balky lander airbag continues to slow the readying of the Spirit rover to start its science-gathering duties on the surface of Mars. An attempt Wednesday to retract an airbag that could foul the robot’s egress off its platform was not successful. Engineers here at the Jet Propulsion Laboratory (JPL) are strategizing alternate pathways Spirit can hit the dirt running. Another attempt to retract the problem airbag is slated for Friday. There is a tension building between cautious Spirit engineers and heavy-breathing scientists, forced to basically look but not yet touch the tantalizing terrain with their instruments.