Happy Independence Day from the International Space Station

Astronaut Doug Wheelock and the rest of the space station crew are off today for the holiday, but Wheelock has been sending greetings and posting updates on their journey on Twitter.

The gorgeous photo you see on the right, for instance, is the Southern Lights playing over the South Pole, which Wheelock posted on June 20th.

Yesterday, July 4, the crew supervised the docking of a supply ship, the Progress 38, which launched from Kazahkstan on June 30 and is shown below approaching the space station, with the island of Sicily laid out beneath it.

The supply ship is carrying, according to NASA, "1,918 pounds of propellant, 110 pounds of oxygen, 220 pounds of water and 2,667 pounds of experiment equipment, spare parts and other supplies."

An attempted docking of the supply ship on Friday was aborted, which may be why the crew was working yesterday. From NASA:

The most likely cause of Friday’s aborted docking was traced to the activation of the TORU “Klest” TV transmitter, which created interference with TORU itself, causing a loss of the TORU command link between Progress and the International Space Station that triggered the abort of the Progress docking. TORU was not activated for today’s docking. The TORU TV system is designed to provide a view of Zvezda's docking target to station Commander Alexander Skvorstov, if he had to operate a joystick in the service module to dock Progress manually.

You can follow Wheelock's updates on Twitter -- he goes by the handle of Astro_Wheels -- here.

Go here if you want to download a 2010 calendar from NASA that describes what the crews are doing on the International Space Station and marks major events in space exploration through the years.

You can print it on 8-1/2 by 11-inch paper, and you've still got most of the last half of 2010 to enjoy it.

This post was originally published on Smartplanet.com