1. SEX IN SPACE

Performance of the sex act during a journey to Mars, may require potentially complex sexual gymnastics. On the other hand, any difficulties associated with sexual intercourse in space may turn out to be an easily solved problem of docking and entry as human are notorious for inventing ways of having sex despite all manner of logistical impediments (Joseph 2000a). However, what impact will sexual activity have on team dynamics and morale? And what if an astronaut became pregnant during the journey? Would the fetus be viable? How would this impact the crew?

NASA has no policy regarding sex in space and its repercussions (Office of Audits, 2010), other than to request, in 2008, that astronauts voluntarily abide by an "Astronaut Code of Professional Responsibility" and maintain "a constant commitment to honourable behaviour." As summed up by the NASA Astronaut Health Care System Review Committee (NASA 2007), "the absence of a code of conduct and its enforcement, and the lack of management action to limit inappropriate activity increases the likelihood of aberrant behaviour occurring and decreases the likelihood of such behaviour being reported." According to NASA's review committee (NASA 2007), and a panel of experts assembled by the National Academy of Science (Longnecker and Molins 2006), this is a serious oversight: if male and female astronauts share a cramped space ship for years, surrounded by stars blazing in the blackness of night, thoughts are bound to turn to sex and romance. Thus, "ignoring the potential consequences of human sexuality is not appropriate when considering extended-duration missions" (Longnecker and Molins 2006), and this includes a human mission to Mars.

2. BIOLOGICAL DESTINY: SEX AND PREGNANCY

Biologically, females serve one purpose: to get pregnant (Joseph 2000a, 2001a,b, 2002). However, the human female is also the only female regardless of species, who is sexually receptive at all times and who has evolved secondary sexual characteristics, e.g. the enlarged breasts and derriere, which signal to males and females alike, her sexual availability (Joseph 2000a,b). Almost all non-human primate species that exhibit genital and breast swelling live in multi-male groups and they only develop these secondary sexual characteristic when sexually receptive (Clutton-Brock and Harvey, 1976; Fedigan, 1992; Wallis, 1992). These swellings serve to attract males and to arouse male sexual interest when the female is in estrus (Carpenter, 1942; Chevalier-Skolnikoff, 1974; Fedigan, 1992; Ford & Beach, 1951; Zuckerman, 1932) and the same can be said of the female human derriere and breasts which have evolved and increased in size over the course of human evolution so as to signal continual sexual availability (Joseph 1985, 2000a,b). Moreover, the human female has evolved the cognitive and intellectual capacity to employ cosmetics, perfumes, colorful clothing, push up bras, high heels, and so on, which draw attention to her breasts and derriere, and which emphasize and exaggerate her sexual availability by mimicking the signs of estrus common in other social primates (Joseph 2000a,b). And just as female primates and other female mammals seek sex with high status males whom they most prefer (Allen & Lemmon, 1981; Carpenter, 1942; Chevalier-Skolnikoff, 1974; Fedigan, 1992; Ford & Beach, 1951; Zuckerman, 1932), the same can be said of the human female (Joseph 2000a,b).

3. PREFERENCE FOR HIGH STATUS SEX PARTNERS: ASTRONAUTS

Like other mammals, human females are "choosy" and prefer sex with high status males who can offer prestige and resources (Buss, 1994; Betzig, 1985; Betzig et al., 1988; Symons, 1979; Townsend, 1989). Like their human female counterparts, nonhuman primate females, such as baboons, rhesus, and chimpanzees, prefer and have sex with high ranked males and avoid lower ranking and in particular, the lowest ranked males (Carpenter, 1942, Hausfater, 1975; Lancaster, 1978; Seyfarth, 1977; Smuts, 1987; Tutin, 1975; Zuckerman, 1932).

The Antarctic has long been viewed as an excellent analog for long-duration space missions and the same preference for high ranking males has been observed (Stuster 1996). Female crew members seek sexual intimacies with senior, high status personnel to the exclusion of the other men.

Moreover, female primates will emphasize their sexual availability and may actively pursue desirable males (Fedigan, 1992). Hence, not surprisingly, male astronauts are often targeted by females who have emphasized their sexual availability (Mullane 2007).

As related by former Shuttle Astronaut Mike Mullane (2007), male astronauts are commonly flown all over the U.S. to locations where they often attend coctail receptions and dinners and are actively solicited by young sexy women. "Beside the open bars at our soirees, there were other attractions for the males... young, beautiful women. Lots of them.... a potpourri of pussy.... I had been in enough officer's clubs in my life to know that aviator wings had babe-attracting power... but there was an even more powerful pheromone than jet-jockey wings: The title "astronaut." We males found ourselves surrounded by quivering cupcakes. Some were blatantly on the make, wearing spray-on clothes revealing high-beam nipples and smiles that screamed, "take me." Even the gold bands on the fingers of the married were no deterrent to many of these woman. They were equal opportunity groupies." A common sight in the mornings were the "married colleagues with red-blasted all nighter eyes trailing the odor of alcohol and sex as they exited a motel room with a smiling young woman" (Mullane 2007).

