Space travel has always been a hazardous activity, as noted by New Atlas. But even with the loss of several American crews during the Apollo and space shuttle eras, most Americans feel that the benefits are worth the risks. Even so, if SpaceX, NASA, and other organizations are going to be sending human beings to Mars or other planets in the coming decades, it only makes sense to try to minimize the dangers involved in space travel.
Of course, with any exploration, unknown dangers that engineers and scientists don’t anticipate could crop up. But while we may have to deal with such unexpected dangers on the fly, there are several known dangers we can address before manned space travel to Mars or elsewhere.
Radiation Dangers in Space
Travel in space offers a number of dangers for human beings, but one of the most significant is radiation. Human beings on the surface of the Earth are protected from solar radiation and other types of radiation found in outer space by our atmosphere and surrounding magnetic fields.
But during space travel away from the Earth – such as to the moon or to Mars – the only thing protecting human beings from potentially hazardous, or even lethal radiation damage is whatever shielding exists on the outside or inside of the spacecraft.
There are two types of shielding that can be used to protect astronauts during space travel. The first is passive shielding and can be anything from the metal walls of the spacecraft to the machinery and equipment lining the inside of those walls. Even compacted dirt from mined asteroids could be used.
— Apex Magnets (@ApexMagnets) January 24, 2015
Some designers have suggested that supplies used by both the crew and the spacecraft itself could be used as passive shielding. For instance, the massive supplies of water that a space traveler would need during the long journey to Mars could be stored along the inner walls of the spacecraft to act as passive shielding.
Active shielding is another possible approach to radiation shielding. A powerful magnetic field could be generated around a traveling spacecraft that would deflect incoming radiation particles. This would likely require a substantial power source. However, if superconductors were employed in the mechanism in a vacuum, power loss would only occur when a particle of radiation was actually stopped.
Zero Gravity and Space Travel
One of the more obvious effects of space travel is zero gravity. As NASA points out, it’s not really zero gravity – it’s microgravity. Of course, from a human physiology standpoint, it amounts to the same thing. The human body evolved in a 1G environment – the Earth – and all of its functions are designed to operate under those conditions.
Research on space stations and other spacecraft have revealed that long-term exposure to a zero gravity environment has an extremely detrimental effect on human health. For one thing, bone loss becomes a very serious concern during long-term space travel. While attempts have been made to address this through the use of exercise equipment and other strategies, the ultimate solution for the problem of zero gravity is to simulate gravity during the journey.
@JasDnldTerry Any constant thrust drive like VASIMR would greatly improve transit times. Rotate the entire spacecraft to give crews gravity.
— Just A. Tinker (@John_Gardi) July 6, 2015
The best way to accomplish this is through rotating either the entire spacecraft or some portion of it during the trip. NASA has, for decades, studied the construction of large rotating space colonies and spacecraft, but these would be prohibitively expensive because of the massive scale that would be required.
Unfortunately, because of the human inner ear, astronauts can detect rotational effects if the radius of the rotation is below a certain size. For this rotation to have little or no effect on a hypothetical astronaut traveling to Mars, the spacecraft in question – or at least that section of it rotating – would have to be enormous.
However, there is a possible alternative. Instead of having a single large spacecraft that either rotates or has a large rotating section – similar to that used by the space travelers in 2001: A Space Odyssey – a much smaller spacecraft could be designed so that it separates into two parts that then rotate around the axis of a tether connecting them. In this way, NASA might be able to simulate gravity without having to build a colossal spacecraft.
Psychological Concerns in Space Travel
In the past, another major concern about space travel to Mars or elsewhere in the solar system related to the psychological problems that might result from long-term isolation. After all, even in the rosiest propulsion scenarios, it will take months to get to Mars. This means that human crews would be essentially trapped with one another for an extended time.
However, recent experience with space travel aboard the space shuttle and the International Space Station – as well as research carried out by the Russians aboard their various near space stations – indicate that this is not as much of a concern as once believed. Plus, it’s hardly a new phenomenon for people on long voyages to be stuck together for months. Colony ships traversing the Atlantic spent just as much time traveling to North America as space travel to Mars would demand from astronauts.
More than this, maintaining connection with the Earth via transmissions of email, news, photos, and video have done a great deal to alleviate the boredom and claustrophobia of the International Space Station. It’s safe to assume that – even with the time delay caused by the speed of light limit – space travel to Mars or elsewhere would still permit the astronaut voyageurs to keep in contact with home.
[Featured Image by NASA via Getty Images]