Will the COVID-19 pandemic spread in space?丨Young looks up at the stars and chases his dreams

Before we know it, time has already arrived at the door of 2023. Looking back at the past 300 days and nights, it seems like a series of steps, each of which records the development of China's aerospace industry. As the New Year's Day is approaching, we have prepared the 9th season of the "Young Stargazing, Chasing Stars and Dreams" popular science New Year's Eve event for our readers. Please join us for an exciting journey of chasing stars and dreams!

Reviewer: Gu Haitong

Deputy Chief Physician, Department of Respiratory Medicine, Beijing Tongren Hospital, Capital Medical University

Recently, the social media has been full of people saying that they are either having a fever or recovering from a fever. Let alone the record-breaking high temperatures, the body's gradual recovery is enough to make people talk for days and nights - from "driving an electric drill" on the head to "swallowing glass" in the throat to "sealing the nose with cement", the road to recovery is really full of obstacles.

Source: Weibo picture

When I felt that I was about to suffocate due to lack of oxygen, I kept imagining that I would let the viruses also experience the feeling of "holding their breath". If the air is first made into a vacuum, and then added with extreme cold and super strong radiation, the "Ten Tortures of the Qing Dynasty" will be complete.

Wait...it sounds like this environment is the universe .

So, if the new coronavirus is accidentally brought into space by a spacecraft, can it survive in the space station and outer space?

Do astronauts catch colds in space?

Although today's astronauts' physical condition and health are carefully monitored before they go into space, like all the precautions in a laboratory manual, every prohibition is a result of a major mistake that has occurred in the past .

During the Apollo 7 mission in 1968 , the then commander Wally Schirra caught a cold while hunting three days before the launch, but his symptoms disappeared during the launch, so he went into space normally.

But he obviously wasn't alright.

The pathogen did not easily adhere to objects in a vacuum environment, but floated in the air, so his two teammates were soon infected with the cold.

In addition, because the astronauts were in a state of weightlessness for a long time, the mucus accumulated in the nasal cavity and could not be discharged smoothly, causing them to endure the pain of tinnitus and blow their noses desperately. Coupled with the physiological problems in space, the cold made the three astronauts exhausted.

Schirra with a cold

Source: NASA

Pilot Walter Cunningham recalled, "Our little spaceship quickly became a used tissue box." The living cabin was filled with used tissues, so much so that he thought the mission might be terminated because of the tissue problem.

On the return trip, Schirra insisted on not wearing helmets. Because the three astronauts all had colds, the air pressure increased during the descent, and the pressure on the sinuses could cause the eardrum to rupture. Pinching the nose to breathe can effectively avoid ear damage. Of course, they finally returned smoothly without helmets.

Later, Schirra became the spokesperson for a TV commercial for a cold medicine.

But after that, the United States did not seem to have learned its lesson, and the astronauts of Apollo 8 and 9 encountered similar difficulties. It was not until later that NASA decided to implement pre-flight quarantine, requiring astronauts to have very limited contact with others and to place those in contact under medical isolation to ensure the health and safety of the crew.

However, this is already a very early case in space. How has the situation changed with the new coronavirus today?

Pathogens change their faces once they enter space

Not only pathogenic bacteria that are harmful in themselves, but also some microorganisms that are harmless on Earth may turn into pathogenic bacteria in space and pose a threat to the safety of all astronauts and the completion of the mission.

Because microorganisms will undergo various changes in space due to environmental pressure, space radiation will also cause microorganisms to mutate, and the microgravity environment will also cause some changes in the physiological and biochemical characteristics of microorganisms, such as increased toxicity, pathogenicity or drug resistance.

Atlantis astronauts discover salmonella becomes more toxic in space

Source: NASA

Additionally, scientists have found that dormant viruses can respond to the stress of spaceflight , with herpes simplex virus, for example, being reactivated during spaceflight, and ongoing research suggests that enhanced bacterial virulence in space could reduce the effectiveness of antibiotic treatment.

Infection is not easy

As we can see from the text above, once a pathogen actually enters a spacecraft or space station, its spread becomes difficult to stop . The lack of gravity prevents particles from settling, making pathogens such as influenza viruses and even coronaviruses easier to spread.

However, no matter how many tricks viruses have, humans always have ways to crack them.

In order to prevent viruses from Earth from being accidentally brought into space, all types of space-related launchers and capsules must keep their surroundings absolutely clean during construction, testing, transportation and final launch. When necessary, sterilization measures such as high-temperature sterilization or radiation sterilization will be used.

Source: National Space Science Center, Chinese Academy of Sciences

In addition, during the mission in space, in order to prevent germs from being suspended in the air, each cabin must be ventilated, and the high-efficiency air filters in the space station will remove particles. At the same time, the circulating water system also has the function of disinfecting microorganisms.

If the components of the spacecraft and the air, food and water inside are safe, the remaining source of infection is the astronauts. To prevent the virus from being brought into space, astronauts will be medically isolated and undergo relevant examinations before performing space missions to ensure that they do not carry active viruses into space.

NASA medical staff said that countries have been committed to preventing any viruses from entering the space station, "given the enhanced safety measures, the possibility of the new coronavirus entering the space station is very small."

Let's get back to reality.

After talking about the situation in space, let's go back to real life and take a look:

1: How long can the new coronavirus survive?

How long the new coronavirus can survive is not fixed, because it is affected by many factors such as environmental humidity, temperature, whether the surface of the object is smooth, sunlight ultraviolet rays, etc. Under normal circumstances, the new coronavirus can survive for about 2 hours in dry air, about 3 hours in aerosols, and 4 hours on copper.

2: Factors affecting the survival time of the new coronavirus

Ambient humidity

The new coronavirus prefers moisture to dryness. It generally survives longer in a relatively humid environment, and shorter in a relatively dry environment, only 48 hours. After 2 hours in the air, its activity decreases significantly.

Ambient temperature

The higher the temperature, the shorter the survival time of the new coronavirus. At a high temperature of 56 degrees, all new coronaviruses can be completely killed in about 30 minutes. In an environment of about 4 degrees, the virus can survive for about 14 days.

UV rays

The new coronavirus is sensitive to ultraviolet rays and will be killed by exposure to ultraviolet rays for about 15 to 30 minutes.

75% alcohol

75-degree alcohol can also kill the new coronavirus. Wiping or soaking objects with such alcohol can kill the virus within 30 minutes.

In short, it is unlikely that the virus will suffer the same way as us, but it is also unlikely that the virus will successfully enter the space station. With the recent experience of large-scale "positive" cases, people's mentality towards the new coronavirus is also quietly changing. The Shenzhou 15 astronauts returning in half a year may see a different China.