The world’s skies are becoming crowded, posing a risk to airlines as rockets, drones and, in the near future, “flying taxis” begin to use airspace.
The huge number of new rockets – pioneered by Elon Musk’s SpaceX – is set to exacerbate the problem as the growing commercial space industry will share airspace used by tens of thousands of passenger planes. Meanwhile, drones and the expected emergence of electric vertical take-off and landing aircraft (eVTOLs), so-called flying taxis, are set to complicate the management of the lower levels of airspace through which planes take off and land.
The number of passenger planes is forecast to grow by a third to more than 36,000 aircraft by 2034, according to consultancy Oliver Wyman. By that point, they will be sharing the skies with more than 10,000 eVTOLs, according to Bain, and thousands of rocket launches.
Aviation experts believe the way airspace is managed will need to change.
“There are more users and more vehicles that want to use airspace ... the way that we provide our services will probably need to change significantly,” said Eduardo Garcia, senior manager for future skies at Canso, the body that represents the air traffic management industry.
“It is a key topic, and it will not be easy. Ours is a safety critical industry,” he said.
The issues facing airlines were illustrated last month when Qantas delayed several flights between Australia and South Africa after the US government warned about the risk of SpaceX rocket parts re-entering the atmosphere in the southern Indian Ocean.
Chris Quilty, co-chief executive of space business consultancy Quilty Space, said the Qantas delays could be the “tip of the iceberg” in a rapidly developing space industry.
It is not just rocket companies that are developing vehicles designed to return to Earth. A host of start-ups are targeting the manufacturing of products such as pharmaceuticals in space, using the benefits of zero gravity, all of which will need to be brought back down to earth.
“It is the Wild West. The rate at which this is happening is starting to impact the aviation community,” he added.
The latest disruption of Qantas flights was by a “controlled re-entry”, where the booster section of a rocket returns to Earth to land on an ocean barge or land-based launch pad.
But “uncontrolled re-entry” of space objects – essentially space junk returning to Earth without guidance – is a potentially greater risk.
In 2022, hundreds of flights were delayed when Spain’s airspace was partially closed because of concerns about the uncontrolled re-entry of the remains of a Chinese rocket.
While regulators increasingly require “end of life” deorbit plans for satellites and rockets to try to reduce space debris, there is no universal rule ensuring a controlled re-entry for all spacecraft into Earth’s atmosphere over remote regions.
Controlled re-entry is usually reserved for larger satellites or spacecraft, and requires extra propellant and advanced guidance systems, significantly adding to the cost and complexity of the mission.
Instead many operators take a passive approach to deorbiting defunct satellites or rocket bodies, relying on the gravitational pull of Earth to draw the debris into the atmosphere where most of it will burn up.
Ken Quinn, a partner at law firm Clyde & Co and formerly chief counsel of the US Federal Aviation Authority (FAA) and Flight Safety Federation, said: “The management of orbital debris is becoming a critical safety and air traffic control issue, which means it poses an increasing threat to commercial aviation and needs to be managed better.”
[ Simulation test using drones to deliver life-saving equipment is a successOpens in new window ]
In a study published last month in the scientific journal Nature, academics at the University of British Columbia in Vancouver found that while the probability of space debris colliding with an aircraft was low, “the risk is rising due to the increase of both re-entries and flights”.
Authors Ewan Wright, Aaron Boley and Michael Byers said the failure to equip rockets with systems to ensure controlled re-entry in areas away from people and aircraft could lead to dire consequences. “Even a small piece of debris could be devastating to an aircraft,” the study says.
Air taxis
In the lower reaches of airspace, widely available small drones are causing problems for airlines.
Perhaps most notably, London’s Gatwick airport was closed for 36 hours in December 2019 following reports of drone sightings, affecting about 140,000 passengers.
[ Flights resume at Gatwick Airport following further disruptionOpens in new window ]
Flights out of Dublin Airport have been disrupted multiple times over the past two years by drone sightings.
But bigger battery-powered aircraft – carrying passengers and that take off and land like a helicopter – are expected to break through and enter commercial use in the coming decade.
While the eVTOL industry has been perennially over-optimistic in forecasting when these aircraft will be certified to carry passengers, many companies are flying prototypes, and industry experts believe their emergence into a significant part of the travel network is only a matter of time.
A 2024 Bain study suggested commercial air taxi services could begin in the next two to three years, and then will take about a decade to “reach scale”.
All these flying taxis – which ultimately are not expected to have pilots – will need to be safely integrated into airspace below roughly 5,000ft.
Regulators and air traffic management agencies in Europe and the US are racing to prepare for the new era, by knitting spacecraft and the flying taxis into the air traffic control network.
In London, Nats, the UK’s air traffic control company, has run simulations of eVTOLs carrying passengers on the 40km trip between Heathrow airport, to the west of London, and City airport, in the east, with stops-offs at “vertiports” in the centre of the city.
Andy Sage, director of safety transformation at Nats, said: “The future promises a rapidly increasing number of diverse airspace users, both crewed and uncrewed, which we see being managed within a single, integrated traffic environment.”
The Nats test essentially treated the eVTOLs as though they were helicopters, which needed integrating into air traffic control.
Over time, as the technology is better understood, the disruption could be expected to decline.
In the US, the FAA – which regulates civil aviation – said it had cut airspace closures because of space vehicles travelling through an area from an average of “more than four hours” per launch to “more than two hours”.
But while small numbers could be handled by traditional air traffic control – likely operating in their own safe corridors of airspace – there could come a point where there are simply too many to handle.
The likely answer at that point, said Canso’s Garcia, will be automation. “There is a limit in the cognitive capacity that humans have to manage vehicles with different speeds and performances, and more crowded airspace,” he said. “We will need ... more automation and artificial intelligence, helping and supporting the way we do things.” – Copyright The Financial Times Limited 2025
