Washington, D.C. ? A second try is about to get under way at sending a little yellow submarine gliding across the Atlantic Ocean to collect scientific data from beneath the waves.

“The launching is tremendously exciting because there is just so much that we don’t really know about what happens in the oceans,” said Jane Lubchenco, head of the National Oceanic and Atmospheric Administration.

“The capacity to fly through the ocean, across the Atlantic, taking data about temperature, salinity and other properties of the water gives us keen insight into what’s happening down there,” she said in a telephone interview.

The first glider was lost last year before it completed its trip.

The second, improved version has been put together by the same team at Rutgers University in New Brunswick, N.J. If conditions cooperate, the launch is set for Wednesday — Earth Day.