The Most Interesting International Space Station Experiments Ever Conducted

Key Takeaways

• ISS experiments turn microgravity into a working research tool for science and medicine.
• Human-health studies help explain how spaceflight changes bones, blood, vision, and genes.
• Station science supports future spacecraft, space farming, materials testing, and astronomy.

Experiments That Turned Orbit Into a Working Laboratory

The International Space Station has hosted more than 20 years of continuous human research in orbit, giving scientists access to a laboratory where gravity no longer dominates flames, fluids, plants, cells, crystals, and human physiology. The most interesting International Space Station experiments are not interesting only because they happen in space. They are interesting because they use the station’s orbiting environment to make physical behavior easier to observe, medical changes easier to measure, and long-duration spaceflight risks easier to test before crews travel farther from Earth.

The station orbits more than 200 miles, or about 320 kilometers, above Earth. That altitude gives researchers a sustained microgravity environment, meaning people and objects appear weightless because they are falling around Earth together. Microgravity does not remove gravity entirely, but it reduces many gravity-driven effects that shape daily life on the ground. Hot gases do not rise in the same way, liquids do not settle at the bottom of a container, crystals can grow with fewer gravity-driven distortions, and human bodies experience changes that reveal how much daily health depends on standing, walking, and resisting weight.

The station’s research value comes from its combination of laboratory hardware, trained crew members, visiting cargo spacecraft, external mounting points, and ground-based science teams. NASA’s Space Station Research and Technology program describes the station as a microgravity lab that supports scientific investigations and technology demonstrations across many fields. That range includes human biology, combustion, materials exposure, quantum physics, plant growth, pharmaceuticals, robotics, astronomy, and Earth observation.

Selecting the “most interesting” experiments is partly a matter of public appeal and partly a matter of scientific reach. The Alpha Magnetic Spectrometer is compelling because it turns the station into a cosmic particle observatory. The Twins Study is compelling because it compared astronaut Scott Kelly with his identical twin Mark Kelly during long-duration spaceflight. Veggie and the Advanced Plant Habitat are compelling because they made fresh food production in orbit visible and practical. The Cold Atom Laboratory is compelling because it cools atoms to temperatures colder than naturally occurring matter in the universe.

The table below groups selected experiments by research area, station use, and wider relevance. It focuses on investigations that are accessible to a broad audience, widely documented by official sources, and connected to questions that matter beyond a single mission.

These experiments also show how the ISS changed the definition of a space mission. Earlier crewed missions often treated science as a short-duration activity fitted around spacecraft operations. The ISS made science part of the spacecraft’s operating model. A visiting cargo vehicle may deliver biological samples, plant pillows, combustion inserts, tissue chips, hardware patches, or replacement parts for an observatory. Crew members then become laboratory technicians, medical test subjects, photographers, gardeners, equipment installers, maintenance workers, and data collectors in the same workweek.

Human Health Experiments That Changed Space Medicine

Few station experiments have drawn as much public attention as NASA’s Twins Study. The study compared retired astronaut Scott Kelly during his 340-day spaceflight with his identical twin brother, retired astronaut Mark Kelly, who remained on Earth. That design gave researchers an unusually strong comparison point because identical twins share the same genetic background. The study did not produce a simple before-and-after story. It examined physiology, cognition, immune response, gene expression, microbiome changes, body mass, telomeres, and other measures across flight and recovery.

The Twins Study appealed to the public because it turned long-duration spaceflight into a human story without losing its scientific value. Scott Kelly became the in-flight subject, Mark Kelly became the Earth-based comparison, and 10 research teams examined how a body adapts to months in orbit. NASA’s published results described changes in gene expression, immune function, body mass, vascular measures, telomere behavior, cognition, and other biological markers. Many measures shifted toward preflight values after return to Earth, although some changes persisted long enough to matter for planning longer missions.

