In April 2013 Planet Labs launched two demonstration satellites, “Dove 1” and “Dove 2”. November 21 two more satellites Dove 3 and Dove 4 were placed into orbit by a Dnepr rocket. Dove 4 conforms to the 3U CubeSat specification, with a launch mass of 5.2 kg. Basic physical dimensions are 100 mm × 100 mm × 340 mm, with two 260 mm × 300 mm deployable solar arrays. Power storage is provided by Lithium-Ion cells. The batteries will be recharged by solar cells mounted on the body of the satellite and on the two deployable solar panels.
Yesterday January 9 Orbital Sciences Corp. launched its Cygnus cargo spacecraft aboard its Antares rocket at 1:07 p.m. EST Thursday from NASA’s Wallops Flight Facility in Virginia. Its primary mission is to resupply the International Space Station. Solar array deployment has been reported as complete for the Cygnus spacecraft. It is scheduled to rendezvous with the International Space Station on Sunday, Jan. 12.
In addition to the suppplies for the Space Station the Cygnus carries CubeSats for 23 experiments designed by students for a variety of technology demonstrations.
And it also carries a constellation of CubeSat based satellites that will form Planet Labs' 28 satellite Earth observation constellation. These mini-Earth observing satellites will orbit the Earth at an altitide of 400 km. The satellites can provide much more frequent snapshots (revisits) of the same location on Earth than current Earth observation satellites. This means basically 4D (2D/3D+time) allowing users to track changes—from traffic jams to deforestation—in close to real time. The satellites will send their images to at least three ground stations—two in the U.S. and one in the U.K. The data will be processed and uploaded for use by customers almost immediately.