Subject to increasing costs and shrinking budgets, NASA has had to postpone or even cancel many research projects. Some worry that the U. S. Congress will not approve costly projects such as bringing Martian rocks back to Earth Analysis-This is the only way scientists think they can determine if the activity has ever been alive. The most accurate summary of the meaning of this text is:. ['The current budget for aerospace research purposes is increasing.', 'Congressional Resolution Affects New NASA Project.', 'Research on the existence of life on Mars may be unsustainable in the future.', 'Budget pressure will be the main cause of suspension of large U. S. space projects.']