WASHINGTON — Managers of three key NASA exploration programs said May 10 that they are making good progress towards a first launch of the Space Launch System heavy-lift rocket as soon as September 2018.

Managers of the SLS, Orion, and Ground Systems Development and Operations (GSDO) programs said at a Space Transportation Association luncheon here that while the programs are working towards a first launch of SLS and Orion, called Exploration Mission 1 (EM-1), in November 2018, they believe that they could launch up to two months earlier.

“The agency’s baseline commitment is November of 2018,” said Mike Bolger, manager of the GSDP program. “The September date we’ve talked internally about, and pressed them to see if we can make it by September. It gives us a little margin at the end.”

His comments came after an earlier presentation by Mark Kirasich, the Orion program manager, who discussed preparations for the EM-1 launch, including photos of the pressure vessel of the spacecraft being assembled at the Kennedy Space Center.

“This is the pressure vessel that, about 28 months from now, will be on its way towards the moon and into a distant retrograde orbit around the moon,” he said, a timeframe that corresponds to a September 2018 launch.

NASA has not provided a firm launch date for the EM-1 mission, which will be the first flight of the SLS and the second for Orion, after a brief December 2014 test flight in Earth orbit. The November 2018 date is tied to a review of the SLS program completed in August 2014, which concluded there was a 70 percent chance SLS would be ready for its first flight by November 2018.

John Honeycutt, NASA SLS program manager, said work on various components of the first SLS is proceeding as planned. “We’re moving rapidly towards the launch pad,” he said, calling development of the SLS a “good news” story.

OWork on SLS has not been entirely good news: he acknowledged earlier problems with the Vertical Assembly Center, a giant tool at the Michoud Assembly Facility used to weld elements of the core of the vehicle. “We did have some issues with the startup of that Vertical Assembly Center,” he said. “But, I can tell you today that we’ve overcome those issues and we’re making good progress.”

Honeycutt said the major structural pieces of the core stage for the first SLS should be completed by the end of July. That will be about a month after a second and final qualification test of the five-segment solid rocket boosters in Utah. The former space shuttle main engines that will be used on the first SLS flight have already completed acceptance testing, he said.

Kirasich said work is going well on the crew module for the Orion spacecraft, where the pressure vessel is being outfitted with various subsystems. That component recently completed a series of pressure tests and engineers will soon add its propulsion and life support systems.

Work on ground systems, Bolger said, includes upgrades to the Vehicle Assembly Building at KSC, the mobile transporter for moving the rocket to the launch pad, and the pad itself, Launch Complex 39B, previously used by the shuttle program. That work, he said, is proceeding on schedule to support a fall 2018 launch.

Honeycutt said the SLS program is making progress on the Exploration Upper Stage (EUS), a more powerful upper stage planned for future SLS missions after EM-1. The EUS has also become a political issue, as Congress provided additional funding and direction for EUS work not requested by the agency in its recent budget requests.

Congress directed NASA to spend at least $85 million on EUS in the fiscal year 2016 omnibus spending bill, and have it ready in time for the second SLS mission, EM-2. NASA, however, did not request enough funding in its fiscal year 2017 budget request to support development of the EUS in time for EM-2, even as it directed agency engineers to stop work on human rating the interim upper stage that will be flown on EM-1.

A funding bill for 2017 approved by the Senate Appropriations Committee April 21 sets aside at least $300 million of the $2.15 billion provided for SLS to continue work on EUS. That bill has not been taken up by the full Senate, and the House has yet to introduce a companion spending bill.

Honeycutt suggested he assumed the higher spending levels would continue to be available for EUS, which will complete a preliminary design review by the end of this year. Citing “favorable appropriations” for the program this year, he said, “our plan now is to fly EM-2 with the Exploration Upper Stage.”

NASA’s message overall to the audience at the event, which included Rep. Bill Posey (R-Fla.), a member of the House Science Committee whose district includes KSC, is that the main elements of NASA’s exploration program remain on track. “Congressman Posey,” Kirasich said, “I wanted to tell you that the Orion team is focused, funded, and we are on schedule.”