Saturday, December 1, 2007

Yikes, indeed!

A couple of days ago the GAO report on ARES was released. At first glance it looked pretty sugar coated. After all, even Congress would like the space program to succeed, they just don't know how to help.

We promised to offer a more in-depth look at the report, but when someone else volunteers to do promised work, we usually take them up on the offer. So, today, we are re-posting a comment from one of dear readers, in case you missed it. It pretty much makes the point forthwith....

Our reader, "space" said,

After you peel back the fair-and-balanced boilerplate that GAO always bookends these reports with, the panoply of crippling problems is pretty devastating:

“NASA has not yet established firm requirements or developed mature technologies, a preliminary design, or realistic cost estimates, or determined the ultimate time and money needed to complete the program [Ares I] and so is not in a position to make informed investment decisions.”

“While NASA still has 10 months to close [the aforementioned] gaps in knowledge, it will be challenged to do so.”

“For the Ares I program, 14 of the project’s self-identified risk factors are tied to unstable requirements—many of which are interrelated between Ares I and Orion projects.”

“Both the Orion and Ares I vehicles have a history of weight and mass growth, and NASA is still defining the mass, loads, and weight requirements for both vehicles.”

“a design analysis cycle completed in May 2007 revealed an unexpected increase in ascent loads (the physical strain on the spacecraft during launch) that could result in increases to the weight of the Orion vehicle and both stages of the Ares I.”

“Requirements instability is also increasing risk for the individual elements of the Ares I.”

“NASA has not yet matured guidance, navigation, and control requirements for the upper stage subsystems. According to an agency official, these requirements cannot be finalized until mass, loads and weight requirements are finalized. Since these requirements are not expected to be provided until just 2 ½ months prior to the upper stage preliminary design review process start, there is a possibility that the system requirements review design concepts will be highly affected once requirements are received.”

“Requirements instability also contributed to NASA’s inability to definitize design, development, and test and evaluation contracts for both the first stage and upper stage engine until August and July 2007 respectively—more than a year after the contracts were awarded.”

“Adding the fifth segment and the frustum has increased the length and flexibility of the reusable solid rocket booster. It is currently unclear how the modification will affect the flight characteristics of the reusable solid rocket booster. Failure to completely understand the flight characteristic of the modified booster could create a risk of hardware failure and loss of vehicle control.”

“there is also a possibility that the reusable solid rocket booster heritage hardware may not meet qualification requirements given the new ascent and re-entry loads and vibration and acoustic environments associated with the Ares I. This could result in cost and schedule impacts due to redesign and requalification efforts.”

“the added weight of the fifth segment to the boosters is forcing the contractor to push the state of the art in developing a parachute recovery system.”

“In January 2007, an independent review of the first stage development questioned the cost-effectiveness of continuing with a reusable booster design… NASA may need to consider expendable first stage options given the weight issues associated with both the Ares I and Orion vehicles. If NASA opts to pursue an expendable solution for the first stage, the overall Ares I design and requirements could change dramatically.”

“NASA’s development effort for the Ares I upper stage has resulted in the redesign of its propellant tanks from two completely separate tanks to two tanks with one shared, or common, bulkhead. While the prior two-tank configuration was a simpler design with a lower manufacturing cost, it did not meet mass requirements. The current common bulkhead design involves a complex and problematic manufacturing process that plagued earlier development efforts on the Apollo program. In fact, IRMA indicates that one of the lessons learned from the Apollo program was to not use common bulkheads because they are complex and difficult to manufacture.”

“there is a possibility that upper stage subsystems will not meet the Constellation program’s requirements for human rating unless the Constellation program grants waivers to failure tolerance requirements. NASA’s human rating directive generally requires that human spaceflight hardware be “two-failure tolerant,” that is, the system should be designed to tolerate two component failures or inadvertent actions without resulting in permanent disability or loss of life. According to Ares I project officials, NASA’s directive allows the use of ascent abort in response to a second failure during launch; however, Constellation program requirements do not allow abort and require Ares I to reach orbit even if there are two failures.”

“Although the J-2X is based on the J-2 and J-2S engines used on the Saturn V, and leverages knowledge from the X-33 and RS-68, the extent of planned changes is such that both the ESAS and Ares I standing review boards reported that the effort essentially represents a new engine development. The scope of required changes is so broad, the contractor estimates that it will need nearly 5 million hours to complete design, development, test, and evaluation activities for the J-2X upper stage engine… According to Pratt and Whitney Rocketdyne representatives, these design changes will result in the replacement and/or modification of virtually every part derived from the J-2 or J-2S designs.”

“Pratt and Whitney Rocketdyne is also redesigning turbo-pumps from the X-33 program that feed fuel and oxidizer into a newly configured main combustion chamber, to increase engine thrust to 294,000 pounds—the J-2S had 265,000 pounds of thrust. The element also faces significant schedule risks in developing and manufacturing a carbon composite nozzle extension in order to satisfy these thrust requirements. According to contractor officials, the extension is more than 2 feet—i.e., about one-third—wider in diameter than existing nozzles.”

“the J-2X development effort is accorded less than 7 years from development start to first flight. In comparison, the Space Shuttle main engine, the only other human-rated liquid-fuel engine NASA has successfully flown since the Apollo program, development required 9 years… If the engine does not complete development as scheduled, subsequent flight testing might be delayed. The J-2X development effort represents a critical path for the Ares I project. Subsequently, delays in the J-2X schedule for design, development, test, and evaluation would have a ripple effect throughout the entire Ares I project.”


THANKS, space!

1 comment:

Gaetano Marano said...


it's strange that GAO concern is about time and costs since the #1 problem of the Ares-1 is that it can't fly:

it's interesting to know that, while the 5-segments SRB adds lots of delays, costs and problems, may increase the (Orion) payload by just a (ridiculous) 1.3 mT (vs. the standard SRB)

also, the J-2X has 43% less power, despite the payload has increased by over 15%