TAMPA,  United States - There is a sense of sadness among some personnel at the John F. Kennedy Space Center in Florida due to the termination of the space shuttle program.

But at the Jet Propulsion Laboratory, there's exhilaration as the Mars Science Laboratory rover enters its final testing stages.

The space shuttle Atlantis' landing, due Thursday, brings to a close the NASA program. Operational flights for the space shuttle program began in November 1982.

Despite two flight accidents, in 1986 and 2003, that killed 14 astronauts, the vast majority of the 135 missions were accomplished without serious problems.

During Atlantis' final mission, which lasted 12 days, the spacecraft docked at the International Space Station and delivered the Raffaello multi-purpose logistics module.

According to NASA estimates, anywhere from 3,400 to 3,600 engineers and other personnel will no longer work on the space shuttle program when it closes at the end of 2011.

"NASA has been phasing out workers for years," said Mark Ryan, city manager of Titusville, Fla.,one of many towns that collectively are known as eastern Florida's Space Coast.

"A lot of what we (city government officials) are seeing is that a lot of people who are scheduled to be laid off at NASA are instead opting to retire and live in the Titusville area," Ryan said.

The mothballed space shuttles will be sent to various US museums.

Atlantis will remain at the Kennedy Space Center, which was named after the late US President John F. Kennedy. It was Kennedy, in a 1961 address to Congress, said that "this nation should commit itself to achieving the goal, before the decade is out, of landing a man on the moon and returning him safely to the earth."

That was accomplished on July 20, 1969, when astronaut Neil Armstrong became the first man to walk on the moon. "That's one small step for man, one giant leap for mankind," Armstrong said as he gingerly took his first steps on the gray powdery surface of the moon.

Afterwards, NASA's space program provided many "leaps for mankind," from the hand-held calculator to the Atlantis space shuttle's mouse stem cell experiments that have benefited mankind.

"There are still lots of work to be done. We have the Orion Project, which will employ many people. We have affirmed our commitment to the ISS until 2020, so there are still manned flights which will occur in the future," said NASA spokesman Joshua Beck.

To benefit the thousands of NASA engineers and others who may soon be unemployed, Space Florida - a business development organization of Florida - is actively trying to attract as many space industry-related companies as possible to the area.

"One of the misconceptions is that NASA is the only space industry business in Florida. There's much more here than the space shuttle program. There is, for example, the Atlas and Delta rocket programs, which have been launched, and are scheduled to be launched," said Tine Lange, spokeswoman for Space Florida.

One of the leading space transport companies in the US is Space Exploration Technologies Corp., better known as SpaceX. NASA recently awarded SpaceX 12 launches to deliver cargo to the ISS.

SpaceX has conducted successful demonstrations showing that it can launch both crew and cargo into space. The first of the 12 launches is likely to occur in 2012.

As for Space Florida, "our job is to make sure that these (aerospace) companies come here to Florida," Lange said.

"We have the ability to offer tax breaks and other incentives," Lange said. "We are as competitive as possible to try to attract these companies away from other states."

Compared to the many workers at the Kennedy Space Center who are sad to see the end of the space shuttle program, "here at JPL, we are upbeat, because the unmanned missions will continue," said Joy Crisp, a scientist who works at the Pasadena, Calif., NASA affiliate.

Crisp is one of two deputy project managers for what will be NASA's next notable adventure: the Mars Science Laboratory Rover mission.

"The (Mars) rover will be launched on an Atlas rocket from Cape Canaveral. It's already there," Crisp said. "The launch window is from November 25 to December 18 of this year. The rover is being tested now, through it's normal set of functions that it will be doing and working on Mars. The testing will end this month."

Crisp and her colleagues will be trying to assess an area of Mars, in regards to life habitation.

"The actual length of the mission depends on what we find and how long many of the instruments last," Crisp said.

Rather than having the rover touch down on Mars using inflated air bags as protection,the new rover will employ a different type of landing mechanism, Crisp said.

"We have six minutes to have the rover go from 12,000 miles an hour to zero miles an hour," Crisp said.

The scientist said that a 70-foot parachute attached to the rover will deploy at Mach II (a speed of over 1,000 mph) and then a 15-foot heat shield will be deployed. By the time the rover touches down, it will be going at a speed of less than two mph.

A drill attached to the Rover will penetrate rocks on the Mars' surface, which will help to tell Crisp and the other scientists which minerals are abundant and how much is in the samples.

"The minerals are clues to what was going on when the rocks were being formed. We'll find out such things as if water was then on the planet, or if there was much acidity on Mars," Crisp said.