NASA Launching ISS-RapidScat



NASA will be launching two instruments this month which will bolster efforts for monitoring global trends in climate and pollution. The ISS-RapidScat and Cloud-Aerosol Transport System (CATS) will be mounted on the exterior of the International Space Station, joining the 17 other Earth-observing missions currently collecting data for NASA.

The ISS-RapidScat will monitor ocean wind direction and magnitude, allowing for more accurate weather predictions and hurricane monitoring.

The Cloud-Aerosol Transport System will measure the worldwide distribution of clouds, as well as airborne particles, such as pollution, mineral dust and smoke in the Earth’s atmosphere.

The instruments will be launched from Cape Canaveral, Florida by the end of September and installed on the space station via the station’s robotic arm, which will be controlled from the ground.

NASA held a briefing in Washington, D.C. with scientists from NASA and scientists directly involved with the ISS-RapidScat and CATS.

Julie Robinson, ISS Program chief scientist at NASA’s Johnson Space Center in Houston discussed the advantages the ISS-RapidScat provided when compared with NASA’s data-gathering polar satellites.

According to Robinson, the orbit of the ISS gives it a unique perspective of the Earth as opposed to other Earth-monitoring devices, allowing it to pass over the same location at different times of day, providing more comprehensive measurements of changes in winds throughout the day.

“Over a long period of time, you can see different parts of the Earth at any possible time of day. That’s very different than our polar orbiting satellites which see basically across the equator at exactly the same time every day.”

Steve Volz, associate director for flight programs in the NASA Earth Science Division said this precessing orbit “allows us to look at the same phenomena at different perspectives, different angles, different times of day and give us a more complete picture of the environment that we’re trying to measure.”

Volz highlighted the advantage of using the ISS as a platform for these newer instruments, allowing NASA to “put an instrument up for a shorter period of time, test it out and then go to a longer duration, free-flyer satellite with that measurement if we so decide.”

Ernesto Rodriguez, ISS-RapidScat project scientist from NASA’s Jet Propulsion Laboratory in Pasadena, noted that the data that ISS-RapidScat will monitor is “critical for weather forecasting. Winds over the ocean tend to change very quickly. One of the challenges we’ve had is to maintain a constellation of instruments across many different space agencies that are able to monitor the changes to wind variability on a daily basis.”

Rodriguez illustrated through graphs that ISS-RapidScat’s data coverage, when combined with global coverage already underway through the ASCAT Advanced Scatterometer, a European instrument currently in polar orbit, would cover “over 90% of the Earth every day.”

Rodriguez used Hurricane Katrina as an example of an event in which daily coverage of changing phenomena would be important to have.

Matthew McGill, CATS principal investigator from NASA’s Goddard Space Flight Center in Greenbelt, Maryland called CATS “a spectacular opportunity to utilize the space station infrastructure to obtain important Earth Science measurements at a modest cost.”

CATS will utilize laser light, sending pulses of light towards Earth and then detecting the light that scatters from air particles, generating data and profiles of clouds and layers of particulates.

McGill said “CATS packs a significant scientific capability and a lot of technology into a package about the size of a household refrigerator.”

CATS is expected to remain in orbit from anywhere from six months to three years.

Two more NASA earth science instruments are set to launch in 2016, the Stratospheric Aerosol and Gas Experiment III (SAGE III) and the Lightning Imaging Sensor (LIS), which will measure the upper atmosphere, ozone layer and lightning.