Among social primates, such as the chimpanzee, high status male chimps prefer and preferentially mate with and try to monopolize high status females (Goodall, 1971, 1986; Nishida, 1990; Sade, 1967). Among humans, high status females include movie stars, celebrities, and female astronauts. As detailed by Shuttle Astronaut Mike Mullane (2007), the male astronauts "warmly welcomed the attention. The women probably welcomed it less so. The major focus was on them.... whenever Judy or Rhea or Anna--the triumvirate of TFNG beauty--walked into the room... There wasn't a man or woman in any public setting who didn't stare... They were particularly dazzling when they were dressed in their dark blue patch-covered flight coveralls. What was it about the women in their flight suits? In them Judy, Rhea, and Anna stole the audience. The flight suits seemd to transform them into fantasy creatures like Barbarella or Cat Woman or Bat Girl."

It can be predicted that being of high status, that astronauts of the opposite sex will be sexually attracted to one another and may act on their sexual desires.

3. ASTRONAUTS HAVE SEX: THE CASE OF LISA NOWAK AND WILLIAM OEFELIEN

The frequency of sex between male and female astronauts is unknown, due in part to NASA's unofficial "mind your own business" policy (Mullane 2007) and its failure to mandate an enforceable code of responsibility which "decreases the likelihood of such behaviour being reported" (NASA 2007; Office of Audits, 2010). Inadvertently, NASA encourages sexual behavior by not restricting it, or training for it; and this could be disastrous for a human mission to Mars.

Michael Collins, whose second spaceflight was as commander and pilot for Apollo 11, is one of only 24 humans to have flown to the Moon. In his book Mission to Mars (Collins, 1990), he points out that the crew of a future mission to Mars will likely be multinational and consist of both males and females from different professional backgrounds. He believed that the presence of women on a long duration mission to Mars, would create tremendous sexual tensions and a "singles bar atmosphere...a charged mixture of sexually unattached competitors, would be a disaster."

Consider the well publicized case of female astronaut Navy Captain Lisa Nowak, and Shuttle pilot Cmdr. William Oefelein who flew together on the space shuttle and engaged in an adulterous relationship which allegedly almost led to the kidnapping and murder of Nowak's rival, Air Force Captain Colleen Shipman.

Nowak, a married mother of three, was a highly regarded professional who had logged more than 1,500 hours in different aircraft, had received a BS in aerospace engineering from the U.S. Naval Academy in 1985; an MS degree in aeronautical engineering and a degree of aeronautical and astronautical engineer from the U.S. Naval Postgraduate School, and who was qualified as Mission Commander and an Electronic Warfare lead in her flight squadron (NASA 2006). She subsequently underwent astronaut training, was qualified as a mission specialist, worked at Mission Control as prime communicator with on-orbit crews, subsequently flew on the Space Shuttle and performed complicated manuevers on a 13-day mission on the International Space Station (ISS) in 2006 (NASA 2006). The Shuttle pilot was Cmdr. William Oefelein (the father of two children and a former "Top Gun" Navy pilot) with whom she was having an adulterous sexual affair.

According to Orlando Police Department investigators (2007a,b), unknown to Nowak, Oefelein was also having sex with Air Force Captain Colleen Shipman who he had met while training for the Shuttle Mission which would carry him and Nowak to the ISS. Subsequently, when Nowak logged onto Oefelein's computer at his home one evening, and discovered emails to and from Oefelein and Shipman which made explicit their sexual activities, Nowak allegedly decided to kidnap and kill her rival. Nowak drove 900-miles from Houston to Orlando, dressed in a trench coat and a wig to disguise her identity, and then attacked Shipman in the parking lot of the Orlando International Airport (Doukopil 2007; Hauser 2007, Kluger, 2007). Detectives found 30 unused diapers in her car, and a rope and a knife which she'd packed for her confrontation with Shipman.

The exact nature of Oefelein's feelings toward Nowak when he turned his attentions to Shipman is unknown. According to Orlando Police Department investigators (2007b), Nowak thought the affair was ongoing. According to Shipman, Oefelein once called Shipman by Nowak's first name when they were in bed (Orlando Police Department investigators 2007b). What we know for a fact is that Nowak and Shipman were willingly having sex with Oefelein while Nowak and Oefelein worked together as astronauts and these affairs were ongoing before and after Oefelein and Nowak flew on a 13 day mission together. We should ask: what would have happened if commander Oefelein, captain Nowak, and captain Shipman, were flying together on a 9 month mission to Mars where they would be together for over 2 years?

One answer comes from studies of female primates. Primate females will compete for access to preferred males, and will fight and threaten one another for the privilege of having sex with these males (Fedigan, 1992). However, primate males also try to monopolize females, and high status males tend to attack and drive off low status males (Goodall, 1971, 1986; Nishida, 1990; Sade, 1967). Male primates will also rape high status estrus female primates who resist.

4. ROMANCE AND SIMULATED MISSIONS TO MARS

If a crew of 3 males and 3 females were sent on a journey to Mars, it can be predicted that males would experience sexual interest in the female astronauts, and female astronauts may or may not always reciprocate depending on their hormonal status, and the status and attractiveness of the males vying for their attention. Male astronauts may not always take "no" for an answer.

Consider for example, the case of 32-year-old Dr. Judith Lapierre, a Ph.D. health sciences specialist, sponsored by the Canadian Space Agency, who participated in a 110-day isolation experiment designed to simulate a long duration space mission (Oberg 2000; Warren, 2000). According to Dr. Lapierre, two of her Russian international crew mates became embroiled in a 10 minute violent blood splattering fight, immediately after which she was physically accosted and manhandled by the team commander, a Russian, who began forcibly kissing her and sticking his tongue in her mouth (Oberg, 2000; Warren, 2000).

