For a mission, the pair move south to the equator at 154 degrees West Longitude.

BBC: Science & Environment

For a mission, the rig and control vessel are moved south to the equator at 154 degrees West Longitude.

BBC: Sea Launch rocket company returns to service

They achieved one of the most hotly contested aviation goals on Saturday when they passed over Mauritania and crossed the 9 degrees west longitude mark -- the official finish line for their flight around the world.

CNN: Balloonists: '20 days of beautiful moments'