Friday, September 25, 2015

Space will be ours! Golden Collection of Soviet space posters.

Space will be ours! Golden Collection of Soviet space posters,
Moscow, CONTACT-CULTURE Publishing House, 2012

I received this collection from my colleague, Professor Inessa B. Kozlovskaya of the Institute of Medico-Biological Problems, of the Russian Academy of Sciences in Moscow. IMBP is the counterpart of of NASA Human Research Program so we have a lot of interactions. Inessa is much, much better at choosing gifts than I am, and never arrives empty-handed.

Posters and slogans reproduced here from the commemorative folder. My comments are at the bottom of the post. 

1957. V. Viktorov. The greatest victory of Soviet science and technology. 
1959. V. Viktorov. Creative resources of Socialism are boundless!

1960. L. Golovanov. Let's conquer Space! 

1960. K. Ivanov. The way is open for a human being!

1960. V. Viktorov. We are born to make dreams come true!

1961. E. Soloviov. For the glory of Communism!

1961. V. Volikov. Long live Soviet science. Long live the Soviet man--the first astronaut!

1961. V. Viktorov. Long live the first astronaut Yu. A. Gagarin!

1961. B. Berezovskii. Long live the son of the Communist party!

1961. B. Staris. The dreams came true on 12 April.

1961. N. Smolyak. We'll pave the way to distant worlds  And get into the mysteries of the Universe!

1962. M. Soloviov. A Soviet citizen, be proud - / The way to distant stars is discovered!

1962. B. Berezovskii. Long live the Communist Party of the Soviet Union!

1962. V. Volikov. Long live the Soviet people--the Space pioneers!

1962. V. Viktorov. Long live courage, labor and intellect of the Soviet people!

1962. V. Viktorov. Socialism is our launching pad.

1963. Yu. Kershin. Long live the first woman cosmonaut!

1963. V. Viktorov. Our triumph in Space is the hymn to the Soviet country!

1963. A. Vinokurov. The distance to even the furthest planet is not that long, folks!
1964. Yu. Kershin and V. Trukhachev. Long live the USSR--the birth-place of Space exploration!

1965. V. Ivanov. In the name of peace and progress!

1968. G. Illarionov. Being long for the future is our life!

1970. V. Viktorov. Sputnik of friendship and co-operation.

1971. A. Yakushin. Space is going to serve people!

1982. M. Getman. We are creative and friendly and clever / We're making space to be peaceful forever!

The posters track the latest space victories, with greatest emphasis on the flight of Gagarin.

1957: 1     1959: 1     1960: 3     1961: 6     1962: 5     1963: 3
1964: 1     1965: 1     1968: 1     1970: 1     1971: 1     1982: 1

Based on year of publication, it looks like official space enthusiasm peaked in 1961-1962. (Not considering any selection bias in producing this Golden Collection--who knows how many posters were actually printed, and why these were chosen.)

V. Viktorov is the most popular artist in this collection, and had the long career as measured by selected artworks.
Viktorov 1958, 1959, 1960, 1961, 1962 x 2, 1963, 1970
Berezovskii 1961, 1962    Ivanov 1960, 1965    Volikov 1961, 1962
Getman 1982     Golovanov 1960     Illiarnov 1968     Kershin 1963
Kershin & Trukhachev 1964     Smolyak 1961     Soloviov E 1961   Soloviov M 1962    Staris 1961    Vinokurov 1963    Yakushi 1971

General themes from 1957 to 1964 seem to be about the glory of Socialism and the Soviet People. Thereafter they are more generic and seem focused on peace, knowledge and prosperity. I was particularly struck by the poster from 1971: "Space is going to serve people." That was the year when the Soviet program began flying Salyut space stations with earth benefits as the primary goal, to replace the failed manned lunar program. Ironically, the first successful Salyut mission in 1971 ended with the deaths of its crewmen during the landing process.

The message on Vinokurov's 1963 poster, "The distance to even the furthest planet is not that long, folks!" seems to be chiding the Soviet populace to quit worrying that space is too big, when in fact, space is the biggest thing there is. I wonder what general mood this was intended to address.

The last poster in the series, by Getman in 1982, has the slogan: "We are creative and friendly and clever / We're making space to be peaceful forever!" This bears an unfortunate resemblance to the catchphrase of Al Franken's Stuart Smalley character on Saturday Night Live in 1991: "I'm good enough, I'm smart enough, and doggone it, people like me!"

Tuesday, September 22, 2015


William R. Carpentier, M.D., and John B. Charles, Ph.D.

In September 2015, Bill Carpentier and I submitted this brief article to the NASA History Newsletter for consideration for inclusion in the 2015 year-end issue dedicated to Project Gemini.

In January 1965, through a combination of preparation and luck, I (WRC) joined NASA‘s Manned Spacecraft Center, (now the Johnson Space Center) as a flight surgeon trainee and was privileged to participate in a truly great adventure. In July, I became a staff flight surgeon in the Medical Operations Office. I was soon assigned the job of flying in the recovery helicopter on Gemini 5, 6, 7 and 9 and working with the Navy Underwater Demolition Team (UDT) swimmers in order to provide medical support for astronaut rescue operations.  This gave me a unique perspective on this ambitious manned program.

Project Gemini was initiated in 1961 to bridge the knowledge gap between the successful but rudimentary one-man Project Mercury flights then under way and the ambitious three-man Apollo moon missions still a few years in the future. Gemini was intermediate in the number of astronauts it would carry, the durations of most of its flights, the altitudes of its orbits and the scope of its extravehicular activities. But there was nothing intermediate about its unprecedented challenge to its pilots. Gemini was intended to define the operational limits of astronauts in upcoming lunar missions including the most unique feature of spaceflight, weightlessness, for up to fourteen days—the duration of the longest foreseen lunar mission—compounded by extended confinement in a small cockpit inside a bulky, restricting space suit.

