The Navy defended its Littoral Combat Ship (LCS) as being sufficiently survivable–and easily upgunned where needed–after taking heat from House appropriators Tuesday on the LCS program and the Navy's plans to reassess whether to keep the ship as is or adjust its requirements for a small surface combatant. Though the Navy set up a task force to examine its small surface combatant requirements for the future, Greenert said the LCS is a viable ship: it can take a hit, survive…