Is The Aerospike Back To The

Dave Rauschenfels
4 min readDec 10, 2018

Imagine this scenario for a moment. Far out in the cold depths of the Atlantic ocean is a nuclear submarine. Tensions are high with Russia following continued hacking of government organizations and corporate interests. Relations have been further aggravated by the Russian shootdown of an American airliner near Finland. Happy 🎁 President Trump commands the navy to retaliate. Out in the Atlantic the submarine commanders verify the launch codes and release the keys.

Inside a sealed watertight container, a rocket motor igniters for a few unbearably loud seconds. In the immense heat, the water vaporizes to steam and it presses on the Trident missile like a piston. Seconds later the missile breaks through the turbulent ocean surface like a whale. Narrowly avoiding a big wave, the booster ignites its engines in the cloud of spray, steam, and smoke. Fighting a brisk gale, the missile deploys a drag reduction Aerospike and climbs into the overcast sky.

You don’t have to say it. I’m right here.

Did you expect a political thriller?

About that missile, this is a story about new rockets. The proposed Starship, New Glenn, and OmegA rockets. Each vehicle is scheduled to take to the skies sometime in the next decade.

Starship aka BFR aka Big Falcon Rocket

The proposed BFR is a completely reusable heavy lift booster under private development by SpaceX. The first stage (Super Heavy) is to be built out of carbon composites and fueled by subcooled liquid methane. Weighing in at 6,757,000 pounds, the stage is powered by 31 Raptor Engines and capable of returning to its launch mount. The second stage (Starship) is a long duration spacecraft capable of hauling satellites, fuel, and passengers to orbit. The Starship is expected to weigh in at 2,943,000 pounds and have the capacity of landing retropropulsivly near the launch mount.

New Glenn

The New Glenn is a partially reusable heavy lift booster being built by Blue Origin. The seven-meter diameter vehicle is powered by seven BE-4 methane engines and will feature two or three stages. Blue Origin is anticipating that the two stage version will have the capacity of 29,000 pounds to Geostationary Transfer Orbit and ability to carry dual payloads. Blue Origin is also promising customers that all dual launch payloads will liftoff on time. Any delayed payloads will have to wait for the next launch.


The OmegA is a new launch vehicle being built by Northrop Grumman. It is derived from the defunt Ares 1 rocket that flew once nine years ago. The revised vehicle is built from a space shuttle influenced solid rocket booster capped by a cryogenic upper stage. The vehicle is intended to launch national security payloads for the military. It could also be enlisted to launch astronauts.

And this takes us back to the Drag Reduction Aerospike. At the moment these boosters are still shrouded in secrecy. The final design of the Starship is still in flux, but I expect it to resemble the Space Shuttle when finished because it was a proven design. The engineering of launch and re-entry are identical. The New Glenn specifications are also speculative, but the final vehicle should resemble an upscale Falcon 9 with a similar flight profile. The OmegA is fundamentally a reboot of the defunct Ares and is fully expendable.

And this takes us back to drag.

As a rocket accelerates through the atmosphere, the pressure on its face steadily increases. This pressure is drag and it is proportional to the velocity of the object. The pressure steadily climbs until max-q or maximum aerodynamic pressure. At this moment the vehicle breaks through the sound barrier and produces a shock wave. A condensation cone is sometimes an effect of the shock wave, and the flight loads are abusive. The Space Shuttle needed to throttle down to avoid damage and this feature is common to many vehicles. In order to lighten the drag load, Lockheed created the Drag Reduction Aerospike. The device resembles an antenna. Its job is to disrupt the shock wave ahead of the missile. Drag reductions of up to fifty percent are possible. Redirecting the shock wave also permits the engineers more volume in the nosecone. During the Cold War the Russians developed a similar system.

In the Cold War each side sought strategic advantages over the other. The new race should be no different.

What other flight technologies are underrated?



Dave Rauschenfels

Field Service Engineer with a passion for technology and entertaining readers.