Mercedes driver Nico Rosberg topped the time sheets throughout the opening day of the second official Formula One test.
However, times were less meanigful than normal, as only the first hour of the test was completed in the dry. Once the rain began to fall, most teams opted to send their cars out on track for only short runs.
However, McLaren (pictured) caught the attention by running several ungainly wind flow sensors and probes early on.
"We feel it's necessary to put as much emphasis as we possibly can on accurately measuring the flow structures we encounter at the track so that we can match them to the flow structures we are able to simulate in CFD," a team spokesman explained.
Virgin Racing became the first new F1 team to run at an official test session, albeit with driver Timo Glock initially completing only one shakedown lap before returning to the pits, and then runninga brief three lap stint in the wet.