What is happening to Mark Shuttleworth's body in zero gravity today?
Balance problems
With the space shuttle in zero gravity orbiting the earth, the cosmonauts can float around the interior of the cabin. They are able to walk up walls and ceilings and pick up heavy objects on their fingertips.
Read more about balance in space in Health24's Body in Space feature
Puffy faces and skinny legs
Due to the lack of gravity, the body's fluids do not concentrate in the lower half of the body, but shift to the head and chest area. Yesterday, cosmonaut's faces were puffy and swollen and their sinuses were blocked.
Today, they will be over the worst in terms of puffiness, although their faces will still be swollen. The kidneys have begun to adapt to space and have reduced their urine output.
Read more about body fluids in space in Health24's Body in Space feature
The circulatory system
Since yesterday, the cosmonauts have been losing blood plasma and red and white blood cells. This does not cause any problems yet.
Read more about blood in space in Health24's Body in Space feature
Immune system
A cosmonaut's immune system is affected by space. Fewer of the body's T-cells, which fight infection, are produced, and those that are, are less effective than here on earth.
Their saliva will already contain more bacteria and viruses than it would on earth.
Read more about the immune system in space in Health24's Body in Space feature
The heart
The initial increase in volume of blood in the chest area yesterday caused the heart to enlarge. The heart may enlarge further today to deal with the extra blood.
Although an enlarged heart does not cause harm, Shuttleworth's heart rate will still be slower because of this.
Read more about the heart in space in Health24's Body in Space feature
Space sickness
The body still does not know which way is up or down. Cosmonauts usually fell very ill by now and can even vomit. They also lose their appetite and can suffer from headaches and a lack of concentration.
The skeleton
The weakening of bones that began yesterday continues. The loss of bone density is the most serious side-effect of space travel.
Mark will exercise for two and a half hours per day to prevent bone and muscle loss. He will be strapped to his training apparatus to prevent him from flying all over the shuttle.
Read more about the muscles in space in Health24's Body in Space feature
Muscles
Cosmonauts can lose 10 to 20 percent of their muscle mass during a space trip. Muscle fibres can even change their type to adapt to motion in space. Within a week, slow-twitch muscles can become fast-twitch muscles.
The greatest loss of muscle occurs in the spine and leg muscles. This will already have started in Mark's body.
Exercise is essential to prevent muscles from atrophying.
Read more about the muscles in space in Health24's Body in Space feature
- (Health24, April 2002)