except that its landing point would be moved 84 kilometers (53 statute miles) either to the east or the west of its polar orbital track (Table a). In both cases, the capsule would have intersected the upper atmosphere at the official re-entry altitude of 400,000 feet (122 kilometers, 76 miles) at an angle of no more than 1.3 degrees and a velocity of 7,872 meters per second (see Table 2). 

Table 2. Effects of Nose-down Pitch and Yaw on Gemini and Gemini-B Descent Orbit Characteristics

All that would seem to be required is to tell the recovery forces which way the Gemini-B would be aiming so they could position themselves appropriately to the east or west of the polar orbit ground track. 

But wait—there’s more. The effect on Gemini-B would have been even further complicated by the geometry of the retrorockets’ mounting in the adapter module. They would all have been mounted at or below the module’s left-right centerline (see Figure 1) because the top half of the module would have accommodated the transfer tunnel from the Gemini-B cabin back to the MOL. Remember that plug hatch in the heat shield I mentioned in Part 1? It would have opened up into the transfer tunnel to allow the pilots to transit in shirtsleeves from their capsule to their habitat for their month-long mission without ever passing through the vacuum of outer space (2).  The NASA Gemini retrorocket arrangement could not have been used because, among other reasons, one arm of its cross-shaped braces would have interfered with that tunnel.

Figure 1. Retrograde rockets in NASA Gemini (4 retrorockets) and Air Force Gemini-B (6 retrorockets) illustrating the central symmetrical arrangement in Gemini and the asymmetrical off-center arrangement in Gemini-B. Note that the Gemini retrorockets are viewed from the top while those of the Gemini-B are viewed from the bottom. (If this figure looks familiar, it was previously Figure 3 in Part 1.)

I estimated that this arrangement of the Gemini-B retrorockets would have required the command pilot to aim about 25 degrees nose down, compared to 21 degrees for Gemini, to keep the direction of the thrust through the spacecraft’s center of mass in the same relative direction as on Gemini (see Figure 2). Early in the Space Age, there had already been considerable nervousness about making sure the retro thrust was delivered in the correct direction, compounded by the fact that the Gemini-B may have also required a unique decision about whether to aim left or right of the ground track. If I were a MOL planner, I might well have decided that the 21-degree nose-down pitch was already well-established by Gemini and that the small loss (9% by trigonometry) in retro thrust due to the 4-degree offset would not have had a significant effect on the velocity change delivered by the six retro rockets.

Figure 2. Thrust vectors of Gemini-B retrorockets (approximated graphically).

I don’t know if the 48-degree yaw or the 25-degree nose-down pitch were ever established as standard procedure for Gemini-B; maintaining the standard Gemini yaw of 180 degrees and 21-degree nose-down pitch during Gemini-B retrofire would have produced a flight path angle still within acceptable limits and only a slightly higher entry velocity, so the 48-degree yaw may not even have been evaluated. Maybe there is one among the 825 MOL documents (3) declassified in October 2015 that confirms or refutes my hypothesis, but I have not found it yet. 

This has been a circuitous disquisition on some arcane aspects of an almost invisible aspect of a cancelled space program from five decades ago; it certainly justifies the “crypto” and “trivio” parts of this blog’s name, as well as the “astro.” However, these are the details that lure me to this type of in-depth analysis. If you have read this, I thank you for your patience and congratulate you on knowing something that practically nobody else in the world knows, or even knows they don’t know. 

My thanks to Ryan Whitley of NASA Johnson Space Center for doing the calculations, and to Roger Balettie, Jorge Frank, Jonathan McDowell and Jim Oberg for their patience and good humor in educating me about orbital mechanics.


  1. “A Jones for MOL #11: Retroactivity of MOL (Part 1),” (accessed July 23, 2016).
  2. “A Jones for MOL #3: Down the hatches,” (accessed Oct. 4, 2015) and “A Jones for MOL #7: Hatches? We Don’t Need No Stinking Hatches!” (accessed Oct. 4, 2015).
  3. National Reconnaissance Office, Declassified Records, Index, Declassified Manned Orbiting Laboratory (MOL) Records, (accessed July 23, 2016).

