SAN JOSE, Calif. — Vulcan Aerospace expects to make a decision this fall on the rocket, or rockets, it plans to use with its Stratolaunch air-launch system as it reorients itself toward a promising-looking launch market for small satellites.

Vulcan Aerospace President Chuck Beames, in a July 17 interview during the NewSpace 2015 conference here, said his company was looking at a wide range of potential vehicles that would be launched from a giant aircraft currently under construction.

“We are still doing a lot of engineering in house to lay out a revised way forward,” he said. “We’ll be making announcements in the fall.”

Beames said the company started its analysis by examining more than 70 different launch vehicle configurations. The company may end up selecting more than one vehicle option to serve different classes of payloads. “I’m anticipating, very likely, we’ll want to offer multiple launch vehicle variants, to try and be more responsive to the customer,” he said.

Stratolaunch of Huntsville, Alabama, has already gone through two earlier iterations of its launch vehicle. When Stratolaunch unveiled its plans in December 2011, it planned on using a variant of SpaceX’s Falcon 9 rocket. Less than a year later, though, Stratolaunch announced it was ending that agreement because SpaceX wanted to focus on the standard version of its Falcon 9.

Stratolaunch then teamed with Orbital Sciences Corp., now Orbital ATK, to develop a launch vehicle. That rocket, called Thunderbolt, featured two solid-fuel stages provided by ATK and an upper stage powered by RL-10 engines from Aerojet Rocketdyne. Like the earlier SpaceX design, Thunderbolt was designed to launch medium-class payloads.

Chuck Beames
Chuck Beames. Credit: Vulcan Aerospace

Stratolaunch, though, has set that design aside as it seeks to launch smaller satellites, where the company sees a burgeoning market. “There’s really a revolution going on in low Earth orbit,” Beames said, citing a number of efforts to develop constellations of small satellites, including cubesats, for remote sensing and communications applications. “A lot of these entrepreneurs are building 1U or 3U [cubesat] systems.”

Cubesat’s are cube-shaped satellites measuring about 10 centimeters on each side. Single-unit, or 1U versions are often bolted together in threes to form 3U cubesats.

Beames said Stratolaunch is still working with Dulles, Virginia-based Orbital ATK. “They are a part of our trade space. They are a part of the analysis that we’re looking at,” he said, adding that Stratolaunch would likely use a “variation” of the Thunderbolt design if it chooses to go with Orbital ATK.

He added that the company is looking at a range of options for the production of the selected launch vehicle or vehicles. “Vulcan itself won’t be tin-bending,” he said, but is open to joint ventures with other companies and other approaches. “We’re considering basically all options when it comes to business arrangements.”

Decisions on launch vehicles and business arrangements, he said, will ultimately be made by Paul Allen, the billionaire Microsoft co-founder who serves as chief executive of Seattle-based Vulcan Aerospace. “He’s very involved” in the company, but delegates work to the staff, Beames said of Allen. “He’s not a CEO who is everyday coming down and telling everyone on my team what their job is for the day.”

While Stratolaunch’s choice of launch vehicle has shifted, the company is making steady progress on the aircraft that will serve as the launch platform. That airplane, being built at the company’s hangar in Mojave, California, will have a wingspan of 117 meters, the longest ever for any airplane.

“Everything’s progressing on track,” Beames said. The company plans to roll out the aircraft for the first time in early 2016, with flight tests beginning in the middle of the year.

Beames said the company plans to take a slow, conservative approach for the aircraft’s test flights, gradually expanding its flight envelope and allowing time to make modifications. “I’m expecting probably a year and a half or maybe two years of envelope testing of the aircraft, because we only have one,” he said.

He dismissed concerns that, as the company shifts to launching smaller satellites, the Stratolaunch aircraft is now too big. “The nice thing about having an aircraft as the first stage is that it’s much cheaper than the first stage of a rocket that you throw away,” he said. “It’s kind of foolish to think that we’re overbuilt.”

By focusing on smaller satellites, though, Stratolaunch is entering a crowded market, with several other companies developing launch vehicles designed to serve small satellites. “I think it’s great that we have lots of people jumping into this market. Will all of them succeed? Probably not,” he said. “But it’s a really exciting time.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...