Space ship Challenger's troubled mission is a pointed reminder that humanity is still at an early stage of space pioneering. Two failures of the communication satellite booster rocket show that a launching procedure which has been accomplished a number of times before still cannot be considered ''routine.'' Likewise, the loss of the target balloon, which prevented planned rendezvous exercises, has been blamed partly on relaxation of quality controls on some items of space hardware.
Meanwhile, on the positive side, the astronauts' maneuvers with the jet-powered backpacks have opened a new dimension in space operations. Like scuba divers freed from the restrictions of air hoses to the surface, astronauts freed of their tethers to a mother ship can begin to move and work in three dimensions. The pre-launch words of mission commander Vance Brand proved prophetic: ''We're beating a pathway into the future.''
The United States has a great deal at stake in the shuttle program. As Mr. Brand noted, it is the pathway to the country's space future. Yet, from its beginning, the program has been hampered by penny-pinching ''cost containment.'' As some of its managers have pointed out from time to time, this has sometimes led to cutbacks in quality control. And that, in turn, can ultimately cost more than was initially saved if equipment failure prevents fulfillment of an expensive mission's objectives. Whether or not such false economy should be blamed for the satellite booster failures was not known at this writing. But the equipment involved with the failed balloon was purchased ''off the shelf'' as part of a NASA money-saving program. It reportedly was not optimized for use in space.
The astronauts on this mission have performed faultlessly so far. They have earned the praise which mission controllers have given them. But they also deserve the best in equipment with which to work. Those who control NASA funding should think again about the danger of emphasizing ''cost containment'' over excellence.