A snapshot of MOL in 1968

The National Reconnaissance Office (NRO) declassified and released 825 documents spanning the history of the Manned Orbiting Laboratory (MOL) program for a public gathering of MOL pilots, managers, historians, and fans at the National Museum of the US Air Force in October 2015. One of the most informative is number 521 in the NRO list, the MOL Flight Test and Operations Plan, dated May 8, 1968. Its 523 pages give a detailed overview of the MOL flight program, including management organizational structure, flight objectives, and ground support. It is a snapshot of planning for MOL three years before the scheduled date of the first launch, and describes a maturing—but not yet mature—program. 

Click here to read the article published on-line in The Space Review, January 11, 2016.

A Jones for MOL #11: The Retroactivity of MOL (Part 1)

I am not trained in orbital mechanics, also called “astrodynamics,” as practiced by Rich Purnell in the movie The Martian. But I feel some kinship with him because, except for his youthful good looks, his grasp of extreme mathematics and his access to the “NASA Supercomputer,” he and I are a lot alike. He used orbital mechanics to solve a life-or-death problem on a Mars mission gone wrong twenty years in our future. I used orbital mechanics to decipher an obscure feature of a military space program cancelled almost fifty years ago.

If the U.S. Air Force’s secret Manned Orbiting Laboratory (MOL) had flown into low Earth orbit in the 1970s, its astrospy[1] pilots would have ridden in the Gemini-B variant of NASA’s retired Gemini spacecraft during launch and landing (Figure 1). Gemini-B looked outwardly very similar to its predecessor (see Figure 2), but it was stripped down for its supporting role during month-long reconnaissance missions. It would have gotten its on-board electricity from batteries instead of hydrogen-oxygen fuel cells, giving it an independent lifetime of only 14 hours, shorter than all but two Gemini missions. Gemini-B would have been launched already bolted to the MOL, so it wouldn’t have needed rendezvous radar or a full set of maneuvering thrusters. Fuel cells and maneuvering thrusters would have been on the MOL, the central component of the mission.

 Figure 1. Stylized view of Gemini-B/MOL in low Earth orbit. Note the absence of any maneuvering thrusters, antennae or reconnaissance telescope aperture, but the gratuitous addition of a red nose on the Gemini-B. (Credit: McDonnell-Douglas, 1967)

One area in which Gemini-B was not stripped down was its retrograde rocket complement. It was to carry six of the same Star-13E rocket motors[2] as Gemini (see Figure 3). But the MOL mission called for orbits as low as or lower than those of Gemini, which had only used four retrograde rockets: de-orbiting from a lower orbit should not have required more retrograde rockets. Why did Gemini-B need six?

Figure 3. Retrograde rockets in NASA Gemini (4 rockets) and Air Force Gemini-B (6 rockets). (Credit: McDonnell-Douglas.)

Not being an engineer or astrodynamicist like Rich Purnell, I inquired among known experts. They didn’t know either, but they made some reasonable guesses.

Was it because Gemini-B was carrying more mass than Gemini at deorbit? I estimate that Gemini-B was to be only 10% heavier than Gemini,* certainly not requiring 50% more retrograde rocket thrust for de-orbit.

Was it some sort of military requirement to "get 'em down ASAP," or to simulate a lunar re-entry profile, or a need for a shorter orbital arc from retrofire to re-entry to minimize any guidance (“aiming”) errors during the de-orbit maneuver. The first two seem unlikely, but the shorter arc was mentioned by a few experts as being a factor in NASA Gemini re-entries. Using an even shorter arc on Gemini-B might have stressed its heat shield with more thermal loading than Gemini experienced. But a re-entry test validated the modified heat shield with a plug hatch cut into it[3]under similar conditions as for the original Gemini heat shield.[4] Clearly the re-entry conditions for Gemini-B were planned to be the same as for Gemini.

Was it somehow driven by the geographical limitations of available equatorial ground stations tracking the re-entry trajectory of a polar orbiting spacecraft? This suggestion seems to assume that the entire de-orbit, re-entry and landing sequence could be accomplished within view of a single tracking station, which were scattered around the Earth within about 30 degrees of the equator.[5] Such an extremely abrupt de-orbiting seems unlikely, unsafe and unnecessary; more likely, a tracking ship or aircraft could be stationed in the high northern or southern latitudes far outside the existing U.S. network, which sounds like a good idea in any case.

