DARPA Testing Phantom Express Spaceplane Engine

The Boeing Phantom Express spaceplane will launch with a smalsat launcher strapped to its back.
The vertical launch configuration of the Phantom Express spaceplane. The smallsat-capable “upper stage” is strapped to its back | Image credit: Boeing

DARPA is currently putting the AR-22 engine that will power their supersonic Phantom Express spaceplane through its paces. Built by Aerojet Rocketdyne, the AR-22 is based on the RS-25, the engine that powered the space shuttles.

Over the course of 10 days, the AR-22 will be started for 10 100-second firings. The engine is currently well on its way to successfully completing the test firings having undergone 7 of the 10 as of July 3. It’s hoped that the rigorous testing will provide insight that will prove to be invaluable in refining flight and turnaround procedures for the Phantom Express

“Phantom Express builds on our legacy of reusable spaceflight experience to provide the ability to quickly augment and replace on-orbit capabilities, which face an increasing array of threats from potential adversaries,” said Aerojet Rocketdyne CEO, Eileen Drake. “Our immediate task is to demonstrate this rapid turnaround capability for this engine on the ground, paving the way for a demonstration program.”

AR-22 Phanton Express engine test fire on July 2.
An AR-22 engine test fire at Stennis Space Center on July 2 | Image credit: Aerojet Rocketdyne

Although more capable than any engine before it, the AR-22 is based on the decades-old RS-25 engine. In fact, very few, if any new parts have been manufactured for the engine with most of the components being taken from NASA and Aerojet Rocketdyne’s inventories. The one major update to the RS-25 design is the use of the flight controller being developed for NASA’s Space Launch System.

DARPA is not alone in attempting to launch and reuse a vehicle within 24 hours. SpaceX has stated that their Block 5 Falcon 9 rockets will attempt back to back launches over a 48-hour period towards the end of 2018. The Falcon 9 is also significantly more capable than the Phantom Express with the ability to launch 22,800 kilograms to low Earth orbit (LEO). In contrast, the Phantom Express is capable of launching just 1,361 kilograms into LEO.

Featured image credit: Boeing

Andrew Parsonson is a space enthusiast and the founder of Rocket Rundown. He has worked as a journalist and blogger for various industries for over 5 years and has a passion for both fictional and real-life space travel. Currently, Andrew is the primary writer for Rocket Rundown as we look to expand our reach and credibility.