Aerospace: Space is the place

Aerospace parts are not only used to make aircraft that transport people and cargo from one place on Earth to another but to make spaceships to explore outside this planet’s atmosphere. Artemis is one such space program. NASA reports that Artemis I, which performed its mission late last year, was the first in a series of increasingly complex missions that will enable human exploration to the moon and Mars.

Ingersoll Machine Tools Inc. in Rockford, Illinois, has been a partner in the Artemis program for nearly a decade, said Jeffrey Ahrstrom, CEO of the machine tool builder. The crew capsule for the program is named Orion.

“We machined five of the six components that make up the Orion crew capsule,” he said.

Each workpiece started as a massively thick ring of 20 series aircraft-grade aluminum that ends as “an intricate skeleton that needs to be light and strong outside Earth,” Ahrstrom said.

A presentation event by the Artemis/Orion program management team was hosted by Lockheed Martin and Ingersoll Machine Tools at Ingersoll’s facility July 19. Image courtesy of Ingersoll Machine Tools

One component, for example, weighed as much as 6,350 kg (14,000 lbs.) before machining, and its final weight was about 363 kg (800 lbs.).

Ahrstrom described the parts as “incredibly complex,” with numerous pockets, thin walls and standoffs for mounting items.

“A wonderful challenge in engineering and art,” he said.

During internal and external machining, the company needed to compensate for drift, draw and distortion.

“No matter how much pre-treating, heat treating and stress relieving you do,” Ahrstrom said, “you’re going to impart stresses into it.”

As material is removed, the stiff, rigid ring becomes “flimsy” out of necessity, he said, and vacuum fixturing is employed for workholding.

“There’s not a lot to hold on to,” Ahrstrom said.

In addition to controlling machine vibration and the toolpaths, it is critical to control the temperature at the shop by ±2 degrees Fahrenheit.

“If we get outside of that 2-degree window,” Ahrstrom said, “we shut down manufacturing till we can stabilize the temperature for the machine and the part.”