A stinging report on the demise of the space shuttle Columbia is increasing congressional pressure on President Bush to resolve long-postponed questions about his plans for space, but aides said yesterday that he plans no immediate upgrade of NASA’s budget or mission as the space agency struggles to restart the shuttle program. Administration officials disclosed in an interview that the White House will begin work next week on a blueprint for interplanetary human flight over the next 20 or 30 years, with plans calling for Bush to issue an ambitious new national vision for space travel by early next year.