The same slice. The share of U.S. discretionary spending going to research hasn't changed much since the days of the Apollo program.
SOURCE: AAAS, FROM 2008 U.S. BUDGET REQUEST via Science magazine. 11 May 2007 > Mervis , pp. 817 - 818

Comment: While other nations spend more of GDP on research and development, the United States does not. Since those other nations are also growing their GDP's, they will eventually produce much more science and technology. JAD