Why Does Pikachu Float in Space? The Science of Microgravity on the ISS

Orbital Mechanics and Microgravity on the ISS

The spaceflight offers a practical demonstration of how orbital physics creates microgravity environments for objects in low-Earth orbit. Operating at an altitude of approximately 400 kilometers, the ISS experiences roughly 90 percent of the gravitational pull felt on Earth’s surface, according to the European Space Agency. The station floats because it travels forward at high speed while gravity pulls it downward, creating a continuous state of free fall as the craft follows the curve of the planet. According to the European Space Agency, this shared trajectory causes the spacecraft, its occupants, and items like the Pikachu plush to move together at the same rate, resulting in apparent weightlessness known as microgravity.

Fluid Dynamics and Life Support in Space

While floating toys demonstrate physics principles, microgravity creates distinct engineering challenges for daily routines and equipment maintenance inside the station. Without downward pull, fluids behave differently; poured water escapes containers and forms floating droplets held together by surface tension, according to mission reports. To solve basic tasks like drinking water or coffee, engineers designed specialized cups utilizing capillary action—the same physical property that allows paper towels to absorb liquid—to guide beverages safely along the container walls toward the mouth.

Liquid control is also critical for thermal regulation aboard the spacecraft, where computers and electrical systems generate heat continuously. The ISS uses pump-driven liquid circuits similar to automotive cooling systems to absorb heat and transport it to exterior ammonia loops and radiators that release it into space, according to the European Space Agency. Researchers study boiling behavior in microgravity using advanced hardware like the Flow Boiling and Condensation Experiment (FBCE), which arrived at the station in August 2021 and began operational tests in February 2022. High-speed cameras and sensors on the FBCE capture how vapor bubbles behave when they do not naturally rise to the surface, providing data that engineers use to build better cooling systems for future missions.

Water Recycling Milestones

Managing resources efficiently remains a priority for long-duration spaceflight, with life support systems achieving high recovery rates for essential supplies. In 2023, NASA announced that the station’s environmental control and life support system successfully demonstrated a 98 percent water recovery rate. The technology recycles wastewater by capturing moisture from cabin air—released through crew sweat and respiration—along with processed urine, purifying the liquid into potable water through advanced filtration and treatment stages.

Public Outreach and Ground Activities

The collaboration between the European Space Agency and The Pokémon Company International extends beyond the orbit of the ISS into public science institutions across Europe. Following the conclusion of the space mission, participating European science and space museums will host special public events and Pokémon GO activities, including appearances by an astronaut-themed Pikachu, running from October 4, 2026, to April 30, 2027.