Thirty years after the space shuttle Challenger exploded during liftoff, a new generation of spaceships continues to build on changes made after NASA's fatal accident.

Challenger blasted off from the Kennedy Space Center in Florida on the frigid morning of Jan. 28, 1986. The flight lasted just 73 seconds after a rubber seal in one of the shuttle's twin booster rockets failed, triggering an explosion and killing all seven people on board.

Families of the Challenger astronauts who died 30 years ago gathered with NASA today to mark the space shuttle accident's 30th anniversary.

The disaster exposed shuttle design shortcomings and operational problems in the U.S. space program. But it also 
helped seed a commercial space transportation industry that is now developing passenger spaceships.


The Challenger crew takes a break during countdown training at NASA's Kennedy Space Center in this January 9, 1986 NASA file photograph. L-R: Teacher-in-Space payload specialist Sharon Christa McAuliffe, payload specialist Gregory Jarvis, and astronauts Judith A. Resnik, mission specialist; Francis R. (Dick) Scobee, mission commander; Ronald E. McNair, mission specialist; Mike J. Smith, pilot; and Ellison S. Onizuka, mission specialist. The NASA lost seven of its own on the morning of January 28, 1986, when a booster engine failed, causing the Shuttle Challenger to break apart just 73 seconds after launch. (NASA/Reuters)

Accident investigators also found that pressure to maintain a busy flight schedule contributed to Challenger's demise. At the time, NASA's four-ship shuttle fleet, flying several times a month, was the nation's sole space transportation system.

After the accident, then-president Ronald Reagan banned commercial satellites from the shuttles and bolstered military 
efforts to develop alternative launchers.

The policy shift laid the groundwork for today's commercial space transportation industry, which generated global revenues of $5.9 billion US in 2014, according to a report last year by the Satellite Industry Association.
Accidents remain inevitable as the field matures, said Mike Leinbach, a former NASA shuttle launch director.
"Spaceflight is like any other big engineering system," he said, noting that cruise ships and aircraft became safer after 
accidents. "You get smart by successes. You get smart by failures. ... It's an evolution."
Six astronauts and a high school teacher flying aboard Challenger had no chance of escaping due to a spacecraft design decision, which is not being repeated on the passenger spaceships now under development.
These will launch on top of rockets, not alongside them, and have separate systems to fly crews to safety if a booster 

The Challenger accident also exposed NASA management problems. For example, the night before launch, engineers warned that freezing temperatures might be a problem for the shuttle booster rockets, but their concerns were quashed.
"I just hope that the new entrants into the market learn from the mistakes of the past," Leinbach said. "I see that 

So far, the only fatality in the emerging industry occurred in October 2014 when a pilot died testing an experimental 
passenger spaceship for Virgin Galactic, founded by British billionaire Richard Branson.
Investigators cited safety shortfalls and pilot inadequate training as key factors behind the accident. 

Families of the Challenger astronauts established the Challenger Center for Space Science Education just three months after the shuttle disintegrated in the Florida sky. 

Today, there are more than 40 Challenger Learning Centers focusing on science, technology, engineering and math, mostly in the U.S., but including one in Canada. More are being built.
"They're not just a field trip for kids. They're actually lessons learned," said June Scobee Rodgers, the widow of Challenger commander Dick Scobee Rodgers, an educator who lives in Chattanooga, Tennessee. "That's why they've lasted."

With files from the Associated Press