The study’s wider value lies in the way it connected different layers of health. Spaceflight affects bones, muscles, blood, eyes, sleep, radiation exposure, immune response, and mental performance at the same time. A long mission to the Moon, Mars, or a commercial station will not stress one organ system in isolation. The Twins Study helped researchers examine the body as an integrated system, with molecular measurements and clinical observations linked to the same human experience.

Bone and muscle investigations form another major area of station science. Astronauts exercise for hours each day because microgravity removes the normal loading that bones and muscles receive from walking, standing, and lifting on Earth. NASA’s account of station research breakthroughs notes that space studies have contributed to knowledge of muscle atrophy and bone loss, including countermeasures that help protect crews. This research has direct relevance to spaceflight, but it also connects to osteoporosis, rehabilitation, aging, and long-term immobility on Earth.

Vision and fluid-shift studies are among the station’s more medically significant investigations. In microgravity, body fluids shift toward the head because gravity no longer pulls them toward the lower body in the same way. Some astronauts experience eye and vision changes associated with long-duration missions. Station experiments have measured pressure, eye structure, blood flow, and biochemical markers to help explain the condition commonly discussed under spaceflight-associated neuro-ocular syndrome.

The Tissue Chips in Space initiative adds a smaller, more automated form of biomedical research. Tissue chips are tiny systems that use living human cells to model tissue or organ behavior. The National Center for Advancing Translational Sciences partnered with the ISS National Laboratory to send tissue-chip platforms to orbit so researchers could study how microgravity changes human physiology and disease processes. These experiments are especially valuable because they can examine cell-level behavior without relying only on astronaut subjects.

Human-health research on the station also shapes daily operations. Exercise systems, nutrition, sleep scheduling, radiation monitoring, medical sampling, immune studies, and behavioral health all draw from station experience. That makes ISS biomedical science both experimental and practical. The crew members are research subjects, but they are also beneficiaries of decades of research that refined the countermeasures keeping them healthy enough to work in orbit.

Biology and Food Experiments That Made Space Farming Real

The sight of lettuce, zinnias, and chile peppers growing in orbit changed how many people understood space science. Plant growth experiments are easy to grasp because their basic question is familiar: can living things grow normally away from Earth? The answer is more complicated than a yes-or-no result. Plants can grow in orbit, but they face unusual water behavior, altered root-zone conditions, restricted volume, artificial lighting, microbial concerns, and the absence of familiar gravity cues.

NASA’s Veggie plant-growth system is one of the most recognizable station experiments because it connects research with food. Veggie was designed to study plant growth in microgravity and add fresh food to astronaut diets. The system is relatively simple compared with larger growth chambers. It uses light, a small growth area, and plant “pillows” that hold seeds and growing media. Crew members water plants, monitor growth, harvest samples, and sometimes eat the produce after safety checks.

The psychological appeal of plant experiments is real, but the science goes far beyond crew morale. Plants must manage water, oxygen, nutrients, root growth, leaf development, flowering, and fruiting in an environment where fluids do not drain or settle normally. NASA’s Growing Plants in Space material explains that the Advanced Plant Habitat uses LED lights and a porous clay substrate with controlled-release fertilizer to deliver water, nutrients, and oxygen to plant roots. This kind of research helps engineers design food systems for longer missions that cannot rely only on packaged supplies.

Plant Habitat-04, which grew chile peppers on the ISS, attracted public attention because the crew used the harvest in a meal. That moment was memorable, but its deeper research value came from testing a more complex crop with flowering and fruiting stages. Leafy greens are useful, but exploration crews need crops with different nutrients, growth patterns, and food value. Peppers, tomatoes, dwarf wheat, and other candidate crops push space agriculture beyond symbolic sprouting.

Protein crystal growth is another biology-related station research area with broad relevance. NASA’s station research summary explains that protein crystals grown in microgravity can help researchers study structures connected to disease and potential treatments. On Earth, gravity-driven settling and convection can interfere with crystal growth. In orbit, some crystals may grow more uniformly, giving researchers better structural information.

