EU’s first Sentinel satellite images Earth

{Sentinel-1a radar satellite }

{{The European Union’s new Sentinel-1a radar satellite has returned its first images of Earth.}}

Launched on 3 April, the spacecraft is part of a fleet of orbiting sensors that will go up over the next few years to monitor the state of the planet.

Its maiden pictures depict Brussels, flooding in Namibia and one of the mightiest ice features on Earth – Pine Island Glacier in Antarctica.

The images give a flavour of the sort of work Sentinel-1a will be doing.

Radar data is particularly useful for urban planning purposes, for making maps following natural disasters, and for monitoring remote locations such as polar ice fields.

The sample of images released by the European Space Agency (Esa) is just a taster. The satellite’s imager will require further calibration before full operational service can begin in about three months’ time.

“It’s going fine; the satellite is performing really well – as you can tell from the new images,” confirmed Ian Shurmer, who leads the team that is operating the Sentinel from Esa’s “mission control” in Darmstadt, Germany.

“We took the very first image just three days after launch, but that was just a functional test. We’re now operating the Synthetic Aperture Radar instrument on a daily basis, with the input of [the mission planners].”

One task requiring attention is a refinement of the Sentinel’s near-700km-high orbit.

It is a few kilometres lower than perfect in its semi-major axis, but Shurmer’s team can easily fix this with a sequence of firings on the spacecraft’s thrusters.

And in what is a sign of the times, the engineers have already had to manoeuvre Sentinel-1a to avoid the possibility of a collision with a defunct American satellite.

Space debris is a growing problem, and Esa’s operations teams have to be alert to other objects moving through their orbits.

“Maybe once or twice a year, you have to give yourself a little nudge to get out of the way of something,” explained Shurmer. “We just pushed Sentinel-1a down by about 50m to make sure nothing happened.”

{wirestory}