Dr. Lapierre forcefully protested immediately before, during, and after the assault, and was so frightened of additional sexual attacks that locks were placed on the doors to the passageway linking her test module with the Russian module. She and her crew mates also hid all the knives as they feared more violent outbursts and physical assaults. The experiment, called Sphinx-99, was designed to observe group dynamics under both routine and emergency conditions.

In the case of Dr. Lapierre, it was the commander in charge of the mission who assaulted her and she appealed to outside supervisory personnel for help. On a human mission to Mars, there will be no doors which can lock out sexual predators, and no one from Mission Control who can come to a female astronaut's rescue.

If women accompany men on a human Mission to Mars, are they at risk for rape? Or is the greater risk, falling in love and then pregnancy?

Dr. Judith Lapierre, was the only woman in a crew of eight and who were confined to a replica of the Mir space station. In another simulation, which included more females, romantic relations developed between willing partners. According to Pletser (2010), during the EuroGeoMars project designed to simulate a mission to Mars, in the Utah desert, two crew members engaged in a romantic relationship which involved open displays of affection and physical intimacy such as holding hands, spending exclusive time together in the evenings and while performing chores and various duties. Although privacy prevailed behind closed doors, these romantic activities were not welcome by other team members, and it was felt this behavior was detrimental to the unity of the group and team social activities.

According to an analysis of NASA's (2005) "Bioastronautics Roadmap: a risk reduction strategy for human exploration of space" (Longnecker and Molins 2006), not only are male and female astronauts on extended missions or a mission to Mars likely to have sex, but failing to plan for and ignoring the likelihood of sexual activity could have profound and even life threatening consequences: "Areas of concern for the 30-month Mars mission include the potential psychological and physiological consequences of sexual activity, consequences that could endanger life, crew cohesion, performance, and mission success."

What are some possible consequences? Rape, murder, the monopolization of female astronauts by one or two high ranking males?

5. SEX IN THE ANTARCTIC

The polar environment has been viewed by numerous scientists, and NASA, as an excellent analog for long-duration space missions. The findings are unequivocal: men and women have sex and form temporary romantic and sexual relationships (Leon 2005; Palinkas 2002; Rosnet et al., 2004; Stuster 1996): "One cannot send unmarried men and women" to the Arctic "and not expect them to form bonds" (Leon 2005); bonds which often lead to pregnancies (Ayton 2006; Bowden 1999).

For example, on Australian stations in the Antarctic seven pregnancies were recorded between 1989 and 2006 (Ayton 2006), although "no one wants to become pregnant down there, no one wishes a baby to be born down there" (Bowden 1999). The general belief is that pregnancy in the Antarctic poses increased risk to the mother, to her unborn child, to the team, and to the success of the expedition program (Ayton 2006). Nevertheless, women team members, regardless of nationality, become pregnant.

In fact, just having women as members of the team in the Antarctic can cause significant sexual tension and stress for both men and women (Palinkas 2002; Rosnet et al., 2004; Stuster 1996). Some men harass females for sex, women will behave seductively, sexual frustrations increase, and romantic rivalries develop (Rosnet et al., 2004; Palinkas 2002; Stuster 1996). Moreover, women in these settings are perceived by men and women alike as having tremendous sexual power over men, and thus have greater control over men, as it is the female's choice as to which of the men will receive their sexual favors (Palinkas 2002). Although this "choosiness" can certainly enhance the morale of the male she chooses, group cohesion can be negatively impacted (Suster 1996).

Palinkas (2002) provides an illustrative case, involving "John" who had left a wife and two children back home, was profoundly depressed, and then became embroiled in a sexual relationship with a female crew member, which resulted in an elevation of his mood and increased productivity. Although, temporary sexual relationships between male and female crew members are common in the Antarctic (Palinkas 2000; Stuster 1996), "John's" sexual relationship met with group disapproval.

When a woman chooses to have a sexual relationship during her sojourn in the Antarctic, it is often with senior (rather than junior) personnel, including the station leader who is usually seen as having the most status by the women, as well as an unfair advantage by the other men, thereby creating considerable tension and conflict (Stuster 1996).

On the other hand, most studies report that including women as team members has a very positive effect on morale (Rosnet et al., 2004; Leon 2005), especially if they are married and accompanied by their spouse (Leon 2005; Leon et al., 2003). For example, in a study of three married couples from different countries icelocked on a boat in the High Arctic for a 9 month period, partners provided each other with significant emotional support. Married partners were also instrumental in alleviating interpersonal and group tensions, and contributed to the effective functioning of the team (Leon et al., 2003).

Women also tend to provide emotional support to other team members and try to help solve interpersonal problems, behaviors which are not common in all-male groups (Leon 2005; Leon et al., 2003; Palinkas 2002; Rosnet et al., 2004). Women also serve as "peacemakers" reducing non-sexual competition, tensions, and arguments among the men, and the men often turn to women to share their emotional and personal concerns--though these same men have little interest in listening to these women share their feelings.

6. SEX AND OUTER SPACE

Like other female mammals, the human female is most likely to actively seek sex when she is ovulating and most likely to get pregnant (e.g., Gold & Burt, 1978; Matteo & Rissman, 1984; Udry & Morris, 1968, 1970; Wolfe, 1991). Hence, women become pregnant in the hostile conditions of the Antarctic; and there is no reason to suspect they may not become pregnant on Mars.

