Controversial plans to launch 50,000 mirrors into area would disrupt sleep ‘on a planetary scale’, scientists warn

Plans to launch 50,000 mirrors into space to offer ‘sunlight on demand’ would disrupt sleep ‘on a planetary scale’, scientists have warned.

California–based startup, Reflect Orbital, is poised to secure permission to launch a 60–foot (18.3–metre) prototype mirror into orbit to beam sunlight back to the Earth’s surface.

Once it has reached an altitude of 400 miles (640 km), the mirror will unfurl and illuminate a patch of Earth about three miles (4.8 km) wide.

The company says its space mirrors could allow solar power plants to operate 24 hours a day, provide lighting for disaster–struck regions and even replace street lights.

But leading researchers have warned this could have far–reaching consequences for human health and ecosystems.

Experts – including the presidents of four international scientific societies – have raised concerns in letters to the US Federal Communications Commission (FCC).

‘The proposed scale of orbital deployment would represent a significant alteration of the natural night–time light environment at a planetary scale,’ said the presidents of the European Biological Rhythms Society (EBRS), the Society for Research on Biological Rhythms, the Japanese Society for Chronobiology and the Canadian Society for Chronobiology.

They argued that the move could disrupt biological clocks that regulate sleep and hormone production in humans and animals, could cause havoc for migration and affect the seasonal cycles of plants.

The US government is also considering plans from Elon Musk’s Space X to put up to one million more satellites in Earth’s orbit.

The international scientific groups, representing about 2,500 researchers from more than 30 countries, urged the FCC and other regulators to conduct a full environmental review and set limits on satellite reflectivity and cumulative night sky brightness.

Prof Charalambos Kyriacou, a geneticist at the University of Leicester and president of the EBRS, told The Guardian: ‘We’re saying, please think before you go through with this, because this could have global implications for things like food security.

‘Plants need the night. You can’t just get rid of it.’

A separate letter from the presidents of the World Sleep Society, European Sleep Research Society, Sleep Health Foundation, Australian Sleep Association and Australasian Chronobiology Society said that circadian disruption ‘is not mere inconvenience, it is a physiological mechanism driving major adverse health consequences’.

‘We do not argue against space innovation,’ the letter added. ‘[But] the alternation of light and dark is not a trivial background condition. It is one of the oldest organising principles of life on Earth.’

Reflect Orbital, which has already raised more than $28 million (£20.8 million) from investors, says it plans to harness the vast quantities of sunlight that normally pass Earth by, and sell it on demand to people, companies and governments.

The biggest appeal will be for the growing solar power industry, which is currently facing the unavoidable problem that solar panels can’t generate electricity at night.

Ben Nowack, Reflect Orbital’s chief executive, told the New York Times: ‘We’re trying to build something that could replace fossil fuels and really power everything.’

By the end of 2027, Reflect Orbital plans to launch two more prototype mirrors with hopes to launch 1,000 larger satellites by the end of the following year.

According to the company’s current plan, that number will expand to 5,000 by 2030 and reach a full constellation of 50,000 orbiting mirrors by 2035.

Mr Nowack says the company will charge about $5,000 (£3,700) for an hour of sunlight from one mirror if a customer signs an annual contract for at least 1,000 hours.

He also says that solar power plants may be able to arrange for lighting by agreeing to split the revenues of the energy generated with Reflect Orbital’s light.

While that might come as a boon for renewable energy, scientists have raised major concerns about the plan’s safety and efficacy.

Critics warn that the mirrors could distract pilots, interfere with ground–based observatories, and wreak havoc on the natural sleep cycles of animals and humans.

Circadian rhythms, the natural biological cycles that help organisms know when to sleep, are hugely influenced by the presence or absence of sunlight.

If they’re disrupted, animals might breed at the wrong times when food is scarce, hibernating animals and insects might wake up in the middle of winter, and plants might bloom when there are no pollinators.

The additional light could also confuse migratory birds, sending them flying off into the deadly cold when they think summer is approaching.

That could also be a problem for humans in the affected areas, with additional light in the evenings sending our natural sleep cycles into disarray.

The campaign group DarkSky says that these activities ‘pose serious risks to the nighttime environment’.

DarkSky adds: ‘Such illumination would introduce an entirely new source of artificial light at night, with far–reaching consequences, including disruption to wildlife and ecosystems that depend on natural cycles of light and dark, as well as serious public safety concerns.’

Unfortunately, the FCC does not take any of these factors into consideration when considering Reflect Orbital’s application.

The agency’s official policy is that anything that happens in space is, by definition, not on Earth and therefore not subject to environmental review.

Besides the environmental impacts, scientists are also extremely concerned that Reflect Orbital could jeopardise astronomy.

Astronomers have been warning for years that the light bouncing off the thousands of satellites in orbit is making it more and more difficult for telescopes to look out into space.

Even as SpaceX are voluntarily trying to make its satellites darker, Reflect Orbital is trying to make its spacecraft as bright as physically possible.

Professor Gaspar Bakos, an astronomer from Princeton University, previously told the Daily Mail: ‘It will disrupt ground–based astronomy big time.’

The company claims that the beam of light would be restricted to a limited area, avoiding the most sensitive ground–based observatories.

However, Professor Bakos points out that light would inevitably scatter through the atmosphere on clouds and air molecules, adding a glow of light pollution to the sky.

Professor Bakos says that Reflect Orbital should ‘absolutely’ be prevented from placing mirrors in orbit, adding: ‘This is harming our environment in so many ways.’