This 1986 photo shows the crew of the space shuttle Challenger. From left are Ellison Onizuka, Mike Smith, Christa McAuliffe, Dick Scobee, Greg Jarvis, Ron McNair and Judith Resnik.

The crew members of space shuttle Challenger flight 51-L, leave their quarters for the launch pad at Kennedy Space Center in Cape Canaveral, Florida on January 27, 1986.

From foreground are commander Francis Scobee, Mission Spl. Judith Resnik, Mission Spl. Ronald McNair, Payload Spl. Gregory Jarvis, Mission Spl. Ellison Onizuka, teacher Christa McAuliffe and pilot Michael Smith.

The space shuttle Challenger lifts off from the Kennedy Space Center in Cape Canaveral, Florida on January 28, 1986, shortly before it exploded with a crew of seven aboard.

Spectators at Kennedy Space Center watch as the space shuttle Challenger lifts from Pad 39-B on January 28, 1986, in Cape Canaveral, Florida.

The space shuttle Challenger lifts off Pad 39B at Kennedy Space Center in Cape Canaveral, Florida on January 28, 1986.

The booster rockets from the Space Shuttle Challenger fly off after the shuttle exploded after lift-off from the Kennedy Space Center in Cape Canaveral, Florida on January 28, 1986.

An unusual flame is seen jutting from the side of a solid rocket booster on the space shuttle Challenger during its launch from the Kennedy Space Center in Cape Canaveral, Florida on Jauary 28, 1986. A subsequent explosion killed its crew of seven.

The solid fuel rocket booster of the space shuttle Challenger starts to explode over Kennedy Space Center on January 28, 1986, in Cape Canaveral, Florida.

The solid fuel rocket booster of the space shuttle Challenger starts to explode over Kennedy Space Center on January 28, 1986, in Cape Canaveral, Florida.

A solid fuel rocket booster disappears behind the contrail of the explosion of the space shuttle Challenger on January 28, 1986, over Kennedy Space Center in Cape Canaveral, Florida, as debris from the orbiter begins to fall to earth.

This image made from a television screen shows the space shuttle Challenger after exploding during its launch from the Kennedy Space Center in Cape Canaveral, Florida on January 28, 1986.

A solid fuel rocket booster disappears behind the contrail of the explosion of the space shuttle Challenger on January 28, 1986, over Kennedy Space Center in Cape Canaveral, Florida, as debris from the orbiter begins to fall to earth.

Spectators at the Kennedy Space Center in Cape Canaveral, Florida, react after they witnessed the explosion of the space shuttle Challenger on January 28, 1986.

President Ronald Reagan is shown in the Oval Office of the White House after a televised address to the nation about the space shuttle Challenger explosion on January 28, 1986.

A cross and wreath with a picture of the space shuttle Challenger stand on the shore as a Coast Guard cutter heads out to sea searching for debris from the shuttle in Cape Canaveral, Florida on February 1, 1986.

Customer David Kimball of Manchester, N.H., reacts as store employees Lynne Beck of Salisbury, N.H., and Lisa Olson, far right, of Manchester, N.H., embrace as they watch the Houston memorial service for the astronauts who died in the Challenger explosion on a television in a store in Concord, New Hampshire, on February 1, 1986. Pictured on the television screen are family members of one of the astronauts.

A drawing made by a first grade student is shown on January 31, 1986. The student's class at the Our Lady of Lourdes School in Melbourne, Florida, was asked to draw what they thought happened to the space shuttle Challenger and the people aboard.

Pieces of the Space Shuttle Challenger are arranged in a hangar on February 27, 1986, after being salvaged from the Atlantic Ocean where they were scattered on January 28, 1986, when the spacecraft exploded.

This April 1986 photo taken at Kennedy Space Center in Cape Canaveral, Florida, shows an approximately 1800-to-2000 pound, 6-by-10 foot piece of the Space Shuttle Challenger's right-hand solid rocket booster.

It was recovered by the Stena Workhorse northeast of Cape Canaveral in 600 feet of water.

This April 1986 photo taken at Kennedy Space Center in Cape Canaveral, Florida, shows the wreckage from the Space Shuttle Challenger displayed in the Logistic Facility. The wreckage was set up to assist the process of studying the Challenger accident.

This April 1986 photo taken at Kennedy Space Center in in Cape Canaveral, Florida, shows the wreckage from the Space Shuttle Challenger displayed in the Logistic Facility. The wreckage was set up to assist the process of studying the Challenger accident.

• STORY: 30 years later, Challenger's final voyage remembered
• PICTURES: Remembering Fallen Astronauts
• VIDEO: Jan. 28, 1986: Challenger disaster plays out on live TV