We will admit: it's not the biggest of target markets. Nevertheless, it's worth asking whether astronauts and space tourists also need to add sunscreen to their packing list before taking off on their missions. Let’s head off into the stratosphere and beyond.

It's likely also happened to you, at least once: You're looking forward to the holiday, your suitcases are packed, the toys are stowed away for the kids – and barely have you set foot in the hotel when you realize you forgot the sunscreen. It's not a problem, though: you can buy more even in remotest regions of the world. Even trekkers heading for Everest in the Himalayas: they can still buy sunscreen from a Nepalese lodge at an altitude of over 5,000 meters. But as an astronaut or space tourist, you'd better not forget anything. Especially not anything you need to protect yourself. 

Let's get straight to the point: Astronauts don't need to pack any sunscreen. Although they do need to protect themselves from UV radiation even more than people on Earth, the commercially available sunscreen that we know and use would simply not be adequate for their needs. Because when we talk about sun/UV protection down here, the first thing we are referring to is the earth’s own protective shield: the ozone layer.

The other 95% is in the longer UVA wave range. The amount and strength of solar radiation that ultimately finds its way to us humans varies, and depends on a number of factors and external influences. These include, in particular: the ozone concentration, the level of cloud cover in the sky, the time of day and season, our geographical latitude and our altitude above sea level. The highest ever value measured according to the guidelines for the UV index was: 43.3. This measurement was taken on 29 December 2003, and this incredible value was reached in the Andes. It is essential to simply avoid going outdoors when values are this astronomical. 

But let’s get back to our astronauts. During their stay in space, which starts around 100 kilometers above the Earth, they are not protected by the ozone layer, and this is extremely dangerous for many reasons. In this almost unlivable environment, men and women in space need to be protected from the hazards they face in a variety of ways. 

In addition to ultraviolet radiation from the sun, it is cosmic radiation above all that poses a major threat to the health of astronauts. This type of radiation consists of high-energy particles that can cause severe damage. They can penetrate the human body and cause cancer or else lead to heart problems and cataracts, for example. Cosmic radiation can also destroy the nervous system's tissue and damage cellular DNA.