When cargo spacecraft leave the International Space Station (ISS), they are usually sent to burn up in Earth’s atmosphere with a bunch of waste on board (apart from SpaceX’s Dragon, which comes back to Earth).
But things have been a bit different this past week for one spacecraft, Orbital ATK’s Cygnus. This unmanned vehicle has been used to transport cargo to the ISS in the past, before being sent to burn up in the atmosphere.
In June this year however, before the spacecraft burned up, it performed a unique experiment called Saffire-I, where it tested out how fire spreads in the microgravity environment of Earth orbit. Such an experiment would not be possible on the ISS, due to crew safety reasons.
And this experiment was repeated on Monday, November 21, when the Saffire-II experiment was carried out inside the Cygnus OA-5 spacecraft – named SS Alan Poindexter after the late NASA astronaut – after it had left the ISS.
Above, a video from the Saffire-II experiment. NASA
That’s not all this spacecraft was up to though. After the Saffire experiment, it was moved to an orbit of about 500 kilometers (310 miles), about 100 kilometers (62 miles) above the ISS. This is the highest orbit ever achieved by a Cygnus spacecraft.
Here, the vehicle released four small satellites – known as CubeSats – for a company called Spire Global. At this increased height, the satellites will survive for two years before they burn up in the atmosphere. If they had been released from the ISS, they would have lasted just nine months. This is also the first time a cargo spacecraft has deployed satellites above the ISS.
The small satellites will form part of a larger constellation of satellites operated by Spire, bringing the total up to 16. These satellites are being used to track ships around the world and monitor weather.
“Spire, NanoRacks, NASA and Orbital worked closely to make this unique opportunity a reality and it highlights yet another commercial application of the ISS that is beneficial to the satellite industry,” Spire said in a statement. “Spire is incredibly pleased to have been a part of this historic joint effort between industry and government.”
This is all a good example of how scientists are making use of Earth orbit at the moment. More than ever, companies big and small are getting a chance to perform science never possible before.
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