RADARSAT-2 Due For Launch Later This Year

ANN has learned that earlier this year, Canada's National Research Council Institute for Aerospace Research (NRC Aerospace) has successfully completed an acoustic qualification test on RADARSAT-2, a new remote-sensing satellite built by MacDonald Dettwiler and Associates Ltd. (MDA) under contract to the Canadian Space Agency (CSA).

The test was conducted to certify RADARSAT-2 can withstand the noise environment generated by the rocket engines during launch later this year. Conducted in February, it simulated noise generated during the first 60 seconds of launch, which is the worst structural environment that the spacecraft will experience during its mission. It took place in NRC Aerospace's reverberant acoustic chamber and was completed two days ahead of schedule.

The acoustic test complemented a sinusoidal vibration test campaign that simulated the launch rocket's excitation at the spacecraft attachment points. These tests are part of a series of assembly and testing activities presently underway at the CSA's premier space qualification centre, the David Florida Laboratory (DFL) in Ottawa, to enhance confidence in the spacecraft design and performance before it is shipped to the launch site.

"NRC has the only facility in Canada capable of performing these tests," said Dr. David Zimcik, NRC Aerospace aeroacoustics expert. "The RADARSAT-2 test accomplished two things: it proved that the spacecraft is strong enough to withstand the loads, and it confirmed that the analytical predictions from the mathematical model of the spacecraft were accurate."

In all, four test runs were carried out: the first at low level to identify the structure's signature and ensure everything was working, a second at predicted flight level, a protoflight/qualification test at three decibels above flight level, and a final low level test to confirm that the structure survived the acoustic environment. The protoflight test, a 60-second blast at 143 decibels, simulated the worst random, acoustic environment the spacecraft might expect during the first minute of launch.

"We had some pretty tight tolerances to achieve," Zimcik said. "If we had too little noise, we would end up under-testing; if we had too much, we might have broken the structure. With the automated control system we've developed, however, we were able to control the noise input into the chamber and match the input spectrum provided by the supplier. It's a capability unique to our facility by which we can provide a more accurate environment with less risk to the spacecraft."

RADARSAT-2 will provide the most advanced commercially available C-band radar imagery in the world. It is the first commercial radar satellite to offer multi-polarization, a capability that aids in identifying a wide variety of surface features and targets. Its primary payload is a Synthetic Aperture Radar (SAR) antenna that can capture images at spatial resolutions of 3 to 100 metres over swath widths of 10 to 500 kilometres. This capability will be invaluable for a variety of applications, including ice and coastal monitoring, land use and resource management, cartography, and disaster response. During its seven-year mission, RADARSAT-2 will orbit in the same sun-synchronous, polar orbit as its predecessor, RADARSAT-1, but offset in time, and will circle the earth 14 times a day at 798 km altitude, covering the entire globe every 24 days.

Established in 1989 and with headquarters situated in Longueuil, Quebec, the Canadian Space Agency (CSA) is responsible for coordinating all civil, space-related policies and programs related to science and technology research, industrial development, and international cooperation on behalf of the Government of Canada. The CSA directs its resources and activities through four key thrusts: Earth Observation, Space Science and Exploration, Satellite Communications, and Space Awareness and Learning. With the overall responsibility for advancing Canada's space policy and programs, it leverages international cooperation to champion world-class scientific research and industrial development for the benefit of humanity.

The National Research Council (NRC) Institute for Aerospace Research is Canada's national aerospace laboratory, undertaking and promoting research and technology development in support of the Canadian aerospace community in matters affecting the design, manufacture, performance, use and safety of aerospace vehicles.

FMI: www.nrcaerospace.com, www.space.gc.ca/asc/eng/satellites/radarsat2