NASA's chief emphasized the importance of the Space Launch System megarocket if the United States plans to meet its space exploration goal.

During a U.S. Congress hearing on NASA's 2020 budget, agency administrator Jim Bridenstine highlighted the need to finish the SLS rocket soon to achieve the objective of sending people to the moon by 2024.

The budget request has reportedly delayed the installation of necessary upgrades to the rocket and forced some of its scheduled payloads to be transferred to other spacecraft.

Bridenstine had also discussed the potential of having the Orion crew capsule be launched into space using a private rocket at a recent Senate hearing. The congressmen's questions during the House hearing were focused more on clarifying Bridenstine's earlier statements.

NASA's SLS Megarocket

Bridenstine elaborated on some of the points mentioned by U.S. Vice President Mike Pence regarding the goal of sending American astronauts back to the moon over the next five years.

To be able to have boots on the moon by 2024, as Pence stated, the NASA chief said they would need to have the SLS rocket. They would need to speed up the production of the megarocket and have as many of those spacecraft as soon as possible.

Bridenstine added that the space agency would also need to have the Exploration Upper Stage [EUS] available too. The EUS will serve as the second stage for the SLS's Block 1B, and it will activate after the Block 1's Interim Cryogenic Propulsion Stage. It will allow the megarocket to deliver larger payloads during missions.

The current NASA budget does not provide for the development of the EUS.

While the space agency is committed to meeting the vice president's goal of an initial SLS rocket launch by June 2020, Bridenstine expressed his apprehension that the exact launch date would be feasible. However, he stressed that the megarocket is still key to getting the Orion capsule sent into space as possible.

Bridenstine mentioned his earlier statement to senators that NASA would review all available options, including commercial ones, in order to meet the deadline.

"We did look at those commercial options, as you identified," Bridenstine said.

"We came to a determination that while some of those options are feasible, none of those options ... are going to keep us within budget and on schedule."

Keeping NASA Builders On Schedule

The NASA chief explained that they are conducting a 45-day study to determine how they could speed up the SLS's production without having to increase costs. He said they will be able to wrap up the study within the next few weeks.

The space agency purchased hardware that would allow the SLS to be integrated horizontally and not vertically, according to Bridenstine. With this component, builders can now work on other parts of the rocket even when the engine section is not available yet. They have had a difficult time developing the engine, which is proving to be more challenging than initially thought.

Bridenstine also talked about how they could try to shorten the SLS's engine-testing stage. NASA is looking to test the megarocket's RS-25 engines individually since they have been used in space shuttle launches before. This would allow workers to review the rockets' performance without having to combine them in one big test launch, which would add to the SLS's preparation time.

When lawmakers asked Bridenstine about the cuts to NASA's budget this year, he was confident that the space agency will be able to achieve its goals without having to go over budget.

However, the House hearing did reveal that adjustments to the budget need to be considered in order for NASA to meet its objectives moving forward.