Today, NASA is going to live stream the departure of a private spacecraft from the International Space Station (ISS). Normally, this would be quite a routine procedure – but an intriguing experiment that will take place should whet the appetite of space exploration fans.

Live coverage of the spacecraft, Cygnus, leaving the ISS will begin at about 9 am EDT (2 pm BST). The spacecraft, which arrived in March with 3,400 kilograms (7,500 pounds) of cargo, will be detached by NASA’s Tim Kopra and ESA’s Tim Peake using the station’s robotic arm at about 9.30 am EDT (2.30 pm BST).

Five hours later, the Saffire-I experiment will begin, led by NASA’s Glenn Research Center. Normally, Cygnus vehicles are simply sent to burn up in Earth’s atmosphere after detaching from the ISS. But this experiment will start a fire in a small box the size of a chest of drawers inside the unmanned spacecraft. The fire will be closely monitored to see how it behaves in space. It will be limited to the box it is in, though, so the whole spacecraft won’t catch fire.

Sadly, the actual fire itself won't be streamed live, only the departure. Images from the test are not expected until tomorrow. But you can still tune in for the departure below. Live shots of Cygnus are expected to continue until 10.03 am EDT (3.03 pm BST), with a NASA spokesperson telling IFLScience "it will be daytime so we should get some good views of Cygnus flying away."

^{The departure will be live streamed on NASA TV, above}

Experiments like Saffire-I are not possible on the ISS for obvious safety reasons, but Cygnus provides a unique opportunity in that the spacecraft will be destroyed on re-entry regardless, just in case something does go wrong. Instruments will measure flame growth, oxygen use, and more, with potential benefits including determining flammability limits for spacecraft materials in the future.

This will be the first of three Saffire missions planned for Cygnus spacecraft. In total, the fire is expected to last for six minutes. You can check out a video explanation of how this first mission will work here, and tune in today to catch the start of the action.