The periphery of our planet is cluttered with rubbish. Pieces of old satellites and rockets circle the world, travelling at incomprehensible speed.
For anyone wishing to work there, or go beyond Earth's orbit - a surprising number these days - it's a burgeoning problem. Leaving Earth is like crossing a beach for a swim when a discarded beer can could hit you at 17,500mph. Worse still, every time space debris collides - or a government blows up a satellite to show its muscle - the problem grows exponentially, an effect known as the Kessler Syndrome. Anything longer than 1cm is potentially 'mission degrading' or 'mission terminating', but even flakes of paint have left divots in the windscreen of old space shuttles.
Confronting this problem, three stellar engineers have come to the Chamberlin Observatory in Denver, Colorado, partners in a new start-up, Privateer Space. In the middle is Steve 'Woz' Wozniak, who knows a fair bit about start-ups, having founded Apple in 1976, with his fellow college drop-out Steve Jobs. The second is the scientist and environmentalist Moriba Jah, a 'space heretic', according to the third, tech entrepreneur Alex Fielding.
They are an appealing team to have hanging on to the back of an orbiting rubbish truck, which is why the Hawaii-based Privateer is garnering a lot of interest right now. They have just announced a partnership with Omega, which famously made the watch worn by the Apollo astronauts who walked on the moon. 'This is very meaningful to us, because it's a connection that goes back to the watch that Buzz Aldrin wore,' says Wozniak. Although they won't reveal how much money they've raised, Fielding says Privateer is 'backed by fantastic Tier 1 venture capital firms globally', and points out, 'Steve, our president, is also a fantastic supporter.'
Assembled beneath the Chamberlin's 1894 telescope, Wozniak is big, bearded and benevolent, Jah is warmly irascible with dreads and jewellery-stretched earlobes, and Fielding, whose head vaguely resembles the rocket in The Adventures of Tintin's Explorers on the Moon, plays CEO, offering both the dream and a steady hand.
While Privateer is a classic tech start-up, for once they don't seem to want to move fast and break things: too much of that is already going on up there. What they want is to map as many pieces of debris in orbit as possible, along with size, shape and trajectory. But to achieve this, they need to build their own 'constellation' of satellites, and to pay for that by opening up space to us all - or at least access to the cameras that look down on us.
And that, of course, is controversial, even if Wozniak has a warm, soothing tone as he says, 'We intend to gain the reputation as Privateer being the steward of space.'
Jah fell in love with space while guarding nuclear missiles in Montana as a US Air Force recruit. During long nights 'keeping cows away from the silos', he would gaze up and imagine navigating the stars. After leaving the military, he got himself an education. The son of a Sierra Leonean father and Haitian mother, he became a navigation engineer on Nasa missions to Mars including the Mars Global Surveyor, Mars Odyssey and Mars Rover.
Now, at 51, a professor at the University of Austin at Texas, he is one of space's original thinkers, increasingly concerned about the mess we are making up there. 'Back in 2006, I saw the problem going on in space,' he says. 'And I juxtaposed that with issues on Earth, with landfill, with what we're doing to the oceans with plastics. It pissed me off. And I want to do something about it.'
A growing problem
The situation is growing worse. The state of 'low Earth orbit' - roughly between 100 and 1,250 miles above Earth's surface - is the subject of intense global concern. In the words of Darren McKnight, senior technical fellow at Privateer's US-based competitor LeoLabs, 'In certain regions we are running out of margin.'
In November last year, Russia mimicked the opening of the film Gravity when it exploded an old satellite, the Kosmos-1408, with a missile, sending debris everywhere and causing the crew of the International Space Station to shelter in its escape pods. This followed similar demonstrations by China in 2007 and the USA in 2008 (America has now vowed to end such activities). Each in its way added to the jetsam circling above us. According to the European Space Agency (ESA), 36,500 pieces of debris bigger than 10cm are up there, including several Russian rocket boosters the size of buses.
Those are just the bits that scientists can see. The ESA estimates that there are tens of millions of smaller pieces - a million of them over 1cm. Each will be travelling at horrendous speed, up to 20 times the velocity of a bullet, at least the one Dirty Harry liked to fire from his Magnum .44. Do you feel lucky, Major Tom?
