MarkWhittington writes: NASA released a document describing the steps involved in its Journey to Mars program (PDF). But, as the Wall Street Journal suggests, the "plan" has a conspicuous lack of specifics. It doesn't go into how much the program will cost or what intermediate steps have to be taken before human beings set foot on Mars in the 2030s. This is likely because of the upcoming and subsequent changes of governing administrations — the space agency's deep space exploration goals are likely to get a reevaluation. The plan serves as a public relations document more than anything else.