Science & Environment

Satellite will 'chase' tropical storms

GPM artist's impression Image copyright NASA

Daniel Alvarado Varela is a 31-year-old with no children of his own, but he does have a "baby" of sorts. One weighing nearly four tonnes.

That baby is the Core Observatory of the Global Precipitation Measurement (GPM) mission, a freshly-built satellite designed to observe storms forming in the tropical oceans and track their movement into other latitudes.

The spacecraft is also designed to improve measurements of rain and snowfall.

Mr Alvarado, a Puerto Rican mechanical engineer who has worked on the probe's structure, has watched this baby develop since 2005, and was recently chosen to travel with it on what he calls the child's "graduation": a journey from the US State of Maryland, where the satellite was built, to the Japanese island of Tanegashima.

It is from here that the satellite will be launched in February on a Japanese rocket.

Days before setting off on that continental journey, the BBC visited Alvarado in his "playground": Nasa's clean-room at Goddard Space Flight Center in Greenbelt, Maryland.

It was there that he helped build the satellite, in a process he compared to "playing in my childhood with Lego blocks and GI Joes and imagining that different things happen".

"It's great fun," says Mr Alvarado, who likes to prepare mojitos at a bar in his spare time. "This gives a sense of reality to all that imagination I had when I was a kid".

An eye on the Earth

The satellite is a highly complex structure the size of a small private jet and is capable of "seeing" what happens inside clouds.

Developed by Nasa and the Japanese Space Agency (Jaxa), the core GPM observatory will carry two instruments that will help scientists to study the internal structure of storms, in order to understand how they change over time and why their intensity alters as they move from the tropics to other latitudes.

One of the instruments, a microwave radiometer, will be capable of measuring the size or the intensity of rain and snowfall.

Image caption Daniel Alvarado says the mission has helped him realise his childhood dreams

The second, a dual-frequency radar, was designed to create three-dimensional precipitation measurements. Together, they are expected to follow weather events as they develop, and spanning the Arctic to the Antarctic.

The measurements that scientists hope to gather from the GPM core observatory will be combined with those from a constellation of other satellites that are already keeping tabs on the Earth's water and energy cycle.

The goal is to provide information approximately every three hours on where and how much it is raining or snowing across roughly 90% of our planet.

Image copyright NASA
Image caption The satellite was transported on a military cargo plane for part of its journey

By collecting this information, scientists working on the GPM mission believe they will not only gain a better understanding of the Earth's water cycle and its link to climate change, they will also be better able to predict extreme weather events such as hurricanes.

"The data that GPM provides will help to better inform the community of where to carry out evacuations and how those should be done," Dalia Kirschbaum, an applications scientist at Nasa, told the BBC.

Speaking to me in the Nasa clean-room at Goddard, with the satellite standing behind her, Dr Kirschbaum adds that "especially in higher latitudes where storms can be very powerful, such as hurricane Sandy or blizzards, we will have a much better understanding of those types of systems".

Road to Japan

But before scientists can turn their objectives into reality, they need to comprehensively test the probe's components. That analysis began in Maryland and continued in Japan after Mr Alvarado and his team safely transported the satellite in what was one of the most delicate parts of the mission.

The crew was in charge of "monitoring the health" of that "fragile baby" on a land, sea and air journey that lasted nine days and consisted of transporting the satellite on several lorries, a US Air Force C-5 cargo plane and a barge.

Image caption Dalia Kirschbaum says the spacecraft could also aid disaster management

And that did not include a series of unforeseen events that delayed the transfer and increased the challenge for the accompanying engineers: Everything from strong headwinds that forced the plane to land in Alaska for refuelling, to rough seas that temporarily diverted the barge in Japan.

For Daniel Alvarado, these types of experiences are all part and parcel of what he argues is the most important project he has undertaken in his life. "I've been working on something I really enjoy", he says with a big smile on his face.

That work will reach its climax on 27 February, when his baby will be launched from Jaxa's Tanegashima Space Center.

He makes no attempt to conceal the importance of that moment: "We have spent long hours designing and building (the spacecraft). It's our creation and I am very excited," he says.

"It's a special feeling to know that I will have a part of me in space".