The decision is in, and the decision is — to be decided.

US Defense Secretary Chuck Hagel has accepted the Navy's recommendation that the design of the small surface combatant (SSC), a more powerful ship to follow the littoral combat ship, will be based on existing LCSs, Pentagon sources said Thursday.

The decision rules out several choices that included new designs or a version of the Huntington Ingalls patrol frigate.

But Hagel — contrary to widespread expectations — did not decide whether the SSC would be based on the Lockheed Martin Freedom class, or Austal USA's Independence-class ship.

Nor, apparently, did the Navy favor either design in its recommendations.

Hagel, a senior defense official said, will give the Navy several tasks:

Develop an acquisition, design and procurement strategy to support buying the new ship no later than fiscal 2019, and sooner if possible.

Submit the strategy to the undersecretary for acquisition, technology and logistics (AT&L) no later than May 1.

Continue to look for opportunities to increase survivability and lethality in the ships.

Provide AT&L and the Pentagon's office of Cost Assessment and Program Evaluation with a service cost position to support the fiscal 2017 budget request, along with a plan on how to control overall program costs.

Provide an assessment by May 1 of back-fitting SSC enhancements into Flight 0 LCSs already in service, under construction or under contract, and for eight more ships to be ordered through 2018. The overall intent, the senior Pentagon official said, is to improve the lethality and survivability of Flight 0 ships as much as possible.

Hagel's decision still assumes buying a total of 52 LCS and SSCs, said the senior Pentagon official.

"The final number and mix will depend on fleet requirements, procurement costs and overall Navy resources," the senior Pentagon official said. "He's leaving it open as to how many of each type."

The SSC task group that developed the Navy's recommendations did not have specific direction to choose a single SSC design, said the senior Pentagon official. "This is not a down-select," nor is there any direction for one. "That wasn't the goal of the tasking," the official added.

Specific design decisions, such as which hull, combat system or engineering plant to use, have not been made, the senior Pentagon official said, but some requirements have been listed, including a more robust self-defense capability, better hull protection systems, an upgraded combat system, the ability to carry out multiple warfare tasks such as anti-submarine and anti-air warfare, inclusion of a towed-array system, and installation of an over-the-horizon missile battery.

While the SSCs will not carry the full mission modules being provided for LCS, they should maintain the ability to carry modules.

Lockheed Martin and Austal USA each submitted SSC proposals based on more powerful versions of their LCS designs. Both companies have said they are prepared to incorporate many of the improvements into the LCSs.

The Navy, the senior Pentagon official said, is expected shortly to provide further details on what lies ahead for the LCS and SSC programs.