It is not space aliens or black holes that kill space explorers. It is faulty gaskets, a broken vent and an electrical fire. It is a damaged thermal protection system, the inability to fix it, and the lack of any other way to get seven doomed astronauts home.
The things that kill us in space are not the monsters we mould out of rubber and CGI. They are flaws in thinking or equipment. Sad, small, preventable and yet unknowable until they occur.
Which is why, in a few days time millions of us will crowd into cinemas and watch a millionaire Hollywood actor pretend to bravely explore the stars. This fictional champion will reach other worlds and distant shores, battle the elements and the reaches of Christopher Nolan's computer-generated graphics budget, and come through, one way or another, with a new appreciation for life back home. And it will look easy, and mostly safe.
This is our dream for space. Not only that we'll all live to see it, but that no one will ever die in trying to get there.
But in an age where rockets still blow up on the launch pad for no immediately obvious reason, and test pilots for private companies plummet from the sky and no one knows why, we have to recognise the gap between our dreams and reality.
Space is close, but our victories there are still small, and hang on a knife edge. And we will probably not live to see them all completed. But that - as ever - is no reason not to try, or to give up before the fight is over.
We explore space to educate and inspire and to learn. We explore to escape, and survive. We explore because we are human, and we mourn those who die in the attempt because we admire their courage, and fear the unknown.
But even for those of us sold on the dream, it is worth dwelling on the cost - and the context.
Because let's face it: we are still a weak, vulnerable species. We still live mostly nasty, mostly short lives on a destructive hostile rock. And we remain helpless against both the volcanoes bubbling beneath our feet, and the private, quiet doom of the inescapable hospital ward that faces us, if we're lucky, at the end.
To support space travel can seem heartless and cold in this kaleidoscope of crisis.
And it is no surprise that many - out of spite, sometimes, but also out of empathy for the victims of deadly accidents, and other causes altogether - make the case that we should stop.
In the case of space tourism, this call to pull back from the edge of delusion is almost deafening. Why should anyone die, even knowing the risks, so that the same millionaires we watch pretend to explore space in films can go and see it for real?
But before we give up on space and join the retreat, we should reconsider the value of these small victories, and the honest value of these recent, devastating, but somehow also mundane and private disasters.
We are a hundred million everyday inventions away from going back to the Moon, and beyond. SpaceX, Orbital Sciences, Virgin Galactic and dozens of other private companies, as well as NASA, ESA and their Chinese, Japanese and Indian equivalents, are heroes not for their grand moments of glory, but for their daily erosion of those small, prosaic boundaries. Their failures - the explosions, and crashes, and disasters - are tragic. But they are also what get us closer. They enable us to learn, and rethink, and prepare. They are awful human disasters, but they have value too.
In this sense, the heroes of space are not just those that pilot the crafts. The heroes are also the engineers who check and re-check their maths 50 times before tightening each bolt and screw. They are the lobbyists who go to tedious drinks parties seven nights a week to get even the tiniest budget increase to pay for all that overtime. And they are the private companies who reinvent our way to the Space Station, not out of ego or overwhelming desire for profit, at least short term, but because it's the only way our politicians will ever allow us to keep going there.
The dream of space remains as profound and hypnotic as it ever has. The heroism of small victories, and the profound devastation felt in seemingly small, or private disasters, are no less important in the face of the scale of our imagination and vision.
They are all part of the same long journey to the stars.
Yes, we all want Interstellar to be a documentary... But for the rest of our lives we may instead have to be content with commonplace, simple victories, and celebrate them with equal pride as we did Apollo 11: the invention of a better fuel pump, an unbreakable gasket or a slightly more efficient cargo mission to the Space Station.
And one day, yes, the ability to lift a fee-paying celebrity to the edge of space.
They all get us closer. The value might not be obvious. The destination might not be clear. But when it comes to space even acts of ego and expressions of wealth take us closer to something bigger than we could imagine.
And surely that's what we're here for?Suggest a correction