Already the ISS, 250 miles up, has to manoeuvre several times a year to avoid collisions. And low Earth orbit is about to get more congested. At present there are about 8,800 satellites in this space, 2,600 of them already dead and in the words of Fielding, 'just junk'. Yet vast new constellations of satellites are being launched.
Elon Musk's Starlink communications system, currently providing comms aid to Ukraine, uses 2,700 satellites but he wants 40,000 more. Other groups, such as OneWeb and Amazon, plan constellations in the thousands. Industry specialists say it's not inconceivable there will be 100,000 satellites in orbit by 2030.
That sort of Wild West expansion worries Jah: 'If we are going to explore space, do we keep doing what we always do when we explore a new domain, the "I own this," "I own that," the non-sharing and the polluting?' he asks. 'Indigenous people, when they interact with the environment, they don't just do a bunch of stuff saying, "It'll be fine." Their ability to keep on existing depends on a successful conversation with the environment. But that's not what we're doing in space.'
And so comes Privateer, with its base in Maui (no one can answer why we meet in Denver, beyond Wozniak having a new holiday home there that he doesn't actually have time to visit). 'Why call it Privateer?' I ask. 'Amazon was taken,' Fielding replies. At 44, Privateer's CEO is the youngest of the partners. He met Wozniak at Apple, and they obviously know each other well.
They started Wheels of Zeus together in 2001, a company that used GPS to track items (a little like Apple's Find My iPhone app). The name came because Wozniak owned the domain name woz.com, Fielding says with a laugh: 'Neither of us should work on branding.'
With Privateer, the idea is first to create a database of debris databases, drawing on every available resource to pinpoint as many pieces of space junk as possible. 'Because we are interested in making this information available to humanity in general, we won't say no to data whoever it is from,' says Jah, pointing out governments' inherent scepticism of each others' information.
The team then wants to iron out discrepancies between the various databases. 'We don't have agreement between the people tracking these things,' says Fielding. 'The gaps between where we think things are can be 200km. Then we don't treat things like the objects that they are in terms of size, shape and material properties. We treat them all like bowling balls.'
So phase two of the business plan requires Privateer to launch its own constellation of satellites, armed with sensors, starting later next year. The man responsible for designing them is Justin Bellucci, Privateer's senior director of engineering. 'We want satellites to map the debris,' he later tells me, 'and compare those measurements with what is being measured from Earth, reducing the margin of error.' They will offer this information cheaply to companies operating in orbit, forcing out those Fielding calls 'extortionists'.
They intend to work with other start-ups, which will actually remove the junk - for example ClearSpace, a Swiss company developing a spider-like robot that will grab debris, which was recently awarded an £86 million contract by the ESA to remove a 112kg section of rocket left over from a 2013 mission. ClearSpace also has a partnership with Omega , the watchmaker clearly keen to keep its cosmic heritage up to date.
Meanwhile, Tokyo-based Astroscale has been developing both a docking system that it hopes will be installed on all future satellites allowing them to be collected later, and a magnetic spacecraft to attract smaller debris. It has won contracts from several national space agencies to study options for clearing up their leftovers.
Enough is going on around the world for McKnight to tell a conference recently, 'I love the fact that [the US] said, "Yes, we're concerned about picking up debris." But I will tell you, the US is woefully behind the rest of the world in this area.' (When I spoke to McKnight, he said he doesn't see Privateer as a competitor, though there may be some 'overlap', as LeoLabs relies on land-based radar.)
On the clock
Timing is at the heart of all this (which should please Omega). Because gravity will pull all debris back to earth eventually, lower Earth orbit is actually self-cleaning. But while anything below 375 miles will return within years, debris at the congested 500-mile zone will take centuries to fall, and anything above that, millennia.
The Privateer founders discuss the science behind this. 'Ask people whether the force of gravity on the International Space Station is around zero or about the same as on Earth,' says Wozniak. 'Most people say about zero, but it's about the same as on Earth. Instead of being 4,000 miles from the centre of Earth [as we are on the surface], it's 4,250 miles. It's almost the same distance.'