Microbial studies add a less visible but highly practical layer. The ISS is a closed habitat where humans, equipment, air handling, water systems, surfaces, food, and experiments share a compact environment. Researchers track microbes to understand how communities change in space and how they interact with crew health, hardware, and life-support systems. This research matters for any future habitat where crews must live for months or years with limited resupply and no easy evacuation.

The most interesting station biology experiments often work on two levels at once. They help answer deep scientific questions about life under altered gravity, and they address practical needs for missions that may spend long periods away from Earth. A lettuce leaf grown in orbit may look simple. Behind it sits a network of plant physiology, food safety, lighting, water management, microbial monitoring, crew psychology, mission logistics, and life-support planning.

Physics Experiments That Could Not Work the Same Way on Earth

The Alpha Magnetic Spectrometer is one of the most ambitious experiments ever mounted on the International Space Station. Attached to the station’s truss, the instrument detects cosmic rays, which are high-energy particles arriving from space. NASA describes the Alpha Magnetic Spectrometer, also known as AMS-02, as a particle physics experiment module that has collected and analyzed billions of cosmic ray events. It searches for patterns in particles and antiparticles that could improve understanding of cosmic rays, antimatter, and possible dark matter signatures.

AMS-02 stands out because it turned the station into a platform for fundamental physics. A particle detector of this size and capability would face atmospheric interference on Earth. Mounted in orbit, it samples particles before they pass through the full atmosphere. The experiment also stands out because astronauts conducted complex spacewalks to repair and upgrade its thermal pump system, extending its scientific life. That repair effort linked science, engineering, and human spaceflight in a way few experiments can match.

The Cold Atom Laboratory takes the opposite approach in scale. Instead of catching high-energy particles from the cosmos, it slows atoms almost to stillness. NASA’s Jet Propulsion Laboratory operates the facility remotely, using lasers and magnetic fields to cool atoms to extremely low temperatures. In microgravity, ultra-cold atom clouds can be observed for longer periods than on Earth because they do not immediately fall through the experiment chamber.

Cold Atom Laboratory experiments explore quantum behavior, the realm where atoms follow rules that can seem strange compared with ordinary experience. Technologies such as transistors, microchips, atomic clocks, and some advanced sensors depend on quantum phenomena. The station gives researchers a new setting for studying Bose-Einstein condensates and other ultra-cold states of matter. The research is abstract, but its long-term relevance may reach precision navigation, sensing, and timekeeping.

The Neutron star Interior Composition Explorer, known as NICER, adds astrophysics to the station’s experimental portfolio. Mounted outside the station, NICER studies neutron stars, black holes, and other X-ray sources. Neutron stars are the dense remnants of massive stars after supernova explosions. Their matter is compressed under conditions that cannot be recreated in laboratories on Earth. By measuring X-ray emissions, NICER helps scientists study size, mass, rotation, and behavior in these extreme objects.

NICER also demonstrated a navigation concept using pulsars, which are rapidly rotating neutron stars that emit regular pulses. The Station Explorer for X-ray Timing and Navigation Technology test used pulsar signals to demonstrate autonomous spacecraft navigation concepts. That makes NICER one of the rare station experiments that connects astrophysics with spacecraft operations. It studies distant objects and tests a technique that could help future spacecraft determine their position without relying only on Earth-based navigation support.

Combustion experiments may sound familiar because fire is common on Earth, but flames behave differently in orbit. NASA’s Combustion Integrated Rack supports fire and combustion research inside a contained chamber in the Destiny laboratory. Without normal buoyancy, flames can become more spherical, soot behavior can change, and extinction limits can differ from ground tests. These experiments help scientists understand combustion physics and help spacecraft designers reduce fire risk.

