Docking their SpaceX Crew Dragon capsule to the International Space Station in May completed the first part of the mission for NASA astronauts Robert Behnken and Douglas Hurley on the first crewed test flight for the Commercial Crew Program (CCP). But their task was far from over. The following months contained another important piece of their journey: living and working aboard the orbiting laboratory. Together, they spent more than 100 hours assisting or conducting science and technology demonstrations on station.

The CCP increases the crew time available for science on the orbiting lab and provides more opportunities for station research. Behnken and Hurley’s recent months have been filled with numerous scientific experiments that are helping humans learn to live and explore farther into space and benefiting us back on Earth.

It takes two

Behnken and Hurley worked together to install a new European Drawer Rack Mark 2 in the space station’s Columbus module. Launched aboard the recent HTV-9 mission, the rack serves as a flexible experiment facility, able to support a wide range of experiments and technology demonstrations. While the rack is not heavy in microgravity, the pair had to work together to carefully maneuver it through station and into place.

Looking back at our planet

Both Behnken and Hurley contributed images to the Crew Earth Observations (CEO) study. The top image, taken by Behnken, shows a cloud formation as it spirals in the Balearic Sea between Valencia, Spain, and the island of Ibiza. In the bottom image, taken by Hurley, what looks like land is actually a Saharan dust cloud that has blown over the Atlantic Ocean and is nearing the Caribbean Sea.

CEO images help record how the planet is changing over time, from human-caused changes, such as urban growth and reservoir construction, to natural dynamic events, such as hurricanes, floods and volcanic eruptions.

Getting technology ready for space

Launched aboard the 19th SpaceX commercial resupply mission, the Robotic Tool Stowage (RiTS) will serve as a protective storage unit for critical robotic tools. NASA astronaut Chris Cassidy worked alongside Behken and Hurley to prepare RiTS for installation during a spacewalk. RiTS’s first residents are two Robotic External Leak Locators (RELL). Outfitted with mass spectrometers capable of “sniffing” out the presence of gases such as ammonia, which is used to operate the station’s cooling system, the Canadian Space Agency’s Dextre robot can use these robotic tools to detect leaks from the station.

RELL is a result of a successful technology demonstration aboard station. The technology proved fully capable, so a second RELL was also launched to be stored in RiTS. Cassidy and Behnken installed the unit with its tools inside during a spacewalk, the 10th for both of them.

ACE in the hole

Hurley took photos of modules for the Advanced Colloids Experiments (ACE) aboard the space station. The ACE experiments use microgravity to examine the behavior of colloids, suspensions of microscopic particles in a liquid. Colloids are found in products ranging from milk to fabric softener. A better understanding of these substances could influence a number of industries on Earth and even improve product shelf lives.

Walking the BEAM

No longer an ongoing experiment, the structure where Behnken floats in this image started out as a study. The Bigelow Expandable Activity Module (BEAM) was attached to the station’s Tranquility module in April 2016. It began as a technology demonstration to test an experimental expandable capsule inflated to create a space large enough for an astronaut, such as Behnken, to enter.

Switching it up

While many experiments on the space station can be conducted without an astronaut monitoring it, others require crew members to swap out pieces throughout the process. Behnken and Hurley worked on numerous sample switch outs for the Electrolytic Gas Evolution Under Microgravity (Electrolysis Measurement) experiment, which looks at bubbles created using electrolysis. Bubbles may seem simple, but using this method to better understand how they grow could improve devices like medicine delivery skin patches.

Creating droplets in microgravity

Behnken and Hurley conducted the Droplet Formation Study inside the Microgravity Science Glovebox (MSG). This experiment evaluates water droplet formation and water flow from Delta Faucet’s H2Okinetic shower head technology. To conserve water, flow rates in shower devices have been reduced, but this lower flow rate also reduces the effectiveness of these devices. As a result, consumers often take longer showers, undermining the goal of using less water. Gravity’s full effects on formation of water droplet size are unknown, and this research in microgravity could help improve the technology, while conserving water and energy.

The research MVP

In addition to scientific samples, hard drives also sometimes need a change out. Hurley assisted with hard drive replacement for the Multi-Use Variable-g Platform (MVP). This facility includes two internal carousels that simultaneously can produce up to two times the force of Earth’s gravity. MVP is used to conduct research in space with a wide variety of sample types, such as fruit flies, flatworms, plants, fish, cells, and protein crystals.

Fruit punch and foam

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When Hurley squeezed a bag of fruit punch, he did not get a refreshing drink. Instead, the red fluid wound down a clear tube and soaked into a block of white foam. While it might look simple, this experiment is providing researchers with better information about managing liquids in microgravity.

Hurley conducted his foam infill demonstration as a part of the Capillary Structures investigation, which studies the use of different structures and containers to manage fluids and gases. The experiment may provide researchers with a better understanding of capillary forces, the small pushes and pulls that move liquid up a narrow tube.

Although Behnken and Hurley’s chapter of research aboard the orbiting laboratory ends with their return to Earth aboard the Crew Dragon, science aboard the space station continues. Their return also supports station science by bringing scientific samples home to researchers. Commercial flights like this one have the capability to put samples in the hands of researchers more quickly, opening up the microgravity lab to even more types of research.