In prolonged weightlessness, bone mass appears to decrease because the lack of stress on the bones slows the formation of osteoblast cells. Fewer bone-building cells, along with a constant level of bone-destroying activity, translates into a net loss of bone mass.

Some of the very real effects of this “apparent weightlessness” include:

• Loss of bone mass (similar to osteoporosis)
• Reduced total blood volume, particularly loss of red blood cells.
• Giddy, light-headed feeling.
• Space sickness with nausea and vomiting.
• Decrease of heart size.
• Nasal congestion.
• Muscle weakness.

One of the major effects of weightlessness that is more long-term is the loss of muscle and bone mass. In the absence of gravity there is no weight load on the back and leg muscles, so they begin to weaken and shrink. Even destruction and construction processes of bones change when in space.

As we grow older, the body begins to absorb bone much faster than it produces new bone. This leads to a lowered bone density, the same effect that microgravity has on astronauts. As a result, bones become more fragile and are more susceptible to fractures, especially in the hip, spine, and wrist.

Bone loss occurs in the weightless environment of space because bones no longer have to support the body against gravity. On Earth, gravity applies a constant mechanical load to the skeletal system, that causes healthy bones to maintain a certain density so that they are able to support the body.

They found classic symptoms of what is now known as Space-Associated Neuro-Ocular Syndrome (SANS). Symptoms include swelling in the optic disc, which is where the optic nerve enters the retina, and flattening of the eye shape.

NASA makes it clear that your body wouldn’t explode and your eyes wouldn’t pop out of your head like many science fiction movies suggest. However, you would swell up and get really painfully puffy.

NASA Radiologists have finally figured out why astronauts who spend a lot of time in space get impaired vision. The problem, called visual impairment intracranial pressure (VIIP) syndrome, has been reported in two-thirds of astronauts who go up to the International Space Station.

A study found that the vision deterioration in astronauts is likely due to the lack of a day-night cycle in intracranial pressure. Researchers found that in zero-gravity conditions, intracranial pressure is higher than when people are standing or sitting on Earth, but lower than when people are sleeping on Earth.

To add salt to the wound, season 1 gradually revealed another unfortunate ramification of his extended bouts in space: Misha has developed space blindness. Away may be a fictional show, but it’s based on real science. Nasa has admitted that deep space travel may cause blindness or visual impairment in astronauts.

When he was questioned about his eyesight, Misha admitted he had memorised the letters on the eyesight test to make out his sight was perfectly normal. The loss in eyesight is caused by the level of cerebrospinal fluid (CSF) in astronaut’s brains. Those who spend longer in space have more CSF than those on short trips.

Salt and pepper are available but only in a liquid form. This is because astronauts can’t sprinkle salt and pepper on their food in space. The salt and pepper would simply float away. There is a danger they could clog air vents, contaminate equipment or get stuck in an astronaut’s eyes, mouth or nose.

As a result NASA’s official policy forbids pregnancy in space. Female astronauts are tested regularly in the 10 days prior to launch. And sex in space is very much frowned upon. So far the have been no confirmed instances of coitus, though lots of speculation.

In space, not so much. Sensors inside our ears, which are part of the vestibular system that controls balance, are thrown off — often causing astronauts to feel dizzy or queasy the first few days in space. Once they get back to Earth, it takes a while for their bodies to readjust. Hence, the walking problems.

Here are five foods that NASA Astronauts can’t eat in space:

1. Bread. U.S. Food and Drug Administration.
2. Alcohol. United States Embassy, Berlin.
3. Salt and Pepper. Getty Images / iStock.
4. Soda. Getty Images / iStock.
5. Astronaut Ice Cream. The Franklin Institute.

The first-ever pizza party in space is getting sky-high reviews. After making their own individual-size pizzas, the six astronauts tossed and twirled them like floating frisbees before heating and devouring them. Commander Randy Bresnik called the pizzas “flying saucers of the edible kind”.

Today’s astronauts can enjoy many of the same chocolate candies that they would at home. NASA has a policy against endorsing any commercial goods or services, so it does not name any of the chocolate brands that have flown in space.

What do astronauts drink in space? Astronauts mainly drink water while in space, but flavoured drinks are also available. Freeze-dried drink mixes such as coffee or tea, lemonade and orange juice are provided in vacuum sealed pouches.

Astronauts say that “Today’s coffee is tomorrow’s coffee!” Sometimes, astronaut poop is brought back to Earth for scientists to study, but most of the time, bathroom waste – including poop – is burned. Poop is vacuumed into garbage bags which are put into airtight containers.

Humans are well-adapted to the physical conditions at the surface of the earth, and so in response to weightlessness, various physiological systems begin to change, and in some cases, atrophy. Though these changes are usually temporary, some do have a long-term impact on human health.

A total of 18 people have lost their lives either while in space or in preparation for a space mission, in four separate incidents. All seven crew members died, including Christa McAuliffe, a teacher from New Hampshire selected on a special NASA programme to bring civilians into space. …

Astronauts have also died while training for space missions, such as the Apollo 1 launch pad fire which killed an entire crew of three. There have also been some non-astronaut fatalities during spaceflight-related activities. As of 2020, there have been 30 fatalities in incidents regarding spaceflight.

Fun fact: What does space smell like? In a 2012 article published in the Atlantic, astronauts describe being met with a peculiar smell after removing their helmets following a spacewalk. That smell has been described as “seared steak,” “hot metal” and “welding fumes.”

Outer space is teaming with fields and particles, as depicted in this artistic rendering. Even a “perfect” vacuum would still hold vacuum energy, the Higgs field, and spacetime curvature. Space seems empty to humans because we can’t see most of the stuff there, and because there is much less air than we are used to.

Not every STEM (science, technology, engineering and math) degree will qualify you to be an astronaut. NASA is looking for people with a degree in engineering, biological science, physical science (like physics, chemistry or geology), computer science or mathematics.

But in 1970 future Apollo missions were cancelled. Apollo 17 became the last manned mission to the Moon, for an indefinite amount of time. The main reason for this was money. The cost of getting to the Moon was, ironically, astronomical.

Current status. Since the nylon flag was purchased from a government catalog, it was not designed to handle the harsh conditions of space. A review of photographs taken by the Lunar Reconnaissance Orbiter (LRO) indicates that flags placed during the Apollo 12, 16, and 17 missions were still standing as of 2012.

All soft landings took place on the near side of the Moon until 3 January 2019, when the Chinese Chang’e 4 spacecraft made the first landing on the far side of the Moon….Early U.S. uncrewed lunar missions (1958–1965)