In 2020, the non-profit research firm Draper announced it was partnering with Stratolaunch. Under a new contract, it would develop guidance, navigation, and control (GNC) software for the company’s Talon-A hypersonic test vehicle.

Draper’s history dates back to the early space age. Now, it’s leveraging its expertise to help a key player in the US hypersonic industry. 

In March this year, Stratolaunch flew Talon-A for the first time. The company has revealed little about the specifications of that test mission. However, Draper’s GNC helped it complete the test flight.

In an interview with IE, Draper program manager Brandon Jalbert explained that the company leveraged its software expertise from the NASA Apollo, Space Shuttle, and Artemis programs to guide the autonomous hypersonic vehicle.

Draper’s space age heritage

Draper played a key role in helping Neil Armstrong and Buzz Aldrin reach the Moon in 1969. The engineering firm was awarded the first contract for the Apollo 11 mission. Under that contract, it was tasked with developing the Apollo Guidance Computer and training astronauts to use it.

Since then, Draper has also worked on the Space Shuttle program and the International Space Station (ISS). Most recently, it has lent its software expertise to the Artemis program. 

The knowledge from these missions is leveraged across Draper’s different programs. One of these, the Stratorlaunch Talon-A GNC project, doesn’t go to space. However, Jalbert told IE that much of the work Talon-A does is comparable to spacecraft reentries.

“Draper is a matrix organization, so we have all these different functions of electrical software, and all the different subcategories of each of those,” Jalbert said. “So we have certain core capabilities we have developed over the years, and then we’re able to use those across our portfolio programs, whether it’s in space systems or electronic systems.”

“Draper also has a very long history with the Navy, the US Navy, and strategic deterrence,” he continued. “So there are a lot of different areas where we’re able to apply the same sort of core capabilities across different applications.”

Stratolaunch’s Talon-A is a fully reusable, autonomous hypersonic test vehicle. It measures 28 feet (8.5 meters) in length and has an 11.3-ft.-span delta wing. The vehicle uses a liquid-propellant rocket engine that enables it to fly at speeds of up to Mach 6, or 4,600 mph (7,400 km/h). This allows it to perform as a testbed for hypersonic payloads. After hypersonic tests, it flies back down to the ground for an autonomous horizontal landing.

While the Space Shuttle didn’t fly quite as fast as Talon-A, the spacecraft could also perform horizontal landings. It did so using Draper GNC.

The work with Talon-A is “leveraging a lot of our heritage from Apollo, the Space Shuttle, and other programs,” Jalbert explained to IE, adding that Draper was able to “utilize that heritage for the GNC of several reentry bodies, and apply it to an application like Talon-A.”

Ready to Roc

Stratolaunch air-launches Talon-A from its Stratolaunch Carrier, also known as “Roc”. The aircraft—the largest in the world by wingspan—was originally designed and built by Scaled Composites. Arguably, this means Draper has less work to do compared with its space projects.

“Instead of dealing with a vehicle coming back through the atmosphere from outer space at very high speeds, we’re launching from an aircraft and going into a boost guidance phase, where we’re trying to control the vehicle as it’s going up in speed and altitude,” Jalbert explained.

“And then once it’s at altitude, [we use] a lot of those very similar algorithms for doing the glide phase and controlling the vehicle during those very fast periods,” he continued. “Then, coming back down for a splashdown or landing uses lot of similar algorithms to the ones we’ve used for previous applications that we’ve done.”

For the Stratolaunch Talon-A test flight (TA-1), Jalbert explained, “Draper was responsible for the GNC software from release all the way through to touchdown.” 

“So we supported the first two flights that they’ve had so far,” he said, referring to the fact that Stratolaunch’s TA-0 flight test ended in an abort with the vehicle gliding down to Earth. 

“As the aircraft is released, the GNC software takes over and stabilizes the vehicle,” Jalbert continued. Draper’s boost guidance algorithms control the vehicle for powered flight as it increases its speed and altitude. Once the engine is cut off, it uses the firm’s glide algorithms.

The TA-1 mission went supersonic

For TA-1, Stratolaunch announced that the Talon-A vehicle reached speeds close to Mach 5, though it didn’t quite go hypersonic. 

The company didn’t release exact speed stats. However, it announced in a press statement that it reached high supersonic speeds and successfully carried out “all primary and customer objectives of the flight.”

The stage is set for the TA-2 mission, which will aim to go hypersonic, showing that Stratolaunch can provide a new hypersonic test platform for US customers.

Jalbert told IE that Draper would only have to make a few algorithm changes. “There’s really not that much difference,” he said. The first flight was highly successful in getting close to [Mach 5]. And the algorithms and the vehicle itself were all designed for getting up to hypersonic speed. So it’s just a matter of taking the lessons learned from the previous flight and applying them to the next flight.”

Reaching hypersonic speeds

Stratolaunch was originally going to launch small satellites to low Earth orbit using the Roc. However, the company came close to bankruptcy in 2019. It then successfully repositioned itself as a hypersonic vehicle launcher for customers, including the Pentagon.

Draper came onboard in 2020, and Jalbert believes this era could be a turning point for hypersonic technologies.

“With worldwide conflicts today, there is a lot of focus on hypersonics,” Jalber said. “A number of different nations, including the US, are developing their own hypersonic capabilities.” 

So Talon-A provides an important test platform for validating simulated environments, getting out of wind tunnels, and getting real world data,” he continued. “Stratolaunch is doing an amazing job with what they’re trying to set up and offer in support of those missions and capabilities, using a low-cost mechanism for testing technologies related to hypersonics.”

Draper’s heritage could play a big role in moving the hypersonic industry forward.

Thanks to the company’s history, “we’re able to evolve and adapt our algorithms to the next challenge,” Jalbert explained. “A lot of our algorithms can be reused or tailored and tuned to a different mission set. That’s largely what we did here. We did provide some novel algorithms – boost is one of those. But a lot of our glide and landing algorithms have that heritage going back through the space programs.”

While Stratolaunch has yet to announce a date for the TA-2 mission, the company will likely go hypersonic on that next flight test. As its test vehicle flies at speeds of Mach 5 and upwards, it will be guided by steady hands—a large set of algorithms, some of which have helped spacecraft return from the Moon.