The only justification I have ever seen for carrying six retrograde rockets is that they were primarily for off-the-pad launch aborts of the Titan III-M launcher with its two highly-explosive side-mounted seven-segment solid boosters (see Figure 4). If an abort was required before liftoff or up to 31 seconds later, salvo-firing all six retrograde rockets simultaneously would rocket the Gemini-B to a safe distance from the exploding booster, allowing the pilots to eject and land under their personal parachutes.[6] In any abort from 31 seconds to separation of the solid rocket boosters, the pilots would not eject but would stay in their Gemini-B capsule through re-entry and splashdown. The NASA Gemini also had a salvo-fire option of its four retrograde rockets, but only for launch aborts above 70 thousand feet.[7] Lower altitude aborts would have used only the ejection seats because the Titan rocket without the solid rocket boosters represented less explosive potential.

Figure 4. Gemini-B/Titan-IIIM abort modes. Note “salvo fire” of all six retrograde rockets near point B during the period when the solid rocket boosters are in operation, compared with one-at-a-time “ripple fire” near point C for an abort late in the launch phase. (Credit: McDonnell-Douglas.)

In fact, I have concluded that Gemini did not even need its four retrograde rockets to de-orbit at all, and Gemini-B certainly did not need six. The first two piloted Gemini missions demonstrated a fail-safe de-orbit option in case their retrograde rockets failed to fire.[8] On its final orbit, Gemini 3 fired its Orbital Attitude and Maneuvering System (OAMS) thrusters, already known to be functioning correctly from maneuvers on earlier orbits, for two minutes while passing near Hawaii, setting up an orbit with a low point of 54 miles, well below the 76-mile altitude used as the “top” of the atmosphere.[9] Then the retrograde rockets were fired as planned near Los Angeles, bringing the spacecraft to its intended landing site about 70 miles east of Grand Turk Island in the Atlantic Ocean. If the rockets had not fired, the spacecraft would still have landed about 1,000 miles west of Ascension Island in the central Atlantic (see Figure 5).

Figure 5. Possible re-entry trajectories.

Of course, the Gemini retrograde rockets worked on-time every time on every mission, and the fail-safe option was discarded after Gemini 4, permitting the full maneuvering fuel supply to be applied to rendezvous maneuvers. For example, Gemini 10 de-orbited near Canton Island in the Pacific Ocean[10] (due south of Hawaii), began re-entry over Mexico south of Texas and splashed down in the western Atlantic Ocean.[11]

The fail-safe maneuver provided only slightly more than the theoretical minimum velocity change required, which would have produced an arc of 180 degrees and 12,400 miles (20,000 km)—halfway around the Earth—in what is called a Hohmann orbit (see Table 1.) Thus, both Gemini 3 and Gemini 10 started their descents from approximately the same longitude, but Gemini 3 followed a shallower trajectory until it fired its four retrograde rockets to end up splashing down approximately where Gemini 10 did.

Table 1. Approximate travel in orbit from de-orbit maneuver to atmospheric entry for the Gemini 3 standard and fail safe cases compared with Gemini 10 (typical de-orbit) and theoretical minimum de-orbit maneuver.

The highest circular orbit from which the four retrograde rockets could de-orbit a standard Gemini (using a Hohmann orbit with a perigee of 400,000 feet, which is 122 kilometers or 76 miles) was much higher than any Gemini ever flew unless it was docked to an Agena-D rocket stage (see Table 2). This demonstrates that the four retrograde rockets were overkill for de-orbiting purposes.

Table 2. Maximum-altitude circular Gemini orbit consistent with de-orbit using four retrograde rockets, compared with highest typical Gemini mission orbits.

Gemini-B/MOL would have been in an even lower orbit than Gemini to improve its high-resolution Earth photography, and constant atmospheric drag would have been slowing the vehicle enough to de-orbit it in hours or days. This would surely have required frequent orbital boosts from the on-board maneuvering engines in the MOL’s Attitude Control and Translation System (ACTS). Mock-ups and images of MOL from late in its design phase show the largest ACTS thrusters were those pointed to the rear (“+x” in spacecraft parlance) (Figure 6) to speed up the MOL. There didn’t seem to be any thrusters at all pointed forward; maybe the designers didn’t foresee any need to slow MOL down more than atmospheric drag would already achieve.

Figure 6. Full-scale mockup of MOL with Attitude Control and Translation System (ACTS) quad shown in detail. The Gemini-B spacecraft was to be mounted atop this module, indicating the "forward" direction. Note absence of any forward-directed thruster nozzles, and thus an absence of deceleration capability.