The first two-hour orbital flight of Soviet cosmonaut Yuri Gagarin in April 1961, followed by six more flights lasting up to five days, did not revealed any unexpected life-threatening difficulties, but the Soviets did not disclose many medical details. American Mercury astronauts flew two suborbital and four orbital missions with excellent performance and no significant deleterious effects of weightlessness. 

However, Gordon Cooper had a very high heart rate and was lightheaded when he stood up for the first time on the deck of the recovery ship after the final Mercury flight, the 22-orbit, 34-hour mission in May 1963. This “orthostatic intolerance” was not entirely unexpected because Walter Schirra had an increased heart rate and decreased systolic blood pressure when standing compared to lying down after his 6-orbit, 9-hour flight the previous October. 

Figure 1. Cooper standing quietly on the aircraft carrier deck immediately after egressing his Mercury capsule, while heart rate and blood pressure were measured. (Photograph credit: NASA.)

Orthostatic intolerance means “intolerant of the upright posture while standing” and its symptoms include trembling, weakness, fatigue, poor concentration, lightheadedness, accelerated heart rate, and even fainting on standing because the cardiovascular system has trouble maintaining blood pressure and blood flow to the brain. These symptoms  were believed to  result from a decrease in blood volume during spaceflight, exacerbated by the fact that veins in the lower body may become more distensible post-flight, allowing more blood pooling in the legs.

All Mercury astronauts had weight loss and increased heart rates, and five out of six had decreased systolic pressure after landing. No one knew how much to be concerned about these findings, but they influenced planning for the upcoming Gemini flights, which were to gradually increase the time astronauts stayed in weightlessness: from just five hours on Gemini 3 (as short as the Mercury flights of John Glenn and Scott Carpenter), to four days on Gemini 4, eight days (matching early Apollo missions) on Gemini 5, and finally 14 days on Gemini 7.

A defining feature of Gemini was its nearly-horizontal attitude during landing, as required for its initial plan for a land landing at an air base under pilot control instead of an undignified parachute splashdown in the ocean. The paraglider, an inflatable triangular wing developed by Francis Rogallo of NASA’s Langley Research Center, was to replace the parachute used by Mercury, and a successful—and safe—landing required the pilot to initiate a “flare” maneuver just before landing, bleeding off speed by slightly lifting the nose of the capsule.

Figure 2. If the Rogallo inflatable wing had been used for Gemini landings, it would have looked like this test except with skids instead of wheels. (Photograph credit: North American Aviation and NASA.)
The Gemini capsule was to be tilted horizontally under the inflated Rogallo wing, permitting the astronauts to see the landing strip through their forward-facing windows. This meant that they were sitting upright under normal earth gravity, as in an aircraft, only a few minutes after leaving the weightlessness of orbital flight.  Orthostatic intolerance may be merely annoying on the deck of a recovery ship, but if it occurred while landing the Gemini capsule, then it could result in a crash, astronaut injury or worse.

Engineering problems eliminated the paraglider from the Gemini program in late 1964. The Mercury-style parachute was restored, with the capsule still suspended horizontally under the parachute, but at a slight nose-up angle to permit it to splash down on the edge of its blunt heat shield instead of flat on its widest face, in order to slice into the water to minimize the shock of impact. The critical piloting task was no longer a problem, but the astronauts would still be sitting nearly upright during parachute descent after two weeks of weightlessness, and then again while floating in the ocean for as long as it took to be rescued.

We routinely conducted pre- and post-flight tests on the astronauts during the Gemini program to measure their orthostatic intolerance by putting them on a “tilt table” that tipped them from horizontal to 70 degrees upright for 15 minutes while we recorded their heart rates and blood pressures every minute. This was among the earliest provocative testing done on astronauts returning from space, but not the first. In 1963, Gordon Cooper had 11 preflight tilt tests—including 5 prior to spacecraft checkout procedures and 6 following those procedures—and 4 post-flight tilt tests out to 19 hours after splashdown.

Figure 3. Dr. Charles Berry, director of space medicine, demonstrated the routine pre- and post-flight tilt test procedure for measuring heart rate and blood pressure during 70-degree tilt. (Photograph credit: NASA.)
NASA had assembled a large recovery team to go out on the aircraft carrier to pick up the Gemini astronauts. The recovery team included the Navy UDT swimmers, predecessors of today’s U.S. Navy Seals. They jumped from the recovery helicopter to assist the crew out of the capsule and into a life raft, so they could be hoisted into the helicopter using a “horse collar” rescue sling. If the astronauts were injured or required medical attention, they would instead be hoisted horizontally in a Stokes Litter Basket up into the helicopter, to be attended by a recovery physician en route back to the carrier. A group of medical specialists were stationed on board the carrier to conduct the postflight medical evaluations.

Figure 4. Astronaut Conrad was hoisted up into the recovery helicopter after Gemini 5 using the "horse collar" rescue sling. (Photograph credit: NASA.)
After Gemini 3 in March 1965, it was decided that, on future splashdowns, the physician in the helicopter should be able to jump with the frogmen in order to provide medical help immediately if required. However, the physician assigned to Gemini 4 indicated that he was not a very good swimmer and did not relish the idea of jumping into the ocean. The lead NASA recovery flight surgeon had to stay on the carrier. I, on the other hand, being a new, gung-ho flight surgeon with a background in competitive swimming and scuba diving, thought jumping out of helicopters with the UDT would be a great job.

Even though it was likely I would never actually have to jump, I was required to have some practice training. A colleague in the medical office told me the frogmen went out of the helicopter 40 feet above the water at a speed of over 20 knots—something that definitely required being in good shape. I was able to do some training jumps from a U.S. Coast Guard helicopter into the Gulf of Mexico near NASA. The pilot wanted to try 20 feet and 10 knots, but I insisted on 40 feet and 20 knots (and then talked him into increasing the speed close to 40 knots). It gave me quite a jolt, but I kept telling myself I could do whatever the UDT divers did. 

When I went out to the carrier for the Gemini 5recovery, I met the UDT team, men much larger than I and much younger than my 29 years. I was asked, “Have you ever jumped out of a helicopter?” When I responded, “Yes, I went out at 40 feet at 20 knots,” they were somewhat stunned: “You did what?” I learned that they usually went out much lower and slower.

