Congress recently sent a message to NASA: Go build a bigger and better rocket to replace the old current shuttles.

Although NASA would like to, they believe they just can’t with the current budget set by Congress.

"We have done calculations with current models and approaches to doing this type of development and it doesn’t work with funding constraints combined with schedules that were laid out in the Authorization Act," Doug Cooke, NASA’s associate administrator for exploration systems, told CNN.

Even with all the facts lain out, Congress is still sticking to the point that until NASA can undoubtebly prove that they can’t build the rocket with current budgets, then by law the rocket must be built, by the 2016 deadline.

Although the scientists at NASA all believe that they won’t have the capabilities or money to build a bigger and better rocket, which will need to have a longer maximum distance (for Mars), Senator Bill Nelson, D-Florida believes it’s within reach.

"NASA must stop making excuses and follow this law. I believe the best and brightest at the space agency can build upon the $9 billion we’ve already invested in advanced technology to design a new heavy-lift rocket, while taking a stepping-stone, pay-as-you-go approach."

NASA, now being tossed out of the "space taxi" business, is allowing them to save for their rocket project.

They no longer need to be burdened with costly delivery trips to the space station, and also expect for commercial companies to begin the ferrying of astronauts to and from the International Space Station.

Cooke told CNN that the vehicle will have solid rocket boosters like the current shuttles, just larger. Also, that they would use shuttle main engines, which like the current shuttles, have a liquid fuel stage. They plan on using a lot of existing hardware for the early test flights.

"We have engines that will be freed up when shuttle retires. We do have solid rocket casings that are from the shuttle program that we can use," he said.

Although every effort is being done to provide NASA with the maximum amount of money to complete this project, all-the-while trying to avoid making taxpayers pay, some people say it’s not enough.

Citizens Against Government Waste President Tom Schatz is not happy.

"NASA is unfortunately becoming a black hole for the taxpayers and something needs to be done to turn things around," Schatz said. "The Constellation program has taught us the things that work, the things that we could have done better."

No matter the outcome, NASA is to announce to Congress by spring or early summer whether it will need more money to be finished for the 2016 deadline.