According to the Bioastronautics Roadmap (Longnecker and Molins 2006), "the risk of pregnancy might be mitigated by crew selection" and the use of contraceptive medications. Unfortunately, the many "questions about the efficacy, safety, and side effects of contraceptive medications may require that studies to answer these questions be completed prior to crew selection or that other measures be used to mitigate the risk of pregnancy."

But would these pregnancies lead to the first babies born in space, or on Mars?

Reproductive medical issues that pertain to astronauts have generally received scant clinical scientific attention, and there is little information on 1) the effect of long duration spaceflight and gravity on normal menstrual functioning including menstrual efflux and retrograde (intra-abdominal) menstruation, 2), the impact of microgravity on normal hypothalamic and pituitary functioning which in turn impacts and influences gender-specific hormone production and ovarian function, and 3) the effect of space radiation on fertility, reproductive success, and the future childbearing capacity of both men and women.

Of concern is the effect of microgravity (in space) and reduced gravity (once on Mars), on testosterone and estrogen secretions, the menstrual cycle, ovulation, and sperm production and viability. For example, if ovulation ceases the female astronaut may be continuously exposed to high levels of estrogen. By contrast, if the hypothalamus is impacted testosterone and estrogen levels may significantly decrease or increase, all of which would effect sexual and reproductive success. One concern is that "the exercise necessary for long-term cardiovascular and musculoskeletal fitness may be so strenuous enough that it may cause hypothalamic-induced hypogonadism with reduced serum estrogen levels" (Harm et al., 2001).

6.1. MENSTRUATION AND OVULATION If females are to be part of a human mission to Mars, then the long exposure to microgravity may cause menstrual efflux and retrograde menstruation. Many women commonly experience some retrograde intra-abdominal bleeding during menses which remains confined to the pelvis due to the forces of gravity. However, because of lack of gravity these menstrual blood products may induce retrograde menstruation and menstrual efflux during spaceflight.

No symptoms of endometriosis have been as yet detected in female astronauts on the space shuttle (Jennings and Baker, 2008). However, since the longest space shuttle flights are 18 days, and women cycle 28 days, no definite conclusions can be drawn from this finding.

Another concern is the effects of radiation. Radiation exposure has caused endometriosis in various species of primate (Fanton and Golden 1991; Wood et al. 1983). Endometriosis ("inside the womb") is caused by hormonal changes and radiation exposure, and is associated with the flourishing of endometrial-like cells outside the uterine cavity and on the ovaries. A common symptom is severe cramping and pain in the lower back, the legs, and the rectal and vaginal area, thereby making it difficult to walk, sit, or have sex (Ballard et al. 2010; Buyalos and Agarwal, 2000). Moreover, the increased number of endometrial-like cells on the ovaries, can cause anatomical distorsions and adhesions which results in infertility (Buyalos and Agarwal, 2000).

According to Jennings and Baker (2008), menstruation during space flight lasting up to 18 days has never proved a problem and no symptoms of retrograde menstruation or pain associated with endometriosis have been reported. Unfortunately, although a few women have flown on the International Space Station for periods longer than 100 days (e.g., Sunita Williams, 194 days, Dr. Peggy Whitson, 350 days) privacy concerns have prevented the collection and reporting of data on female menstrual functioning for long duration space missions.

The hypothalamus, pituitary, gonadal (HPG) axis regulates the ovulatory cycle, and is highly susceptible to environmental factors including stress (Joseph 1998a, 1999a). Stress can exert adverse effects on the ovaries and can lead to ovulation failure (Tau et al., 2002). Although it appears that short term spaceflight does not affect the ovaries, the effects of a long duration mission are unknown. For example, examination of the ovaries of postpartum rats after 9–20 of gestation showed no effect on ovarian weight or number of preovulatory or atretic follicles (Tau et al., 2002) and female rats ovulated and cycled normally (Serova and Denisova 1982). However, although these females successfully mated with male rats during space flight, no births resulted. Thus, spaceflight might be correlated with negative effects on the capacity to become pregnant and/or on the viability of the fetus while in space.

6.2 MALE TESTOSTERONE, TESTES, AND FERTILITY The ovaries are more radiation resistant than the testes (Suruda 1998), which suggests that males are more likely to become infertile than females following long term radiation exposure, which can be expected in space and on Mars. Perhaps the greater resistance of the female ovum is due to its being approximately 20 times larger than the human sperm cell. The ovum carries the X chromosome, whereas the male sperm may carry either an X or a Y chromosome thus determining if the fetus is male (XY) or female (XX). It is also believed that the male Y chromosome is more fragile than the larger female X chromosome.

In contrast to women, men are at a much greater risk to suffer damage to gametes (Jennings and Baker 2008), i.e. sperm, which then puts the smaller Y chromosome at risk. Damage to sperm can result in infertility or effect the sex ratio of offspring. Likewise, alterations and reductions in testosterone levels can effect the sexual orientation, and the sexual anatomy and sexual differentiation of the developing brain leading to feminization (Joseph et al., 1978, 1982). It is noteworthy that jet pilots and astronauts subjected to high G-force exposure have a higher frequency of daughters than those who experienced low G Forces (Little et al. 1987).

