WASHINGTON — U.S. military space initiatives would lose up to $27 billion if a congressional supercommittee tasked with reducing federal spending fails,  triggering a $600 billion reduction to be applied evenly across Pentagon programs.

Satellite communications, space protection, and intelligence, surveillance and reconnaissance programs could face delays or termination if the supercommittee misses the Nov. 23 deadline for drafting legislation to reduce federal spending by $1.5 trillion over the next decade, U.S. Defense Secretary Leon Panetta said in a Nov. 14 letter to key lawmakers.

Under the Budget Control Act of 2011 signed into law by U.S. President Barack Obama in August, the Pentagon would absorb half of the $1.2 trillion cut to federal spending that would be applied automatically starting in 2013 should the 12-member supercommittee fail to agree on more-targeted reductions. With time running short, the panel has yet to produce its legislative proposal, raising concerns about cuts that defense advocates say would compromise the nation’s war-fighting ability.

Sequestration, the term for what would happen if the supercommittee fails, likely would force the Pentagon to abandon plans for a European missile shield and eliminate the ICBM leg of the strategic nuclear triad, Panetta said.

Generally speaking, sequestration would be “devastating for the Department,” Panetta said. The White House already plans to trim the Pentagon’s budget by $450 billion during the next 10 years. The cuts imposed by sequestration would come on top of that, leaving the military services at their smallest size-levels in several decades, he said. The Air Force, he said, would be reduced to its smallest size in history.