Virgin Orbit Earned Their Name

Yesterday, Virgin Orbit became one of the rare group of companies that privately developed a rocket and successfully launched it into orbit.  The special twist is that with its LauncherOne rocket dropped from a 747 aircraft, the California-based company has become the first to reach orbit with an air-launched, liquid-fueled rocket.  Just last June, seven months ago, their last attempt ended in the loss of vehicle moments into the flight.  The fact they recovered and made it on their second try is noteworthy.

"This magnificent flight is the culmination of many years of hard work and will also unleash a whole new generation of innovators on the path to orbit," said Sir Richard Branson, the founder of the company. "Virgin Orbit has achieved something many thought impossible."

Something that struck me as unusual is that this flight had paying customers for small payloads into orbit; an ELaNa mission for NASA, Educational Launch of Nanosatellites.  It seems like quite a bet to gamble on a rocket that has never launched successfully.  The LauncherOne rocket paid off on the bet and delivered all nine satellites to orbit.

LauncherOne is a two stage rocket, and the upper stage reportedly was fired multiple times, leading to a very good test of the system. 

An air-launched rocket like this has some advantages over a ground launched vehicle; the "first stage," in this case a Boeing 747 called Cosmic Girl, is fully reusable and the aircraft has a wonderful history of reliability as well as a known ability to operate safely in inclement weather compared to launch from the ground.  Those upper stages that the rocket represents are still challenging.   

Compared to a reusable booster called the Falcon 9, LauncherOne gives up a lot of performance.  The F9 booster carries the second stage much higher, typically around 70 km or ~230,000 feet, and going much faster.  A 747 will fly around 35 to 40,000 feet.  The F9 at Main Engine Cutoff (MECO) will be going around 4500 miles per hr, while the 747 will be around 600 to 700 mph.

Air launched rockets have been done before, notably the Pegasus, which may now be an obsolete program, and which was a solid fuel rocket, not liquid fueled like LauncherOne.  Something not many people stop to think about is that when a rocket like that F9 shuts its main engine, the upper stage starts slowing down.  Because of that, they start the second stage quickly, within about 4 seconds, giving the booster just a sideways nudge to get it out of the second stage exhaust plume.  When the 747 drops LauncherOne, it also starts to slow and fall down.  Virgin Orbit had to design a liquid-fueled rocket that could be dropped horizontally from an aircraft, ignite its engines, and rapidly orient itself into a more vertical trajectory. 

A rocket dropped from an aircraft cannot ignite its engines immediately due to the proximity of the plane and its pilots. In the case of LauncherOne, the rocket's NewtonThree engine is ignited 3.25 seconds after being dropped. Main engine start comes at 5.2 seconds. During this time, the rocket is falling and losing the velocity it gained from the aircraft at about 30,000 feet.

Boeing 747 Cosmic Girl with LauncherOne on the release pod - Virgin Orbit photo.

It might not be "fair" to compare the LauncherOne to a Falcon 9.  The F9 carries bigger payloads; something like Rocket Lab's Electron might be closer to a 1:1 comparison, but it's reusability isn't really established yet; they've recovered one booster by picking it out of the ocean. 

Congratulations to the Virgin Orbit team!  Rocket design is hard; orbital rockets are harder.  It's good to see success.