Challenges of space travel

Last month Sunita Williams entered the cosmos as part of NASA’s Expedition 32 which aims to perform more than 240 experiments at the International Space Station in addition to testing a micro-satellite deployment system and transporting new research equipment. September 17 is when the crew will next be on terra firma after seventy-nine days in zero gravity.

Re-adjusting to a life restrained by gravity has its complications particularly when propelling one’s body is achieved merely by wiggling fingers. Accidentally bumping into a surface often results in the astronaut careering through the cockpit.

In his book “Do Your Ears Pop in Space?” Col. Mike Mullane, a three-time astronaut, indicates that even eating in space involves slow, controlled movements to avoid spillage, not least because directing floating spheres of ‘spilled’ food into one’s mouth is a tiring and time-consuming exercise.

From getting accustomed to sleeping in weightlessness like a zombie with arms floating in front of one’s face to putting things down on a Velcro surface and then forgetting which of the many possible planes the object lies on, life in space requires adopting and adapting to a different lifestyle.

Spending extended periods of time in zero gravity has some adverse effects on the body, namely muscle and bone atrophy. According to NASA Science, muscles can disappear at a rate of 4 per cent per week, while bones atrophy at 1 per cent per month. In the absence of gravity, the body no longer recognises a need for the muscles (particularly those in the calves and spine) that ‘fight’ it and help maintain posture.

Periodic exercise maintains the body’s cardiovascular system but does not have the same effect as exercise on Earth because of the unnecessary (and therefore absent) resistance to gravity. Protracted exposure to weightlessness causes a loss of calcium and reduction in bone mass for the same reason, called osteoporosis. While post-menopausal women on earth are more prone to osteoporosis, both genders are equally prone to decalcification in space.

Furthermore, the mere act of living in space for days on end exposes an astronaut to a dose of space radiation equal to the dose an Earthling receives in a year. However this is only a fraction of the intake that scientists perceive as harmful. Also, the launch of space shuttles and the duration of expeditions are adjusted to avoid high solar activity.

If being bombarded by higher levels of cosmic and neutrino radiation is the downside of space travel, then physical growth is one of the perks. It certainly is true that disembarking astronauts are taller than embarking ones! This growth is due to zero gravity — the vertebrae of the spine spread out.

While this effect is permanent, not every aspect of adjusting to life in space is long-lasting. Space Adaptation Syndrome or ‘space sickness,’ which scars the start of an expedition for some astronauts, is caused by a sudden change in spatial orientation. The satisfaction of weighing zero Newton is also temporary, and ends once the shuttle re-enters the Earth’s atmosphere and gravity comes into play.

KASTURI SHAH

(The author graduated from boarding school at the Cheltenham Ladies' College in the U.K. and will be joining Princeton University next month)