Figure 5. Navy UDT divers with who I helped recover the Gemini 5 astronauts. (Photograph credit: personal collection of William Carpentier.)
Back on the carrier after the recovery, our testing showed that the Gemini 5 crewmembers were both significantly affected by eight days in space. During tilting, their heart rates soared and their blood pressure dropped. When we added these results to those from Gemini 3 and 4, we were concerned to see the astronauts’ orthostatic heart rates increasing and blood pressures decreasing as flights got longer. When extrapolated out to 14 days in weightlessness, a hand drawn graph predicted tilt heart rate increases of more than 100 beats per minute above supine resting rates which averaged over 85 beats per minute. There was no way an astronaut could maintain that kind of heart rate during a tilt test, or, by extension, any other orthostatic stress, perhaps not even sitting upright for a long period in the floating capsule. 

Figure 6. My hand-drawn graph of the increasing trend in heart rate with increasing Gemini flight durations predicted a heart rate after a 14-day flight that was 105 beats per minute higher than preflight—an unsustainable increase. (Photograph credit: personal collection of William Carpentier.)
Earth-based studies suggested that orthostatic intolerance resulted from an actual decrease in measured blood volume. This was borne out by tests on the Gemini 4 and Gemini 5 astronauts. We measured reductions in both their volume of plasma (the liquid part of blood) and their number of red blood cells. Based on our measurements of the astronauts’ calf circumference, we also determined that increased pooling of blood in the legs was at least part of the reason for the Gemini 5 results.

Gemini 7, which was scheduled to last 14 days in December, was my major concern. Although the Gemini 5 astronauts had returned to normal within 2 to 3 days, I was most concerned about the data from their first few minutes and hours back on earth, especially because previous Gemini spacecraft had landed a considerable distance from the carrier; Gemini 5 had been about 90 nautical miles away—about an hour by helicopter.

As the physician member of the team that was going to have to rescue this crew if they should be incapacitated, I was incredibly concerned how we were going to get them out of the spacecraft, into the helicopter, back to the carrier and into sick bay. I had a vision of me, a newly qualified flight surgeon, with three frogmen and two unconscious astronauts an hour away from the aircraft carrier and additional medical help. 

Figure 7. This photograph from a training session illustrates the challenges involved in providing medical care to incapacitated astronauts on a raft in the ocean. (Photograph credit: personal collection of William Carpentier.) 
So I did a lot of practicing with the UDT, trying to work out the best method of getting the crew out of the spacecraft and onto the life raft, and also work out some way to do cardiopulmonary resuscitation on a pliable raft in 6-foot seas. 

Figure 8. These photographs show me jumping from the recovery helicopter in a practice session, lower than 40 feet and slower than 20 knots. (Photograph credit: personal collection of William Carpentier.)
I also told the Gemini 7 commander, Frank Borman, “When you land, don’t just sit there and let the blood pool in your legs. You’ve got to keep your feet moving, keep your legs moving, and keep your blood pumping upward until we can get you out of there.” In a later television interview, Borman commented, with some astonishment, that some people were afraid the crew was going to faint. I was certainly one of them.

Although neither astronaut fainted during the recovery, one did faint during a tilt table test about an hour after splashdown, but the other, tested about two hours after recovery, did not. In fact, his tilt test showed him to have a lower heart rate than either one of the pilots who were in space for only eight days. I was greatly relieved because this finding demonstrated that orthostatic intolerance didn’t inevitably continue to get worse over time—in fact, it appeared to level off as the missions got longer, and was also very variable among individual astronauts. With this new data, we concluded 1965 with confidence that astronauts could complete the longest planned Apollo mission.

Although I did numerous jumps during training and practice exercises, medical assistance was never necessary for any crewmember during actual recovery operations. They remained conscious, not only throughout the whole parachute and floating periods, but also while being hoisted up to the recovery helicopter using the rescue sling that supported them under the arms and left their legs dangling free—an ideal way to cause fainting. (The crew of Gemini 6 and Gemini 9 elected to stay in the spacecraft and be hoisted aboard the carrier using a crane. The Gemini 8 crew climbed up a cargo net to board their recovery vessel.)

The Gemini data showed that the decreased blood volume was highly related to weight loss as was the increased heart rate and decreased pulse pressure. There was considerable weight loss variability among crewmembers, and factors other than duration of weightlessness must be considered. This would include caloric intake versus energy expended. It would also include fluid and electrolyte intake versus fluid and electrolytes lost in the urine plus sweating as well as insensible loss which may vary secondary to the dryness and warmth of the environment, especially while suited. The Gemini 7 astronauts were the only ones who were issued light-weight spacesuits that could be doffed in-flight, a capability that greatly enhanced their comfort and that they recommended for future missions. 

Figure 9. I took this photograph of James Lovell being hoisted to the recovery helicopter after Gemini 7 using the horse collar rescue sling, still wearing his light-weight space suit. (Photograph credit: NASA and personal collection of William Carpentier.)
I went out to the carrier for Gemini 5, 6 and 7 as an assistant recovery physician, and then as the lead for Gemini 9, before transitioning to Apollo medical operations and planning. At the end of the Gemini program, I believed that there was still much to learn and that further comprehensive quantitative biomedical measurements should be made on Apollo to gain a better understanding of the effects of spaceflight on human physiology prior to landing on the moon. As for the astronauts, they believed they could take anything that was thrown at them. And, almost always, it was true.

Monday, December 29, 2014

Going Nuts in Orion to Mars?

The successful Orion test flight in early December focused attention on the Orion capsule’s role in future NASA missions beyond low earth orbit. Much of the discussion on the Internet has dealt with the necessity of Orion at all, and whether it could be replaced by one of the commercial crew vehicles NASA recently funded.

The on-line discussion is frequently sidetracked by the all-too-common misunderstanding that Orion will be the sole habitat for 4-6 astronauts on the 2-3 year Mars mission. I Googled “orion mars” and found a comment to a Gizmodo article wondering how 5 or 6 astronauts could spend months in such a tiny capsule heading for Mars—it was posted 2 days after the Orion test flight!

