John Pike, a national security analyst and space specialist, said NASA still has not recovered from the Challenger disaster.
"I think it's clear that NASA today is a consequence of the Challenger accident, because prior to the accident NASA had a confidence about where it was going and its ability to get there that it simply doesn't have today.
"NASA has no idea where it's going and is tremendously confused about how to get there."
In 2004, after America lost a second shuttle, Columbia, President George W. Bush announced the retirement of the aging shuttle fleet by the end of the decade -- after nearly 30 years and more than 100 missions -- and the development of a new, more modern space exploration vehicle.
"Our current programs and vehicles for exploring space have brought us far, and they have served us well," Bush said. "It has been used to conduct important research and to increase the sum of human knowledge."
Last year, President Obama announced a new direction for the nation's space program, scrapping plans to send another astronaut back to the moon and instead focusing efforts on reaching Mars.
Obama came under considerable fire in recent weeks for his decision to cancel the Bush administration's plan to send an American manned mission to the moon for a seventh time.
Obama insisted he was 100 percent committed to NASA's mission and future.
"For me, the space program has always captured an essential part of what it means to be an American -- reaching for new heights, stretching beyond what previously did not seem possible," Obama said last April to an audience of several hundred astronauts, engineers and members of the NASA community at the Kennedy Space Center near Cape Canaveral, Fla. "And so, as president, I believe that space exploration is not a luxury, it's not an afterthought in America's quest for a brighter future -- it is an essential part of that quest."
Just two or three more space shuttle launches remain -- Discovery, which is scheduled to launch on Feb 24; and Endeavour, which is scheduled for April 19. A launch of Atlantis is timelined for June but is not yet funded.
Astronaut Mark Kelly, the husband of Rep. Gabrielle Giffords, is scheduled to command the Endeavour mission.
Just as President Reagan promised in the hours after the tragedy, Americans still remember the Challenger and its crew. This week, the seven astronauts were honored at memorial services at Johnson Space Center in Houston and at Arlington National Cemetery in Virginia.
Today, there are nearly 50 Challenger Learning Centers worldwide, where hundreds of thousands of school children are encouraged to reach for the stars.