Based on the same type of analysis as for the NASA Gemini orbits, the six retrograde rockets on Gemini-B would have permitted de-orbiting from a circular orbit over twice as high as the final orbit we assumed for the MOL missions and forty percent higher than the initial orbit we assumed (see Table 3).

Table 3. Maximum circular orbit for Gemini-B consistent with de-orbit using six retrograde rockets, compared with highest (initial) and lowest (final) MOL orbits modeled in Reference 5.

If the MOL provided adequate propulsion capability and if the retrograde rockets were even more overkill on Gemini-B than on Gemini, why didn’t Gemini-B dispense with retrograde rockets entirely and utilize the MOL’s ACTS thrusters to de-orbit the entire vehicle? This would obviously have been immediately followed by separating the Gemini-B from the MOL so it could land safely while the single-use MOL burned up in the atmosphere as intended. 

I have not seen an authoritative discussion of this topic, but maybe it is there, deep in some yet-to-be-declassified documents. So, I can only guess. Perhaps there was concern about ensuring adequate distance between Gemini-B and MOL to avoid re-contact and collision during the buffeting of re-entry. For comparison, the Apollo service module actively distanced itself from the command module during re-entry (see Figure 7) with no instances of recontact. It used a thruster configuration apparently not available on MOL, so perhaps that was one reason.

Figure 7. Apollo Service Module (SM) used its forward-firing maneuvering thrusters to insure adequate separation from the command module (CM) during re-entry. MOL apparently did not have a similar capability due to its lack of forward-firing thrusters (see Figure 6). (Credit: NASA.)

Air Force mission planners may also have been interested in targeting MOL to a different disposal site than the splashdown site of Gemini-B. Dan Adamo and I speculated[12] that Gemini-B would be aimed to land near Hawaii but MOL would be targeted to the Marianas Trench several thousand miles to the west to prevent Soviet retrieval of any heavy elements that survived re-entry. This may have required MOL to remain in orbit several hours longer than Gemini-B. 

There were also other risks. The ACTS thruster fuel could have been exhausted before the planned end of the mission, preventing a targeted de-orbit and leaving the military MOL pilots to an inevitable but uncertain landing in a large swath of the Earth—including in a country they may have been spying on from orbit. However, ACTS fuel status would certainly have been monitored regularly and the mission could have been shortened if necessary to protect re-entry capability. 

There was also a small risk of failure to separate the Gemini-B equipment adapter module from the laboratory after the ACTS de-orbit maneuver, but the MOL design already envisioned a sequence of separations between the Gemini-B and the MOL: first a shaped charge would have split the connection to MOL at the bottom of the equipment adapter (C in Figure 8); then, prior to retrofire, another shaped charge would have split the retrograde adapter from the equipment adapter (D in Figure 8); finally, after retrofire, two pyrotechnic charges would have broken the structural and electrical connections between the re-entry vehicle and the retrograde adapter (A in Figure 8). Those same steps could have provided triply-redundant assurance of Gemini-B separation from MOL after de-orbiting using the ACTS.

Figure 8. Separation points of Gemini-B and MOL. [A] Pyrotechnically-driven cutter for two mechanical linkages and electrical connection of re-entry vehicle and retrograde adapter. [B] Shaped explosive charge to separate retrograde and equipment adapter modules. [C] Shaped explosive charge to separate equipment adapter module and MOL unpressurized module. [D] Interface mating lugs (bolts) connecting Gemini-B and MOL (26 places). (Credit: McDonnell-Douglas with annotations by author.] 

These alternatives all have one thing in common: once safely in orbit, without having to salvo-fire the retrograde rockets during a launch abort, it was a better idea to fire them for de-orbiting and use them up than to have unexpended ordnance in proximity during re-entry heating, when they would certainly explode, spraying shrapnel in the vicinity and damaging the Gemini-B’s heat shield, or possibly fire and push the retrograde module into a collision with the re-entry vehicle.

Thus, Gemini-B would simply have continued the tried-and-true Gemini practice and used its available launch abort rockets to shorten the arc of its re-entry orbit. One may quibble over whether those rockets should have been named “launch abort rockets” instead of “retrograde rockets” but the former would have represented an improbable eventuality while the latter represented a certainty.

