Image: Proba-1 pyramid spotting
A view looking north to south of Egypt's famous Giza Pyramid Complex, as seen by ESA's Proba-1 minisatellite.
The smaller Pyramid of Menkaure is seen to towards the centre of the image, with the larger Pyramid of Khafre down and left of it, with the Great Pyramid of Giza – the largest and oldest of the three – below and left of that.
Three smaller pyramids are adjacent to the Pyramid Menkaure. The Giza Plateau sits on the edge of Cairo, fringed by suburbs.
The cubic-metre Proba-1 is the first in ESA's series of satellites aimed at flight-testing new space technologies. It was launched on 22 October 2001 but is still going strong, having recently became the Agency's longest-serving Earth-observing mission.
Proba-1's main hyperspectral CHRIS imager is supplemented by this experimental High-Resolution Camera, acquiring black and white 5 m-resolution images.
Other innovations include what were then novel gallium-arsenide solar cells, the use of star trackers for gyroless attitude control, one of the first lithium-ion batteries – now the longest such item operating in orbit – and one of ESA's first ERC32 microprocessors to run Proba-1's agile computer.
Proba-1 led the way for the Sun-monitoring Proba-2 in 2009, the vegetation-tracking Proba-V in 2013 and the Proba-3 precise formation-flying mission planned for late 2020.