Male rats mated 5 days after space flight to nonflight female rats bred successfully, but their offspring were grossly abnormal. Abnormalities including physical retardation, showed growth retardation, hemorrhages, hydrocephaly, ectopic kidneys, and enlargement of the bladder (Serova et al., 1982). Male progeny also showed reduced epididymis weight at 30 days of age. By contrast, females mated to male rats 2.5–3 months after short duration spaceflight produced healthy, viable offspring (Santy et al. 1982). Unfortunately, these studies tell us nothing about the effects of long-duration flights.

Significant and profound reductions in testosterone levels have been found in both men and male rates following short duration flights (Tau et al., 2002). Reductions in testosterone would effect male sexual functioning and fertility as androgens stimulates sperm production. In most spaceflight studies, reductions in testosterone and the weight of testes has been reported (reviewed by Tau et al., 2002).

6.3 STRESS, SEX AND THE HPG AXIS Stress and abnormal environmental infuences exerts profound effects on the immune system, cardiovascular functioning, the central nervous system, especially the hypothalamus, amygdala and hippocampus, and on cognitive and intellectual functions including learning and memory (Joseph 1979, 1982, 1998, 1998a, 1999b, 2003; Joseph and Gallagher 1980). Stress can also significantly reduce testosterone levels. Decreased testosterone levels in male astronauts have been found in association with increased plasma LH, which returned to normal after flight, suggesting that the hypothalamic-pituitary-gonadal (HPG) axis may have been impaired by spaceflight (Tau et al., 2002). The hypothalamus is directly involved in the mediation of sexual behavior and the secretion of sex-specific hormones (Joseph 1982, 1999a).

The HPG axis is influenced by stress (Joseph 1998, 1999a,b) and by radiation and reduced gravity. Chronic stress in spaceflight rats has been indicated by higher adrenal gland weights compared with controls (Tau et al., 2002). In studies of astronauts aboard the MIR Space Station, increased cortisol was reported during spaceflight (Larina et al., 1997) and increased cortisol levels are classically associated with the stress response and injury to limbic system structures which includes the hypothalamus (Joseph 1999a,b). Increased cortisol excretion can also reduce testosterone and other hormones (Joseph 1999a).

Stress will effect fertility in women, and the viability of the fetus (Joseph 2000c). The fetal and infant brain and other physical organs may be severely injured by stress and the secretion of cortisol (Joseph 1999a,b, 2000c, 2003). Thus, if a female astronaut on a long duration mission to Mars becomes pregnant, she may lose the baby, or it may suffer a variety of physical and intellectual abnormalities.

7. PREGNANCY, GRAVITY, EMBRYO AND FETAL DEVELOPMENT

Ultimately, successful reproduction is the production of viable progeny after the female becomes impregnated. It has been demonstrated that rats can successfully mate in hypogravity, although no viable progeny were produced (Serova and Denisova 1982). However, space-faring mammals can become pregnant after they return to Earth. Several studies have reported no detrimental effects of short-duration space flight on pregnancy, reproductive hormones, fetal development, parturition, or lactation in female rats after they return to Earth (reviewed by Tao, et al., 2002). This suggests that once on Mars, males and females may be able to successfully have children. However, the same is not true of pregnancy in space (Jennings and Baker 2008).

There have been many studies done on embryos in microgravity and a variety of species have been used (Crawford-Young 2006; Ma et al., 2008; Ronca 2003; Serova et al., 1982, 1984; Wong and DeSantis 1997). Existing data suggest that space flight is associated with a constellation of changes in reproductive physiology and function. Space flight studies of pregnant mammals have shown a significant reduction in pregnancy weight gain, prolonged parturition, lower birth weights, and increased perinatal mortality (Serova et al., 1982, 1984; Wong and DeSantis 1997). Increased neonate mortality persisted into the F2 generation (Serova et al. 1984).

In a study of the developmental capacity of mouse embryos in the Chinese SJ-8 Satellite it was found that during space-flight, embryos cultured in a sealed culture did not develop whereas the same experiment performed on the ground in the same device showed that the embryos successfully developed (Ma et al., 2008). It was concluded that the space environment, especially the change of gravity harmed the development of the mouse embryo (Ma et al., 2008).

Extended spaceflight missions require prolonged exposure to decreased gravity. Human sexual reproduction and fetal development evolved in relation to living on Earth, standing upright, and the influences of Earth gravity (Joseph 200a,b,c). Therefore, it can be predicted normal fetal development (Joseph 2000c), would be effected by reduced gravity (Ma et al., 2008; Ronca 2003).

The adverse effects of microgravity on embryos, cell structure and function have been demonstrated by experiments performed in space or in altered gravity induced by clinostats. It is now well established that cellular structure, morphology, and genetic expression may be abnormally effected in microgravity and that the cytoskeleton and microtubules are gravity sensitive and may be grossly altered (Crawford-Young 2006; Ma et al., 2008; Ronca 2003). These gravity induced cellular changes exert a variety of deleterious effects on embryogenesis. These include death of the embryo, failure of neural tube closure, and gross abnormalities in the brain, heart, and limbs.

Cells respond to their environment within a three dimensional tissue structure. The number of adhesive structures in a cell and its resulting cell polarity may change the way it will behave in microgravity. For instance cells that are not polarized are more likely to die and undergo apoptosis or develop abnormally as has been demonstrated in microgravity (Crawford-Young 2006).

