NASA’s RapidScat Ocean Wind Watcher Starts Earth Science Operations at Space Station

Barely two months after being launched to the International Space Station (ISS), NASA’s first science payload aimed at conducting Earth science from the station’s exterior has started its ocean wind monitoring operations two months ahead of schedule.

Data from the ISS Rapid Scatterometer, or ISS-RapidScat, payload is now available to the world’s weather and marine forecasting agencies following the successful completion of check out and calibration activities by the mission team.

Indeed it was already producing high quality, usable data following its power-on and activation at the station in late September and has monitored recent tropical cyclones in the Atlantic and Pacific Oceans prior to the end of the current hurricane season.

RapidScat is designed to monitor ocean winds for climate research, weather predictions, and hurricane monitoring for a minimum mission duration of two years.

“RapidScat is a short mission by NASA standards,” said RapidScat Project Scientist Ernesto Rodriguez of JPL.

“Its data will be ready to help support U.S. weather forecasting needs during the tail end of the 2014 hurricane season. The dissemination of these data to the international operational weather and marine forecasting communities ensures that RapidScat’s benefits will be felt throughout the world.”

ISS-RapidScat instrument, shown in this artist's rendering, was launched to the International Space Station aboard the SpaceX CRS-4 mission on Sept. 21, 2014 and attached at ESA’s Columbus module.  It will measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. Credit: NASA/JPL-Caltech/Johnson Space Center.
ISS-RapidScat instrument, shown in this artist’s rendering, was launched to the International Space Station aboard the SpaceX CRS-4 mission on Sept. 21, 2014, and attached at ESA’s Columbus module. It will measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. Credit: NASA/JPL-Caltech/Johnson Space Center.

The 1280 pound (580kilogram) experimental instrument was developed by NASA’s Jet Propulsion Laboratory. It’s a cost-effective replacement to NASA’s former QuikScat satellite.

The $26 million remote sensing instrument uses radar pulses reflected from the ocean’s surface at different angles to calculate the speed and direction of winds over the ocean for the improvement of weather and marine forecasting and hurricane monitoring.

The RapidScat, payload was hauled up to the station as part of the science cargo launched aboard the commercial SpaceX Dragon CRS-4 cargo resupply mission that thundered to space on the company’s Falcon 9 rocket from Space Launch Complex-40 at Cape Canaveral Air Force Station in Florida on Sept. 21.

ISS-RapidScat is NASA’s first research payload aimed at conducting near global Earth science from the station’s exterior and will be augmented with others in coming years.

ISS-RapidScat viewed the winds within post-tropical cyclone Nuri as it moved parallel to Japan on Nov. 6, 2014 05:30 UTC. Image Credit: NASA/JPL-Caltech
ISS-RapidScat viewed the winds within post-tropical cyclone Nuri as it moved parallel to Japan on Nov. 6, 2014, 05:30 UTC. Image Credit: NASA/JPL-Caltech

It was robotically assembled and attached to the exterior of the station’s Columbus module using the station’s robotic arm and DEXTRE manipulator over a two day period on Sept 29 and 30.

Ground controllers at Johnson Space Center intricately maneuvered DEXTRE to pluck RapidScat and its nadir adapter from the unpressurized trunk section of the Dragon cargo ship and attached it to a vacant external mounting platform on the Columbus module holding mechanical and electrical connections.

The nadir adapter orients the instrument to point its antennae at Earth.

The couch sized instrument and adapter together measure about 49 x 46 x 83 inches (124 x 117 x 211 centimeters).

“The initial quality of the RapidScat wind data and the timely availability of products so soon after launch are remarkable,” said Paul Chang, ocean vector winds science team lead at NOAA’s National Environmental Satellite, Data and Information Service (NESDIS)/Center for Satellite Applications and Research (STAR), Silver Spring, Maryland.