The Solid Fuel Ignition and Extinction project studies how solid spacecraft materials ignite and extinguish under practical spacecraft conditions. That work matters because material flammability standards on Earth may not fully capture behavior in low gravity. A small flame inside a spacecraft would be a severe hazard because air, smoke, power, crew escape, and life-support systems all interact inside a sealed habitat.

Earth, Materials, and Technology Experiments With Practical Uses

Some of the most valuable station experiments are less dramatic than a cosmic particle detector or a twin astronaut study. They expose materials to space, watch Earth from orbit, test fluid behavior, and assess machines that may work with crews in later spacecraft. These experiments matter because future space systems require materials, sensors, autonomous equipment, and life-support hardware that can survive long service periods.

The Materials International Space Station Experiment series, known as MISSE, has tested thousands of material samples outside the station. NASA describes the series as testing samples such as lubricants, paints, fabrics, container seals, and solar cell technologies in the space environment. Outside the ISS, samples face ultraviolet radiation, thermal cycling, atomic oxygen, micrometeoroids, charged particles, and vacuum. A material that performs well in a ground chamber may behave differently after months or years in orbit.

MISSE has direct practical value for spacecraft, satellites, spacesuits, external sensors, coatings, seals, and solar arrays. Space hardware often fails through slow degradation rather than sudden dramatic breakage. A coating may darken, a polymer may erode, a seal may lose performance, or a solar material may degrade under radiation. Exposing samples outside the station gives engineers evidence from the real low Earth orbit environment.

Fluid physics experiments have similar practical value. NASA’s Capillary Flow Experiment studied how fluids move through containers and shapes in microgravity. On Earth, gravity helps engineers predict where a liquid will collect. In orbit, surface tension and container geometry can dominate. That affects fuel tanks, water processors, cooling systems, plant watering systems, medical devices, and waste-management equipment.

Capillary-flow research connects strongly with life-support engineering. Water recovery, urine processing, oxygen generation, coolant loops, and laboratory equipment all depend on fluid movement. If bubbles separate poorly, if liquid clings to the wrong surface, or if a pump draws gas instead of fluid, a system can lose efficiency or fail. Station experiments let researchers see fluid behavior directly and compare it with models used to design spacecraft equipment.

Robotic experiments show a different kind of practical science. NASA’s Astrobee free-flying robot system tests autonomous movement, station inspection concepts, sensor use, and crew support in microgravity. The robots float through station modules using fans, cameras, and onboard computing. Their research value comes from testing how small robots can navigate a crewed spacecraft without colliding with people, laptops, experiment racks, or other hardware.

Earth observation experiments also benefit from the station’s orbit and crew presence. Astronaut photography and mounted sensors observe storms, cities, coastlines, volcanoes, fires, ice, dust, and night lights. The station does not replace dedicated Earth-observation satellites, but it provides flexible human observation from an inclined orbit. Crew members can photograph events of interest, and instruments can test techniques before similar sensors fly on dedicated spacecraft.

The table below compares selected experiment categories by what microgravity or orbital access adds. It avoids treating the station as a single-purpose laboratory because its value comes from supporting very different kinds of investigations in the same operational setting.

Technology demonstrations on the station often begin with a narrow test and end with wider operational meaning. A robot navigation test can reduce crew workload. A material sample can influence a satellite coating. A fluid study can improve a water processor. A plant-growth chamber can guide food systems for lunar missions. The station’s research record shows that small experiments can shape large design decisions.

Why These Experiments Capture Public Attention

Public interest in station science usually rises when an experiment connects an unfamiliar environment with a familiar question. The Twins Study asked how space changes the human body. Veggie asked whether astronauts can grow food. Combustion research asked how fire behaves when hot air does not rise normally. Cold Atom Laboratory asked what matter does near the coldest conditions humans can create. AMS-02 asked whether particles from space can reveal hidden features of the universe.