Microgravity has a significant impact on both cell shape and cytoskeleton (Crawford-Young 2006). Cells show signs of changes in the nucleus and in cell shape, and cells which form layers become disorganized, such that the layers do not develop normally. This would include the brain, the outer coating of which consists of 6 layers, and effect the embroyonic neural tube which is also layered and becomes the brain (Joseph 1982, 1999a, 2000c). Embryonic neural tubes do not close properly due to the changes in cell shape, migration, and adhesion, induced by altered gravity (Crawford-Young 2006).

Embyronic cells of differing types have different surface tensions and will separate into groups and will sort so that the cells with greater surface tension are on the inside of a tissue and those with less surface tension are on the outside. An example of this is the embryonic and fetal brain and heart (Joseph 1982, 2000c). When the brain develops, cells migrate to the surface area to form six layers consisting of different cell types. The heart also develops as a process of cell migration. If cell migration movements are altered in a developing animal in response to microgravity, the heart and other structures formed by the somites will not develop, causing early embryonic death (Crawford-Young 2006). Thus, any situation where cell mobility or cell lamellipodiae are involved could be affected, such that the fetus and its brain, heart, and internal organs, do not develop normally Hence, there have been no births of mammals in space (Tou et al., 2002; Ronca, 2003).

Early embryonic death could also be a direct result of microgravity induced fluid shifts, alterations in cardiovascular functioning, muscle wastage, skeletal demineralization, and decreased red bood cells, all of which would affect the ability to sustain a pregnancy.

And what if women already pregnant were to embark on a long duration space flight to Mars? As summed up by Sekulić et al., (2005): "During space flight it is impossible to apply the existing countermeasures against microgravity deconditioning of the muscular and cardiovascular systems to the fetus. Absence of gravitational loading during the last trimester of gestation would cause hypotrophy of the spinal extensors and lower extremities muscles, reduction in the amount of myosin heavy chain type I in the extensor muscles of the trunk and legs, hypoplasy and osteopeny of the vertebras and lower extremities long bones, and hypotrophy of the left ventricle of the heart muscle. Because of decreased capacity of postural and locomotor stability, acquisition of the gross developmental milestones such as sitting, standing and walking could be delayed.

NASA Medical Standards for space flight (JSC 11570) specifically disqualify any woman who is pregnant from space flight (NASA 1977) because of concerns regarding the adverse effect of toxins, microgravity and radiation on embryogenesis and fetal development, and to prevent on-orbit pregnancy accidents such as preterm labor, ectopic gestations, or spontaneous abortion. Thus all female astronauts are tested for pregnancy repeatedly beginning 20 days before launch (Jennings and Baker 2008).

Female astronauts use essentially every form of contraception to prevent pregnancy and are encouraged to continue using contraceptives during flight. On long duration missions continuous menstrual suppression is often used (Jennings and Baker 2008).

8. MOTHERS AND BABIES IN SPACE

There is now considerable evidence that biologically meaningful interactions between mothers and offspring are changed in the weightlessness of space (Crawford-Young 2006; Ronca 2003). Studies of young rat litters launched at 9 days of postnatal age or earlier, have been characterized by compromised maternal–offspring interactions and behavioral abnormalities (Ronca 2003). Although alterations in gravity would have a profound impact on the maternal-infant relationship, the stress of space flight would also be a factor. Prolonged and chronic stress would effect the mother, fetus, infant and child and disturbances in the mother-infant relationship would have severe effects on the brain and mind of the child (Joseph 1982, 1998, 1999a,b, 2000a,c). In addition, prenatal stress is a direct cause of fetal mortality, abnormal brain functioning, abnormal nursing behavior, and increased postnatal mortality.

However, a major concern must be the effects of pregnancy on the crew of a craft journeying to Mars. It can be surmised that all aspects of the mission would be put in jeopardy. Crew mates would unlikely to be supportive as their ability to perform their duties or to live comfortably would be impacted. Stress levels would rise, as would irritability, resulting in considerable hostility and anger directed toward the mother and father unless, perhaps, she had sex with multiple astronauts and the identity of the father was unknown.

9. RADIATION ON MARS: FERTILITY AND EMBRYONIC DEVELOPMENT

Another concern is the effects of radiation on pregnancy during a long duration mission and after arrival on Mars. Several studies have reported no detrimental effects of short-duration space flight on pregnancy, reproductive hormones, fetal development, parturition, or lactation in female rats after they return to Earth (Reviewed by Tao, et al., 2002). But would female astronauts be able to become pregnant and produce viable offspring on Mars?

The guidelines of The National Council on Radiation Protection and Measurements guidelines limit radiation exposure to 500 mrem for an entire pregnancy and to only 50 mrem per month. On the International Space Station, radiation exposure may approach 35,000 mrem or more (Harm et al., 2001), and these levels would significantly impact the viability of the fetus, producing a range of severe to profound abnormalities (Dekaban 1968; Diamond et al., 1973; Otake et al., 1996; Reyners et al., 1992) and would likely kill a developing human fetus.

If a female astronaut became pregnant during a mission to Mars, she would be subjected to massive doses of galactic cosmic radiation (GCR). GCR consists of heavier nuclei from He to Fe and high energy deep penetrating protons; and which would be very difficult to shield against (ICRP 1991; Straume et al., 2010). The catastrophic effects of radiation not only result from radiation-induced damage in the irradiated cells but in adjacent cells thereby causing widespread tissue damage and triggering genomic instability (NCRP 2000, 2006, NRC 1990, 2006; Straume et al., 2010 and references therein). Radiation of this sort would causes a wide variety of abnormalities in a fetus and the developing central nervous system which is especially sensitive to radiation.

