March 2007 Edition

Aerospace Manufacturing

Not Your Father's Space Shuttle

NASA's new approach to space exploration has implications all the way to the shop floor

While it's been the workhorse of the U.S. manned spaceflight program, the Space Shuttle is nearing the end of its operational life. First launched in April 1981, the shuttle has been in service for almost 27 years. NASA plans to retire the shuttle in 2010 and doesn't plan to replace it with another winged spacecraft.

"We're From the Government and We're Here to Help . . . "

Rather than build its own reusable spacecraft, NASA turned to private industry. The space agency is still involved as a major investor in the new vehicle. The new spacecraft will transfer people and supplies to and from the International Space Station — ISS — after the shuttle is retired. NASA is the big investor, at $500 million, but the actual work of developing the new craft has been awarded to two private companies: Space Exploration Technologies — SpaceX — and Rocketplane Kistler, Oklahoma City.

Jointly, these companies have been contracted under a NASA program called Commercial Orbital Transportation Services — COTS — to develop and demonstrate the vehicles, systems, and operations needed to support a facility such as ISS.

NASA hopes to become just one of many customers for this new, orbiting delivery service.

"This is the first opportunity NASA has taken to engage entrepreneurs in a way that allows us to satisfy our needs and lets commercial industry gain a foothold," Marc Timm, acting COTS program executive of NASA's Exploration Systems Mission Directorate, said. "It could, and should, have profound impacts on the way NASA does business."

Those profound effects will reach beyond NASA. When private industry builds something as big, complex, and expensive as a space vehicle, the "holy trinity" of cost, schedule, and weight is in control.

Virtual Mockup

"When NASA was developing the Space Shuttle, it created a full-scale physical mockup," Dave Cochran, K-1 structures and cargo module program manager at Rocketplane Kistler, said. "There's no way we could do that today. It would take far too long and cost way too much."

Given the way NASA created the COTS program, the incentive to work as quickly and efficiently as possible — without sacrificing accuracy or safety — is tremendous.

NASA has made success the incentive of COTS. According to space agency documents

Partners will be paid only if they succeed. Payments will be incremental and based upon the partners' progress against a schedule of performance milestones contained in each Space Act agreement.

Cochran puts it a little more bluntly: "We're burning private money. Schedule and cost control are absolutely critical."

Because working fast and keeping costs manageable are important for Rocketplane Kistler, the company adopted an advanced digital development process based on product lifecycle management — PLM — technology from UGS, Plano, TX. The technological foundation includes the UGS NX design automation system for computer-aided design along with the Teamcenter solution for managing product and process knowledge.

"The award of a NASA COTS program meant we needed a strong, dynamic design foundation as well as the ability to manage the huge amounts of data we're creating," Joe Cuzzupoli, Rocketplane Kistler's COTS program manager, said. "UGS' high-end functionality and its strong presence in the aerospace and defense market made it the right choice for us.

"The two companies that are doing the bulk of the manufacturing for us — Northrop Grumman for structures and Aerojet for the propulsion system — both use NX," Cuzzupoli said. "That was another reason we chose this solution."

Rocketplane Kistler has been using NX and Teamcenter to develop the K-1, a fully reusable, two-stage orbital launch vehicle for delivering various payloads to a wide range of altitudes and inclinations in low earth orbit.

The K-1 is Rocketplane Kistler's vehicle that will perform the COTS mission of space station resupply. However, the company will use it for other business, too, such as the delivery of commercial, military, and government satellites to various orbits.

Instead of building a physical mockup of the K-1, the aerospace company created a virtual mockup of the vehicle in NX, with details such as wiring and tubing. The digital model of the K-1 is complete and contains about 15,000 components. The actual vehicle is about 75 percent complete. Many of the components are finished, but in different locations around the country awaiting assembly.

While the virtual model of the K-1 provided the same kind of information a physical mockup has, such as the ability to check fit and find interferences, that is just the beginning. Working digitally brings other advantages to the project, extending even to shop floor, so that it is inconceivable that something as complex as a space vehicle will ever be developed any other way.

Vacuumless Work Environment

In the design stage, for example, working digitally saved time on every component of the K-1 through a process known as "design in context."

"When someone is designing a component in context, he isn't working in a vacuum," Cochran said. "He can see what's around the component and make sure it fits. This eliminates a great deal of checking that went on in the conventional design approach.

The K-1 promises the efficiency of an expendable launch vehicle with the economy of a reusable booster as well as fast turn-around time

"This reduces the design effort by about 25 percent per component because checking is almost automatic."

Through the use of NX vs. a drawings-based approach, Cochran estimates the time to design and document each K-1 component was reduced by about 50 percent. Another 25 percent savings came from putting critical manufacturing information into digital models instead of on-paper drawings.

"Now we do Functional, Tolerancing, and Annotation — FT&A — on the 3D model itself so we eliminate all the time it used to take to make a drawing, annotate it, revise it, and so on," Cochran said.

Working digitally saves time and money by providing CAD data that can be reused in later applications.

"The virtual mockup of the K-1 serves as the source of data for many key analyses — loads, stress, thermal, vibration," Cochran said. "This can save as much as a month because it isn't necessary to build analysis models from scratch. The process of ensuring that analysis models accurately reflect the vehicle configuration is greatly simplified, which also contributes to the time saved."

Data and Revision Control

This only works if analysts can find the CAD models they need and if the versions they work with are up-to-date. This is where Teamcenter is useful; it controls the data and revisions. Rocketplane Kistler has a multi-site Teamcenter implementation so it can synchronize data between key locations such as Northrop, Lockheed, Aerojet, and contractors.

"This ensures that the CAD baseline and in-work models are available at all sites and are always up-to-date," Cochran said.

Having worked in the aerospace industry for many years, Cochran said he had no doubt that working digitally enabled his company to accelerate the design cycle for the K-1. But, a faster design cycle was only part of the company's challenge. Rocketplane Kistler needed to get parts ordered and built as quickly as possible. This is another area where the company saw benefits from digital development.

For example, the company provided information to suppliers early in the design cycle because manufacturing information was contained in CAD models, speeding up the procurement process on the front end.

"For our suppliers, this lets them provide a better quote because they can get the file and see exactly what it is we want them to build," says Cochran. "And, it allows them to do this earlier because we don't have to create all that documentation."

Digital Speed

The digital approach is faster as well when it came to the actual manufacturing of parts.

"It allows us to transmit the final configuration to our suppliers in a format they can use directly — for CNC programming, for instance — rather than recreating the information from drawings," Cochran said.

One of Rocketplane Kistler's suppliers, Northrop Grumman, did away with drawings, sending its subcontractors information in digital form.

"A supplier that wants to manufacture K-1 parts for Northrop Grumman and RPK has to be able to receive, interpret, and act on NX files," Cochran said.

"We don't do paper drawings. We send suppliers a 3D electronic model that has all the information in it. It's a way of reducing their development cost. Since Rocketplane Kistler is the ultimate customer, this translates into a three to six-week schedule saving for us on complex assemblies."

The K-1 is expected to launch in the second quarter of 2009. Cochran said vehicle development is the fastest ever accomplished for a spacecraft of this size.

"Developing something as complex as a launch vehicle will never be easy, so the key to succeeding in a commercial environment is to boost efficiency in the development process. It's critical that we use the best tools for the job. This is the key to making the K-1 a reality," Cochran said. UGS

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