That kind of appeal matters because the International Space Station is expensive, complex, and politically visible. Research results help explain why crews and cargo keep flying to a laboratory that most people will never visit. A clear experiment can make the station’s purpose more concrete than a general statement about science. A plant harvest, a repaired particle detector, a free-floating robot, or a comparison between identical twins gives the public a way to understand the station as a working research site.

Many experiments also have built-in tension because the station adds constraints. Samples must survive launch loads. Hardware must pass safety review. Crew time is limited. Power, cooling, data, and storage are finite. Biological samples may need cold stowage. Combustion tests require containment. External instruments face debris, thermal stress, and maintenance problems. Every station experiment sits inside a larger operational system, which means success requires science and engineering to work together.

The most interesting experiments also cross boundaries between fields. Tissue chips combine biology, medicine, engineering, and automation. NICER combines astrophysics and navigation testing. Plant research combines botany, food systems, crew health, and habitat design. Combustion research combines fire science, materials testing, atmosphere design, and crew safety. AMS-02 combines particle physics, spacecraft repair, external operations, and long-term data analysis.

Some experiments are interesting because their answers are uncertain. Researchers did not know exactly how telomeres would behave during Scott Kelly’s long mission. Scientists could not assume that chile peppers would grow cleanly through a full crop cycle in orbit. Engineers could not rely on ground-only material tests to predict every effect of low Earth orbit exposure. A good station experiment often begins where Earth-based testing reaches its limit.

Other investigations are interesting because they make ordinary processes strange again. Water does not pour in orbit as it does on Earth. Flames do not stretch upward in the same way. Plants do not sense up and down through normal gravity cues. A person’s body does not load bones and muscles as it does on the ground. The ISS turns familiar things into experiments by removing the constant influence of gravity-driven behavior.

How ISS Science Points Toward the Next Era of Space Research

The station’s most interesting experiments are shaping the design and purpose of later space platforms. NASA plans to transition from the ISS toward commercially owned and operated low Earth orbit destinations, and research continuity is one of the reasons that transition matters. NASA’s commercial space stations work is tied to maintaining access to low Earth orbit for research, technology development, and crewed operations after ISS retirement.

Human-health research will remain central because astronauts will spend longer periods beyond low Earth orbit. The Moon, Mars, and commercial stations all require better understanding of radiation, sleep, nutrition, isolation, cardiovascular changes, bone loss, muscle loss, immune function, and vision effects. The ISS cannot answer every deep-space health question because it remains inside Earth’s magnetic environment, but it offers the best long-duration human research platform built so far.

Plant research will also grow in value. Packaged food can support missions, but fresh food offers nutritional and psychological benefits. A future lunar habitat or Mars transit vehicle may need systems that grow plants with limited water, limited volume, controlled lighting, and strict microbial safety. Station experiments such as Veggie and the Advanced Plant Habitat provide the evidence base for deciding which crops, chambers, growth media, lighting settings, and crew procedures deserve further development.

Physical-science investigations will continue to influence spacecraft design. Combustion research informs fire safety. Fluid experiments inform tanks and life support. Material exposure informs external hardware selection. Quantum experiments may influence sensors and clocks. Astrophysics instruments on the station show that crewed platforms can host scientific observatories, although dedicated satellites remain better for many observations.

Commercial and government users may also change the mix of experiments. The ISS National Laboratory supports non-NASA research from academic institutions, government agencies, and private companies. That model gives the station a bridge between public science and commercial research. Future stations may expand work in biomanufacturing, pharmaceuticals, materials processing, robotics, crew health services, and technology testing.

The ISS research record suggests that future platforms should be judged by experiment quality, not by size alone. A station that provides steady crew access, reliable power, good data links, modern lab equipment, sample return, and predictable cargo service can support science with high value. A smaller commercial platform may handle selected research well if it is designed around clear experiment needs.

