Posted August 10, 2015

American radar satellite in trouble

A NASA satellite designed to measure soil moisture suffers from a malfunctioning radar. It can no longer achieve its groundbreaking resolution. Hopes of recovery are fading. Can NASA satisfy customers who were counting on the intended specs?

The SMAP satellite, which stands for Soil Moisture Active Passive, had a difficult start to begin with. The idea was born all the way back in the nineties: why not have a satellite which looks at microwaves emitted by soil ('passive'), and at the same time emits radar waves ('active') and looks at the reflections. This way soil moisture can be measured with unprecedented precision: about 9 kilometers for soil moisture itself and even 3 kms for the distribution of frost and thaw. All of this could be of tremendous value to scientists and companies in fields like agriculture, forestry, nature conservation, environment and climate research, geology and much more.

'But in 2005 the Bush administration made budget cuts,' says remote sensing expert Richard de Jeu (previously), who is involved with ATG's Fast Forward programme. 'So NASA had to forget about Hydros, as the project was known then.'

A few years later the idea was resurrected under a different name and in January 2015 SMAP was launched - only to break down on July 7. 'It appears a solar burst has left some electrical charge on the radar, and now it has stopped working,' says De Jeu. The passive microwave receiver is still ok, but on its own it gets nowhere near the resolution you get with the two devices working together. After a month, we can only hope the problem will be solved.'

If it doesn't, the damage will be hard to calculate. The satellite itself cost about a billion dollars to build and launch. Lots of companies were counting on SMAP's data. Ph.D. students too. NASA didn't charge for the data but it will be harder for companies to make money using the data.

What alternatives are there? Says De Jeu: 'NASA has lots of different sensors in space and you may piece together the same information, but not with the same precision and convenience. Europe has the older SMOS satellite, and the new Sentinel 1 and 2, but these lack the prime specs SMAP was supposed to have.'

According to De Jeu an important difference between American and European space policies comes to light. 'American space science is very much dictated by politics. Each mission needs very clear selling points. So you can have a unique mission like SMAP, but often no direct successor in the pipeline if it fails. European space policy is less focused on technological challenges and more on continuity. So Sentinel 3 and further are currently being built.'

Perhaps it's good the planet has both: the 'boldly go where no man has gone before' strategy of the Americans and the slightly more conservative, safer European approach.

About Herbert Blankesteijn

Herbert Blankesteijn is a technology journalist from the Netherlands who has written for many prominent Dutch newspapers. He presented and directed television and radio programmes and has 10 books to his name. Herbert is interested in nascent fields such as 3D printing, drones, robotics and the private space business.