Overnight tonight, SpaceX and NASA will launch Falcon 9 with a Cargo Dragon bound for the International Space Station. Along with the foodstuffs and normal cargo aboard CRS-32, there are also some thirty experiments that astronauts will conduct aboard the ISS-NL orbiting outpost. One of them will test Albert Einstein’s Theory of Relativity.

​Albert Einstein’s theory of relativity—encompassing both Special and General Relativity—has withstood extensive experimental scrutiny for over a century. While it has faced challenges and refinements, it has never been proven wrong in its applicable domain.​ One could easily say that Einstein’s theories are undefeated and likely to stay that way.

Research Into Relativity Continues, With Obvious Benefits

Contemporary research continues to test the boundaries of general relativity. For instance, the Event Horizon Telescope aims to image black holes to examine predictions of general relativity in extreme conditions. Moreover, studies of the universe’s expansion and dark energy have prompted discussions about potential modifications to our understanding of gravity.

Jennifer Buchli, NASA’s Chief Scientist of the International Space Station said Friday that “Over 30 new payloads [will be] enabled by this mission across ISS National Labs, NASA and our international partners.”

She continued to highlight some of the experiments that will be aboard Cargo Dragon Monday morning. “The first is ACEs Atomic Clock Ensemble in space. This is being flown by the European Space Agency with NASA collaborating out of their Science Mission Directorate. According to Einstein’s Theory of General Relativity, gravity affects the passing of time. ASUS tests theories of gravitation by creating a network of clocks.”

ACEs Atomic Clock Ensemble (ACES) is an ESA ultra-stable clock experiment, a time and frequency mission to be flown on the Columbus module of the ISS (International Space Station), in support of fundamental physics tests.

Ms. Buchli is referring to Gravitational time dilation, a phenomenon predicted by Einstein’s general theory of relativity. Clocks situated closer to a massive object, such as Earth, experience stronger gravitational fields and thus tick more slowly compared to clocks located further away in weaker gravitational fields.

This effect has been confirmed through experiments involving atomic clocks placed at different altitudes, which show measurable differences in elapsed time in their results. The Hafele-Keating experiment did the same thing in 1971, albeit on commercial aircraft. The Hafele-Keating experiment has been repeated multiple times with increasing accuracy, proving Albert Einstein correct yet again.

If that sounds like the stuff of science fiction, rest assured it does not. It’s part of the measurements that GPS conducts in order to tell you where you are.

Jennifer Buchli continued, “ACEs will link its own highly precise clock with the most accurate clocks on Earth and compare them on how they measure the flow of time. ACES looks for tiny changes in the laws of physics over time which could hint at new discoveries about dark matter and fundamental forces of nature.

“Results have applications in scientific studies and measurements the search for dark matter and fundamental physics and could contribute to improve navigation for spacecraft as well as global satellites,” Ms.Buchli added. “Super precise clocks are essential on Earth for technologies such as GPS, Internet security, financial transactions and scientific research.”