NASA astronauts took another spacewalk outside the International Space Station on Tuesday, this time to grease the robot arm's new hand. The pair replaced the latching mechanism on one end of the 58-foot robot arm last Thursday. Tuesday's work involved using a grease gun, which resembles a caulking gun, to keep the latching mechanism working smoothly. The two-part lube job is expected to spill into next week, in a third spacewalk. These latches, or hands, are located on each end of the Canadian-built robot arm.

The pair last week replaced the latching mechanism on one end of the 58-foot robot arm, which malfunctioned in August. Now they need to lubricate the newly installed device. The two-part lube job is expected to spill into next week, in a third spacewalk.