The short answer is: nobody expects anything of the sort. Orion is the astronauts’ taxicab from the launch pad in Florida to the Mars transit vehicle in earth orbit at the start of the mission, then again and most importantly for the high-speed entry into earth’s atmosphere at the end of the mission (see figure 1). This is well-established in the NASA Mars Design Reference Mission that describes the general characteristics of the 100 thousand pound habitat (ref. 1).
Figure 1. Mars mission scenario. See Orion's major usage at steps 7, 9 and 14

However, the misunderstanding was a central feature of the movie “Capricorn One” (1978) (ref. 2). This fictional story of a hoaxed Mars mission includes the image of the three astronauts spending long months inside their cramped Apollo command module en route to Mars.

The movie used accurate mockups of the Apollo capsule, the lunar lander and the space suits, very familiar to TV viewers from the moon landings only a few years earlier, but largely irrelevant to the Mars mission being portrayed. The producers knew that such familiarity could enhance the credibility of their story, encouraging the audience’s willing suspension of disbelief.  The bizarre tale of a faked mission and a government cover-up that required the (spoiler alert!) murder of the astronauts themselves would then have seemed even more thrilling. 

But surely (I thought), no one could seriously believe that NASA would send highly-trained astronauts in peak physical condition on a multi-month trip to Mars in just an Apollo capsule, with no room for exercise or privacy, any more than that they would land on Mars using an unmodified, non-aerodynamic Apollo lunar module.  After all, the movie was an action adventure, not a documentary. 

Apparently I was wrong.  Now, over three decades later, when I lecture on the medical aspects of NASA’s planned exploration-class missions to Mars, lay and professional audiences alike still ask how the astronauts could really stay in such a small capsule for such a long flight without going nuts.  Of course, why should they know any better?  The Apollo astronauts went to the moon inside the command module, so why not all the way to Mars?  If the Mars trip takes 60 to 100 times longer, maybe it is just the price that the astronauts have to be willing to pay.  After I explain that the Mars transit vehicle would be much larger and roomier, everyone seems relieved that NASA wouldn’t be so inconsiderate of its high-value crewmembers. 

What is more surprising is how many space professionals also have that misunderstanding. Even NASA insiders were confused in 2004 when the Crew Exploration Vehicle, or CEV, was announced, whether it was the Mars transit craft that would house the six astronauts for the half-year transits to and from Mars, or just the capsule they rode in from Earth to the transit vehicle.  This confusion was exacerbated by the name: if it was just the taxicab, why was “exploration” part of its name? 

Back in October 2007, I lined up with NASA Johnson Space Center workers who waited patiently for a chance to sit inside the new, low-fidelity Orion mockup.  It was in the configuration with six seats, one of which was occupied by mannequins and another left empty.  When four of us—all space professionals but not engineers—were seated inside it, marveling at the close quarters, it quickly became clear that three of us actually thought this was the condition in which the six-person crew would make the six-month trip to Mars!

After a lecture at a space life sciences conference in February 2008, a long-time NASA employee—also not an engineer—confessed his relief that the crew wouldn’t be cooped up in the Orion for the long trip to Mars. Other NASA science managers have wondered the same thing, judging from comments I have frequently heard.

Not surprisingly, it is not just NASA people that are confused.  A well-informed science writer asked me the question during an interview some years ago.  About the same time, a retired astronaut sheepishly admitted that he thought the same, but added that he hadn’t kept up with the Mars vehicle design details.  I have also read a comment by a respected leader of a space advocacy organization who wondered how Orion’s life support system would support a crew en route to Mars.

Apparently the misunderstanding predates even Capricorn One. In 1966, Eric John Bishop felt it necessary to describe his work designing an underwater training mockup of what became the Skylab space station as supporting the development of a large vehicle for planetary missions, because the astronauts couldn’t be expected to stay in the Apollo for such a long durations (ref. 3).

In 2006, NASA gave the name Orion to the CEV, and in 2011 the acronym CEV was replaced by MPCV for Multi-Purpose Crew Vehicle. Exploration was gone from the moniker but not from its mission; in fact, Orion was specifically focused on atmospheric entry at interplanetary speeds, and thus over-engineered and overpriced for anything less, as NASA managers have publicly confirmed. But the confusion remains.

Why do so many people seriously think that NASA would confine half a dozen astronauts in such a small space for six months or longer?  Why does that seem even remotely possible, let alone acceptable, to anyone who has imagined the effects of such confinement on the crew’s mental and physical health and on mission success? 

Part of the answer is probably unfamiliarity with the realities of long-duration spaceflight, at least among the general public. Another possibility became clear during the Orion flight test. Orion was described by the press as the vehicle that will take astronauts to the asteroids and Mars. Message boards were overflowing with confusion on that point. The official Orion fact sheet describes it as “this new spacecraft [that] will take us farther than we’ve gone before, including Mars” (ref. 4). And the Fall 2014 issue of Roundup (ref. 5), the self-described official publication of the Johnson Space Center, has a cover image of what is clearly a late-model design for Orion with what is clearly Mars in the background and with what is clearly no other vessel nearby (see figure 2). This constitutes an official graphic statement that Orion will at least operate near Mars alone, in direct contradiction to all NASA Mars DRM planning! Thus, NASA’s own messaging is misleading.

Figure 2. NASA Johnson Space Center Roundup showing Orion spacecraft all alone in Mars orbit.

That such a central feature of the NASA’s exploration architecture is so poorly grasped is troubling as well as surprising.  NASA has released high-quality animations of lunar and Mars mission scenarios, which are available on agency websites and on YouTube.  Program officials and industry experts have described the architecture in public presentations around the country. Still the misunderstanding persists.

Space flight sometimes seems inherently mystifying. For example, the physics of weightlessness are a mystery to many people who have never experienced it, and are frequently misrepresented in movies.  But most people working in space development venues do not require more than a passing knowledge of such things.  They understand enough to do their jobs well, and they leave the rest to other specialists. 

