ATK [ATK], prime contractor on the Ares I rocket that will loft the Orion space capsule into orbit, maintains the program cost, schedule and technical performance are on track, as the Obama administration awaits the results this month of a review of NASA’s space hardware development and procurement effort.
“From day one designing a system to be the simplest approach, to maximize affordability, to maximize safety for the crew, is what Ares I was all about,” Michael Kahn, executive vice president, ATK Space Systems Group, said at a recent briefing at company offices in Arlington, Va.
Ares I falls under NASA’s Constellation Program. The launch vehicle is expected to loft the next-generation Orion crew vehicle to the International Space Station (ISS), the Moon and even further.
Charles Precourt, vice president and general manager of ATK Space Launch Systems, said safety and simplicity drove the rocket design, using some of the same charts the company had presented to the administration’s review committee led by Norman Augustine examining what comes next after the current Shuttle retires in 2010. The review will issue its report and options for the administration at the end of the month.
The Ares I design draws from the Columbia Accident Investigation Board (CAIB) that said Shuttle replacement safety requirements should be “above all else,” geared toward maximizing crew safety, Precourt said. “I look at the Ares I design philosophy as one that minimizes moving parts and maximizes the performance capability of what you understand from the history of previous systems like the Shuttle with the first stage in particular.”
The odds of losing a Shuttle crew are said to be roughly one in 200, while the odds of losing a combat aircraft crew are about one in 20,000, and the odds are even higher for commercial airlines, he said. For ATK, “one in a thousand, or one in several thousand is the goal.”
Another foundational principle is putting Ares I in an envelope where it is safe for the crew to abort, Precourt said. Traditional satellite launchers take advantage of higher trajectories that are more cost efficient, but G-factors are too high at those trajectories for a safe crew abort.
“What we’re looking for is the highest performance with a simple vehicle,” he said. The inline design configuration maximizes the chance of better safety.
Kahn said getting to orbit in a fraction of the time it takes other systems minimizes a lot of the failure modes that cause concern when several engines are running.
“Simple is safer,” one of the company charts said. “A two-stage design with one engine per stage provides four to five times the reliability and safety of a more complex architecture.”
Precourt said NASA’s Constellation program has “attempted to leverage the lessons all the way back to the Apollo program. From the safety aspect standpoint, the inline configuration offers the best attributes for safety.”
Looking at moving more cargo to orbit, the current concept with Ares V–a heavy lift capability–maximizes the amount of cargo that can be placed in orbit on a single flight. The ability to pre-assemble payloads on the ground means it is less complex to assemble payloads in space. Thus there would be fewer launches and fewer payloads and fewer in-space assemblies. That “drastically increases” the probability of success, he said.
Working on a heavy-lift capability, Kahn said, ATK considers how to maximize “the infrastructure, the tooling, the workforce.”
What history has taught also is important. he said. “We want to maximize use between Ares I and Ares V, but we also want to maximize what we’ve been able to get the benefit of the system that’s flying to day on Shuttle,” he said.
The Shuttle motor has flown for 21 years. “We have not had a launch scrub or abort…” he said. Another advantage of leveraging the shuttle motor is that the hardware comes back and can be closely examined for flaws or updates added.
For Ares I, ATK added a center segment to the four-segment Shuttle motor. In 2003, ATK had a successful firing of a five-segment motor to demonstrate models and capability.
“At the end of August, we plan on firing DM-1, the first static test of the Ares I five-segment motor,” Precourt said. “And we expect its performance to be the same.”
Kahn added, “It’s not just having a booster that is capable of delivering the performance required for first stage, it’s also having one that has demonstrated performance over 20-plus years that has remarkable repeatability.”
In the three years of the program to date, a substantial number of milestones and tests have been conducted, all on track allowing the program to proceed.
All the Ares I-X hardware has been delivered to [Kennedy Space Center] and is in the stacking process. Kahn said.
“We’re hitting our milestones on time. We’re also hitting them on budget,” Precourt said. “We’re running slightly under budget for the three-plus years we’ve been at this.
Countering some critics of the program’s ability to lift the necessary payload, Precourt said, he’s at a loss to explain where that criticism comes from. The project office allocated almost 245,000 pounds, and “it looks as though the first stage will come in well under that at 232,000,” he said. The NASA figure also has a built-in margin.
Kahn said, “What ATK worries about is what the first stage inert weighs and what kind of performance will we deliver to the stack.”
There are other misperceptions, the officials said, for example, about thrust oscillation, the vibration felt in the last 10 seconds of thrust. “We fully understand that issue. It’s very common to virtually every launch vehicle,” Precourt said. “It’s a system issue, not a first stage issue.” ATK currently has four ways to mitigate the issue.
While there are studies of alternatives to Ares I, the question is if they would “deliver more and will it be significantly more in any of these attributes than we’re already on,” Precourt said. “We’re not seeing an alternative that will deliver more than what the Ares concept is currently on a path to deliver on any of those attributes.”
“We have a very high degree of confidence in our ability to deliver on the requirements of first stage,” Precourt said. “It’s based on past history; it’s based on current developmental events, such as all of the tests.”
An Orion 1 test flight comes in 2014, and the company said it is ready.
“Our readiness for that is pretty solid. As the first stage provider, we’ve withstood a lot of scrutiny along the way, numerous reviews, and we’re meeting the highest standards that have been expected of us without major surprises,” Precourt said. “We’ve got a system we think is unmatched compared to any other alternative in terms of being able to meet safety, schedule, cost and performance targets.
Ares I represents a national capability beyond a Shuttle replacement, Precourt said. “I would suggest that it needs to be looked at more broadly than it’s being seen to this point in time.”
For example, Ares I should be considered for a cargo variant that can deliver payload to orbit, such as ISS cargo.
Ares should also be considered as the Defense Department studies the need to move from two versions of the Evolved Expendable Launch Vehicle (EELV) to one. “Certainly a vehicle [Ares I] that has this kind of reliability and has a cargo capability potential equal to or greater than current EELVs would be an enabler for that downselect and it broadens our assured access capability,” Precourt said.