25 Years of Discovery on the International Space Station — Breakthroughs That Matter for Space and Earth

Quarter Century of Continuous Science in Orbit

The International Space Station (ISS) recently marked 25 years of uninterrupted human presence in low Earth orbit. Launched in 1998 as a multinational research laboratory, the station has hosted more than 280 people from 26 countries and supported experiments using a wide range of organisms — from butterflies and rodents to fruit flies — to advance science in microgravity.

Microgravity Boosts Drug Development

Microgravity provides a unique environment for pharmaceutical research. On Earth, gravity can disrupt the delicate formation of protein crystals used in many life-saving drugs. In orbit, crystals often grow larger and more uniformly, helping researchers and companies refine drug formulations and production methods. For example, experiments involving the cancer immunotherapy pembrolizumab aboard the ISS yielded insights that can simplify manufacture and administration — enabling potential reformulations for injection rather than slow intravenous infusion, which would ease treatment for patients and caregivers.

Cold Atom Lab and the Fifth State of Matter

Inside the refrigerator-sized Cold Atom Lab, researchers produced Bose–Einstein condensates — the so-called fifth state of matter predicted by Satyendra Nath Bose and Albert Einstein and first observed in 1995. In this ultracold state, clouds of atoms "coalesce, overlap and become synchronized like dancers in a chorus line," according to NASA. These condensates, cooled to temperatures on the order of one ten‑billionth of a degree above absolute zero, are easier to create and study in microgravity. Future instruments that exploit waves of Bose–Einstein condensates may improve detection of extremely subtle signals, such as those from gravitational waves or dark-energy phenomena.

Human Health in Long-Duration Spaceflight

Understanding how the human body adapts to prolonged microgravity has been a major focus of ISS research. Long-term studies have documented bone and muscle loss, shifts in vision and changes in gene expression. A high-profile example compared astronaut Scott Kelly, who spent nearly a year aboard the ISS, with his identical twin Mark Kelly on Earth: Scott experienced roughly a 7% reduction in body mass, alterations in eyeball shape, and measurable changes in gene expression, among other effects reported by NASA in 2019. To study organ-level responses more precisely, scientists are using organ-on-chip devices — microfluidic chips seeded with living cells that mimic the structure and function of specific tissues. These platforms accelerate the search for countermeasures to spaceflight-related health problems and may translate into new treatments for aging-related conditions on Earth.

Growing Food and Recycling Water for Deep Space

Preparing for longer missions to the Moon, Mars and beyond requires reliable food and water systems. Since 2015, NASA has tested the Passive Orbital Nutrient Delivery System on the ISS — a nonpowered setup that uses capillary-like wicking materials to deliver water and nutrients continuously to plant roots. This low-energy approach supports steady plant growth and could supply fresh produce to crews on long voyages. Water recycling is equally critical: on the ISS, NASA's life-support systems reclaim water from cabin humidity and even from astronauts' urine, producing potable water and significantly reducing the need to launch new water supplies from Earth.

Why These Findings Matter

The ISS has become a proving ground where discoveries in physics, biology and engineering are tested in a way impossible on Earth. Advances in drug formulation, precision physics enabled by ultracold atoms, organ-on-chip health models, and sustainable life-support technologies all directly support future crewed exploration and deliver practical benefits for healthcare, manufacturing and sustainability back home.

Lead image: NASA