Human exploration of space promises great benefits but only at great risk and great expense. Any meaningful public debate of the costs and benefits should be based on reality, not misunderstanding.

  1. Drake, Bret G. (editor), Human Exploration of Mars Design Reference Architecture 5.0 (NASA/SP-2009-566), NASA, Washington, D.C., 2009, (accessed Dec. 23, 2014). See “bat chart” on page 5, and Mars Transit Vehicle description on p. 36.
  2. Capricorn One (, accessed Dec. 8, 2014).
  3. Bishop, E.J. Brooklyn, Buck Rogers and Me. iUniverse, Inc., 2003, (accessed Dec. 23, 2014).
  4. Orion spacecraft overview, NASA, 2012.  (, accessed Dec. 8, 2014).
  5. Roundup, Fall 2014, (accessed Dec. 23, 2014).

Monday, December 22, 2014

A Tale of Two Martins

Back in 2008, while trolling for obscure space history trivia in back issues of Aviation Week, I found a good one from 1965: a black and white illustration (figure 1) from The Martin Marietta Corporation of a lifting body rescue vehicle coming to the aid of an Apollo spacecraft that had somehow become stranded in low Earth orbit (ref. 1).  The rescue vehicle had an attached service module, and both the lifting body and its service module were labeled NORS, which I recalled from somewhere stood for National Orbital Rescue Service.

Martin developed the “SV-5” lifting body shape (ref. 2),  which the U.S. Air Force flight-tested as the X-24A in the early 1970s (ref. 3).  NASA applied the concept to its X-38 Crew Return Vehicle, evaluated as an attached rescue vehicle for International Space Station astronauts before it was cancelled in 2002 (ref. 4).  There are other shapes for lifting bodies, such as the Dreamchaser spacecraft now in development by Sierra Nevada Corporation (ref. 5).

Figure 1. Astronaut from a SV-5 lifting body rescue vehicle coming to the aid of an Apollo spacecraft in low earth orbit. Credit: Martin Marietta Corp., 1965.

Figure 2. Astronaut from a SV-5 lifting body rescue vehicle coming to the aid of an Apollo spacecraft in low earth orbit. Credit: Columbia Pictures, 1969.
Compare that image to the color photo (figure 2) that is a press release from Columbia Pictures for the movie, Marooned, released in December 1969 (ref. 6).  It shows the climactic scene from the movie. The similarity is striking, but maybe not a coincidence. Martin Caidin, the author of both the 1964 novel Marooned—in which a stranded Mercury astronaut is rescued by his best friend flying the new Gemini spacecraft—and the 1969 up-dated novel-of-the-movie and also a technical consultant for the movie, certainly read Aviation Week and would have seen that Martin Marietta concept artwork. Caidin may have been struck by the familiar space-rescue theme, and recalled it when he revised his novel for a movie. Maybe this is a peek behind the movie-magic curtain.

On closer inspection, the Martin Marietta concept’s service module appears to be a Gemini capsule and adapter section, which in 1965 was the new spacecraft built by another company, McDonnell. It seems to have Gemini-style windows and open right-side crew hatch as well as its general shape. It is impossible to tell from the picture, but perhaps Martin imagined that the nose section of the Gemini containing the parachutes and the re-entry maneuvering thrusters could be eliminated entirely and the remainder of the spacecraft bolted directly to the lifting body, to be disposed of before re-entry. It is unusual to see a company explicitly subsume another company’s product, but Martin provided the Titan boosters for the Gemini capsules and the company’s artist may have felt comfortable enough with it to use Gemini in the supporting role.

Martin Caidin (1927-1997) was an American author and authority on aviation and astronautics and an accomplished pilot (ref. 7).  He described his involvement with the Mercury and Gemini programs as “a government consultant, newsman and broadcaster” (ref. 8).  I didn’t read much of his aviation work in my youth, but I have vintage hardcover editions of his spaceflight novels Marooned (1964), No Man’s World (1967), Four Came Back (1968), Marooned (updated for the movie, 1969) and The Cape (1971) (ref. 9).  As an adolescent space geek at a time before the Internet provided abundant space information, I read Caidin’s books as contemporary technical fact with a heavy overlay of human drama. Today I can re-read them to recapture the zeitgeist of outer space as Cold War battleground, its single-combat victor not yet determined.

In his later years, Caidin claimed the power of telekinesis although he declined invitations from well-known debunker James Randi to be tested in controlled circumstances (ref. 10).  The non-telekinetic aspects of his lifestyle were manifested in his writing style—sort of Dashiell Hammett for the Space Age. Marooned (ref. 11),  in particular, appealed to me because of its high technical accuracy and gritty realism in describing the Mercury and Gemini programs: the 1964 novel has eleven appendices listing the technical data, calculations, etc., substantiating the action in the novel. Caidin liked to say that Mercury astronaut Wally Schirra found only one technical error in the book but never divulged what it was, so he could always stay one step ahead of the author. Schirra was a prankster and it would have been typical of him to tell Caidin something like that just to keep him guessing.

Caidin’s technical accuracy and ability to put his characters in real-world dramatic situations had a direct influence on actual space progress on at least two occasions. Deke Slayton gave Caidin’s movie treatment some of the credit for helping to thaw the Cold War enough for his own overdue flight to dock with the Soviets(ref. 12):
Oddly enough, one of the things that moved the joint flight closer to reality was a fictional movie called Marooned, based on a novel by Martin Caidin. In the original version, published in 1964, a Mercury-Atlas 10 astronaut is rescued by a Soviet cosmonaut. The movie had been updated (and Caidin wrote a new novel version as well) showing how a Skylab crew might be saved by a Soviet Soyuz pilot. 
The movie never made much money in the United States, but it apparently impressed the Soviets that Americans were ready to consider international flights—especially to demonstrate the concept of space rescue.
The original version Slayton mentioned also had an influence on reality, even more directly than its eventual movie successor, which really only encouraged an international technical project that was already in progress. When the novel was published in mid-1964 (ref. 13),  NASA was preparing to send two-man astronaut teams into orbit aboard the new Gemini spacecraft. By mid-December, just a few months before the first manned Gemini flight, NASA managers directed that mission procedures be modified to avoid the Marooned scenario if the retrorockets failed.

