Social Media Sidebar


Please sign up, comment on articles and bring your friends!

Current poll

PlanetTech is asking:

What do you think about our new web site?

Love it, indeed
Really good solution
Same as old one
The old one was better
This is a new option

Quote of the day

When seen through the lens of technology, few resources are truly scarce; they’re mainly inaccessible. 


Peter Diamandis

How Long Can You Stay in Space, and What Happens if You Stay Too Long?

Posted in Science on 15th May, 2015 05:48 PM by AlexMuller

The longest contiguous amount of time a human has spent in space is 437 days. That was done by Valeri Polyakov, almost twenty years ago. Sergei Krikalev, over six flights, has spent 803 days in space. Space is a harsh environment for humans. Systems throughout our body have evolved to function under the stresses of gravity.

Our muscles are constantly working against gravity on Earth. Those muscles have less work to do in space, and so they atrophy, waste away. That includes the heart, which shrinks a little, the neck muscles that hold up our heads, and our calves.
Since our bones are not experiencing the loads they experience on the ground, they feel no need to maintain themselves. Bone tissue is absorbed and not rebuilt. This absorbed bone can cause kidney stones. The places where the bone has weakened can easily fracture.
There is evidence that extended periods in space can result in dysregulation of the immune system. While there isn’t too much risk of exposure to pathogens, a compromised immune system can result in autoimmune responses and hypersensitivity.
Aside from the deleterious affects of microgravity, a potentially larger threat is radiation. We take for granted how much our planet protects us from radiation. Out in space, astronauts are exposed to galactic cosmic radiation, solar radiation, solar cosmic particles, and geomagnetically bound radiation. This radiation is so prevalent that when astronauts close their eyes, they often “see” bright flashes, as cosmic rays hit their optic nerves.
Radiation exposure can result in cell death or can cause mutations that result in cancers or epigenetic effects. Some systems are quite sensitive to radiation and their functions can become impaired, such as the immune system and the bone marrow system and the eyes, resulting in cataracts.
We do our best to provide shielding, but paradoxically, shielding can result in more exposure by what is called secondary radiation. When an energetic particle hits the shielding material it can emit gamma rays and energetic neutrons.
NASA takes astronaut radiation exposure very seriously. When they hit the allowed threshold, they can be prohibited from flying again.

Tags: spaceNASAradiationhealthmedicinemicrogravitygravity

Read original article » Back to category


Author: Guest
Posted: 2015-05-16
With all ambitions to send humans to mars and beyond and establish colonies, this is kind of insight that is essential and this type of research should be a priority Reply


Recent headlines

  • Posted in Software on 2018-03-24 00:24:10
    Algorithm will allow for simulating an entire brain more
    Posted in Software on 2018-03-24 00:16:27
    DeepMind explores inner workings of artificial more
    Posted in Medicine on 2018-03-24 00:12:47
    Rise in cancers 'caused by weight' more
    Posted in Hardware on 2018-03-21 20:44:48
    Study: Apple Watch Cardiogram app bested EKG band more
    Posted in Medicine on 2018-03-21 20:42:10
    The wearable brain scanner you can move around more
Posted in Business on 2013-10-10 01:33
China is working towards a manned lunar mission in more
Posted in Business on 2013-10-20 07:17
Spacex says China is their main competitor for more
Posted in Software on 2013-10-20 06:43
Pirate Bay Browser Clocks 1,000,000 more
Posted in Medicine on 2013-10-10 02:10
Google reportedly investing hundreds of millions into more
Posted in Medicine on 2013-10-14 03:13
Endothelial Cells Can Repair and Regenerate Organs, more
Posted in Science on 01.01.2010
Spacex says China is their main competitor for more
Posted in Science on 01.01.2010
Staring at Your Phone Could Be Making You Short more
Posted in Science on 01.01.2010
Oculus Rift virtual reality headset coming to mobile, more
Posted in Science on 01.01.2010
China is working towards a manned lunar mission in more
Posted in Science on 01.01.2010
Delivering drugs via nanoparticles to target more

Recent Blog Posts

  • Posted by AlexMuller
    In five years quantum computing will be more
    Posted by AlexMuller
    Google partners with Johnson and Johnson to make lower more
    Posted by AlexMuller
    Electron holography microscope with spatial resolution down more
    Posted by AlexMuller
    Lower cost advanced Nuclear power could dominate future US more
    Posted by AlexMuller
    Why Hasn’t AI Mastered Language Translation? more

Login to your Account

Login to your PlanetTech Account here

Remember me

Create a New Account

You just need username and password

The following errors occured:
Verify password:
Remember me