The way things behave in microgravity may seem obvious to us now, after people have ventured into space for over 50 years.
But I wasn’t always sure how space might affect certain things. Like fire. Or planar worms. Or even plants. Only by conducting experiments can we learn the answers to these burning questions.
This led to some quite fascinating experiments, sometimes annoying and sometimes even crazy, performed in space.
A space suit becomes removed from a blockage
The video above plays like a nightmare. A space suit floats, unconnected, away from the International Space Station (ISS), the vast black space gap yawning in front of it.
You may be relieved to learn that no one was injured in the experiment – no one in the Russian space suit Orlan, nicknamed Ivan Ivanovich or Mr. Smith – is filled with a pile of old clothes and a radio transmitter.
The idea was that old space suits could be used as satellites. SuitSat-1 – officially designated AMSAT-OSCAR 54 – was implemented on February 3, 2006, but the experiment was only partially successful; reports vary, with NASA claiming that the transmitter died shortly after launch, and Russia reported a final broadcast for a full week. The last confirmed signal was received on February 18.
SuitSat-1 continued to spend a few months in silent orbit, before entering Earth’s atmosphere and burning on September 7, 2006.
Hammer and feather
At the end of the 16th century, Galileo Galilei dropped two spheres of unequal mass from the Leaning Tower of Pisa in Italy. When they both reached the ground at the same time, he contradicted the classical views, showing that the mass has no influence on the gravitational acceleration. All objects, regardless of the table, should fall at the same rate – even if it is a feather and a hammer.
On Earth, this is difficult to demonstrate due to air resistance. But almost 400 years later, a man sitting on the moon repeated the experiment.
On August 2, 1971, Commander David Scott of Apollo 15 took a geological hammer in one hand and a hawk feather in the other. He lifted them to a height of about 1.6 meters from the ground and dropped them. Because the astronaut was essentially in a vacuum, without air resistance, the two objects fell in sync.
“In the accuracy of simultaneous release, it has been observed that objects undergo the same acceleration and simultaneously hit the lunar surface,” wrote NASA astronaut Joe Allen, “which was a predicted result of a well-established theory, but a reassuring result given both the number of viewers who attended the experiment, as well as the fact that the trip home was critically based on the validity of the particular theory tested. “
The hammer and panels are still up there.
Gas tablet in a blob of water
In microgravity, if you spray a little water from a nozzle, it just hangs there, all blobby and wobbling.
This can result in a lot of fun. Experiments and demonstrations included water balloons that appeared in comet vomit (the plane that makes parabolic flights to create short periods of free fall) and the ISS, attaching a water diffuser with a large bubble inside to a diffuser to observe vibrations , and putting a GoPro camera in a water blob to film it from the inside (you’ll want stereoscopic 3D glasses for that).
In 2015, astronaut Scott Kelly stained a water stain with food coloring, then introduced effervescent tablets, watching them dissolve and release gases into the water. It was filmed using the space station’s new 4K camera, so you can view the whole alien thing that generates algae … with brilliant resolution.
Fire in space
(ESA / NASA)
Just as water behaves differently in microgravity, so does fire. The 1997 Mir space station fire was fortunately a unique event so far, but working on how fire behaves in microgravity can help plan fire safety for future long-term missions, such as the equipped mission to Mars. and the permanent moon base. It can help you inform fire safety protocols here on Earth.
To this end, a number of ongoing research projects have studied what happens to flames in space. The combustion and suppression experiments of solids on board the ISS investigated the combustion and extinguishing characteristics of a wide range of microgravity fuel types. The data from these experiments can be used to construct more complex models to understand the finer details of Earth’s gravitational combustion.
On board the Cygnus spacecraft, scientists investigated how the spacecraft’s flames behave under different conditions in the Saffire experiments. And NASA’s investigation into the design of the flame – part of Advanced Combustion via Microgravity Experiments – explores soot production and control.
