Safety limit for people when flying to space

Scientists are constantly studying to accelerate the speed of the spacecraft, however, the safe limit for accelerating ships is still a must. The human body can be torn apart if the spacecraft has too much acceleration.

Limit human body when flying to space

According to the BBC, the record of vehicles with the largest movement speed of humans is now held by three NASA astronauts . In 1969, the Apollo 10 on the way back to Earth after flying around the Moon reached a speed of 39,897 km / h compared to Earth. However, according to scientists, this record will soon be broken in the near future.

Equipment to test the level of the pilot's acceleration force.(Photo: Science Photo Library)

"A hundred years ago, no one could have imagined that humans could travel at nearly 40,000 km / h ," said Jim Bray of aerospace company Lockheed Martin. Bray is currently NASA's Orion project director.

The Orion spacecraft designed to fly around the Earth in low orbits, is expected to break Apollp 10's speed record for 46 years. High speed is synonymous with flight time and duty. will be shortened, reducing the risk of cancer due to cosmic radiation exposure to astronauts.

The spacecraft launch system used for Orion is expected to be commissioned for the first time in 2021, investigating an asteroid "captured" by the Moon as it passes by, then performing its task. spacecraft to Mars. The designers expected Orion's speed to be around 32,000 km / h. However, according to Bray, the speed of Orion in the future when put into operation can break the record that Apollo 10 holds.

" Orion is designed for a lot of different destinations in the universe, its speed may be much higher than the current expected speed, " Bray said. He also said that there is no limit that humans cannot reach, except the speed of light.

However, the problem here is whether people can be inside the spacecraft moving too fast or not.Inertia is an attribute of the universe whereby every object with mass tends to resist changes in the state of motion. If accelerated or decelerated too quickly, overcoming limits , the human body will suffer serious injuries. The reason is that the structural elements on the body have different inertia, the moving state of the elements will change unevenly. Too much spacecraft acceleration can cause the body to be torn apart.

Another problem that Orion needs to overcome, is the accelerating force (Gs) acting on astronauts , due to the acceleration or deceleration process. This force can be directed from head to toe or vice versa, vertically. When the force is directed from the foot to the head, the astronaut will feel as tense as when growing a banana, the red face due to the blood rushing to the lower eyelid is pulled up to cover the pupil. In contrast, when this force is directed from the head to the bottom of the legs, the eyes and brain will be deprived of oxygen as the blood is cornered into the lower limbs, which will cause astronauts to lose their sight and faint. There have been many aviation accidents due to fainting of pilots.

Orion spacecraft needs thick shields to cope with drift meteorites.(Photo: NASA)

Human limit

A normal person can withstand a maximum of 5Gs of accelerating acceleration from head to toe before falling into the unconscious state. The pilots have trained and are equipped with special outfits that can be kept awake to control the aircraft when subjected to a 9Gs acceleration force.

' For a short time, people can withstand a much greater force of acceleration than 9Gs, but maintain that condition for a long time, very few people can do it,' said Jeff Sventek, Chief Executive Officer. of the Aerospace Medicine Association, based in Alexandria, Virginia The astronauts often suffer from an acceleration of about 3-8Gs when taking off and landing.

Another problem to consider is the meteorite drifting in the universe. They can cause heavy damage, like birds to airplanes. To protect the ship, Orion will be equipped with a protection layer of 18-30cm thickness depending on the location and shields. Important parts of the ship also need to be streamlined.

" We need to figure out which direction the meteorites can come from ," Bray said. In addition, although the density of elements in the universe is very low, but when the train moves at a rate of several hundred million km / h colliding with hydrogen nuclei in space, they will be broken down into the lower particles. atoms (protons, neutrons), pierce the hull and harm the crew and equipment. If the velocity is about 95% of the speed of light, exposure to subatomic particles will almost instantly kill people. To ensure safety, scientists recommend not to speed up to more than half the speed of light.

In terms of fuel, the most abundant energy source that humans can exploit is currently traditional fission atomic energy . Technology has not yet allowed the exploitation of nuclear energy in the form of fusion, just as the reaction is taking place on the Sun.

With these two forms of energy, the spacecraft can reach 10% of the speed of light, about 100 million km / h. In the future, the optimal fuel type for high-speed spacecraft is antimatter. When matter and antimatter touch each other, they will cancel each other out and release energy. There is now technology to create and store antimatter, though only on a very small scale. With the antimatter fuel engine, the spacecraft will take several months to achieve a speed comparable to the speed of light, but will keep the acceleration at a moderate level, within the tolerance level. be of astronauts.