Sally Ride, the first American woman in space, came out quietly and posthumously in her obituary. Wikimedia Commons

The late astronaut Sally Ride came out of the closet this week with neither a bang nor a whimper, but with a quiet, matter-of-fact phrase released after her death that identified Tam O'Shaughnessy, a former science teacher and science writer, as her partner of 27 years.

Ride's sister, Bear, told the Seattle Times that Sally "never hid her relationship with Tam" but cited the pioneering astronaut's sense of privacy as the reason she never came out with fanfare while she was alive.

But Daily Beast writer Andrew Sullivan criticized the first American woman in space not coming out sooner.

Ride "had a chance to expand people's horizons and young lesbians' hope and self-esteem, and she chose not to," Sullivan wrote on Tuesday.

While there are many openly gay men and women of science, there are many more that choose to remain in the closet in order to keep their place in the laboratory. We may commonly think of academics as a liberal, open-minded lot, but lesbian, gay, bisexual and transgender scientists have had as rocky a road to acceptance in the scientific community as in other segments of society.

For much of its history, NASA was hardly an enlightened place. The agency only got around to sending a woman into space 20 years after the USSR, despite privately funded programs that showed women were able to pass the same physiological screening tests undergone by male astronauts and a 1971 report acknowledging that data from the Soviet cosmonaut program showed women adapting faster to weightlessness than men. An anonymous agency official told the Milwaukee Sentinel in 1963 that the idea of a woman in space made him "sick to his stomach."

So one can only imagine how reluctant Ride might have been to tell her superiors that not only were they about to send a woman up into space, they were also about to send up a lesbian.

Even in modern-day academia, LGBT scientists may feel reluctant to come out even to co-workers or superiors, not knowing whether they'll be met with support or scorn.

They may also worry about being seen as too vocal about LGBT issues like marriage equality or discrimination, according to Rochelle Diamond, the chair of the National Organization of Gay and Lesbian Scientists and Technical Professionals, or NOGLSTP, an advocay group for LGBT scientists.

"In the scientific community, it's frowned upon to be an activist," Diamond told Science Careers in 2010. "When seeking tenure, one needs to be apolitical. When seeking grants, one never knows who's reviewing them."

In the present day, there are some notable openly queer scientists: geneticist Dean Hamer, formerly the chief of gene structure and regulation at the National Institutes of Health; Canadian biologist Bruce Bagemihl; and British-born neuroscientist Simon LeVay.

Hamer, Bagemihl and LeVay have all dealt with homosexuality in their academic work. Hamer made a splash in 1993 when he published a paper in the journal Science linking certain DNA markers on the X chromosome to sexual orientation. Bagemihl's book "Biological Exuberance: Animal Homosexuality and Natural Diversity," which documented scholarly studies of same-sex affection throughout the animal kingdom, was cited in an amicus curae brief in the Supreme Court case Lawrence v. Texas, which ended up striking down Texas' anti-sodomy law. LeVay's 1991 Science paper on differences in certain brain structures between homosexual and heterosexual men sparked a media firestorm.

NOGLSTP keeps a roster of queer scientists of historical note. But many scientists in the past were mum about their sexuality, so it's difficult to definitively determine just how many of them were LGBT.

One name is Florence Nightingale, the famous nurse who tended troops during the Crimean War and whose work establishing training procedures for nurses had a huge influence on hospital planning.

"Although there is no specific documentation that Nightingale had physical homosexual relationships, she shared her emotional life primarily with other women and adamantly rejected any offer of marriage that came her way," NOGLSTP writes.

Artist and inventor Leonardo da Vinci's sexual orientation has long been the subject of debate and speculation. He was accused of sodomy by contemporaries, and in his will, he left all of his possessions to his pupil, Francesco Melzi.

But even though da Vinci was never known to have a relationship with a woman, he seems to have held a dim view of any kind of sexuality whatsoever.

"The act of procreation and anything that has any relation to it is so disgusting that human beings would soon die out if there were no pretty faces and sensuous dispositions," da Vinci wrote in one of his notebooks.

Even as homosexuality has become more accepted in recent years, some of the more prominent openly queer scientists over the last century faced discrimination and persecution thanks to their identity.

Lynn Conway, who pioneered microelectronic chip design in the 1970s while working at Xerox's Palo Alto Research Center, a hotbed of innovation, was fired from her first job after grad school at IBM after undergoing sex reassignment surgery in 1968.

An even sadder case is that of Alan Turing, the British computer scientist and mathematician who helped break German codes during World War II and devised the Turing test for determining if a machine has human-like intelligence.

Though Turing's accomplishments earned him the award of Officer of the Order of the British Empire, they weren't able to protect him from UK laws against homosexuality in his day. He was unwillingly outed in 1952 after he reported a break-in orchestrated by an accomplice of his young male lover and later charged with gross indecency. Faced with either prison or a probation hinging on undergoing chemical castration, Turing chose the latter.

Being outed also stripped Turing of his security clearance, thanks to fears within the British government that gay men were vulnerable to seduction by Soviet spies.

Turing was found dead in 1954 with a half-eaten apple lying near his bed. Some suspected Turing committed suicide by lacing the fruit with cyanide, but one expert recently disputed this characterization.

Jack Copeland, a professor of philosophy at the University of Canterbury in New Zealand, pointed out in a paper in June that the supposedly poisoned apple was never tested for cyanide and argued that Turing was in good spirits just before his death, even writing out a to-do list for the coming week -- not the usual habit of a despairing, suicidal person.

Copeland argues that the more likely explanation is that Turing accidentally exposed himself to cyanide gas. His home laboratory contained cyanide, and he was known to be somewhat careless about lab safety. Furthermore, the autopsy found that Turing's liver did not contain as much cyanide as other organs in his body.

"This finding is certainly suggestive of poisoning by inhalation of cyanide gas rather than by ingestion of cyanide solution," Copeland wrote.

In 2009, then-UK Prime Minister Gordon Brown apologized for Turing's treatment on behalf of the British government. On Wednesday, Lord John Sharkey introduced a bill that would go even further and grant Turing an official pardon.

Some have argued against pardoning Turing in the past, saying it's not fair to single him out when many others were also convicted under the same laws.

"We understand that argument, but it should not stop us from getting on with the case of someone who was indeed exceptional," University of Leeds mathematician Barry Cooper told the Guardian on Wednesday. "Can you imagine us treating Charles Darwin or Sir Isaac Newton like this?"