Still, questions remain. Wouldn’t applying fifty percent more retro-thrust have made the Gemini-B re-entry significantly steeper and hotter than it was qualified for? And if so, were there options that maintained those conditions while not leaving unfired ordinance in proximity to the re-entering Gemini-B?

Those are the topics of an upcoming post.


Thanks to Roger Balettie, Jorge Frank, Jonathan McDowell, Jim Oberg and Ryan Whitley, among others, for their patience in explaining aspects of orbital mechanics to me, and to Dr. Dwayne Day for documents and illustrations used in this analysis.

* The six rocket motors would weigh 58.7 kg (129.4 lb) more than just four on Gemini, until they were fired. The film canisters from the KH-10 DORIAN cameras, assuming four of the type flown by Corona reconnaissance satellites weighing 36 kg (80 lb) each, would add 145 kg (320 lb) more than Gemini. This was estimated based on data retrieved from searches on various websites, including the National Reconnaissance Office collection of declassified documents; see for example (accessed Sept. 27, 2015).

[1] “Astrospies,” NOVA, PBS, air date Feb. 12, 2008, (accessed Oct. 4, 2015).

[2] Also called the TE-M-385; see ATK Thiokol's solid fuel STAR motors (source: ATK catalog), updated July 26, 2012, (accessed Nov. 15, 2014).

[3] “A Jones for MOL #3: Down the hatches,” (accessed Oct. 4, 2015); “A Jones for MOL #7: Hatches? We Don’t Need No Stinking Hatches!” (accessed Oct. 4, 2015).

[4] Launch Evaluation Report MOL/HST Spacecraft, McDonnell Co., Dec. 3, 1966. Not available on-line; contact author.

[5] Charles, John B., and Daniel R. Adamo, “Thirty Days in a MOL: Biomedically Relevant Aspects of a Reconnaissance Mission Inferred from Orbital Parameters,” Quest, The History of Spaceflight Quarterly, vol. 22, no. 2, pp. 3-14, 2015.

[6] Shayler, David J., Space Rescue: Ensuring the Safety of Manned Spacecraft, Springer Praxis, Berlin-Heidelberg-New York, 2009, p. 204-6, “Launch escape, 2: Ejection seats. Gemini and Manned Orbiting Laboratory”, (accessed Nov. 9, 2014).

[7] “Launch to insertion abort boundaries, launch heading = 72°,” Gemini Design Certification Report, Feb. 19, 1965, p. 2.1-11, Figure 2.1-2. Not available on-line; contact author.

[8] Charles, John, “A Tale of Two Martins,” The Space Review, Jan. 5, 2015, (accessed Sept. 27, 2015). 

[9]Short news article quoting Dr. Christopher C. Kraft originally appeared in the Galveston News-Tribune, Feb. 16, 1965, reproduced in the NASA Astronautics and Aeronautics Report for 1965, p. 68, (accessed Sept. 2, 2013)

[10] “Canton Island Tracking Station (CTN),” (accessed Oct. 10, 2015).

[11] Gemini X Mission Report, NASA Manned Spacecraft Center, Houston, Texas, August 1966, p. 4-38, Figure 4-2c Re-entry, (accessed Nov. 22, 2014)

[12] Charles, John B., and Daniel R. Adamo, “Thirty Days in a MOL: Biomedically Relevant Aspects of a Reconnaissance Mission Inferred from Orbital Parameters,”Quest, The History of Spaceflight Quarterly, vol. 22, no. 2, pp. 3-14, 2015.

Thirty Days in a MOL: Biomedically-relevant Aspects of a Reconnaissance Mission Inferred from Orbital Parameters

The Manned Orbiting Laboratory (MOL) Program of the U.S. Air Force is well-known but poorly understood because it was both widely-publicized and largely secret. It is of historical interest today for many reasons, not least because of the characteristics of its planned orbit and their possible influence on the physiology and psychology of the men intended to occupy it. But the biomedical aspects of MOL are perhaps the least represented aspects of the available literature. So Dan Adamo and I wrote this article to present some of them.

Hoodies in Outer Space: Functional and Fashionable

Recently, the hooded sweatshirt, or “hoodie”, has been elevated from ubiquitous casual wear to political statement in the aftermath of a tragedy. An earlier and very different tragedy led to the widespread adoption of hooded space suits. By the end of 2011, hooded soft-helmet space suits had been used 284 times, by 23% of all space flyers, and those numbers will increase for the foreseeable future.