WASHINGTON — Dogged by rumors that Ares 1 would not be able to lift the Orion Crew Exploration Vehicle if the rocket was built as currently envisioned, NASA’s Constellation program manager shot back Nov. 13 at unnamed critics in an e-mail missive he said he wrote to set the record straight.

“[M]any who carp from the sidelines do not seem to understand the systems engineering process. They instead want to sensationalize any issue to whatever end or preferred outcome they wish,” wrote Jeff Hanley, the NASA official leading the development of the rockets and spacecraft the United States is building to replace the space shuttle and to return to the Moon.

In the Nov. 13 e-mail, which circulated beyond NASA just hours after he hit the send button, Hanley said he was writing in part to respond to a posting that had appeared over the weekend on the Web site NASA Watch declaring “Big Problems with the Stick.”

NASA Watch’s short Nov. 11 posting said the Ares 1, also known as the Stick, “is underpowered to the tune of a metric ton or more” and would not be able to lift Orion. The information was attributed to reports from “sources inside the development of the Ares 1 launch vehicle.”

What NASA Watch was reporting was the latest twist on what the aerospace community has been whispering about for months ‑‑‑ that the space shuttle-derived design NASA picked for Ares 1 and its heavy-lift follow-on, the Ares 5, is rife with problems and the agency would be better off taking some other approach.

That the aerospace community was buzzing with talk of Ares problems was not lost on Hanley and other senior NASA officials. Steve Cook, NASA’s Ares program manager, was dispatched to speak at a Space Transportation Association breakfast here in October in an attempt to get ahead of the rumor mill, officials familiar with the behind-the-scenes preparations said.

Hanley said in an interview he normally does not respond so directly to what he characterized as misinformation that appeared in “the pseudo media .”

But the NASA Watch posting spurred him to action.

“I thought it was important that we set the record straight on some of the external stuff that’s been going around. I don’t want people to think that because they don’t see us responding to it on a regular basis that has any basis in truth,” said Hanley in a Nov. 15 telephone interview from Johnson Space Center in Houston, where the agency’s first systems requirement review for Orion and the Ares rocket had concluded the day before.

Hanley was joined on the interview by Cook and Scott Horowitz, NASA’s associate administrator for exploration systems.

Hanley said the review, which was attended by NASA Administrator Mike Griffin , found that Ares 1 remains on track to lift the Orion spacecraft with performance to spare.

Reiterating points made in his e-mail, Hanley said the latest analysis shows that Ares 1 can lift 26,100 kilograms to low Earth orbit . Its intended payload, Orion, is still running 15-20 percent below its NASA-imposed 21,825-kilogram weight limit fully fueled, he said.

The Ares 1 main stage is a larger five-segmented version of a space shuttle solid rocket booster. The rocket would be topped with a cryogenic upper stage powered by an updated version of the J-2 engine that flew on the Saturn 5.

NASA originally planned to use a four-segment booster for the Ares 1 main stage and the shuttle main engine for the upper stage, but decided in January to go with the five-segment booster and J-2X greater commonality with the Ares 5, the heavy-lift rocket NASA for Moon missions.

Cook, who runs the Ares program from Marshall Space Flight Center in Huntsville, Ala., said the mass and performance of Ares 1 and Orion get a lot of attention from the program, but he said claims Ares 1 is underpowered are simply not true.

“Mass and performance are things you are going to always have to track on any aerospace vehicle, especially one that wants to go to orbit,” Cook said. ” But we can lift what we need to lift with 15 percent performance margin.”

Cook said Ares 1 weight and performance projections have fluctuated in the 10 months since NASA switched to the five-segment/J-2X combo, but said that is typical for any aerospace vehicle making the transition from detailed concept to preliminary design.

“And the first time you do that, you find that everybody starts putting margin in the system and it comes out weighing more and getting less performance than you initially projected,” he said. “Then you start working . . . back down through the process. This is standard 101 stuff that goes on. . . It’s part of the normal design cycle.”

The Ares 1 preliminary design review is in February 2008 . The critical design review, when NASA nails down the design and starts producing the vehicle, is slated for late 2009. Orion’s preliminary and critical design reviews are slated for summer 2008 and summer 2009, respectively.

Hanley said Denver-based Lockheed Martin Space Systems, selected in late August as the Orion prime contractor, has spent the last two months incorporating a few NASA changes into its winning spacecraft design. All indications are that Orion is staying well within its mass targets.

Hanley said weight will remain at the top of his watch list until Orion and Ares actually launch.

“Six months from now, the Orion guys could come in and say, ‘hey, we are 1,000 pounds (450 kilograms) over.’ Okay, so back to work. Go solve it,” Hanley said. “That’s the way the game is played.”

Ares gossip heard from industry sources is often accompanied by advocacy for alternative approaches, such as using the Atlas 5 or Delta 4 Evolved Expendable Launch Vehicles as the basis of NASA’s new transportation system.

Cook said that is to be expected given the stakes.

“Part of this is because we haven’t done a design of an exploration-class system, whether it’s the crew vehicle or the launch vehicle, in 40 years … so when it happens, everybody is clamoring to get a piece of it and want to help” Cook said. “And I don’t think it helps, frankly, that over the last 15 years NASA has been a little inconsistent in what it wants to do. But when the president put out the vision in 2004 we got a very clear message of how to go be focused. .”

Horowitz dismissed anonymous claims of trouble on Ares as “rumblings from people who didn’t get their particular favorite rocket design picked.”

Horowitz said NASA looked at 10,000 to 20,000 iterations of different designs as part of an intensive Exploration Systems Architecture Study before selecting the crew and cargo launcher concepts the agency unveiled in September 2005.

“Are there other solutions that would work? Sure,” Horowitz said. “But so does this one. This is ours. And this is where we are going. And occasionally you’re just going to get noise in the system. We try to educate people. It’s just noise.”