10 YEARS AGO — 2000
Air-breathing rocket passes 1-hr milestone: NASA engineers at the Marshall Space Flight Center in Huntsville, Ala., together with partners Rocketdyne, Canoga Park, Calif., Aerojet Corp., Sacramento, Calif., and the Pennsylvania State Univ., completed 1 hr of testing on an air-breathing rocket — also known as a rocket-based, combined-cycle engine. The air breather will let future spacecraft use atmospheric oxygen rather than relying on LOX carried onboard. Once the spacecraft leaves the atmosphere, the engine converts to a pure rocket and uses onboard oxygen. Testing covered performance in all engine operating modes and transitions between modes.

30 YEARS AGO — 1980
Laser looks for flaws: Brilliant laser beam creates a zigzag pattern as it bounces from mirror to mirror at Goodyear’s Akron Research Laboratories in Ohio. Scientists use the lasers to prepare “photo” images for analysis in eliminating flaws from tires, air springs, hose, and other rubber products.

50 YEARS AGO — 1960
Hydraulic motor gives 1 hp/lb: Designed for aerospace, a compact hydraulic motor packs 1/3 hp in less than 1 cu in. It is 100× smaller than an electric motor of the same power, says its developer, Bendix Corp., Southfield, Mich. It has a displacement of 0.02 cu in. and 6,000-rpm maximum speed. Unusual port arrangements permit rapid reversal of rotational direction, and the motor maintains smooth, rather than pulsing motion, even at low speeds. Probable uses: Directional equipment such as servocontrols for space and marine vehicles.