The next era of space research will inherit the ISS lesson that microgravity is not a novelty. It is a research condition. Scientists use it to remove a dominant Earth effect, reveal hidden behavior, and test systems that must work away from Earth. The most interesting International Space Station experiments have already shown that orbit can be a laboratory for the body, the cell, the atom, the flame, the plant, the machine, and the universe.

Summary

The most interesting experiments conducted on the International Space Station show how an orbiting laboratory can answer questions that ground laboratories cannot fully address. The Alpha Magnetic Spectrometer studies cosmic particles before Earth’s atmosphere interferes. The Twins Study used a rare identical-twin comparison to examine long-duration spaceflight effects. Veggie and the Advanced Plant Habitat turned plant growth into a practical spaceflight discipline. Cold Atom Laboratory opened a microgravity path for quantum research.

Other experiments carry equal practical weight even when they receive less public attention. Tissue chips help researchers study human disease and drug response in a spaceflight environment. MISSE exposes materials to the real conditions faced by spacecraft. Capillary-flow experiments help engineers understand liquids when weight no longer tells them where to settle. Combustion studies improve spacecraft fire safety. Astrobee tests robotic helpers that may reduce crew workload.

Station science is strongest when it links curiosity with use. A neutron star observation can test navigation ideas. A plant experiment can support future food systems. A flame study can improve habitat safety. A tiny tissue chip can connect spaceflight physiology with medicine on Earth. The ISS has made those links possible because it keeps people, equipment, samples, power, data, and international research teams working together in orbit.

The most lasting result may be cultural as much as technical. The station normalized the idea that human spaceflight is research infrastructure. Crews do not only visit space. They run experiments, maintain instruments, grow crops, process samples, repair observatories, test robots, and help scientists learn what changes when Earth’s gravity no longer shapes every process. That record will guide commercial stations, lunar habitats, Mars mission planning, and future laboratories designed for research beyond Earth.

Appendix: Useful Books Available on Amazon

• Endurance: A Year in Space, A Lifetime of Discovery
• An Astronaut’s Guide to Life on Earth
• Packing for Mars
• Spacefarers: How Humans Will Settle the Moon, Mars, and Beyond
• The Ordinary Spaceman

Appendix: Top Questions Answered in This Article

What Makes an International Space Station Experiment Interesting?

An ISS experiment becomes interesting when it uses microgravity or orbital access to answer a question that Earth-based research cannot handle as well. The strongest examples connect a clear scientific question with a practical need, such as astronaut health, fire safety, plant growth, material survival, robotics, or astronomy.

Why Was the Twins Study So Widely Discussed?

The Twins Study compared Scott Kelly during a 340-day mission with Mark Kelly on Earth. Identical twins gave researchers an unusually strong comparison for measuring changes connected to long-duration spaceflight. The study examined many biological systems at once, including gene expression, immune function, cognition, body mass, and vascular measures.

Why Is Veggie One of the Best-Known ISS Experiments?

Veggie is easy for the public to understand because it grows real plants in orbit. The system helps NASA study plant growth in microgravity, fresh-food production, crew experience, and future food systems. It also produced memorable harvests that made space agriculture visible to people on Earth.

What Does the Alpha Magnetic Spectrometer Study?

The Alpha Magnetic Spectrometer detects cosmic rays from its position outside the International Space Station. It measures particles and antiparticles that can help researchers study cosmic rays, antimatter, and possible dark matter clues. Its location in orbit lets it collect data before particles pass through Earth’s full atmosphere.

Why Is the Cold Atom Laboratory Unusual?

The Cold Atom Laboratory cools atoms to extremely low temperatures and studies their quantum behavior in microgravity. Atoms can be observed longer in orbit because they do not fall through the experiment chamber as quickly as they do on Earth. The work supports fundamental physics and may benefit advanced sensing technologies.

How Do ISS Experiments Help Future Space Missions?

ISS experiments help engineers and doctors understand what long missions require. Human-health studies shape crew medical planning, plant experiments support food-system research, combustion studies improve fire safety, and materials exposure tests help spacecraft designers choose better hardware. These lessons are useful for lunar, Martian, and commercial platforms.

