I am sitting on a sofa, floating through the void. Above me, a massive silver sheet billows in a gentle breeze. The chair drifts on through the blackness, with nothing to stop it carrying on forever.
The peculiar sensation of flying through space on a cushioned bench is extremely relaxing – disorientating but not dizzying. The smoothness of travel means that my companion on the sofa – a Nasa spacecraft engineer – is sitting with her legs crossed and eyes shut in an apparent zen-like trance as we spin gently through the dark.
Sadly, all too soon our space sofa bumps up against the boarding platform and we step back onto the solid ground of Nasa’s – literally named – Flat Floor Facility at the Marshall Spaceflight Center in Huntsville Alabama.
The solar sail-carrying Scout is likely to be deployed from Nasa's new Space Launch System (SLS) rocket (Credit: Nasa)
Although the experience of the ride felt as if we were flying through space, Nasa’s space sofa was actually floating only a fraction of a millimetre above a black polished, perfectly flat, floor on tiny columns of compressed air. Imagine a giant air hockey table but with the puck, rather than the floor, producing the jet of air.
The Flat Floor is said to be the flattest floor in the world. Made of black epoxy resin, it covers the base of a 26-metre-long warehouse. Objects can be moved across it on a frictionless cushion of air. This means that once something starts moving, it stays moving (until you hit something) – just as it would in space.
The sofa is used to show off the facility to visitors but the Flat Floor itself was developed to test spacecraft docking systems and other new designs and concepts.
The Flat Floor is currently being used to develop spacecraft able to intercept and capture dead satellites or other orbital debris
“We can’t move up and down but we can move in all the other dimensions,” says Thomas Bryan, the Flat Floor’s senior engineer, who’s been guiding our sofa odyssey by gently nudging us around the building with his finger. “It’s the best thing we have in a room to simulating movement in outer space.”
“If you have a fan, you can blow yourself across the facility,” says Bryan. “In fact that’s what we use for the spacecraft simulators.”
The Flat Floor is currently being used to develop spacecraft able to intercept and capture dead satellites or other orbital debris. These would tackle space junk by locking onto satellites and dragging them down to burn up in the atmosphere. A more immediate mission, however, involves the square two-story high sheet of silver material rippling gently above us in its fragile frame as we drift past on the sofa.
The floor works in a similar way to an air hockey table (Credit: Getty Images)
This towering structure is a prototype solar sail for Nasa’s Near Earth Asteroid (NEA) Scout mission. Made of thin plastic sheet coated in aluminium and stretched apart on flexible steel booms, it is less than half the size of the final sail. The NEA Scout mission, to rendezvous and study an asteroid, is due to be launched in 2018 on the first test flight of America’s new giant rocket – the Space Launch System (SLS).
Solar sails are designed to propel spacecraft using only the force imparted by photons streaming from the Sun. NEA Scout will be one of the first missions to use the technology beyond Earth orbit. It will be released from the rocket as the SLS flies between the Earth and Moon.
“If you think of light as a particle, it has momentum even if it doesn’t have mass,” says Les Johnson, the technical advisor for Nasa’s advanced concepts office. “When you deploy a sail in space, light will push against it and give it a little bit of an acceleration – you can build up quite a bit of speed.”
Think of it as the most complicated game of Tetris you have ever played – project manager Leslie McNutt
The entire NEA Scout spacecraft is only around the size of a large shoebox but the solar sail that has to fit inside opens out to 86 square metres. Engineers have been using the Flat Floor to work out how to pack the sail and still leave room for all the other essential spacecraft systems such as a camera, navigation and communication instruments.
“We’re a fully functioning spacecraft in this very small box,” says project manager Leslie McNutt – last seen sitting cross-legged on the space sofa. “Think of it as the most complicated game of Tetris you have ever played.”
“It’s all done by hand – it took five engineers, six hours continuously to fold this sail,” says lead systems engineer Tiffany Lockett, of the half-sized sail. “We’re using a z-fold – like an accordion fold – coming in from both sides and meeting in the middle on a spool,” she says. “It looks like a bow tie.”
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She admits to dreaming about folding sliver sheets and she is steeling herself for folding up the full-sized sail in the coming months.
If the flight of NEA Scout proves successful, Johnson believes solar sails have tremendous potential for future exploration of the Solar System. “I’d like to see us go to even larger sails,” he says, “for some solar physics missions and deeper exploration into the Solar System.”
Solar sails could even be used to power supply craft, shuttling supplies slowly between Earth and human colonies on Mars.
The biggest problem we’ve ever had here was caused by cats – engineer Thomas Bryan
With its black polished floor, windowless walls, star-like spotlights and shimmering solar sail, the Flat Floor looks suitably space-age and futuristic. There is, however, one feature of this unusual test facility that demonstrates even Nasa’s advanced concepts have Earthly problems to contend with.
The flatness of the Nasa floor has been compromised - by trespassing cats (Credit: Getty Images)
“The biggest problem we’ve ever had here was caused by cats,” admits Bryan, pointing out lines of blotchy spots crossing part of the floor. “These are cat prints – they used to live down in the tunnels of the building and use this as a playroom at night.”
“Their little paw prints caused the epoxy to expand,” he explains. “We’ve put up walls to stop them coming in but we still have a permanent memory of their little paw prints.”
You can understand why the cats liked it so much. I could happily spend hours here, drifting on the frictionless sofa across America’s flattest floor. Just don’t ask me to do any folding.
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