joshuazelinsky

 

There are a few things to note here; the Falcon 9 and Falcon Heavy are the only rockets currently flying in this picture, and no flights of the Falcon Heavy with the extended fairing have actually occurred. But the Falcon 9 fairing is about the same size as the standard fairing for the Delta rockets or the Ariane 5 . In fact, the Falcon 9 is generally more limited by up-mass than volume with the Falcon Heavy under the standard fairing having the reverse issue; SpaceX has used the same fairing for both in order to save money, so the fairing for the Falcon 9 is a little bit big for the rocket, and same fairing is a little small for the Falcon Heavy. An ideal fairing for a rocket with the Falcon Heavy's abilities would probably resemble the extended fairing with a larger diameter, but the fairing cannot be much wider than the rocket's diameter itself (without drastic changes) so even the Falcon Heavy's extended fairing has the same (somewhat small) diameter.

 

But if one looks at the size of the Vulcan fairing, the New Glenn and the Starship, one thing one seeing here a definite trend in the next few years of a projected increase in launch volume. In the case of Starship, this actually understates the case; the intended fairing will actually be a little larger than the fairing as depicted here, about four times the volume of the Space Shuttle's cargo bay. Unlike a normal fairing, Starship's won't actually be jettisoned but will stay attached to the rocket and land with the rocket's second stage; there will be a mass penalty from this, but Starship itself will be so large that this will be a minor issue. Fairing mass grows at about roughly 2/3rds power of the internal volume. This is because the fairing is functionally the surface area of the internal volume so our old friend the square-cube law rears its head. So for very big rockets, the penalty for keeping the fairing attached is smaller than it would be with small rockets.

 

The New Glenn here though is the most striking thing. New Glenn is planned to have a fairing almost as large as Starship, and with total volume larger than Falcon Heavy's extended fairing. This is consistent with the launch masses: While Falcon Heavy has a larger payload mass in its fully expendable mode, New Glenn has a payload mass almost twice that of Falcon Heavy's expendable payload mass. New Glenn is not intended to ever fly in expendable mode, but if it did, it could probably beat the expendable Falcon Heavy. (Strictly speaking when we discuss expendable and reusable it should be clear here that we are only talking about first-stage reusability. Neither New Glenn or Falcon have a reusable second stage. Second stage reuse is a basic aspect of Starship but that's a different rocket. )

 

Vulcan here is the odd one out. Vulcan is not going to be reusable under the initial plans. There is a long-term plan for Vulcan to have partial first stage use where the engines and some other major components will detach from the first stage, parachute down, and be caught by a helicopter https://spaceflightnow.com/2015/04/14/ula-chief-explains-reusability-and-innovation-of-new-rocket/ .

 

I'm uncertain when New Glenn is going to fly. It is currently projected to launch in 2021, but in general Blue Origin has moved very slowly, and the engine for New Glenn is still in development. However, some of the perception of their slow movement may be due to their general secrecy. SpaceX in contrast is very open about everything they are doing, and ULA under the new leadership of Tory Bruno has also been pretty open. That said, the engine for New Glenn is the same engine for Vulcan, (ULA is purchasing it from Blue Origin), and having an external customer who would be upset if their engine were not at least somewhat close to on-time may help push Blue into getting their engine done closer to schedule.

 

But regardless of the exact timelines, there's something important going on. In the last few years, we've seen a general trend that has made launches cheaper, especially for small and medium satellites. We're now starting to see that trend occur in general even for larger satellites, and along with it, starting to see the ability to launch much larger payloads, both in terms of mass and volume. Increases in volume also mean satellites can be simpler and cheaper; for example, one engineering difficulty with the James Webb telescope is that it needs to unfold its mirrors since they wouldn't fit in the fairing. With all the other issues going on right now, it is nice to remember that we're still making progress on many different fronts.