In January 1965 (ref. 14),
…NASA Headquarters sent Flight Operations in Houston a set of preliminary data, with orders to revise the flight plan to protect the Gemini 3 crew against the […] the failure of spacecraft retrorockets to work, stranding the crew in space. Headquarters proposed three OAMS [Orbital Attitude and Maneuvering System] maneuvers to place the spacecraft in a "fail safe" orbit, one from which it would reenter whether the retrorockets fired or not. Actually, Gemini orbits were too low to be permanent, so spacecraft reentry was inevitable. What the fail-safe maneuvers were designed to achieve was the spacecraft's return promptly enough to ensure that the crew survived. [That is, before their oxygen ran out.] Coming as it did less than three months before the planned launch, the new demand threw mission planning into turmoil. But the response was rapid. A revised tentative flight plan was ready in little more than a month, and the final plan followed on 4 March.
NASA planners were capitalizing on the fact that Gemini was the first spacecraft equipped to translate, that is, to maneuver by speeding up and slowing down to change the shape of its orbit around the earth, using its OAMS.  (Of course, every spacecraft the braked out of orbit and landed on Earth was “translating” but that was an irreversible maneuver to lower its orbital altitude to intersect with the atmosphere.)

The conservative, Marooned-inspired belt-and-braces approach was used again on Gemini 4, but then discarded after experience demonstrated that retrorockets were as reliable as the engineers had always said they were. In fact, there were never any failures among the six dozen solid-fuel retrorockets used in sets of three on Mercury spacecraft and in sets of four on Gemini.

Nor were there any failures among the six Apollo spacecraft that flew Earth-orbit missions and used their large, aft-mounted liquid-fueled engines to deorbit; if there had been, they all could have used their side-mounted maneuvering engines to do so. This was the scenario in the movie, but was glossed over lightly to provide the dramatic impetus for the rescue scenario.

In fact, the more likely failure was to orient correctly during the retro maneuver. In 1960, the first test version of the Soviet Union’s Vostok spacecraft accidentally raised its orbit by nearly 250 miles (400 km) because it was oriented nose-forward instead of nose-backward when its single-use liquid-fueled braking engine was fired (ref. 15).  Its two components, the landing capsule and the service module, continued orbiting until 1962 and 1965, respectively. In 1962, the second manned Mercury orbital spaceflight landed 250 nautical miles (460 km) beyond its target due to a combination of misalignment, delayed initiation and underthrust (ref. 16).

Caidin was directly involved in one more non-telekinetic crossover between fiction and reality. In the movie of Marooned, he appeared in a cameo as a radio reporter describing the arrival of the lifting body at Cape Canaveral for its launch on the rescue mission. The fictional news event he was describing on film was the movie manifestation of the 1965 artwork that may have inspired his update of Marooned, which then positioned that movie to influence the course of the first joint American-Russian space mission a decade later.

  1. Photograph caption, Aviation Week, Oct. 18, 1965, p. 69.
  2. Reed, R. Dale, with Darlene Lister, Wingless Flight, The Lifting Body Story, NASA SP-4220, NASA, Washington, D.C., 1997.
  3. “Martin-Marietta X-24A”, (accessed Dec. 13, 2014).
  4. “NASA X-38”, (accessed Dec. 13, 2014).
  5. Described in “Commercial Crew Development”, (accessed Dec. 13, 2014).
  6. “Marooned (1969)”, (accessed Dec. 12, 2014).
  7. “Martin Caidin”, (accessed Sep. 27, 2014).
  8. Caidin, Martin, Marooned, E.P. Dutton and Co., New York, 1964, acknowledgments, p. 359.
  9. “Martin Caidin summary biography”, Internet Speculative Fiction Database, (accessed Oct. 2, 2014).
  10. “Martin Caidin”, (accessed Sep. 27, 2014).
  11. “Marooned (novel)”, (accessed Dec. 15, 2014).
  12. Slayton, Deke, with Cassutt, Michael, Deke, Forge Books, New York, 1994, p. 277.
  13. I don’t know the date when the novel was first published, but it must have been about mid-year because it was reviewed in the October 1964 issue of The Magazine of Fantasy and Science Fiction according to “Martin Caidin summary biography”, Internet Speculative Fiction Database, (accessed Oct. 2, 2014).
  14. Hacker, Barton C., and Grimwood, James M., On the Shoulders of Titans: A History of Project Gemini, NASA Special Publication 4203, Washington, D.C., 1977, pp. 228-9. See note 32, memo, Hall to Schneider, "Interim Status Report on Decay Safe Orbits," 11 Dec. 1964.
  15. “Korabl-Sputnik 1”, (accessed Dec. 10, 2014).
  16. Results of the Second United States Manned Orbital Space Flight May 24, 1962, NASA SP-6, NASA, Washington, D.C., 1962, (accessed Dec. 22, 2014).

Sunday, April 20, 2014

The primary cilium cannot sense the moon's gravity (sorry, you'll have to read the intro to learn more)

A physiologist interested in the effects of gravity on biological process, such as I, must understand how living organisms transduce those effects. In my favorite organism, the human body, there are many avenues for such transduction. At the scale of a meter, the weight of the limbs on the joints is readily sensed in even the most casual of circumstances. The weight of the extended column of bodily fluids as it distends tissues and organs is only slightly subtler, but dramatically noticeable when one hangs upside down by the ankles. At the scale of centimeters, there are the organs of balance, which are collections of cells forming the vestibular system that is specifically sensitized to both static gravity and induced acceleration (which Einstein told us is indistinguishable from gravity). 

