Japanese Astronaut Grew In Space, But Not THAT Much

By Nathaniel Scharping | January 10, 2018 2:36 pm
Norishige Kanai (right) pictured with fellow astronauts Mark Vande Hei of NASA (left) and Alexander Misurkin (center). (Credit: Wikimedia Commons)

Norishige Kanai (right) pictured with fellow astronauts Mark Vande Hei of NASA (left) and Alexander Misurkin of Roscosmos (center). (Credit: Wikimedia Commons)

A Japanese astronaut grew three and a half inches during the course of his trip to the International Space Station.

If that sounds too incredible to be true, you’re right. It’s not. But some people evidently believed Japanese astronaut Norishige Kanai when he tweeted out a mistaken measurement from aboard the ISS Monday.

He quickly re-measured himself after a Russian colleague questioned the measurement and found that the growth spurt was actually less than an inch — well within the range of what astronauts usually experience in space. Kanai tweeted out an apology, calling his initial measurement “fake news” and saying that he’s happy he’ll be able to fit in the Soyuz capsule that will take him home. His initial measurement was so extreme that he worried he’d be too big for the tight space, which contains seat liners custom-molded for each astronaut and cannot fit anyone above 6 feet, 3 inches tall.

It’s well known that astronauts grow a bit taller in the weightlessness of space, a result of the spine decompressing. The stretching is usually limited to no more than two inches though — Kanai’s mistaken measurement put him at almost double that. It’s not a permanent change though, as astronauts’ spines compress again to their normal length when they return to the pull of Earth’s gravity. Spinal stretching isn’t just limited to spacefarers, either. Just laying in bed overnight, the spine will stretch out just a little bit, and then shrink again once we stand up.

Adding an inch or two isn’t the only bodily fluctuation astronauts experience. Most experience changes to their eyesight, probably caused by fluctuations in the fluid pressure behind their eyeballs. There are indications that astronauts are also at higher risk for heart disease after going to space, and they experience bone loss and diminished muscle density due to the effects of weightlessness as well.

CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: space exploration
  • OWilson

    It’s OK!

    We are used to breathless reporting of phenomena, like the end of the world, only to find that on Monday morning we still have to show up for work, and pay our credit card.

    This stuff is really bad for science though.

    It shouldn’t ever be a joke!

  • Mike Richardson

    Our bodies evolved under a constant gravitational pull, so it isn’t surprising that body parts adapted to compensating for gravity would expand in its absence. More worrisome for the long-term term is the bone loss, muscle atrophy (including even cardiac muscle), and other physical deterioration that can occur when astronauts are in micro-gravity or zero gravity for extended periods. More studies need to be done on generating artificial gravity with rotating habitats, if we are serious about long duration space missions or permanent colonies in space.

    • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

      “artificial gravity with rotating habitat” Coriolis force – you’ll barf every time you turn your head. OTOH, your bladder may delight in Ekman transfport.

      • Mike Richardson

        That may not be the case if the habitat is of a sufficient diameter, or if its residents have time to adjust to those forces. There may also be pharmaceutical or surgical therapies to alleviate that kind of vertigo. Either way, we need to see what is feasible to determine determine what the actual physiological limitations are for human expansion into space. We are a pretty adaptable species.

        • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

          ISS FUBAR has been manned 17 years, 2 months, 10 days (as of 12 January 2018). Call it 6279 days. Wild mouse generation time is 45 days, thus 139 generations in ISS FUBAR (3060 human generation years). We would know whether mammals can evolve into micro-gee.

          Man-in-Space is an obscene joke.

          • Mike Richardson

            FUBAR??? Okay, but if I follow your reasoning about the mice, yes, we don’t want to attempt living without gravity. But if we can simulate it as discussed in my previous posts, then no, humans living in space is no joke.


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