Infants and children exposed to high doses of radiation prenatally, suffer significant intellectual deficits, including mental retardation, the severity of which increases with radiation dose, but which also varies depending on the time and length of exposure (Straume et al., 2010). According to Straume et al., (2010) intellectual deficits are greatest in those children exposed to radiation during 8th to 15th week of gestation with sensitivity continuing until the 25th week. However, for the first 8 weeks and after 25th weeks the fetal brain is more radiation resistant.

Unfortunately, even if the female astronaut is not pregnant when exposed to radiation, genetic alterations may be passed on to progeny such that genomic instability and abnormalities become transgenerational (NRC 1990, 2006; Straume et al., 2010 and references therein). However, even if she may become pregnant depends on if she and her ovaries can be shielded from radiation. Exposure to chronic gamma rays will damage the ovaries and can induce temporary or permanent sterility (ICRP 1984, 1991; NRC 1990).

However, it is not just the human female on Mars, but the fertility of the men which may be effected by radiation. Sperm production can be profoundly reduced and effected by radiation, thereby causing radiation-induced fertility which may be permanent or temporary depending on dose and length of exposure (NRC 1990). Straume et al., (2010), argue, however, that nominally shielding in interplanetary space or on the surface of Mars would protect sperm production.

According to Straume et al. (2010), fortunately, "permanent sterility in men requires at least 5 Sv chronic low LET radiation, which is not anticipated for Mars missions... and... we would not expect decreased fertility from exposures to the radiation received during transit to/from Mars or living in a Martian base... though the possibility that human females may also have a sensitive prenatal stage should be given serious consideration."

Thus, it would appear that if male and female astronauts are properly shielded during the journey to and after arriving on Mars, that they will remain fertile and should be able to successfully reproduce.

On Earth, almost all female astronauts have delayed child bearing until after they have completed one or two space flights. Fertility and the ability to bear children has been negatively impacted in almost half of these women. As summed up by Jennings and Baker (2008), "the average maternal age at the time of delivery for the 15 children born to 13 U.S. female astronauts after flight is 41 years. The mean maternal age of the 12 postflight pregnancies that ended in spontaneous abortion is also 41 years.... because of the relatively advanced maternal age of female astronauts, there has been considerable need for infertility services and assisted reproductive technology... the success rates have been low."

10. SEX ON MARS: THE FIRST MARTIANS

Humans have sex and pregnancies result. If a baby is born on Mars, what predictions can be made?

From the moment of conception on Mars, the developing embryo-fetus-neonate-child, and its genome, will be subjected to a Martian environment markedly different from Earth, the most obvious distinctions being gravity, sunlight, radiation, temperature, and the biosphere. It is now well established that environmental influences early in life profoundly effects intelligence, learning, memory, vision, language, social-emotional functioning and the development, size, functioning, and interconnections of neurons and the brain (Casagrande & Joseph, 1978, 1980; Joseph 1979, 1982, 1998a,b, 2003; 1999a,b; Joseph, & Casagrande, 1978,1980; Joseph & Gallagher 1980); a function of the environment acting on gene activation vs suppression.

It has also been demonstrated "that populations contain a surprising amount of unexpressed genetic variation that is capable of affecting certain typically invariant traits" (Rutherford & Lindquist, 1998). There are thousands of "silent" genes within the human genome and the genome of other species, which code for or express functions which are as yet unknown (IHGSC 2001). However, fluctuations in temperature, oxygen levels, and diet can activate these "silent genes" (e.g., de Jong & Scharloo, 1976; Dykhuizen & Hart, 1980; Gibson & Hogness, 1996; Polaczyk et al., 1998; Rutherford 2003; Wade et al., 1997) which may express novel traits (Joseph 2009; Rutherford, 2003).

Environmental influences on gene expression are mediated through regulatory proteins such as Hsp90 (Feder and Hofmann 1999; Rutherford 2003; Sangster et al., 2004). Hsp90, for example, is a highly conserved multifunctional protein which targets multiple signal transducers and act as "molecular switches" which control gene expression in eukaryotes ranging from yeast to humans (Feder and Hofmann 1999; Rutherford 2003; Sangster et al., 2004). Hsp90 does not act alone but is part of a networks that includes other proteins such as Hsp70, and p23 (Pratt and Toft 2003). These proteins "normally suppress the expression of genetic variation affecting many developmental pathways" (Rutherford & Lindquist, 1998). These proteins prevent DNA expression by acting as a buffer between silent genes and the environment. However, changes in the environment can directly impact regulatory genes and change the configuration of these proteins thereby removing their buffering influences, such that silent genes are then activated which triggers the expression of silent characteristics (Joseph 2009). As demonstrated by Rutherford and Lindquist (1998, p. 341) Hsp90 acts as an "explicit molecular mechanism that assists the process of evolutionary change in response to the environment" and it accomplishes this through the "conditional release of stores of hidden morphological variation.... perhaps allowing for the rapid morphological radiations that are found in the fossil record."

As a variety of genes will be effected by the environment of Mars, then the genome and the development of a fetus conceived on Mars will be differentially effected as compared to the genome and the development of a fetus on Earth.

