More than 50 years after humans entered space, the way things behave in microgravity now seems obvious to us.
But we are not always sure how space will affect certain things. Like fire. Or planarian worms. Even plants. Only through experiments can we understand the answers to these pressing questions.
This has led to some rather interesting, sometimes frustrating, and sometimes outright weird experiments in space.
The space suit is pulled out of the airlock
The video above aired like a nightmare. An aerospace obeyed the International Space Station (ISS) and floated unfettered, with a huge black gap yawning in front of it.
You may find that no one was harmed during this experiment-no one in the Russian Orlan spacesuit was nicknamed Ivan Ivanovitch or Mr. Smith-stuffed with a pile of old clothes and a radio transmitter.
The idea is that old space suits can be used as satellites. SuitSat-1
SuitSat-1 stayed in a silent orbit for several months before entering the Earth’s atmosphere and burning on September 7, 2006.
Hammer and feather
In the late 16th century, Galileo Galilei dropped two spheres of varying mass from the Leaning Tower of Pisa in Italy. When the two reached the ground at the same time, he refuted the classic view by showing that the mass has nothing to do with the acceleration of gravity. All objects, regardless of their mass, should fall at the same speed-even feathers and hammers.
On earth, it is difficult to prove this due to air resistance. But nearly 400 years later, a human standing on the moon repeated this experiment.
On August 2, 1971, Apollo 15 Commander David Scott (David Scott) held a geological hammer in one hand and a falcon feather in the other. He raised them to a height of about 1.6 meters above the ground, and then dropped them. Because the astronaut is basically in a vacuum, there is no air resistance, so the two objects fall synchronously.
NASA astronaut Joe Allen wrote: “Within the accuracy of simultaneous release, the observed objects are subjected to the same acceleration and hit the lunar surface at the same time. This is a result predicted by accepted theories, but With this in mind, you can still rest assured that the number of spectators who witnessed the experiment and the journey home depend strictly on the fact that the validity of the particular theory being tested.”
The hammer and feathers are still there.
Carbonated tablets in bubbles
Under the action of microgravity, if you spray a little water from the nozzle, it will only hang there, and everything will fluctuate.
This can bring a lot of fun. Experiments and demonstrations include popping up water balloons in the vomit comet (a plane that performs a parabolic flight to produce a short free fall) and the International Space Station, attaching a mass of water and large bubbles inside the bubbles to the speaker, observing the vibration, and using the GoPro camera Put it in water drops to shoot from the inside (you need to use stereoscopic 3D glasses).
In 2015, astronaut Scott Kelly used food coloring to color water masses, then inserted effervescent tablets to watch them dissolve and release gas into the water. It was shot using the space station’s new 4K camera, so you can view the entire alien algae spawning… in extremely clear resolution.
(ESA / NASA)
Just as water behaves differently in microgravity, so does fire. Fortunately, so far, the 1997 Mir space station fire is a one-time event, but figuring out how the fire behaves in microgravity can be useful for future long-term missions (for example, manned Mars missions and permanent lunar missions). ) To make a plan for fire safety. It can also help inform fire safety protocols on the planet.
For this reason, many ongoing research projects have studied what happened to space flames. The “Combustion and Suppression of Solids” experiment on the ISS investigated the combustion and extinction characteristics of multiple fuel types in microgravity. The data from these experiments can be used to build more complex models to understand more detailed information about the earth’s gravitational combustion.
On the Cygnus cargo spacecraft, scientists studied the behavior of flames under different spacecraft conditions in the Saffire experiment. NASA’s flame design survey (part of advanced combustion through microgravity experiments) is exploring the production and control of soot.
Of course, all of these are very useful and interesting. But it is so crazy, we bet that some astronauts have an absolute explosion in space, playing in the fire.
In 2011, scientists set out to answer this pressing question: Can spiders adapt to space travel? They sent two golden silk weaving spiders (Trichonephila clavipes), Esmeralda and Gladys, to stay on the International Space Station for 45 days.
They are placed in a nice habitat (can you imagine spiders will loosen on the space station)? The light conditions can simulate the day and night cycle, control temperature and humidity, and a healthy and juicy fruit fly diet.
Both spiders adapted beautifully and continued to spin their webs and prey. Celestial weavers eat their nets at the end of each day to restore protein, and spin again in the morning. This is also why the spider continues to proceed as planned, which is interesting because the different orb looms on the International Space Station are only spinning at any time of the day.
However, not everything is completely normal. Under the action of microgravity, spiders and celestial weavers rotate on the earth in a three-dimensional, asymmetric structure, and the rotating webs are flatter and rounder.
The two spiders returned to Earth at the end of their stay in space. Esmeralda died on the return journey during the normal spider life. Gladys returned to his hometown but turned out to be a boy. He changed his name to Gladstone.
The tortoise goes around the moon
As early as the 1960s, before humans reached the moon, it was unclear how close contact with the moon would affect the body (if any). Therefore, in 1968, the Soviet space program sent two Russian tortoises (Agrionemys horsfieldii) to accompany the earth.
In fact, it’s not just a tortoise. The flight includes fruit flies, mealworms, seeds, plants, algae and bacteria. There is also a dummy equipped with a radiation sensor, because no living creatures on the ship resemble humans. According to a 1969 report, tortoises appear to have been selected because they are relatively easy to fasten.
On September 2, 1968, two unnamed reptile astronauts were placed on the Zond-5 spacecraft, at which time they no longer had enough. They were launched on September 15, 1968, and returned to Earth (in the Indian Ocean) on September 21. They finally returned to Moscow on October 7.
Their journey includes 7 days of space flight, a few days in a tropical climate (including jumping around in the ocean while waiting for retrieval) and transportation back to Russia. In the end, they spent 39 days without food. It will try anyone.
The control turtles remaining on the earth were also deprived of food during the same period. A comparison of the two groups of tortoises found that any changes in space reptiles are mainly caused by starvation, while the atrophy associated with space has little contribution.
What we want to say is that no one sent the tortoise into space again, but sadly, two more tortoise missions were carried out. Zond 7 in 1969 with a tortoise. In 1975, the Soyuz 20 spacecraft transported the tortoise for 90 days. In 1976, two turtles flew on the Salyut-5 space station.
Just as we did not know how space will affect animals, we also did not realize the effect of space on plants. Therefore, when the Apollo 14 mission was launched on January 31, 1971, there was something in its cargo that we might find strange now: about 500 seeds.
Scientists from the US Forest Service want to know whether the seeds of trees flying in microgravity and exposed to space radiation will germinate, grow and look the same as seeds that have never left the earth.
The pot contains five types of trees: Loblolly pine (Omatsu), California Redwood (Sequoia), American Sycamore (American Ginseng),Douglas fir(Pseudomonas) And American Sweet Gum (Liquidambar). Before returning to Earth, they accompanied the command module pilot Stuart Roosa to fly in 34 orbits of the moon.
Then the seeds were sown and nurtured, and most of them survived to grow into saplings, plus control plants that never left the earth. What is not surprising to us now is that there is no obvious difference between the two.
By 1975, the well-known moon tree was large enough to be transplanted and was shipped to various parts of the United States. According to the National Aeronautics and Space Administration’s website, today it can hold less than 100 moon trees, and when the pages are put together, only 57 of them are alive.
This means that there may be hundreds of moon trees in the United States, which are the relics of our curiosity when tiny seeds swayed in space. And we think it is beautiful.