— NASA took a close look last year at an alternative launch system known as Direct 2.0 that its proponents say promises to put the United States back on the Moon faster and cheaper than the Ares rockets NASA has been working on for the past three years. A summary of NASA’s evaluation, publicly released July 3, shows the U.S. space agency reaffirmed its decision to stick with Ares 1 and Ares 5 after concluding the Jupiter rockets proposed by the Direct 2.0 advocates offer neither the performance nor the reliability NASA says it needs to go back to the Moon.

Steve Cook, manager of the Ares project office at NASA’s Marshall Space Flight Center in Huntsville, Ala., told Space News in a July 3 interview that his team took two separate looks at the Direct architecture in 2007: once in May and again in October after Direct proponents presented their revised design at the American Institute of Aeronautics and Astronautics’ Space 2007 conference in Long Beach, Calif.

Cook said the revised concept, dubbed Direct 2.0, showed improved performance over the earlier version but “was still way off the mark” for what NASA needs for lunar exploration.

NASA’s evaluation, summarized in a set of 75 briefing charts that Cook had his team prepare last month after an Orlando Sentinel article depicted Direct 2.0 as superior to Ares in terms of cost, overall performance and job retention, concluded the Direct approach would not be nearly as capable as advertised. Their evaluation concluded that the Direct 2.0 approach would miss NASA’s lander payload requirements by at least 50 percent – and would be nearly twice as likely as Ares to lose the crew in the event of a mishap.

NASA also concluded the cost and schedule advantages claimed by Direct proponents were not supported by much data or analysis.

Stephen Metschan, chief executive of TeamVision Corp., a Tacoma, Wash.-based software firm promoting the Direct concept, questioned the objectivity of NASA’s evaluation. “We are aware of the study, but it has significant ‘finger on the scale’ errors than an organization independent from NASA could easily discover,” Metschan wrote in a July 2 e-mail. “Beyond that they have their finger on the scale for the current approach as well. At the end of the day all we are asking for is an independent review of the current approach versus Direct in terms of engineering, safety, budget, performance and schedule.”

Cook defended NASA’s methodology, noting that used the same tools and ground rules to evaluate Direct that it has used to evaluate more than 1,700 launch concepts since 2005.

In an interview at the National Space Society’s International Space Development Conference here in May, Metschan said the Direct 2.0 approach would enable NASA to reach the Moon sooner and at lower cost by employing two nearly identical Jupiter-120 rockets designed to maximize their commonality with the existing space shuttles. Metschan said such an approach would not only entail less development risk than Ares, which currently incorporates no hardware brought over as-is from the shuttle, but also would allow for a smoother transition for the shuttle work force and result in fewer lost jobs at NASA’s Kennedy Space Center in Florida and Michoud Assembly Facility in New Orleans.

Metschan also said NASA could keep its major Ares contracts intact since the Jupiter rockets also would use solid rocket boosters, RS-68 engines and a J-2X-powered upper stage. But a key difference between Direct and Ares, he said, is that Direct would use that hardware closer to as-is. For example, both the crew and cargo versions of Jupiter would use a pair of the shuttle’s four-segment solid-rocket boosters attached to a core stage that is essentially the shuttle’s external tank with three RS-68 engines attached to the bottom.

NASA’s approach, on the other hand, requires the development of a larger five-segment solid-rocket booster to serve as the main stage for Ares 1 and a pair of larger still five-and-a-half segment solid-rocket boosters for Ares 5, which will have six RS-68 engines attached to the bottom of its core stage, which will be a wider diameter version of the shuttle external tank.

NASA did not produce an independent cost estimate for Direct, or try to quantify how many people the Jupiter rockets would employ compared to Ares. “It’s got to get past the performance gate. If it doesn’t, it doesn’t make sense to look any further,” Cook said.

Still, NASA’s evaluation questioned some of the assumptions that are key to Direct’s claimed advantages. For example, NASA concluded that the Direct approach likely would require three launches instead of the proposed two for lunar missions due to a reliance on what the charts depict as overly optimistic dry mass predictions.

NASA also concluded that Direct proponents underestimated how much technology development their approach would entail and also overestimated how much of the space shuttle’s manufacturing infrastructure is still in place.

Metschan and other Direct proponents, whom he said include NASA engineers and Constellation contractors that have lost faith in the Ares approach, intend to continue to push Direct as a common-sense alternative to NASA’s current path.

At the National Space Society conference in May, he stressed the need for Direct proponents to get organized now if they hope to convince the next Congress and new president that it is not too late to change course. To that end, Metschan and others already have been making the rounds in making the case that Direct is the way to go.

An official at the U.S. Government Accountability Office who met with Metschan and other Direct advocates earlier this year for an extensive briefing told Space News that while Ares likely will cost more and take longer than NASA has said, it does not make sense to start over with a new approach that might have just as many or more hidden flaws. “When you talk to [Direct advocates], you only hear the good. You don’t hear the downside,” the GAO official said. “I don’t see that there’s enough wrong with where [NASA is] now to turn back and start over.”