Why Are Combustion Experiments Conducted on the ISS?

Fire behaves differently in microgravity because hot gases do not rise in the same way as they do on Earth. Combustion experiments study flame shape, ignition, soot, oxygen effects, and extinction behavior. The results help improve spacecraft fire safety and material selection for crewed vehicles.

What Are Tissue Chips in Space?

Tissue chips are small devices that use living human cells to model tissue or organ behavior. In space, researchers use them to study how microgravity affects human physiology, disease processes, and possible treatments. Their small size and automation make them suitable for spaceflight research.

Why Are Materials Tested Outside the Station?

Materials outside the station face radiation, atomic oxygen, temperature swings, vacuum, and micrometeoroid exposure. The Materials International Space Station Experiment series exposes samples to the real space environment. Engineers use the results to improve spacecraft coatings, seals, fabrics, solar cells, and other external hardware.

Will Future Space Stations Continue This Kind of Research?

Future commercial and government-supported stations are expected to continue low Earth orbit research after the ISS. They may support human-health studies, plant growth, materials testing, biomanufacturing, robotics, and technology demonstrations. The ISS has provided the operating model for turning orbital platforms into research infrastructure.

Appendix: Glossary of Key Terms

Advanced Plant Habitat

The Advanced Plant Habitat is a controlled plant-growth chamber used on the International Space Station. It supports experiments that need more environmental control than simpler growth systems, including regulated light, temperature, humidity, water delivery, and root-zone conditions.

Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer is a particle physics experiment mounted outside the International Space Station. It detects cosmic rays and measures particles and antiparticles that may help researchers study antimatter, cosmic-ray sources, and possible dark matter clues.

Astrobee

Astrobee is a free-flying robotic system designed to move inside the International Space Station. It supports research on autonomous navigation, crew assistance, inspection, and robotic operations in a crewed microgravity environment.

Capillary Flow

Capillary flow is liquid motion driven by surface tension and container shape rather than by pumps or gravity alone. In microgravity, capillary effects can dominate fluid behavior, affecting tanks, water systems, cooling loops, and laboratory equipment.

Cold Atom Laboratory

The Cold Atom Laboratory is a NASA facility aboard the International Space Station that cools atoms to extremely low temperatures. Its microgravity environment allows longer observation of ultra-cold atom behavior for quantum physics research.

Combustion Integrated Rack

The Combustion Integrated Rack is a station facility used to conduct contained fire and combustion experiments. It helps researchers study flame behavior, ignition, extinction, soot formation, and spacecraft fire-safety questions in microgravity.

Cosmic Rays

Cosmic rays are high-energy particles that travel through space and can come from the Sun, distant stars, supernova remnants, or other energetic sources. Instruments in orbit can measure them before Earth’s atmosphere changes their path or energy.

Microgravity

Microgravity is the condition in orbit where people and objects appear weightless because they are falling around Earth together. It changes how fluids, flames, cells, plants, crystals, and human bodies behave compared with conditions on the ground.

Neutron Star

A neutron star is the dense remnant left after certain massive stars explode as supernovae. Neutron stars can rotate rapidly, emit X-rays, and create pulsar signals that help scientists study matter under extreme physical conditions.

Tissue Chip

A tissue chip is a small engineered device that uses living cells to model tissue or organ behavior. Researchers use tissue chips to study disease, drug response, and physiological changes under controlled conditions, including microgravity.

Twins Study

The Twins Study was a NASA investigation comparing astronaut Scott Kelly during long-duration spaceflight with his identical twin brother Mark Kelly on Earth. It measured biological, cognitive, molecular, and physiological changes linked to spaceflight exposure.

Veggie

Veggie is a plant-growth system on the International Space Station. It supports experiments on edible crops, plant development in microgravity, crew food options, and the psychological value of growing living plants in orbit.