GPM spreads its wings in solar array deployment test

July 1, 2013 by Kasha Patel
A solar array wing begins to release from the GPM Core satellite in a deployment test on Thursday, June 6, 2013. Credit: NASA Goddard/Debbie McCallum

( —NASA successfully completed two pre-vibration solar array deployment tests of the Global Precipitation Measurement satellite on June 6 and June 15, 2013.

"Cross your fingers. Cross your toes," said Art Azarbarzin, GPM project manager, as he watched engineers take their places around the GPM Core satellite, set up on its end in the middle of the clean room.

A loud hiss filled the room as engineers turned on air hoses. The hoses pumped air through tubes attached to the solar panels' supports and out of hockey puck-shaped coasters. Azarbarzin explained that the support system and air cushion is designed to reduce friction and best mimic how the would float in space.

Next, a man's voice from the adjacent control room started to count down. Five seconds later, five loud pops sounded one after the other. The pops resulted from the triggering of Frangibolts, which discharge in small, controlled explosions to release the solar array. After the loud pops sounded, the four panels of the array started to slowly unfold like an accordion, until the wing fully extended across the floor.

The solar array panels and boom, a large support beam running across the back of the first two , locked into place. Engineers inspected the solar array front and back, closely examining the panels' and wires. After confirming the array was successfully deployed, they manually unlocked and folded the solar array back into the body of the spacecraft.

This video is not supported by your browser at this time.
This video montage shows scenes from the test deployments of both GPM Core satellite solar arrays in a clean room at NASA's Goddard Space Flight Center in Greenbelt, Md., in June 2013. Credit: NASA Goddard

The GPM Core will orbit Earth at an angle that enables the satellite to observe the globe from the Antarctic Circle to the Arctic Circle. Its orbit will also cross the paths of other satellites that will contribute data to the GPM mission's global precipitation data set.

To increase the satellite's exposure to the sun, the GPM Core has two . Each wing has four panels, and each panel has between 800 and 1,200 . Together, the two wings provide a total of 2,000 watts. The arrays convert solar energy to electricity, which help power spacecraft electronics and the satellite's two instruments, the GPM Microwave Imager and the Dual-frequency Precipitation Radar. Excess power charges the satellite's battery, which is used when the GPM Core isn't in direct sunlight.

The solar array wing deployments are part of the GPM Core satellite's series of environmental tests. The thermal vacuum test that simulates temperature changes in the vacuum of space was completed in early February, and the electromagnetic interference test that assures all elements of the satellite work together was performed in May. The Core satellite will also undergo the vibration and acoustic test, which simulate rocket vibration during launch, and shock and separation test, which simulates inducted shock to the satellite when being separated from the rocket. A final solar array deployment test will be conducted following the completion of the environmental test program to assure that the solar arrays will survive the launch environment and deploy successfully.

The GPM Core, the largest satellite built and tested at Goddard, is scheduled to launch in February 2014 from Japan. The GPM Mission is a collaboration between NASA and the Japan Aerospace Exploration Agency, measuring rain and snow worldwide every three hours. GPM data will advance understanding of Earth's water and energy cycles, enhance the forecasting of extreme events that cause natural disasters, and improve researchers' ability to use satellite precipitation information to directly benefit society.

Explore further: JPL radar treks to great white north to study snow

Related Stories

JPL radar treks to great white north to study snow

January 18, 2012

( -- Beginning Jan. 17, NASA will fly an airborne science laboratory, including a unique airborne radar built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., above Canadian snowstorms to tackle a difficult ...

Spaceborne precipitation radar ships from Japan to U.S.

February 9, 2012

( -- Japanese scientists and engineers have completed construction on a new instrument designed to take 3-D measurements of the shapes, sizes and other physical characteristics of both raindrops and snowflakes. ...

Handover of Japan-built radar to NASA

April 4, 2012

On March 30, the Japan Aerospace Exploration Agency (JAXA) officially handed off a new satellite instrument to NASA at Goddard Space Flight Center, Greenbelt, Md. The Dual-frequency Precipitation Radar (DPR) was designed ...

NASA's GPM observatory completes first dry run

October 18, 2012

(—NASA's Global Precipitation Measurement (GPM) Core Observatory satellite went through its first complete comprehensive performance test (CPT), beginning on Oct. 4, 2012 at NASA's Goddard Space Flight Center in ...

Recommended for you

Earth might have hairy dark matter

November 23, 2015

The solar system might be a lot hairier than we thought. A new study publishing this week in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California, proposes the existence of ...

Scientists detect stellar streams around Magellanic Clouds

November 23, 2015

(—Astronomers from the University of Cambridge, U.K., have detected a number of narrow streams and diffuse debris clouds around two nearby irregular dwarf galaxies called the Magellanic Clouds. The research also ...

The hottest white dwarf in the Galaxy

November 25, 2015

Astronomers at the Universities of Tübingen and Potsdam have identified the hottest white dwarf ever discovered in our Galaxy. With a temperature of 250,000 degrees Celsius, this dying star at the outskirts of the Milky ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.