the nasa astrobiology program includes the nai as one of four components, including the exobiology and evolutionary biology program; the astrobiology science and technology instrument development (astid) program; and the astrobiology science and technology for exploring planets (astep) program. program budgets for fiscal year 2008 were as follows: nai, $16 million; grants for the exobiology and evolutionary biology program, $11 million; astid, $9 million; astep, $5 million.