CAPE CANAVERAL, Fla. -- Space shuttle Columbia's pure science mission initially was seen as a vehicle for an all-female crew, but that idea was abandoned.
Then it was proposed as a carrier for GoreSat, the Earth-observing spacecraft dreamed up by Vice President Al Gore, but that was put on ice by a Republican Congress.
Now an Israeli astronaut is at center stage.
After years of delays and numerous incarnations, Columbia's 16-day research flight -- a rarity in that it has nothing to do with the international space station -- is nearing liftoff under extraordinarily tight security.
On board for Thursday's launch will be Israel's first astronaut, Ilan Ramon, a colonel in his country's air force and the son of a Holocaust survivor.
Ramon does not consider himself a terrorist target and does not feel his presence endangers his six U.S. crewmates or the shuttle.
Indeed, NASA's top security man, David Saleeba, a former Secret Service agent, said last week there had been no direct threats against Ramon or the flight.
Nonetheless, NASA has been in close touch with the Air Force, the Homeland Security Department and the Justice Department and is considering expanding the no-fly zone around the launch pad. Three security command posts will be in operation, and Saleeba will have a hot line straight into launch control.
Secret launch time
And under security procedures put in place after the Sept. 11 terrorist attacks, NASA will keep Columbia's launch time secret until 24 hours in advance.
"NASA security is doing everything needed ... and I feel great, safe. I think everybody feels safe," Ramon said during a countdown rehearsal late last month.
Astronaut Laurel Clark, a Navy physician who, like Ramon, will be making her first spaceflight, said she and her family take "a fairly practical and pragmatic view of this whole thing."
"And that's that the actual launching into space is much more dangerous than any of the other security concerns," she said.
Ramon, 48, is a former fighter pilot and weapons specialist who fought in the Yom Kippur War in 1973 and the Lebanon War in 1982. His distinguished military career led to his selection in 1997 as his country's first astronaut.
Ramon began training at NASA in 1998 and was promised a launch as early as 1999. However, for a variety of reasons, his flight -- and the flight of an atmospheric dust-measuring experiment sponsored by Israel -- kept getting delayed.
In the meantime, female astronauts, Sally Ride included, had scorned the idea of a crew of all women as a publicity stunt, even though NASA officials insisted it would provide an opportunity to learn more about how women adapt to weightlessness.
An independent panel of medical experts concluded in 1999 that while more research was needed on women, it did not require an exclusively female crew.
After that plan fizzled, the Israel Space Agency shared the mission with a NASA spacecraft conceived by Gore.
The $100 million-plus spacecraft was set to rocket into orbit aboard Columbia and then fly to a point 1 million miles from Earth to send back continuous TV images of the home planet. But GoreSat, officially called Triana after Christopher Columbus' lookout, was pulled off the mission in 2001 and ended up in NASA storage at Congress' behest. It's now being considered for a 2004 shuttle launch.
Ramon was just one month away from finally launching last summer when NASA grounded the shuttle fleet because of cracked fuel lines. Then space station construction took priority, and Columbia's mission fell behind two others.
Saleeba took advantage of the six-month delay to improve security.
Ramon hopes his flight will provide a welcome diversion for Israelis, who have faced a series of suicide bombings.
"I think people are very happy to be distracted by my flight and NASA flights, maybe to forget a little bit of their problems and get out there with us."