Even in space, bins still have to be put out

The latest invention to come out of Trinity College Dublin is helping the International Space Station

solve an everyday situation that becomes slightly more tricky when you’re in outer space: putting the bins out.

Novel software developed by two researchers in the Trinity School of Computer Science and Statistics will help the European Space Station predict how to safely get rid of space trash from the international station.

Supplies such as water, air and payload are delivered to the space station by an Automated Transfer Vehicle (ATV).

The spacecraft is then filled with rubbish and sent back into the Earth’s atmosphere, where it should burn up completely and safely upon re-entry.

"This is essentially how space rubbish is incinerated, but things can go wrong," said Prof Simon Wilson, one of the TCD researchers. "One of the biggest dangers is that there might be some fuel left in the tanks of the spacecraft."

“As it’s coming in, the fuel would heat up and explode, shattering the spacecraft into lots of bits that fall to the Earth well before they were supposed to. You don’t want bits of spacecraft dropping on people’s heads.”

The risk assessment tool, developed by Prof Wilson and Cristina De Persis, aims to prevent this kind of accident by using complex predictions to account for every eventuality. It runs a computer model of an ATV re-entry with scenarios that take into account such factors as the shape of the spacecraft, how much fuel it might have left, and what temperature it could get to when it burns up in the atmosphere.

This kind of mathematical modelling is even more difficult than it sounds because there is very little data on these re-entries: there have only ever been five ATVs launched and the fifth, named after the Belgian astronomer Georges Lemaître, isn’t due for incineration until sometime next year.

"The important thing is that the tool has to be able to work even if there's not much data on this kind of event," said Prof Wilson. "So what we do is we try to incorporate a lot of expert opinion and knowledge from engineers." He added that they work closely with expert from the European Space Agency.

The researchers expect to collaborate more with the ESA in the future following the next phase, which involves extensive testing while closely monitoring Lemaître’s re-entry.

The software has the honour of becoming the 500th invention disclosure generated by Trinity College Dublin. TCD marked the occasion with yesterday's Knowledge Transfer Impact showcase, opened by Minister for Jobs, Enterprise and Innovation Richard Bruton.

“I view it as a sign that Trinity is really supporting innovation in the university,” said Prof Wilson. “It’s a really good sign of where things are.”

Other research on show at the event includes 3D audio technology for the Oculus Rift virtual reality headset and an eco-friendly alternative to fungicides for cereal farmers.