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J. Marshall Shepherd

Reflecting on NASA's Global Precipitation Measurement mission, launching today

Posted by J. Marshall Shepherd

27-02-2014 11:31 CST

Topics: Earth observing missions, personal stories

This article was originally posted on J. Marshall Shepherd's blog and is reposted here with permission.

Driving to the University of Georgia this morning, I had no intention of blogging on the launch of the NASA Global Precipitation Measurement (GPM) Mission today, but I had to. I spent a substantial part of my 12-year career at NASA Goddard Space Flight Center as the Deputy Project Scientist for GPM. And even today, I am a member of its Science Team.

Hopefully, the satellite launches today around 18:30 UT without a hitch. [Watch live using the embedded livestream below.] I even dug up an abstract that we submitted to an American Meteorological Society Meeting in 2002 called "Towards the Global Precipitation Measurement Mission." 

The mission changed in some ways from what we wrote then, but it is still a mission that demonstrates NASA's scientific and technical mojo. "Towards" is now "Here."

NASA Global Precipitation Measurement (GPM) satellite

NASA / Britt Griswold

NASA Global Precipitation Measurement (GPM) satellite
Visualization of the GPM Core Observatory satellite orbiting the planet Earth.

I remember a Congressional Staffer asking years ago, "Why do we need to measure precipitation from space when we have rain gauges and radars on land?" This question ranks right up there with "beauties" like "Why do we need the National Weather Service when we have TV networks?" or "Why do we need potatoes when we have potato chips?" or "How can climate be warming when it is snowing or cold today?"

Assessment of water cycle, weather (and its extremes) and climate requires global data. Likewise, our weather, climate, and hydrological prediction models require input (e.g., from weather balloon, satellites, etc.) that represents "global" atmospheric circulation, heating, and other processes. The last time I checked, over 70% of the Earth was covered by oceans/water and a significant percentage is not accessible. Sooooooooo, if our weather and climate models need data everywhere then that question about rain gauges and radar seems a bit silly doesn't it? Ask colleagues that run the Euro model or our U.S. models how valuable U.S. satellite data is to today's numerical model forecasts. Valuable is an understatement.

The success of NASA's Tropical Rainfall Measurement Mission (TRMM) paved the way for GPM. TRMM was a research mission slated for 3 years, but almost 2 decades later it is still providing valuable data for weather, climate trend analysis, and a host of applications like landslide assessment, water resource, management, and crop productivity. NOAA and Defense Department hurricane scientists and forecasters have also been big users of TRMM. Yet, TRMM is limited in coverage and technology. GPM is bringing the capability for more frequent, accurate global precipitation measurements for an array of weather, climate, and hydrological applications. As current GPM Project Scientist Gail Jackson notes: "Knowledge of how water moves around the Earth system through precipitation is from the GPM mission provides unprecedented measurements of global precipitation, (including snowfall)."

She's right. This mission is a big deal for the Earth. In fact, Japan is a major partner and other countries are involved as well. Weather, climate extremes, and their impacts on society don't stop at borders and neither should our observations. This fact illustrates why the vantage point of space is critical for studying Earth and improving our life on it.

So yes, NASA is still around and doing great things. It didn't go anywhere because Space Shuttles aren't being launched, and believe it or not, many NASA colleagues work at places beyond Kennedy Space Center or Johnson Space Center and don't know any astronauts.

Remember, Earth is a planet and thankfully, NASA is helping us understand it and protect it. NASA also still demonstrates to kids that science and engineering is cool. Well, at least this big kid thinks so.

Research and development (R&D) is vital to our way of life. You didn't get that iPhone, GPS, advanced forecast of Superstorm Sandy's left turn or that new heart treatment by a stroke of magic. It took years of R&D. So as we celebrate the launch of a science and technology marvel today, let's reverse the anti-science, anti-research, and anti-outreach/literacy tone that I see emerging in disturbing places.

Thanks to all of the scientists, engineers, staff, public affairs colleagues and supporters of GPM. A special thanks to Dr. Eric Smith, the first Project Scientist for GPM and Dr. Arthur Hou, past GPM Project Scientist, who passed recently as GPM was being shipped to Japan for launch. Arthur is smiling today...

See other posts from February 2014


Or read more blog entries about: Earth observing missions, personal stories


LowEarthOrbit: 02/27/2014 11:25 CST

Great words Marshall. And a special thanks to the Japanese team and JAXA for their amazing partnerships with TRMM and now GPM. it's an exciting time to be involved with precipitation science and the many applications that will result. Regards, Joe T.

Tim R: 02/27/2014 11:30 CST

Congratulations to J. Marshall Shepard and that whole project team. I was involved in some support work for GPM. It involved verification and validation of their requirements and design. Not only is the mission objective extremely important but the design and implementation of the spacecraft was well done. And it is a great cooperative between the USA and Japan. Last week, I had the chance to watch a one-man stage performance of the life of R. Buckminster Fuller. A primary objective of his life's work was to instill in all of us that we must work synergistically and function as good stewards of the Earth. GPM is another important tool NASA contributes to improving our stewardship. As Bucky liked to call himself, NASA GPM team members are also "Trim Tabs" helping to set a better path for humanity.

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