The Spacehab research double module was the primary payload carrier for STS-107, and doubled the volume available for experiments; this configuration significantly increased the amount and complexity of research than was possible on STS-95. The Spacehab research module was a pressurized environment carried in Columbia's payload bay that was accessible to the crew while in orbit via a tunnel from the Shuttle's middeck. Experiments in the Spacehab module included nine commercial payloads involving 21 investigations, four European Space Agency (ESA) payloads with 14 investigations, one payload/investigation for International Space Station (ISS) Risk Mitigation, and 18 payloads supporting 23 investigations for NASA's Office of Biological and Physical Research (OBPR).
In the area of biological applications, two separate OBPR experiments allowed different types of cell cultures to grow together in weightlessness to enhance their development of enhanced genetic characteristics - one to combat prostate cancer, the other to improve crop yield. Another experiment was designed to evaluate the commercial usefulness of plant products grown in space. A facility for forming protein crystals more purely and with fewer flaws than is possible on Earth may lead to a drug designed for specific diseases with fewer side effects. A commercially sponsored facility housed two experiments to grow protein crystals to study possible therapies against the factors that cause cancers to spread and bone cancer to cause intense pain to its sufferers. A third experiment looked at developing a new technique of encapsulating anti-cancer drugs to improve their efficiency. Other studies focused on changes, due to spaceflight, in the cardiovascular and musculoskeletal systems; in the systems which sense and respond to gravity; and in the capability of organisms to respond to stress and maintain normal function. NASA was also testing a new technology to recycle water prior to installing a device to recycle water permanently aboard the International Space Station.
In the physical sciences, three studies inside a large, rugged chamber examined the physics of combustion, soot production and fire quenching processes in microgravity. These experiments can provide new insights into combustion and fire-suppression that cannot be gained on Earth. An experiment that compresses granular materials in the absence of gravity was hoped to further our understanding of construction techniques. This information can help engineers provide stronger foundations for structures in areas where earthquakes, floods and landslides are common. Another experiment evaluated the formation of zeolite crystals, which can speed the chemical reactions that are the basis for chemical processes used in refining, biomedicine and other areas. Yet another experiment used pressurized liquid xenon to mimic the behaviors of more complex fluids, such as blood flowing through capillaries.
ESA, through a contract with SPACEHAB, was flying an important payload focused on astronaut health, biological function and basic physical phenomena in space. These experiments addressed different aspects of many of the same phenomena that NASA is interested in, providing a more thorough description of the effects of space flight, often in the same subjects or specimens. ESA performed seven inflight experiments, and one ground-based experiment, on the cardiopulmonary changes that occur in astronauts. Additional ESA biological investigations examined bone formation and maintenance, immune system functioning, connective tissue growth and repair, and bacterial and yeast cell responses to the stresses of space flight. A special facility was designed to grow large, well-ordered protein and virus crystals that are expected to lead to improved drug designs. Another was designed to study the physical characteristics of bubbles and droplets in the absence of the perturbations caused by Earth's gravity.
SPACEHAB also makes it possible for universities, companies and other government agencies to do important research in space without having to provide their own spacecraft. The Canadian Space Agency sponsored three bone-growth experiments, and collaborated with ESA on two others. The German Space Agency measured development of the gravity-sensing organs of fish in the absence of gravity. The U.S. Air Force conducted a communications experiment. One university had an experiment designed to grow ultra-pure protein crystals for drug research, and another university tested a navigation system for future satellites. Elementary school students in Australia, China, Israel, Japan, Liechtenstein and the United States were studying the effects of space flight on spiders, silkworms, inorganic crystals, fish, bees and ants, respectively.
Columbia's payload bay also housed experiments, including three attached to the top of the research double module: the Combined Two-Phase Loop Experiment (COM2PLEX), Miniature Satellite Threat Reporting System (MSTRS) and Star Navigation (STARNAV). There were six payloads/experiments on the Hitchhiker pallet - the Fast Reaction Experiments Enabling Science, Technology, Applications and Research (FREESTAR), which is mounted on a bridge-like structure spanning the width of the payload bay. These six investigations looked outward to the Sun, downward at Earth's atmosphere and inward into the physics of fluid phenomena, as well as testing technology for space communications.
FREESTAR held the Critical Viscosity of Xenon-2 (CVX-2), Low Power Transceiver (LPT), Mediterranean Israeli Dust Experiment(MEIDEX), Space Experiment Module (SEM-14), Solar Constant Experiment-3 (SOLCON-3) and Shuttle Ozone Limb Sounding Experiment (SOLSE-2). The SEM was made up of 11 separate student experiments from schools across the U.S.; this was the 14th flight of a SEM on the space shuttle.
Additional secondary payloads were the Shuttle Ionospheric Modification with Pulsed Local Exhaust Experiment (SIMPLEX) and Ram Burn Observation (RAMBO).
While returning from this 16-day scientific research mission, Space Shuttle Columbia and all seven STS-107 crewmembers were lost over north central Texas on Saturday morning, February 1, 2003, on their final descent to the landing site at Kennedy Space Center in Florida.