We have all seen the images of Astronauts goofing around in space, playing with their food and flying around like an uncoordinated version of superman. But what is it really like up there. Here are six surprising facts that you didn’t know about living in space…

1 -In space no-one can…taste their dinner.

One common complaint made by the modern space-farer is that food eaten up there on the final frontier tastes bland compared to food eaten on the ground. Consequently meals are often garnished with a number of assorted condiments from salt and pepper (in liquid form to prevent loose grains getting up noses or into equipment) to spicy hot sauce, horseradish and Wasabi.

The causes of this diminished sense are not entirely clear but the leading theories put it down to the redistribution of body fluids in micro-gravity causing congestion in the nose, and as the sense of taste is heavily reliant on the sense of smell, food can end up tasting bland. Whatever the cause one thing is certain, a bottle of Tabasco sauce should be included in any would-be astronauts supply kit.

2 -Its’ not really zero gravity!

That’s right folks there is gravity in space, in fact the Earth’s gravity is only 3% weaker at the edge of space than it is on the ground. So if it’s not zero gravity how come everything is floating around up there?

Well it turns out that gravity is actually partly responsible. As the space station travels around the earth at the mind boggling speed of 17,000 mph, the Earth’s gravity tries to pull it back down to the ground, but the station is travelling way too fast for that to happen, so instead of falling down to the ground it falls all the way around the earth. It is because of this that the astronauts are able to fly around inside the space station, they are not floating they are falling. Just like skydivers flying around in formation, the space station and the astronauts are continuously falling around the Earth; here is a cool video to explain it.

…and it turns out that you don’t need to make it all the way into space to experience it. NASA frequently use specially equipped planes to simulate weightlessness by flying them in a series if parabolic arcs. As the plane reaches the top of the arc the engines are throttled back and the plane enters free fall for a few short seconds. During this brief time everyone inside the plane experiences the same weightlessness that Astronauts experience in space. Here is video of it in action.

3 -Space is bad for you.

We have all seen science fiction examples of hapless space travellers meeting their untimely end in the merciless vacuum of space, but it turns out that you don’t have to venture outside the airlock for space to take its toll on you.

Many of the most common problems are actually a result of all that floating about. The micro-gravity environment reduces stress on the muscles and skeleton and as a result astronauts lose muscles mass and bone density at a rate that is 10x that of a 70 year old with Osteoporosis. The micro-gravity environment also causes the heart to weaken as it no longer needs to work as hard to pump blood around.

Naturally keeping these effects at bay is a top priority and to do this astronauts will typically work out for up to two hours a day using specially designed equipment to make sure that their bodies get a proper work out. But even with all of that hard work the return to Earth’s gravity can prove to be challenging and some astronauts find themselves unable to walk when they get back on the ground. Space tourist Anoush Ansari describes this sensation in her space blog.

Other health problems that are known to be caused by extended periods in space include; long term damage to eye sight, nausea, dizziness, insomnia, vitamin D deficiency due to a lack of sunlight and… flatulence. But on the plus side some astronauts have noted that living in space can ease snoring…

4 -Space Smells… and not just because of the flatulence.

First of all let’s be clear, space is a vacuum so there isn’t actually anything there to smell, but nonetheless a lot of astronauts describe encountering the smell of space any time the hatch is opened on a newly docked vehicle or someone comes inside from a spacewalk. Most describe it as being a strong, metallic smell, and it is thought to be caused by materials interacting with ionized particles out there in the vacuum. But don’t just take it from me; astronaut Greg Chamitoff describes the smell in this youtube clip.

5- Living in Space turns your feet upside down.

This might sound like a pretty strange side effect, but according to a number of astronauts the way you use your feet in space can cause some unusual changes.

Walking is not something astronauts do a lot of in space, in fact the only time they use their feet in the normal way is while exercising. Most of the time they are floating around weightlessly and after only a few weeks the soles of their feet start to change. The hard, rough calluses that we have all built up after years of pounding the pavement, peel away (gross) revealing soft, new skin underneath.

… But, just because astronauts don’t use their feet for walking doesn’t mean that they aren’t being used. Floating around in micro gravity is lots of fun, but it can also present a challenge when it comes to staying still at a workstation.

To help solve this problem the surfaces of the International Space Station are covered with hand rails that the astronauts can grab on to with their hands or hook their feet underneath to keep them place. In the same amount of time that it takes for the soles of their feet to soften, many astronauts develop calluses on the tops of their feet from hooking them under the hand rails. Many also report that the muscles in the front of their legs ache from all the extra work they are doing.

6 – So near yet so far.

Often when we think of space we imagine a far off place that most of us will never reach, and sadly while the last part is still true (though hopefully not for too long), space itself is closer than you might think.

Defining the edge of space is a tricky business. The Earth’s atmosphere doesn’t just stop and give way to the vacuum of space, instead it gets gradually thinner until eventually there is nothing left. The point at which this happens varies at different times and places as various factors cause our atmosphere to expand and contract. In fact the Thermosphere (the second furthest reach of our atmosphere) extends so far out that the International Space Station is actually flying around inside it. The very furthest and thinnest reaches of our atmosphere actually extend half way to the moon. In this extraordinarily thin part of the atmosphere (known as the Exosphere) the air molecules are so dilute that they are unlikely to ever come into contact with each other.

So how do we define the edge of space? The most commonly accepted boundary is known as the Karman line and was devised by a smart chap called Theodore Von Karman who noted that above a certain height the atmosphere is so thin that an aircraft would need to be travelling at orbital velocity (i.e. roughly 17,000 mph) to maintain lift. In other words, once you have past the Karman line the only way to prevent yourself from falling back down is to be going fast enough to achieve orbit.

So, how high up is the Karman line? Well Karman was smart enough to realise that the boundary would change as the atmosphere expanded and contracted, so he calculated the approximate height and then rounded the result to 100 km (approximately 62 miles).

By everyday standards this is quite a long way up, for comparison most airliners fly at around 5 to 7 miles above the ground. But try thinking of it this way… The distance to Karman line is roughly equal to the distance between New York City and BridgePort, Connecticut. Search Google Maps for directions between the two and it should draw you a nice straight(ish) line on the map, now zoom out so that you can see the whole of the Earth, that line on the map should now look very small indeed, now imagine that line was stood on its end – and that’s how far it is to edge of space.

Another way to think about the distance to the Karman line is in terms of travel time. Most modern rockets reach space after only a few minutes. SpaceX’s Falcon 9 Rocket is able to reach the 100 km mark after only 3 minutes and achieves orbit in less than 10 minutes, but that what it was designed to do. What if the plane that is taking you Mexico this summer was able to fly straight up to the Karman line (it can’t do this so don’t ask the pilot to try), how long would it take you to earn your astronaut wings. Well assuming you are flying on a 747 and that it is travelling at is average cruising speed of 567 mph then you would reach the edge of space in about six and half minutes… But let’s take this one stupid step further… Let’s assume that the mountain bike that you got for Christmas was somehow capable of overcoming the Earth’s gravity and you could cycle your way in to the heavens, how long would it take you to cover the 62 miles between you and the final frontier. Assuming that you are capable of peddling yourself along at an average speed of 13 mph (this is the lowest estimate I’ve found for the average cycling speed – some go as high as 25 mph) then you will be able to consider yourself an astronaut after a mere five hours. That’s right guys – you could cycle your way into space in an afternoon… providing you ignore the laws of physics.

And there you have it… six surprising things you didn’t know about living in space… So what are your thoughts, did you already know all 5 or do you have another surprising fact that I really shouldn’t have missed? Post me your thoughts in the comments section below…