WASHINGTON — NASA hopes to lay the groundwork over the next six months for developing an affordable heavy-lift launch vehicle with $7.5 million in study contracts it plans to spread across 13 U.S. companies.

The study contracts, announced Nov. 8, are NASA’s initial response to the 2010 NASA Authorization Act, which requires the agency to begin work this year on a vehicle capable of lifting at least 70 metric tons to low Earth orbit by 2016.

The bill, which U.S. President Barack Obama signed into law Oct. 11, gives NASA just 90 days to settle on a heavy-lift architecture and report back to Congress. However, Cris Guidi, deputy director of NASA’s Constellation Systems Division here, said the agency is asking lawmakers for more time.

“NASA is currently negotiating some relief on reporting requirements contained within the Authorization Act,” Guidi said in a Nov. 9 e-mail, adding that NASA hopes to give each of the 13 companies six months to complete work under the terms of the fixed-price study contracts.

The studies are expected to cover options including systems derived from NASA’s space shuttle and from the Ares family of rockets that were being developed under the Moon-bound Constellation program, which Obama canceled in the 2011 budget blueprint he sent lawmakers in February. Obama instead proposed spending up to five years and some $3 billion researching propulsion technologies before choosing a design for the United States’ first exploration-class rocket since the Saturn 5. But the authorization bill has put the heavy-lift rocket back on NASA’s near-term agenda.

The studies are also expected to include alternative architectures that rely on different propulsion combinations and mission scenarios for delivering astronauts to deep space destinations such as asteroids and Lagrange points.

NASA spokesman Michael Braukus said the agency’s Marshall Space Flight Center in Huntsville, Ala., would manage the study contracts and that the $7.5 million would come from a funding line appropriated in 2010 for the Ares 5 rocket, the shuttle-derived heavy lifter designed under the Constellation program.

Guidi said the 13 studies were chosen from responses to a NASA Broad Agency Announcement, or BAA, issued in July.

The specific capabilities of the heavy lifter called for in the 2010 NASA Authorization Act appear to dictate a solution based at least in part on the giant solid-rocket boosters that help lift the space shuttle into orbit. These motors, built by Alliant Techsystems (ATK) of Minneapolis, also were integral to the Ares 1 and Ares 5 vehicles targeted for cancellation by the White House.

ATK is among the companies selected for the latest heavy-lift vehicle studies. The others are: Aerojet General Corp., Rancho Cordova, Calif.; Analytical Mechanics Associates, Huntsville, Ala.; Andrews Space, Tukwila, Wash.; Boeing Co., Huntsville; Lockheed Martin Corp., Huntsville; Northrop Grumman Systems Corp., Huntsville; Orbital Sciences Corp., Chandler, Ariz.; Pratt & Whitney Rocketdyne, Canoga Park, Calif.; Science Applications International Corp., Huntsville.; Space Exploration Technologies Corp., Hawthorne, Calif.; United Launch Alliance, Centennial, Colo.; and United Space Alliance, Huntsville.

Guidi said the studies are expected to meet performance requirements issued by an internal team of NASA experts tasked with fleshing out Obama’s overhaul of the nation’s manned spaceflight program. Formally known as the Human Exploration Framework Team, or HEFT, the group was chartered in the spring to determine requirements for sending humans to visit an asteroid by 2025.

In September the HEFT briefed NASA Administrator Charles Bolden and his deputy on a deep space exploration plan that rejected some key assumptions of the president’s strategy but which aligned technically with a the NASA Authorization Act.

“The goal is to transition HEFT’s strategies and concepts into systems that will actually be built,” Guidi said. “Determining what can realistically be developed is best done by talking to the people who will do the work.”