Can you bake cookies in space?

It has been an interesting few weeks on the International Space Station (ISS). Earlier this month, an automated Cygnus cargo ship arrived at the ISS with supplies. The items included cookie dough and a zero-gravity oven that would form the base for a first-of-its-kind baking experiment in space. The “cookie project" is the result of a partnership between hospitality group Hilton, the Zero G Kitchen, which creates appliances for microgravity use in space flights, and NanoRacks, a company that develops products for commercial use in space.

No date has been announced for the experiment, but the objective is to make long-duration space travel more “hospitable" in the future.

The supplies also included a dozen bottles of French wine. According to an Associated Press report, the wine will be allowed to age for a year before returning to Space Cargo Unlimited, the Luxembourg-based company that sent it. Researchers will analyse how weightlessness and space radiation affect the ageing process. The goal, the report adds, is to"develop new flavours" for the food industry.

In more than two decades of existence, the ISS has provided a unique environment for science experiments. Astronauts have been conducting experiments across fields ranging from human life sciences and biological sciences to biotechnology and physical sciences.

In his book Endurance: A Year In Space, A Lifetime Of Discovery, American astronaut Scott Kelly, a veteran of four space flights, explains that experiments aboard the ISS are classified into two categories. “The first comprises studies that might benefit life on Earth. These include research on the properties of chemicals that could be used in new drugs, combustion studies that are unlocking new ways to get more efficiency out of the fuel we burn, and the development of new materials," he writes. “The second large category has to do with solving problems for future space exploration: testing new life support equipment, solving technical problems of spaceflight, studying new ways of handling the demands of the human body in space."

The findings of a recent study, for instance, show that human heart cells behave differently in space. The research, published in the journal Stem Cell Reports in November, examined cell-level cardiac function and gene expression in human heart cells cultured aboard the ISS for five-and-a-half weeks. These cells transformed after being exposed to microgravity but returned to normal structures and patterns of gene expression within 10 days of returning to Earth.

As it turns out, microgravity induces a range of changes in organisms—be it humans or bacteria.

The absence of gravity affects even something as simple as sleep. Crew members aboard the ISS aim to get at least 8 hours of sleep a night but only manage an average of 5-6 hours. Sleep doesn’t come easy, especially when you are in a sleeping bag that is attached to a cabin wall while the station orbits Earth at a speed of 17,500 miles per hour. Astronauts sometimes experience up to 16 sunrises a day, as the station orbits Earth every 90 minutes. They use a non-invasive device, known as the Dräger double sensor, to measure core temperatures and body chemistry to see how microgravity alters the circadian rhythm. These results could one day help treat insomnia on Earth.

Different materials can be tested in extreme conditions in space: extreme heat, cold, ultra-vacuum, atomic oxygen, and high energy radiation. According to a reference guide to the ISS from US space agency Nasa, the testing and qualification of materials exposed to these extreme conditions have provided data to enable the manufacture of “long-life reliable components" used on Earth as well as in the world’s most sophisticated satellite and spacecraft components.

Here's a look at some of the most fascinating experiments conducted on the ISS:

FLATWORMS AND REGENERATION

In 2017, researchers from Tufts University analysed flatworms that spent five weeks aboard the ISS to study the anatomical, behavioural and bacteriological impacts of the absence of gravity and geomagnetic fields. According to an official news release, the flatworms, launched into space in 2015, were either left whole or amputated and sealed in tubes half-filled with water. Researchers had two sets of flatworms on Earth as controls.

This research has significant implications for future human and animal space travellers, and regenerative and bioengineering science.

The findings were surprising. Researchers found that one of “the amputated fragments sent to space regenerated into a rare double-headed worm.... When the researchers amputated both heads from the space-exposed worm, the headless middle fragment regenerated into a double-headed worm, demonstrating that the body plan modification that occurred in the worm was permanent," the release adds.

This research has significant implications for future human and animal space travellers, and regenerative and bioengineering science.

PRINTING HUMAN ORGANS IN SPACE

Astronaut Nick Hague with the BioFabrication Facility (BFF) aboard the International Space Station.

The BioFabrication Facility, or BFF, which left for the ISS in July, is a 3D tissue bio-printing system that will allow astronauts to print organ-like tissues in microgravity. According to the Nasa website, using 3D biological printers to design usable human organs, including complex internal structures such as capillaries, is a difficult proposition in Earth’s gravity environment. The BFF experiment is not only expected to prove the viability of human organ fabrication in space, but also maintain the health of crew on deep-space exploration missions by producing food and customized pharmaceuticals on demand.

LIVING WITH ROBONAUT

Peggy Whitson, Expedition 50 flight engineer, Shane Kimbrough, Expedition 50 commander, and ESA astronaut Thomas Pesquet with the Robonaut.

Humanoid robots have also made it to space. The Robonaut, a humanoid robot from Nasa first developed in 2000, was designed to assist astronauts in tasks aboard the station, including missions that were considered too risky for the crew. The robot’s current iteration, Robonaut 2 (co-developed with General Motors), has been on board the ISS since February 2011. Many of the technologies developed for the Robonaut are being adapted for use on Earth like the RoboGlove, a grasp assist device that can “augment human tendons to help both astronauts and factory workers with grasping tasks and to potentially minimize the risk of repetitive stress injuries". In the future, robots could be sent further in space to see how their systems respond in extreme radiation and thermal conditions.

THE TWINS STUDY

Twins and former astronauts Scott (right) and Mark Kelly.

Astronaut Scott Kelly and his twin Mark were part of a landmark study where Scott spent a year aboard the ISS, while Mark stayed back on Earth to study how long-term space flight affects the human body. The findings were published in the journal Science in April. Nasa described the Twin Study as the first study of its kind to compare the molecular profiles of identical twin astronauts. Some of the findings suggested that astronauts can, in fact, spend long durations in space. For instance, there were no major changes in Scott’s cognitive abilities and performance during his time in space. Researchers also understood more about the effects of long-duration space flight on the human cardiovascular system after they found indications of inflammation and carotid artery wall thickening in Scott during and immediately after his mission.