When Aeroflex, Plainview, N. Y., needed a manufacturing company to handle the gear-making chores for Curiosity, the next Martian rover, it called on Forest City Gear, Roscoe, Ill. The company had successfully provided most of the gears and some of the other hardware on Spirit and Opportunity, two rovers that landed on Mars in 2004. Despite being designed for 90-day missions, both rovers were so durable that Spirit just stopped transmitting last year, and Opportunity is still functioning.
Aeroflex had Forest City hob, crown, shape, and finish all the drive gears, gearboxes, planetary gears, and wheel assemblies, as well as several spur, helical, and spline gears. Almost all the parts had to be made of exotic high-strength, lowweight materials.
Aeroflex needed gears made to AGMA 13 levels, a quality-level equivalent to ISO or DIN 5. For comparison, many gear companies consider AGMA 10 to be high quality, and there is no level higher than AGMA 15. There are several considerations when making gears and assemblies of this quality. The first is to have enough gear-making technology on the shop floor.
Aeroflex demanded that all parts Forest City Gear be 100% inspected. So Forest City Gear devised a software program that made it easier to process the large data files such a task generated. Aeroflex was so impressed with the results that it used that documentation in its quality-assurance program with NASA’s Jet Propulsion Lab, Pasadena, Calif., the facility that designed and assembled Curiosity.
