The satellite world is undergoing a massive upheaval. Thanks to advancements in computing and new manufacturing techniques, even spacecraft with the most critical responsibilities are becoming smaller and more inexpensive. As a result, satellite owners are building them faster and in greater quantities than ever before. Launch service providers like us, then, have a responsibility to build vehicles that can match this rapid evolution — which means we too must explore and implement new techniques, tools and materials.
We’ve been printing key parts of our engines for some time: early on we recognized additive manufacturing, otherwise known as 3-D printing, as a great enabler. The great minds at NASA’s Marshall Space Flight think so too, which is why we’ve been putting our heads together for a mutually beneficial project partnership, or Space Act Agreement.
Our joint goal was to study the use of additive manufacturing to build multimetallic combustion chambers. Spoiler alert: this technology will change the way humankind designs and builds rockets altogether.
Combustion chambers are a crucial component of all rocket engines. It’s here that the propellants mix and ignite, generating incredibly high pressure and temperature before accelerating past the speed of sound as they exit the nozzle. The punishing operating environment makes combustion chambers one of the most difficult engine parts to develop while keeping manufacturing time short and cost low.
The benefit of developing multimetallic parts, as we are for our own engines, is that you can take advantage of their distinct properties (such as strength or thermal conductivity) to create a more robust, higher performing end product. The problem is developing such parts can be an excruciatingly slow process… that is, unless you have powerful tools like our hybrid additive-subtractive manufacturing machine.
For this partnership, Virgin Orbit engineers used this hybrid machine to modify combustion chambers designed by NASA. The chamber’s geometry was unchanged from the traditionally manufactured design, but we were able to build it more quickly and out of different materials.
An extensive hotfire test campaign then proved that the unit could hold up under realistic operational conditions, and in fact matched the performance of a traditionally manufactured unit.
We’re taking the lessons learned from this partnership and incorporating them into our own manufacturing development. When we hit our production goals, we’ll see an order of magnitude reduction in both cost and lead time for our engines — and it will be thanks in part to the work we’ve done here with the Marshall Space Flight Center.