But some biologists are interested in the effects of gravity at the cellular level, and ask whether a single cell, with a dimension measured in millionths of a meter, can sense gravity independently. There are structures within the cell that might be sensitive enough, but in a normal living cell, the gravitational stimuli would be overwhelmed by non-gravitational stimuli such as thermal agitation.  Determining gravitational sensitivity in isolated single cells requires carefully controlled, well-designed experiments. Unfortunately, some biologists interested in this topic don’t understand the physical phenomena involved (just as some physicists don’t understand biological systems).

In 2009, I read an article in the journal Developmental Dynamics that claimed to demonstrate the gravitational sensitivity of single nerve cells from the developing spinal cord of the zebrafish. I cannot challenge the authors’ knowledge of neural cell physiology, but their interpretation of the physical phenomena involved was in error. Some colleagues (Maneesh Arya and Susan Steinberg) and I drafted a letter to the editor of that journal explaining the errors, but the journal does not print letters to the editor (1).  The editor recommended a full article, which we were not able to undertake.

So, there it ended, with a flawed experiment unchallenged in the published literature. In the interest of making this discussion slightly more public and discoverable on the Internet, I decided to put it here in my blog:

This is all you need to know about the primary cilium for this article.
To the Editor, Developmental Dynamics

I have pondered the article, “The primary cilium as a gravitational force transducer and a regulator of transcriptional noise” (Moorman and Shorr, Dev. Dyn. 2008, vol. 237, pp. 1955-9), for well over a year now, troubled that my understanding of several points of gravity and its influence did not seem to match that of the authors, as detailed on pages 1957-8.  

The authors seem to report that isolated cells in culture can detect changes in ambient earth-surface gravity environment due to the passage of the moon and the sun overhead.  They reported a clever and imaginative comparison of neurogenin-3.1:gfp (ngn3.1:gfp) expression in the Rohon-Beard neurons of the developing zebrafish spinal cord at the times of the local high and low tide as evidence of an influence of the moon’s gravity on ngn3.1:gfp expression, presumably mediated through the primary cilium (2). Their report, while recent, already seems to be becoming accepted by others who cite their findings without further question (3, 4).

Unfortunately, their assertions regarding lunar and solar gravity at earth’s surface are flawed (5).

The authors are correct that the effective gravity at earth’s surface is not quite constant.  In addition to extremely small regional and latitudinal variations, there is indeed the influence of the gravities of the sun and the moon.  

However, the authors mischaracterized the dominance of the moon in generating earth’s oceanic tides as being due to its gravitational pull on objects at earth’s surface. Instead, the tides are actually due to the greater gradient (e.g., decrease with distance) of the Moon’s gravitational force across the width of the earth than that of the sun.  

The tides in the Raritan River near the authors’ laboratory are not reliable indicators of the moon’s gravitational influence in New Brunswick, NJ.  High tides recur at 12.42-hr intervals, first when the moon is above the horizon, and its gravitational influence opposes earth’s downward pull—and again 12.42 hr later when the moon is on the other side of the earth, and its influence would augment earth’s downward pull.  Thus, any randomly selected high tide might be associated with either lunar gravity adding to or subtracting from earth’s surface gravity environment. Low tides occur at the halfway points between successive high tides, so the moon’s gravity influence should be at some intermediate value, neither greatest nor least.

In addition, local high and low tides may be offset from the overhead passage of the moon by many hours.  For example, in New Brunswick on Aug. 15, 2010, moon transit—when the moon was highest overhead and its gravitational influence should have been greatest—was at 17:55 EDT (6) while local high tide was 7.9 hr later (7).

A more appropriate indicator of lowest effective gravity level might be the time of the moon’s transit overhead, when its gravity acts opposite to earth’s; highest effective gravity level might then come 12.42 hours later when the moon is on the opposite side of the earth and its gravity sums with earth’s, which may be calculated as 9.81 m•s-2, defined here as 1.0 G.  In this highly-simplified example, the variation in effective gravity due to the moon’s influence would 0.000034 m•s-2, approximately 0.0000035 G (3.5 micro G), over a period of 12.42 hr, due to the earth’s apparent daily rotation under the moon.  Note that even in this simplified, optimized case, the Rohon-Beard neuron would be required to detect a variation in earth’s surface gravity of one part in 300,000 occurring gradually over more than 12 hours!

The sun’s influence on earth’s surface gravity environment is much greater.  In the simplified case of the Rohon-Beard neuron on earth’s surface directly on a line between earth’s center and the sun, the “weight” sensed by the primary cilium would be greatest when it is on the side of the earth directly opposite from the sun (e.g., at local “midnight”), and thus subject to their summed gravitational pulls, and it would be least when it is directly between the earth and the sun (e.g., “noon”).  At midnight, it would be subject to the sum of earth’s surface gravity plus the sun’s effective gravity at the distance of the earth from the sun, 0.0059 m•s-2, or approximately 0.0006 G (600 micro G); the sum is 1.0006 G.  At noon, it would be subject to the difference, or 0.9994 G.  In our simplified example, the neuron would be subject to this solar variation in effective surface gravity of 0.06% on either side of the average of 1.0 G repeatedly at 24-hr intervals.

Note that the moon’s gravitational influence would be 1/176th of the sun’s, and periodically in phase and out of phase due to its monthly motion relative to the earth.

Thus, Moorman’s and Shorr’s reliance on local tidal occurrence as indicators of greater or lesser lunar gravity at earth’s surface for comparisons of gene expression at high tide and low tide is flawed in at least four respects: 
  1. being timed to the influence of the far weaker of the two supposed gravitational influences (e.g., the moon instead of the sun)
  2. overestimating the supposed lesser lunar influence at low tide which would actually be of an intermediate value
  3. assuming that any particular high tide reflected the greatest lunar influence when it might very well have been the weakest, depending on whether the moon was above the horizon or below at the time of high tide, and 
  4. neglecting a multi-hour lag between the passage of the moon over the laboratory and the occurrence of high tide.  

