10 Very Cool Experiments Done on the International Space Station

Experiments done on the international space station
Astronauts aboard the International Space Station (ISS) have been carrying out some quirky, yet phenomenal research, that has tested and expanded the limits of human knowledge and understanding.
Almost anyone who wants to, can submit a proposal for a research project aboard the ISS. If it is determined to be important and/or interesting enough, NASA launches the experiment and provides astronauts to conduct it.
The main objective behind carrying out experiments in space is that, not all environmental conditions can be recreated in a lab, least of all the condition of weightlessness. It must be noted that, contrary to popular belief, gravity does exist in space. Only thing is that it is considerably weak, and hence, is called microgravity. This microgravity, along with the fact that the ISS is in orbit around our planet, creates the effect of weightlessness, by inducing the conditions of a free-fall. Simulations of weightlessness on the Earth run on the same principle of free-fall. While there exists a few vacuum chamber facilities that can simulate weightlessness, the total length of the simulation lasts for a maximum of just about 30 seconds. This short time-frame is hardly sufficient enough for carrying out any meaningful research, specially in case of biological research, which shows results over a prolonged period of time (months or even years).
This dilemma is solved by conducting the necessary experiments on board the International Space Station (ISS). All experimental equipment and material is sent to the ISS by NASA, and suitable astronauts are assigned with the task of carrying out the experiments. Based on the nature and expected outcome of the experiments, they can be broadly classified into two major categories:

1.Experiments that are designed to study the effect produced when a certain variable is removed. The variable could be gravity, the Earth's atmosphere, etc.
2.Experiments that study the effect of a variable exclusive to space. It can be weightlessness, vacuum, cosmic radiation, etc.
Most experiments belonging to the second category are aimed at understanding the effect of space exposure of humans, in order to be able to make long-term human space travel and exploration possible.
Cool Experiments Being Carried out on the ISS
It refers to Investigating the Structure of Paramagnetic Aggregates from Colloidal Emulsions (InSPACE). It examines the effect of electric fields on the viscosity of magnetorheological fluids, in order to be able to develop refined nanotechnological elements and tools. This study is not possible on Earth, since the particles settle easily, but aboard the ISS, it is able to move freely in a colloidal suspension. The study of the movement and interaction patterns may yield information on developing new nano materials.
It stands for Microencapsulation Electrostatic Processing System (MPS), which involves the creation of micro-balloons in a solution, such that they carry chemotherapy drugs. These would be helpful to physicians to specifically target tumors and not healthy tissue. However, producing these balloons on Earth proved difficult. On repeating the procedure on board the ISS, production of micro-balloons was highly successful. Studying the reasons behind its success in space has allowed doctors to accomplish its production on Earth. This technology is now in its phase of clinical trials, which are using it to target breast and prostate cancers.
Murine Bone Development and Growth
Bone degeneration, or bone loss, is a serious problem affecting people with osteoporosis and astronauts as well (since weightlessness reduces physical activity, and hence impedes the normal growth of bones). In order to prevent this loss, astronauts compulsorily work out for 2.5 - 3 hours everyday in space. But this is not a complete cure, since patients of osteoporosis cannot follow the same course of exercise. Hence, a bone-forming molecule, called NELL-1, which induces stem cells to create bones, is candidate to be studied in space. The injection of this molecule in mice and sheep showed enhanced bone regeneration when the experiment was conducted on Earth. When repeated on the ISS in mice populations, it will help in developing bone loss treatments.
Behavior in Ant Colonies
800 common pavement ants (Tetramorium caespitum) have been sent up to the ISS in order to study if and how the ants adjust to a microgravity environment, and what impact this adjustment has on their collective behavioral pattern. The analysis of their behavioral pattern could offer valuable data in order to design robots, which could forage by themselves. Meaning that, they could explore environs or rescue people from places too hazardous for humans to enter themselves. In order to prevent an ant infestation aboard the space station, only sterile worker ants were sent.
Plant Gravity Sensing
This study involves observing the development and growth of the thale cress plant (Arabidopsis thaliana), a small flowering plant related to cabbage, in a microgravity environment as well as in a simulated gravity environment. The obtained results will reveal if there is any effect of microgravity on the growth of plants and their ability to store starch. This is an incredibly vital study, since its results can help cultivate healthy plants for safe consumption by astronauts on deep-space or long-term missions in space. The findings may even be applied to help solve the problem of food shortage that is seen globally.
The Robonaut
This is basically a humanoid robot developed with a view to be able to function in a high-risk environment, to give a break to the astronauts and possibly even replace them in the future. It can be controlled via a remote control, and directed by ground operators with the help of cabin video and telemetry. It can alternatively be controlled in a Wii-like manner by an astronaut donning a specialized vest, gloves, and a 3D visor, so that the robot-astronaut, or robonaut, mimics the movements of the astronaut. Currently, it has been developed only till its torso. In the future, its body will be fully completed with the addition of functional legs, thus enabling it to carry out tasks inside as well as outside the ISS.
Space Squids
Hawaiian bobtail squids, along with their symbiotic luminescent bacteria, were sent to the ISS in order to study the effect of microgravity on the ability of the bacteria to colonize the host organism (squid). This study actually has very serious implications for human health, as it can help elucidate the effect of microgravity on the microbiota residing in the human gut. Initial experiments revealed that, the bacteria were able to colonize the squid tissue successfully. Further experiments have been planned based on these results.
3D Printing in Space
The ISS is testing the possibility of having a fully-functional 3D printer that is adapted to the microgravity environment aboard the station, in order to be able to print out any tools and implements that may be needed over the course of a mission. If this is successful, it will eliminate the need for additional launches to the ISS to provide tools and replacements. Also, it will help ease the cargo limitations on long-term missions, as one would not need to carry numerous objects, since they can be printed as and when required. This technology would help make space stations mechanically self-sustainable to a great extent.
Windows on Earth
This is basically a virtual reality software system that will enable people on the Earth to access imagery and information regarding what can be viewed from the windows of the ISS. It would be a real-time relay of the events and experiments aboard the ISS, as well as the view of the Earth as seen from space. It would prove extremely helpful in terms of studying the Earth's atmosphere, and in enlisting the help of astronauts to solve relevant problems on the Earth. It would also be able to provide valuable information regarding the damage and aftermath of disasters like tsunamis, floods, earthquakes, and hurricanes. In essence, it would be a direct and instantaneous link between the public on the Earth and the astronauts on the space station.
This is the first clothing-related experiment on the space station. On the Earth, when a person sweats, it forms droplets on the surface of the skin, which are readily absorbed by the fibers of the clothes we wear via capillary action. However, in a microgravity environment, the movement of sweat through cloth is affected. Hence, various types of textiles are being tested to produce a fabric that efficiently absorbs sweat.
While all the above mentioned experiments are downright cool, a new experiment described by NASA might just be a little cooler. NASA is all set to carry out two simultaneous tests by sending two astronauts into space for a whole year. It is the longest any astronaut has spent aboard the space station. While on the ISS, these astronauts will be making detailed reports of their physical, mental, and psychological states. At the same time, the twin of one of the astronauts will be monitored here on Earth, to be able to set up a sort of control for identifying any genetic changes as a consequence of space exposure. Hence, at the same time, NASA will be able to monitor behavioral, physical, as well as genetic changes in a human, in space.