Like so many small businesses in this weak economy, Kaos Worldwide, a sports apparel company just outside Houston, has been struggling. But it has managed to survive while its competitors have folded because it won a five-year, $1.5 million contract last year to supply sports bras to the United States military.

“Without the military contract, we might not still be here,” said Bert Emanuel, who founded the business with his wife, Terri, after a knee injury in 2001 forced him to retire from an 11-year career as a professional football player. Their company sells temperature-regulating and moisture-wicking base layers like T-shirts, shorts, leggings and bras.

While it may seem that only large corporations like Halliburton and Lockheed Martin would have a shot at lucrative military contracts, the Defense Department actually awards more than half, or $55 billion, to small businesses. And the Obama administration’s $787 billion stimulus plan promises to make even more money available.

“Small businesses play an important role in the economy and the military,” said Joseph E. Misanin, deputy director of small-business programs at the Defense Department. “They have an agility and flexibility that gives them an advantage over bigger companies.”