The entire foregoing discussion assumes that the primary cilium of the Rohon-Beard neuron could even detect the gravitational influence of the moon or the sun.  However, the estimated variation of less than 6 percent of one percent is much less than other ambient influences acting upon the neuron, including thermal, vibrational, atmospheric pressure and others.  A 70-kg laboratory technician approaching to within 4 cm of the cell culture before receding again while periodically tending the culture would provide almost as much gravitational influence as the moon!  Modern gravimeters are more than capable of such sensitivities, but they are much more massive than the Rohon-Beard neuron and may require magnetic suspension and liquid helium cooling to eliminate extraneous environmental signals (8).

Even if possible, reliable detection of such a small signal-to-noise ratio would probably require prolonged integration of the signal.  Melvill Jones and Young (9) have proposed that the gravity sensors of the mammalian vestibular system do not signal detection of acceleration until sufficient acceleration has occurred to produce a threshold velocity of approximately 0.20 m•s-1 (recalling that velocity is the integral of acceleration).  Arbitrarily assuming a comparable velocity threshold in the primary cilium of the Rohon-Beard neuron exposed to the moon’s gravitational attraction (0.000034 m•s-2) on earth’s surface, the neuron would need nearly 5,900 seconds (over 1.6 hr) for detection, assuming the force is provided completely and continuously, instead of increasing and then decreasing over a period of many hours.

The authors propose a clever test of their observation of the influence of extraneous gravitational variations by use of a technique they refer to as “gravity clamping.”  Unfortunately, this technique is not further described, but must be assumed to involve centrifugation, as there are no other techniques to increase gravity at earth’s surface by 10% for an extended period of time.  However, centrifugation at 1.1 G would merely increase the background level against which the supposed variation would occur by 10%, since there is no such thing as a “gravity shield” to exclude the presumed influences of the moon and the sun in the authors’ laboratory.  Rotation of the cells during centrifugation would have continually rotated their orientation with respect to the external environment, which might have been responsible for the reported effects if those effects could have been demonstrated convincingly.  An additional control, perhaps using a laboratory test-tube rocker to randomize cell orientations without the putative gravity-clamping confounder, might have produced the same result. 

In short, the authors’ assumptions about the presence of a gravitational perturbation for the primary cilium to transduce appear to be unsupportable and their measurements not well controlled.

Then there is the role of the primary cilium of the Rohon-Beard neuron as a gravitational force transducer.  The authors calculated the approximate shear force that would be applied to the cell’s primary cilium by the assumed cyclic changes in earth’s gravitational field.  They calculated the mass of a 10-micro-m diameter cell by multiplying its spherical volume, 523.6 micro-m^3, by the density of water, which they did not state but which I provide as 10-12 g•micro-m^-3 (i.e., 1 g•cm^-3).  The cell’s mass is thus 5.24x10^-14 g, or 5.24x10^-17 kg—one-millionth of the value calculated by Moorman and Shorr.  Thus, earth’s gravitational force on a single cell is 5.24x10^-17 kg  X  9.81 m•s-2, or 5.14x10^-16 N, a factor of 10 less than the sensitivity of the primary cilium reported by Resnick and Hopfer (10) and cited by the authors.

But even if the sensitivity was appropriate, any such stimulation of the primary cilium would require the capacity for its relative displacement with respect to the cell body—such as embedding the free end of the cilium in a large mass other than its own cell body, so that the presumed gravitational variations could physical displace either the cell body or the cilium but not both.  The authors describe no such mechanism, but it is the subject of at least one recent report (11). 

Finally, the authors find evidence of a gravitational effect on cells in culture through, not their altered rates of gene expression, but their increased variability in gene expression at local high tide, a time of supposedly reduced gravity on earth due to the moon’s pull.  However, they did not hypothesize that such variability would result, and gave no reason why it was a logical or meaningful result from such exposure.

For these reasons, Moorman’s and Shorr’s results cannot be accepted as supporting any gravitational force transduction role of the primary cilium of the Rohon-Beard neuron of the developing zebrafish spinal cord, and, by extension, a direct gravitational effect on any single cell that depends on a mechanism ascribed to the Rohon-Beard neuron.  That is not to say that such an effect may not exist, nor that it could not explain many of the observed responses to weightlessness of biological specimens ranging from isolated cells in culture to intact higher mammals.  But, there is ample justification for most—if not all—of the observed effects of hypo- and hypergravity on complex biological systems to be derived from the influence of gravity on multicellular organ systems at a macroscopic level.  

Extraordinary claims require extraordinary evidence; unfortunately, the evidence provided by Moorman and Shorr does not suffice.

Key words: primary cilium, Rohon-Beard, zebrafish, neurogenin-3.1:gfp (ngn3.1:gfp), gravitational transducer, Moorman, Shorr, Developmental Dynamics, high tide, low tide, lunar tide, solar tide, Raritan River, New Brunswick, Melvill-Jones, gravity clamp

  1. See
  2. Primary Cilia: the sensory organs of our cells?, accessed Apr. 20, 2014.
  3. Satir, P., Pedersen, L., and Christensen,S.  The primary cilium at a glance.  J. Cell Science 123, 499-503 (2010)
  4. Alaiwi, W., Lo, S., and Nauli, S.  Primary cilia: highly sophisticated biological sensors. (Review.)  Sensors 9, 7003-7020 (2009).
  5. I have relied on NASA’s Cosmicopia webpage (, accessed on August 14, 2010) for most of the geophysical background information used in this letter.
  6. Source: U.S. Naval Observatory,, accessed Aug. 14, 2010.
  7. Source: Mobile Geographics,, accessed Aug. 14, 2010.
  8. Source: Gravimeter,, accessed Aug. 17, 2010.
  9. Melvill Jones, G., and Young, L. R.  Subjective Detection of Vertical Acceleration: A Velocity-Dependent Response?  Acta Oto-Laryngologica 85(1): 45-53, 6 January 1978.
  10. Resnick, A., and Hopfer, U.  Force-response considerations in ciliary mechanosensation.  Biophys. J. 93: 1380-1390, 2007.
  11. Blanco, C., Drayer, I., Kim, H., and Wilson, R.  Mathematically modeling chondrocyte orientation and division in relation to primary cilium, published online at, August 6, 2010.