“NOAA is looking forward to using RapidScat data to help support marine wind and wave forecasting and warning, and to exploring the unique sampling of the ocean wind fields provided by the space station’s orbit.”

A SpaceX Falcon 9 rocket carrying a Dragon cargo capsule packed with science experiments and station supplies blasts off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, at 1:52 a.m. EDT on Sept. 21, 2014 bound for the ISS.  Credit: Ken Kremer/kenkremer.com
A SpaceX Falcon 9 rocket carrying a Dragon cargo capsule packed with science experiments and station supplies blasts off from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida, at 1:52 a.m. EDT on Sept. 21, 2014, bound for the ISS. Credit: Ken Kremer/kenkremer.com

This has been a banner year for NASA’s Earth science missions. At least five missions will be launched to space within a 12 month period, the most new Earth-observing mission launches in one year in more than a decade.

ISS-RapidScat is the third of five NASA Earth science missions scheduled to launch over a year.

NASA has already launched the of the Global Precipitation Measurement (GPM) Core Observatory, a joint mission with the Japan Aerospace Exploration Agency, in February and the Orbiting Carbon Observatory-2 (OCO-2) carbon observatory in July 2014.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

New Space Station Instrument Raises Windy Science From The Dead

Here’s a cool example of a satellite recycling project. NASA used to have a probe called QuikSCAT that took a look at ocean wind speeds — including hurricanes, storms and typhoons. After 10 years of loyal service, the satellite failed in 2009 and a full replacement looked expensive. Now, however, spare parts for QuikSCAT are going to be used on the International Space Station for a low-budget fix (which the agency says will work just fine).

The parts are old — they are from the 1990s — but incredibly, they are functional. NASA also added some newer, commercially available hardware to make ISS-RapidScat fit in the space station as well as the SpaceX Dragon spacecraft that will bring it to orbit in early 2014.

Because this is very much a low-cost project, certain design compromises were made — like not using radiation-hardened computer chips, which is normal in scatterometers of this sort. (This type of device harmlessly sends low-energy microwaves off the Earth’s service to get the information it needs.)

Artist's conception of how ISS-RadScat will work. Credit: NASA/JPL-Caltech/Johnson Space Center
Artist’s conception of how ISS-RadScat will work. Credit: NASA/JPL-Caltech/Johnson Space Center

“If there’s an error or something because of radiation, all we have to do is reset the computer. It’s what we call a managed risk,” stated Howard Eisen, the ISS-RapidScat project manager at NASA’s Jet Propulsion Laboratory.

There’s another big difference with this scatterometer mission: it’s flying in a different orbit that most. A typical mission will do a sun-synchronous orbit, making it cross the Earth’s equator at the same local time every time it orbits the planet (say, 12 p.m. local.) The ISS, however, passes over different parts of Earth at different times.

“This means the instrument will see different parts of the planet at different times of day, making measurements in the same spot within less than an hour before or after another instrument makes its own observations,” NASA stated.

A view of Hurricane Irene taken by the GOES satellite at 2:55 p.m. Eastern Daylight Time on August 24, 2011. Credit: NASA
A view of Hurricane Irene taken by the GOES satellite at 2:55 p.m. Eastern Daylight Time on August 24, 2011. Credit: NASA

“These all-hour measurements will allow ISS-RapidScat to pick up the effects of the sun on ocean winds as the day progresses. In addition, the space station’s coverage over the tropics means that ISS-RapidScat will offer extra tracking of storms that may develop into hurricanes or other tropical cyclones.”

NASA plans to share information with the European MetOp ASCAT scatterometer. Between the two missions, NASA expects that about 90% of Earth’s surface will be examined at least once a day,with some parts visible several times a day.

All in all, NASA is presenting the recycling project as a boon at a time when the agency is grappling with its 2014 budget request. Instead of an estimated cost of $400 million to launch a replacement QuikSCAT, the cost of ISS-Rapidscat is expected to reach $26 million.

Source: NASA