CAPE CANAVERAL, Fla. (AP) _ Here are brief sketches of the astronauts who will fly aboard the space shuttle Discovery.

NAVY CAPT. FREDERICK H. HAUCK, who has flown on two previous shuttles since becoming an astronaut 10 years ago, will be commanding the first shuttle to fly since the Challenger blew up little more than a minute after it left the launchpad Jan. 28, 1986.

Hauck, 47, said he has had plenty of time to dwell on Challenger and won't be concentrating on that when he lifts off.

''There's no doubt I'll be looking at the screen, that when it says 73 seconds and it's counting upwards, I'll know we've passed that particular milestone. But it's not like I'm worried about it,'' he said in a recent interview.

The former Navy test pilot, who flew 114 combat and combat support missions in Southeast Asia, piloted the Challenger in June 1983 and commanded Discovery in November 1984 when the crew made the first space salvage mission in history, retrieving two disabled satellites.

Hauck grew up in Winchester, Mass., and Washington, D.C. He received a bachelor's degree from Tufts University and a master's in nuclear engineering from the Massachusetts Institute of Technology.

His wife, Dolly, and 25-year-old daughter, Whitney Hauck Wood, planned to be at the launch, he said, but his 23-year-old son, Stephen, a Navy officer, is stationed on a ship that was sent to the Persian Gulf.

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AIR FORCE COL. RICHARD O. COVEY, an astronaut for nearly 10 years, will pilot the shuttle on which he logged more than 170 hours in space on a previous flight.

The 42-year-old former Air Force fighter and test pilot guided Discovery on an August 1985 mission and will be thinking about the Challenger astronauts when he lifts off on his new mission.

''I'll also be knowing that they would be pleased that we have gotten back to the point where we are going to fly again.''

His wife, Kathleen, and daughters Sarah, 14, and Amy, 12 will attend the launch.

Covey was born in Fayetteville, Ark., and grew up in Fort Walton Beach, Fla. His late father was an Air Force lieutenant colonel.

He earned a bachelor's degree from the U.S. Air Force Academy in 1968 and a master's in aeronautics and astronautics from Purdue University a year later.

As an Air Force pilot, Covey flew 339 combat missions during two tours in southeast Asia. He has flown more than 4,000 hours in more than 25 different types of aircraft.

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MARINE LT. COL. DAVID C. HILMERS, an astronaut since 1980 and veteran of one previous shuttle flight, will be a mission specialist aboard Discovery.

Hilmers' first space flight was in October 1985 - the maiden voyage of the orbiter Atlantis, on which he was a mission specialist.

On Discovery, he will help deploy a $100 million communications satellite.

Hilmers grew up in DeWitt, Iowa, and graduated with a bachelor's degree in mathematics, summa cum laude, from Cornell College in 1972. He earned a master's degree in electrical engineering in 1977 and the degree of electrical engineer from the U.S. Naval Postgraduate School in 1978.

Hilmers said that like the other astronauts, he will be thinking of their Challenger crew members.

But, he added, ''I think that when it gets right down to the last couple of minutes, that we're going to be looking up at the sky and not behind us.''

Hilmers and his wife, Lynn, have two sons, Matthew, 13, and Daniel, 9.

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GEORGE ''PINKY'' NELSON is the only one of Discovery's five-man crew who has walked in space.

Nelson, 38, logged nine hours of space-walking on his first flight, aboard Challenger in April 1984. His second mission, on Columbia, began 16 days before the Challenger tragedy.

On this launch, there are no plans for Nelson to walk in space, unless something goes wrong in deploying a $100 million communications satellite.

He is again a mission specialist and this time has the duty of blowing off an escape hatch and deploying a new escape pole for the five men if an emergency occurs.

''On the one point, you have to be doubly focused on what's happening. On the other hand you just have to be soaking in this amazing experience,'' he said in a recent interview.

Nelson, an astronomer, is the only one on the five-man crew without a military background. He is the son of a high school science teacher, grew up in Willmar, Minn., and earned a bachelor's degree in physics from Harvey Mudd College in 1972 and a master's and doctorate in astronomy from the University of Washington in 1974 and 1978.

His wife, Susan, and daughters, Aimee Tess, 16, and Marti Ann, 13, will be present for the liftoff.

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JOHN M. ''Mike'' LOUNGE, who first flew into space on Discovery in August 1985, will again be a mission specialist on NASA's first flight in 2 1/2 years.

This time aboard Discovery, Lounge, 38, a former Navy aviator, is the lead astronaut in charge of deploying the $100 million communications satellite.

His other flight, which launched Aug. 27, 1985, is described by NASA as its most successful shuttle mission so far, with astronauts deploying three satellites and repairing an ailing satellite.

Lounge, of Burlington, Colo., said the Challenger tragedy will add to the anxiety astronauts always feel during the first few moments after launch, Lounge said. But, he said, once the spacecraft gets into space ''and it gets real quiet, my heartbeat will probably go down quite a bit.''

Lounge, a Colorado native, received a B.S. degree in physics and mathematics from the U.S. Naval Academy in 1969 and a master's in astrogeophysic s from the University of Colorado.

He completed a nine-month cruise in Southeast Asia aboard the USS Enterprise and participated in 99 combat missions. He currently is a member of the Texas Air National Guard and flies with his unit at least once a week.

He was selected as an astronaut in 1980.

His family, including, his children Shannon, 17, Kenneth, 7, and Kathy, 4, plan to be there for the liftoff.