Space Station Demo Holds Prospects for Improved Safety on the High Seas
A technology demonstration underway aboard the International Space Station — of all places — promises to improve safety and security on the world’s oceans.
And that is saying a lot — about 70 percent of the Earth’s surface is covered by water.
The European Space Agency, one of the station program’s five major partners, is sponsoring the COLAIS demo, which examines an improvement in an existing system, the maritime Automatic Identification System, or AIS.
If fully matured, this improvement would enable Earth orbiting satellites to keep track of the maritime traffic moving through the world’s shipping lanes, much as land based Air Traffic Control systems follow the flight of airliners and small general aviation aircraft moving through the air space.
The COLAIS experiment began in June 2010 aboard ESA’s major contribution to the space station, the Columbus science module.
For some time, large international cargo ships and all passenger carriers have been equipped with AIS transponders, which continuously broadcast information on the identity, position, heading, speed of vessels as well as information on the cargo and overall voyage. The transmissions go to other ships at sea, port authorities and coast guard stations.
However, the current system relies on Very High Frequency, or VHF, radio signals, with a horizontal range of just under 50 miles. The limitation leaves most traffic on the open oceans untracked.
The space station offers an alternative for AIS signal reception from a much larger area of ocean — the region between 68 degrees north and south latitude.
The Columbus module was equipped with VHF antennas for the project during a November 2009 spacewalk.
Additional receiver and control boxes, including a new class of space computers, were installed inside Columbus in May 2010.
Since the start of the demo a month later, ground based engineers have been using the external and internal experiment equipment to characterize the signal environment and evaluate the performance of new receiver technologies. Several hundred data sets have been collected and processed with new candidate software to benefit future generations of AIS receivers.
On a good day, approximately 400,000 ship position reports are received aboard the station.
Immediacy is another important criteria.
With improvements in ground systems involved in the demonstration, operators were able to collect and deliver data through the station’s communications network in significantly less than an hour.
Near real-time data delivery has been part of routine operations since Nov. 2011.
Another receiver upgrade is planned for May, this time to support the design of a satellite-based AIS system, perhaps as a component placed aboard future Earth observation satellites.
Norway’s AISSat-1 satellite, which launched into a near polar orbit in July 2010, is also involved in the demo effort.