It must also be recognized that the testes, ovaries, and genome of the parents will have been subjected to markedly adverse environmental conditions as they traversed space to reach Mars (cf Crawford-Young 2006; Ma et al., 2008; Ronca 2003; Straume et al., 2010), and again once on Mars. It is also highly likely subsequent genetic alterations will be passed on to offspring born on Mars (cf NRC 1990, 2006b; Straume et al., 2010). As the environment acts on gene selection in parents and offspring, and as alterations in the environment and the genome effect evolutionary innovation and extinction (Joseph 1993, 2000b; 2009), then not just development but the evolution of humans on Mars will also be differentially effected as compared to humans of Earth.

Hence, if a child is conceived and born on Mars, we can predict at least three possible outcomes:

Naturally, all prospective parents will have to be counseled, before embarking to Mars, on these possible eventualities.

11. CONCLUSIONS AND RECOMMENDATIONS

Women have been an integral part of United States space crews since 1983, and world wide over 50 women have been selected as astronauts thereby providing considerable data on menstruation control and hygiene, contraception, and urination. As summed up by Jennings and Baker (2000) "there are no operational gynecological or reproductive constraints for women that would preclude their successful participation in the exploration of our nearby solar system." Perhaps the age of the female astronaut is the only major limiting factor (women of child bearing age only), if the goal is the colonization of Mars.

Women and men are sexual beings. The likelihood is male and female astronauts, traveling in the same space craft, will have sex during the long duration space-flight to Mars and after they arrive on Mars, even if substantial rules and steps are taken to prevent it. Therefore, training and preparations must be taken to anticipate all possible consequences and to regulate, guide, and modulate sexual activity; not for the purpose of preventing sex, but to prevent catastrophe.

Consider, for example, the possibility that the commander of the space craft may monopolize the female astronauts who prefer to mate with him because of his higher status relative to those he commands. Estrus female chimps may copulate up to 50 times in a day but only with a few of the available males who generally tend to be of high status (Goodall, 1986; Tutin, 1975). In one colony of free ranging rhesus monkeys, consisting of 150 adult females and 52 males, most of the estrus females actively sought out and mated with the same three dominant males (Carpenter, 1942). In some colonies, only about 20% of the males were responsible for 80% of the matings (Freedman, 1979). In one study of 25 male and 25 female captive baboons, five of the males possessed all the females (Zuckerman, 1932). In the military, one case came to light where a major general was having sexual relations with the wives of four of his subordinates (Burns, 1999). In studies of humans in long duration Antarctic analogue (Mars-like) conditions, females also prefer high ranking senior personnel, including station chiefs, often to the exclusion of those with a junior status (Stuster 1996).

Female primates will also attack and fight among themselves for the opportunity to have sex with a high ranking male (Fedigan, 1992). In 2007, captain Lisa Nowak allegedly planned to kidnapped and murder captain Colleen Shipman, her rival for the affections of space shuttle commander Oefelein.

Naturally, if a few males monopolize the available females, the other male astronauts will respond negatively and this may lead to violence. This can be avoided by a rule which relieves the monopolizer of command in cases of sexual monopolization, thereby stripping any male of the high status which made female astronauts prefer him to the other male astronauts.

Astronaut Michael Collins (1990), advocates sending only married couples on these voyages to better be able to survive the hardships of space. "An element of stability, of old-shoe comfort, would be introduced by having one's husband or wife to fall back on." Studies of married couples in the Antarctic support this view. Married couples are a source of stability and married females have a very positive effect on morale not just on their spouse but on the emotional stability of the group (Rosnetet al., 2004; Leon 2005; Leon et al., 2003). Married partners have been reported to have a calming effect and help to reduce interpersonal and group tensions thereby contributing to the effective functioning of the team (Leon et al., 2003).

However, the reality is: divorces are common and relationships often come to an end, and if either or both the male and female astronaut decided to change partners during the course of a voyage to Mars there may be conflict. The changing of partners could be a frequent occurrence during the mission to Mars and once on the Mars surface. Naturally feelings of jealousy, betrayal, and emotional upset would be expected. Therefore, if married couples are to be selected for a mission to Mars, the focus should be on those with very strong emotional bonds.

If the long term goal is the colonization of Mars, then it must be recognized that many older female astronauts are no longer capable of becoming pregnant or having children (Jennings and Baker 2008). This may be due to age or factors associated with exposure to the conditions of space travel. Therefore it is important to send younger versus older female astronauts; i.e. women who are in their early child-bearing years.

Although male and female astronauts could be trained to "share and share alike" so that sexual favors are provided equally to one and all, perhaps a better solution might be to send two space craft, one with an all male crew and another with an all female crew. Not only does this solve the problems which may arise from male-female sexual couplings in space, but it would prevent any possibility of pregnancy.

Naturally, humans are going to have sex and women are going to get pregnant. Pregnancies during a mission to Mars must be avoided. Pregnancies may lead to the death or abnormal development of the fetus. Pregnancy coupled with muscle atrophy, bone mineral loss, radiation, and cardiovascular activity may put the mother's life and the entire mission to Mars at risk.

Therefore, if issues of human sexuality are not addressed, and if necessary precautions are not taken, sex in space could lead to pregnancies, conflict, violence, and catastrophe. By contrast, once safely on the Red Planet, sex on Mars and the subsequent birth of the first Martian, would truly make humans a two planet species, and would be the first step to human colonization of the cosmos.