Jah adds, 'Things are in orbit exactly because of gravity, not because of the absence of it.' He points out that astronauts can somersault in the space station because they are in free fall around the planet, not because they are floating above it. 'We have astronauts to blame for that stupidity,' he goes on. 'Why do they keep on saying "zero gravity"? They tend to be fighter pilots - they don't know the physics really well.' His colleagues laugh a little nervously at this blasphemy.
Having changed the world with one of the earliest, most iconic personal computers, Wozniak at 71 spends most of his time on speaking tours. 'I don't get attracted to things like this very often,' he says. 'Knowing Alex, and knowing the way he thinks and what goodness means to him, that was the big attraction for me.'
He and Fielding are clearly very comfortable around each other. Fielding tells a confusing story of the two of them lost in Death Valley. Friends later called to suggest he shouldn't kill one of America's national treasures. Wozniak loves a joke. He hands me stickers to put in the loo of my plane home that read don't flush over cities.
Fielding may come to need Wozniak's hard-won shield against cynicism, as he makes it clear Privateer is a commercial enterprise. 'We're not building a non-profit,' he says. 'We want to do a lot of good in the world. But, you know, the good that we want to do has to be paid for.'
Accessibility to space
What this means is that Privateer's satellites will have cameras monitoring Earth. 'Talking with investors, seeing where the market's going, the thinking is, if we have satellites up there, why not also have sensors there, that can, you know, provide data,' says Bellucci.
With enough satellites looking down - they won't say how many but assure me they will all be designed not to add to the long-term clutter - they will create a camera system from space extensive enough for developers to create apps we can then all use.
By offering imagery from space cheaply, Fielding wants to make other companies' satellites obsolete, reducing overlaps. 'I mean why are there 40 satellites over Kyiv right now doing the same thing?' he asks. Researchers without government-sized budgets will be able to look down and see 'people doing bad things'.
This puts Privateer in the classic role of disruptor. 'What breaks open any industry is accessibility,' Fielding says. 'Right now if you take a photograph from space it costs thousands of dollars.'
There is a lot to commend it. Silicon Valley venture capitalist John Doerr recently gave $1.1 billion to Stanford University to create a climate school, saying, 'Climate and sustainability is going to be the new computer science.'
'We do most of that [research] from satellites,' says Fielding. 'Our ability to provide accessibility to space is critical. Going from Copernicus to Galileo to Greta Thunberg is a huge leap. But we are on that path.'
He goes on, 'What if a couple of kids at university in Boulder want to have an app that tracks dark ships [ships with their transponders turned off because their cargo is illegal]. You need a camera from space, you need an image classifier and you need a radio deck. What if, instead of millions of dollars, you can do that for the price of a pizza and a six pack of Coke?'
Jah says, 'We're after the removal of ignorance. The removal of ignorance results in the creation of knowledge.' Of course, it doesn't take a rocket scientist to see how such 'creation of knowledge' might be a further intrusion on humanity's already diminished privacy.
I'm trying to work this out when Wozniak helps by bringing us back to Earth with a cuddly bump. 'I've always been for the consumer,' he says. 'Like in that movie Spy Games, you could have little pictures from our satellites of a beachfront property you want to buy.'
'Exactly,' says Fielding.
We've moved a fair way from being the stewards of space, but Fielding insists there is no point in being beholden to the space industry for charity. 'If we don't do this, the future of humanity and our kids, that's at stake. That's a massive project. That's not something you can fake.'
So it turns out that the road to the heavens is paved with good intentions, just like the road to hell.
Such thoughts on unintended consequences make me ask Wozniak if he feels Apple has been a force for good. He thinks about it and at last says yes, 'although there are a lot of things about Apple and, well, mainly the other big tech companies, that make life not that great. You know, unhappiness, a lot of work, frustration, why doesn't this work? Why am I, the human, not more important?'
Fielding jumps in: 'The technology that we bring into the world, it's like giving birth to a child - you don't know if you're giving birth to Greta Thunburg or Mother Teresa, Stalin or Hitler...'
'Or Facebook,' says Jah.
All laugh and Wozniak says, 'You know, Facebook had a good start, it was a great thing. But then it turned into something different, not what it started out to be.'
It's lucky the partners in Privateer are so virtuous, even if the company's name suggests otherwise.