Science: Boost for The Booster

Fire and smoke streamed across the desert outside Brigham City, Utah, last week as Morton Thiokol successfully fired its redesigned booster rocket for NASA's shuttle fleet. With the test, the crippled shuttle program cleared its first major technical hurdle in resuming flights, now set for next summer.

The achievement came after glitches scuttled three scheduled tests. Company engineers are now examining for charring or erosionthe revamped joints that connect segments of the booster. Those signs indicate leakage of burning gases, the problem that led to the Challenger explosion 19 months ago. More stringent testing lies ahead. Still, officials of the space...