US Air Force Rocket Explodes

An unmanned Air Force Titan 4 rocket exploded 40 seconds after blastoff Wednesday at Cape Canaveral, Fla., destroying a classified military spy satellite.

Liftoff at 7:30 a.m. appeared normal as the towering rocket climbed away from its firing stand and began arcing east over the Atlantic Ocean. But about 40 seconds into flight, the vehicle began to explode. Two seconds later flight controllers sent self-destruct commands, and the rocket exploded in a shower of flaming debris. It was a spectacular detonation visible for dozens of miles around.

Brightly burning bits of solid rocket propellant and other debris from the explosion rained down in large arcs into the ocean. The sound of the detonation set off car and house alarms as far south as Cocoa Beach. It's not yet known what caused the failure.

The morning launch was scheduled for 6:01 a.m. but ended up being delayed nearly 90 minutes because of fueling problems. The lift-off seemed to be progressing normally leading up to the explosion. At the time of the blast, only the rocket's two solid-fuel boosters were firing. The liquid-fuel core vehicle was to have been ignited two-minutes into the flight.

An Air Force investigation board has been appointed and all Titan rockets will be grounded until the cause of the accident is fully understood, Air Force Gen. Randy Starbuck said.

Titan 4 rockets are made up of a liquid-fuel core vehicle and two solid-fuel boosters. The liquid propellant is extremely toxic, but an Air Force spokesman said: "There's no danger to the public. All the debris went out into the ocean and the toxic cloud of the fuel has dispersed."

Still, officials are asking those who find debris that might be part of the rocket and satellite report their discovery by calling (407) 494-7001.

The nature of the satellite, owned by the National Reconnaissance Office, was classified, but reporters have speculated it was a powerful communications spacecraft. The cost of the Titan 4 and the satellite together reportedly totaled $1.2 billion, but that tally in unconfirmed.

This was the final "A" model of the Lockheed Martin-built Titan 4, which recently was replaced by an upgraded B model featuring a different type of solid fuel boosters and other improvements. One earlier Titan 4A exploded after launch, that time from Vandenberg Air Force Base in California. That explosion happened in August 1993 and was caused by the rupture of a solid-fuel booster just a few seconds after liftoff.

The last time a rocket exploded at Cape Canaveral was in January 1997, when a Delta blew up 13 seconds into flight. No one was injured, but the accident, so much earlier in the flght than Wednesday's explosion, caused extensive damage as chunks of debris landed on the pad and nearby Air Force facilities.

The Air Force's Titan 4 rockets are the most powerful boosters in the American inventory after NASA's manned space shuttle. They are capable of placing 10,000-pound payloads into the high orbits favored by strategic reconnaissance satellites. The debut of the 1.9-million-pound Titan 4 in 1989 marked the end of the Air Force's reliance on the shuttle for launching high-priority military satellites.

Even before the Jan. 28, 1986, Challenger disaster that grounded the shuttle program for 32 months, the Air Force ordered 10 Titan 4s from manufacturer Martin Marietta (now Lockheed Martin).