All of these are very useful and interesting, for sure. But it is also extremely beautiful and we bet there are some astronauts who have an absolute explosion that plays with fire in space.
Space spiders
In 2011, scientists began answering the burning question: can spiders adapt to space travel? They sent two golden silk spiders (Trichonephila clavipes), Esmeralda and Gladys, for a 45-day stay aboard the ISS.
They were kept in a beautiful habitat (you can imagine free spiders on a space station), with light conditions to simulate a night cycle, temperature and humidity control and a healthy diet with juicy fruit flies.
Both spiders adapted nicely, continuing to spin their sails and hunt their food. Blind weavers eat their sails at the end of each day to regain protein and spin them again in the morning; And this, the spiders continued to do correctly in time, which was interesting, because different species of balloon weavers on the ISS were just spinning their sails at any old time of day.
But not everything was completely normal. In microgravity, spiders spun their webs differently – flatter and more rounded, compared to the more three-dimensional, asymmetrical structures that globe weavers spun on Earth.
The two spiders returned to Earth at the end of their stay in space. Esmeralda perished on the return journey, living a normal spider’s life. Gladys returned home, but turned out to be a boy. It was renamed Gladstone.
Turtles surround the moon
In the 1960s, before humans were on the moon, it was not clear exactly how – if at all – they would affect us physically. So, in 1968, the Soviet space program sent two Russian turtles (Agrionemys horsfieldii) for a trip around the Earth’s companion.
In fact, they weren’t just turtles. Included in the flight were wine flies, worms, seeds, plants, algae and bacteria. There was also a mannequin equipped with radiation sensors, as none of the living organisms on board were analogously remote from humans. Turtles, according to a 1969 report, appear to have been chosen because they are relatively easy to remove.
The two unnamed reptilian cosmonauts were placed aboard the Zond-5 spacecraft on September 2, 1968, when they were no longer fed. They were launched into space on September 15, 1968, returning to Earth (in the Indian Ocean) on September 21. They finally returned to Moscow on October 7.
Their trip included seven days of spaceflight, a few days in a tropical climate (including walking in the ocean while waiting for recovery) and transportation back to Russia. Finally, they spent 39 days without food. He would try anyone.
The control turtles that remained on Earth were also deprived of food for the same period of time. A comparison of the two sets of turtles showed that any change in space reptiles was largely the result of starvation, with a small contribution to space flight-related atrophy.
We would like to say that no one has ever sent turtles into space, but unfortunately, two more turtle missions have taken place. Zond 7 in 1969 carried turtles. In 1975, the Soyuz 20 spacecraft carried a turtle for 90 days. Two turtles also flew on the Salyut-5 space station in 1976.
Lunar trees
Just as we never knew how space would affect animals, so we were unaware of its effects on plants. So when the Apollo 14 mission was launched on January 31, 1971, its cargo contained something we might now find a little strange: about 500 seeds.
Scientists from the US Forest Service wanted to know if the seeds of trees that flew in microgravity and were subjected to space radiation will sprout, grow and look just like the seeds that had never left Earth.
Five species of trees were included in the canister: pine loblolly (Pinus taeda), California redwood (Sequoia sempervirens), American sycamore (Platanus occidentalis), Brad Douglas (Pseudotsuga menziesii), and American sweet gum (Liquidambar styraciflua). They accompanied the pilot of the Stuart Roosa command module in 34 orbits of the Moon before returning to Earth.
The seeds were then planted and cared for, and most survived to become chicks, along with controls that had never left Earth. Surprisingly for us now, there was no distinct difference between the two.
By 1975, the trees of the moon, as they came to be known, were large enough to be transplanted and shipped across America. According to this NASA website, less than 100 lunar trees can be considered today, and of these, only 57 lived when the page was put together.
This means that there could be hundreds of lunar trees hiding in the US, a lost relic of a time when our curiosity sent small seeds swarming around space. And we think it’s beautiful.