In space, the weak force of gravity, also known as microgravity, puts cells under incredible pressure, making them age more quickly.

This phenomenon allows scientists to watch the progression of cancer growth and the effect of cancer treatments much more quickly than they can on Earth.

When the Axiom 3 space flight launched from the Kennedy Space Center in Cape Canaveral, Florida, on January 18, heading to the International Space Station, it took with it 4 miniature tumor organoids that were produced from cancer cells of patients, and which were grown in the laboratory before. Scientists at the University of California San Diego.

According to the Fortune Wheel website, Axiom 3 was scheduled to land on Saturday, but the landing was postponed until Tuesday, at the earliest, due to weather, according to SpaceX, which manufactured the Crew Dragon spacecraft used in the mission.

This was not the first time the team led by Dr. Catriona H.M.

Jamieson, a hematologist and professor of medicine at the college, is sending such samples into space. She has previously released stem cells on multiple Space

"We thought, 'What if I send the cancer up?'" Jamieson told Fortune. "Will the cancer go from bad to worse? And the answer is yes, under the pressure conditions" caused by microgravity.

When cancer develops under stress, it's because of a transcription gene that's turned on, known as ADAR1, according to Jamieson.

In previous missions, her team observed that small tumors sent into space activated the gene before tripling in size in just 10 days, a much faster growth rate than seen on Earth.

Further testing revealed that ADAR1 had “exponentially metastasized” in the satellite tumors where it was growing at an alarming and uncontrolled speed.

In the latest Axiom mission, Jamieson's team sent back small tumors that were treated with two types of anticancer drugs that block ADAR1 in different ways.

The drugs included fedratinib, which is already approved by the US Food and Drug Administration to treat blood cancers, but not solid masses.

Jamieson's team has enthusiastically begun working on an experimental drug called rebecsinib that blocks ADAR1 activation in a different way, by preventing it from producing malignant proteins.

When Axiom 3 was launched last month, small breast cancer tumors were being treated with the new mixture.

So far, researchers have found that it significantly inhibits cancer growth and is even more effective than fedratinib.

“It basically stops breast cancer from replicating itself,” Jamieson says of rebicinib, adding that it may be a “kill switch for cancer.”

Her team hopes to launch the drug into clinical trials by the end of the year.