The US space agency (Nasa) is all set to launch its latest mission to Mars. The Maven orbiter will study the planet's high atmosphere, to try to understand the processes that have robbed the world of most of its air. Evidence suggests Mars was once shrouded in a thick blanket of gases that supported the presence of liquid water at its surface. Air pressure is now too low for this. The probe will be sent up on Monday from Florida by an Atlas V rocket. Controllers at the Cape Canaveral Air Force Station have set aside a two-hour launch window that extends from 11:28 to 13:28 local time (16:28-18:28 GMT). They will, however, endeavour to get the mission off the ground at the earliest opportunity. Full Story at BBC News.