It's not just a case of my-daughter-the-doctor.

American Dr Sheyna Gifford is also the only Jewish member of a year-long simulated Nasa space mission to Mars in which she is serving as a physician and neuroscientist.

She will also chronicle the mission, which "launched" August 28 in Hawaii, in a series of blog posts.

"Light the [Shabbat] candles at the same time as Ground Control," Ms Gifford wrote in a tongue-in-cheek blog entitled "A Shtick by Any Other Name: Being Jewish on Mars".

In the post, Ms Gifford playfully addressed high-school friend Josh Breindel, a Massachusetts rabbi, writing: "I will be the only Jew on the planet."

Ms Gifford, 36, is part of the six-member crew toughing it out in isolation in a 1,700-sq-ft dome sitting on a slope of Hawaii's Big Island.

The two-storey structure is 8,000 ft above sea level, only 12 yards in diameter, and designed to replicate conditions travellers might face on a real journey to the red planet.

The mock mission - an actual return trip would take three years - will test logistics, the participants' ability to cope psychologically in a small space, as well more practical issues such as how much food and water to take along. The official name of the dwelling is the Hawaii Space Exploration Analog and Simulation (HI-SEAS IV).

As well as Ms Gifford, the crew includes a space "architect", a physicist, a field biologist, a spacecraft engineer, and an astrobiologist.

A resident of St Louis, Missouri, Ms Gifford dreamed of being an astronaut as a child, she said in a radio interview prior to the HI-SEAS IV "launch".

She considers herself a "freelance" astronaut, and is uncertain whether she will ever get the chance to blast off for real from terra firma.

"I'm more concerned that we get there as a society," she said.

Ms Gifford was also part of a much less lengthy HI-SEAS III mission that ended in June.

On her Jewish-themed blog post, Ms Gifford refers to the just-deceased neuroscientist Oliver Sacks, who she admired.

"Like Dr Sacks, when shown the door, I opened it," Ms Gifford wrote. The reason so many Jews are attracted to science, she wrote, is that "Judaism disproportionately favours enquiry over tacit acceptance".