U.S . astronaut Sandy Magnus wiped away tears as she and the Atlantis crew prepared to depart the International Space Station for the last time.

“What a generation can accomplish is a great thing,” shuttle commander Chris Ferguson said Tuesday after undocking from the space station. “It’s got a right to stand back and for just a moment admire and take pride in its work.”

It can’t stand still long, however, because with the shuttle hopefully landing safely at Kennedy Space Center around 6 a.m . Thursday, NASA and its N.C . State partners in space exploration are turning their focus to going further than ever.

According to NASA spokesperson Kelly Humphries , Congress and the Bush administration in 2004 decided that once the ISS was completed, it was time for a change.

“We had done a lot of things with the space shuttle, but it was a dangerous vehicle to fly in some ways because of the way it was designed and it was ready to be retired,” Humphries said.

The decision wasn’t popular with some, with former Johnson Space Center Director George Abbey pointing out the shuttle’s vastly superior cargo capacity and its sole ability to carry large pieces of the ISS in the event of large-scale repairs.

“If you stop the shuttle you are really severely impacting not only our ability to take Americans and people into orbit, but also you are making it difficult to support logistically the space station,” Abbey said.

 ”We certainly will miss the capabilities of the space shuttle to bring large pieces of cargo to the International Space Station,” Humphries responded, “but we believe we have a plan in place that will allow us to sustain the station for the remainder of its life.”

That plan includes, according to N.C . Space Grant director Chris Brown, buying seats on the smaller Russian Soyuz and back in the U.S ., using competing private companies to develop a replacement shuttle system that reduces cost as well as sending cargo-only flights in the meantime.

Fred DeJarnette , mechanical and aerospace engineering professor, said the new lower earth orbit system will be two vehicles.

“They would have a separate launch with the materials and supplies and that vehicle doesn’t have to be built from a safety point of view as much as the second that would be carrying astronauts,” DeJarnette said.

Kirsten Grantham, spokesman for SpaceX , the farthest along in the competition, said NASA made the right decision to encourage competition.

“With many companies competing for these contracts, the companies will have to compete on capability, reliability, and on affordability,” Grantham said. “And that means a better deal for the U.S . tax payers.”

SpaceX claims its Dragon crew vehicle will be well under a third of the cost of the shuttle and has created a rocket it claims can carry twice the payload at 1/3 the cost of the closest counterpart. Blue Origin, another competitor, hopes to create a spacecraft that can reuse boosters to further reduce cost.

Abbey said he remained skeptical.

“Design and development always ends up taking more money and takes more time than you predicted that it would take,” Abbey said.

If commercial plans live up to the hype, it will come in handy since the struggling Federal government cut NASA’s budget recently by more than $1.6 billion, according to Brown.

While companies compete for interests in NASA’s lower earth orbit endeavors, NASA and its N.C . State partners are looking to create a new vehicle and rocket that can go well beyond Earth’s orbit.

According to Humphries , President Barack Obama’s efforts are focused on sending humans to a near earth asteroid and eventually Mars in the next 30 years. NASA and its partners are hard at work building the Multi-Purpose Crew Vehicle ( MPCV ) and Space Launch System ( SLS ), a vehicle and rocket system that can be used not only with the ISS , but for taking humans to deep space.

Abbey criticized the Apollo-like capsule as backtracking.

“It can’t do extravehicular activities like a shuttle,” Abbey said. “So it really has a lot of limitations, and it doesn’t give you any real capability that would even compare to a space shuttle.”

NASA, however, along with many at N.C . State, hopes the MPCV will be 10 times safer than the shuttle and University researchers are working to develop technology necessary to sustain life on long missions.

DeJarnette is working on new thermal technology to protect the MPCV when it reenters from deep space at more than 25,000 mph.

“The new technology would provide for greater thermal protection and higher structural loads as well as lighter material,” DeJarnette said.

Another problem facing astronauts is their loss of three percent of their bone mass each month in microgravity —something they will never fully recover, according to the N.C . State news release. A team with the Joint Department of Biomedical Engineering with UNC Chapel Hill just sent 30 mice to ISS to look at the affect of microgravity on bone mass at the molecular level.

“The gravity on mars is 0.36 g (36% that of Earth’s),” said Dr. Ted Bateman, the team’s leader. “Astronauts on a mission to Mars will have around 10 months of microgravity exposure in transit each way,”

Humans will also need life-support systems to sustain life on long-term missions. Imara Perera and her team of researchers, including undergraduates, have an experiment on the ISS researching affects of microgravity on plant growth at the molecular level—essential to being able to grow plants in space in the future.

“Mars has an atmosphere but it is carbon dioxide but at a much lower pressure than what we experience here on earth,” DeJarnette said, “so it would take some adjustments for humans in various cases and would need to have a significant amount of life support system that they take with them.”

Astronauts on Mars will also need water. As part of an aerospace and textile engineering senior capstone research project headed by Warren Jasper that took on the challenges of living on Mars with radiation and meteorites, the existing Sabatier reactor—which uses carbon dioxide and hydrogen to make water and methane— was redesigned to allow the reactor to be smaller and more portable for a long mission.

While the team did not win the contest they entered, Jasper said it was profitable.

“We made some contacts with NASA which was more important for me,” Jasper said. “They were kind of intrigued with the idea.”