The announced plans by the National Aeronautics and Space Administration (NASA) to build a massive rocket are being greeted with both enthusiasm and criticism in the United States.

The new rocket, known as the Space Launch System, or SLS, is expected to have its first unmanned test flight in 2017. A SLS rocket with cargo will be 400 feet (121.92 meters) tall, 50 feet (15.24 meters) taller than the Saturn V rockets which took astronauts, on the Apollo series, into space and to the moon in the 1960's and 1970's.

When the SLS rocket is propelled upwards in 2017, it will be 20 percent more powerful than the Saturn V rockets. Each of the boosters on the SLS rocket will provide 4 to 5 million pounds (1,814 to 2,268 tons) of thrust. NASA has yet to award a contract to any aeronautical company, however, to build the boosters.

"The SLS will give the nation the capability needed to lead technologically. It will take astronauts further into space than ever before, create high-quality jobs across the U.S., and provide the cornerstone for America's future human exploration efforts," proclaimed NASA spokesman J.D. Harrington, who insisted that the plan is "realistic within the current budget environment."

U.S. Representative Dana Rohrabacher, a Republican from southern California and senior member of the U.S. House Committee on Science, Space, and Technology, strongly disagrees.

When NASA announced the SLS rocket plan in mid-September, Rohrabacher issued a statement to voice his doubt about the need to develop such rockets when the economy is facing major problems.

"There's nothing new or innovative in this approach, especially its astronomical price tag, and that's the real tragedy. Unfortunately, after a number of years, perhaps during development or just after a few flights like Saturn, budget pressures will bring this program to an end," he said.

The SLS plan, which has become NASA's successor to the recently retired space shuttle program, is also unusual in the fact that - despite SLS's price tag of 3 to 3.5 billion U.S. dollars annually - it has no prearranged destination.

"It's too early. Once the agency (NASA) has finished design development, and testing of the SLS and Orion MPCV (Multi-Purpose Crew Vehicle), we will make decisions regarding scientific missions and their objectives," Harrington told Xinhua.

NASA may use the SLS missions to investigate asteroids or possibly a manned mission to the red planet of Mars.

Republican Representative Tom McClintock, who represents 4th Congressional District in California, sent a letter on Sept. 22 to Gene Dodaro, Comptroller General for the U.S. Government Accountability Office (GAO), which voiced "serious concerns with NASA's attempts to avoid holding a full and open competition to acquire the SLS."

In the letter, McClintock, one of the favorite politicians of the political action group known as Tea Party in Space, also asserted that "NASA is considering modifying and/or extending existing contracts for retired or cancelled programs resulting in one or more de facto sole source awards."

McClintock is referring to the fact that the aeronautical companies ATK, Boeing, and Pratt and Whitney Rocketdyne all previously had contract with NASA to build various stages of the now cancelled NASA program of rockets known as Constellation. Since the SLS blueprints are based on aspects of the Constellation program, that the three companies appear to be approved soon by NASA to build the SLS rockets.

Neither Dodaro, nor any other GAO official has publicly responded to McClintock's letter.

For every national politician who disagrees with one or more aspects of SLS program, there is another to praise SLS's usefulness. One of the leading supporters of the SLS program is U.S. Senator Bill Nelson, a Democrat who lives in Orlando, Florida. He spoke and discussed the SLS program for five minutes during the Sept. 14 NASA announcement of the program.

Nelson said "This is perhaps the biggest thing for space exploration in decades. The goal is to fly humans safely beyond low-Earth orbit and deep into outer space where we can not only survive, but one day also live."

Another Senator Kay Bailey Hutchison, of Texas, also strongly supports the program as his homeland has strong ties to NASA. The Lyndon B. Johnson Space Center near Houston is an area whose local economy is heavily dependent on NASA-affiliated contract work for engineers and other scientific specialists.

She shared Nelson's enthusiasm for space exploration. "We are pushing the envelope. We are going to the next iteration of space exploration (with SLS)," she stated. Like Nelson, Hutchison is also on the U.S. Senate Committee on Commerce, Science, and Transportation.

However, no politician or political analyst knows if NASA is going to be able to get all of the funding that it wants for the SLS program. With an unstable U.S. economy, as well as Congressional elections and a Presidential election due to be held in 2012, members of the U.S. Congress may be hesitant about voting to give NASA the 3 to 3.5 billion dollars of annual funding needed to complete the SLS program.

NASA Administrator Charles Bolden, a former astronaut appointed to his post in July 2009 by President Barack Obama, may have to testify before many Congressional committees investigating the SLS program.

Bolden has said, on numerous occasions, that one of his goals as the NASA administrator was to begin the long process of creating programs which would allow for a rocket to launch astronauts to the red planet of Mars. "President Obama challenged us to be bold and dream big, and that's exactly what we are doing at NASA. While I was proud to fly on the space shuttle tomorrow's explorers will now dream of one day walking on Mars," he said.

Before that happens, NASA will have to master the many complexities of building the SLS rocket. If the SLS rocket is built to the specifications of previous studies by NASA personnel, it will have a payload of 70 to 130 metric tons, compared to the 27 tons of the retired space shuttles.

"This permits the deployment of more complex systems to allow human exploration of the solar system, such as an asteroid by the middle of next decade, and then to Mars," explained Harrington.