(ARSTechnica) For the last half-decade, NASA has resolutely declared that it has embarked on a Journey to Mars. Virtually every agency achievement has, in one way or another, been characterized as furthering this ambition. Even last summer when the New Horizons spacecraft flew by Pluto, NASA Administrator Charles Bolden said it represented "one more step" on the Journey to Mars.
But as the end of President Obama's second term in office nears, Congress has begun to assess NASA's Mars ambitions. On Wednesday during a House space subcommittee hearing, legislators signaled that they were not entirely pleased with those plans. Comments from lawmakers, and the three witnesses called to the hearing, indicate NASA's Journey to Mars may receive some pushback in the next year or two.
Some of the most critical testimony came from John Sommerer, a space scientist who spent more than a year as chairman of a National Research Council technical panel reviewing NASA's human spaceflight activities. That panel's work, summarized in a 2014 report titled Pathways to Exploration, considered possible pathways to Mars.
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