WASHINGTON — The giant aircraft built by Stratolaunch to serve as an air-launch platform made its first flight April 13 amid questions about the future of the venture.

The aircraft, the largest in the world by wingspan, took off from Mojave Air and Space Port in California at 9:58 a.m. Eastern. The plane flew for two and a half hours before landing back in Mojave, reaching a top speed of 278 kilometers per hour and altitude of 4,570 meters.

Evan Thomas, the Scaled Composites test pilot who flew the plane, said the flight went very well. “I honestly could not have hoped for more on a first flight, especially of an airplane of this complexity and this uniqueness,” he said in a brief media call after the flight.

The test flight came after a series of taxi tests of the plane at increasing speeds, culminating with one Jan. 10 where the plane’s nose gear briefly left the ground. Thomas said this flight started out like those previous tests until they throttled up and did a rotation maneuver to take off. “It definitely was ready to fly and wanted to fly,” he said.

Other than what Thomas described as “a few little things that were off-nominal,” the plane handled well during the flight, closely matching its simulator. “Really, for a first flight, it was spot on.”

“Overall, we’re very pleased with how the Stratolaunch aircraft performed,” said Zachary Krevor, vice president of engineering at Stratolaunch. “The aircraft flew as predicted, which is exactly what we wanted.”

However, neither Krevor nor Jean Floyd, the chief executive of Stratolaunch, said anything about the test flight program, including when the plane will fly again and how long the overall test program will last. The company took no questions from reporters during the call, which lasted 10 minutes.

The flight comes after a turbulent six months for the company. Its founder and principal funder, billionaire Paul Allen, passed away last October. In January, Stratolaunch announced it was abandoning development of its own launch vehicles that would have been air-launched from the plane. A company spokesman said at the time that Stratolaunch was “streamlining operations” to focus on aircraft development.

The only vehicle Stratolaunch currently plans to launch from the aircraft is Northrop Grumman’s Pegasus XL, a small launch vehicle that has struggled in the commercial marketplace in recent years despite the surge in interest in small satellites. The only recent customer for the Pegasus is NASA, and problems with the rocket have delayed for months its latest mission for the agency, the ICON space science satellite.

Stratolaunch has argued in the past that the ability to carry as many as three Pegasus rockets on a single flight would make the system appealing to national security customers, offering the ability to deploy an entire constellation on a single aircraft flight. Military agencies, though, have been supporting other small launch vehicles, including another air-launch system, Virgin Orbit’s LauncherOne, named as a qualifier in the DARPA Launch Challenge April 10 alongside Vector and a stealth-mode launch developer.

Stratolaunch dedicated this test flight to Allen. “I had imagined this moment for years, but I never imagined the experience without Paul standing next to me,” Floyd said. “Even though he wasn’t there today, as the plane lifted gracefully from the runway, I did whisper a thank-you to Paul for allowing me to be a part of this remarkable achievement.”