Anyone with the slightest interest in space exploration and rocketry will have noticed a certain frisson around an otherwise ordinary (for SpaceX) rocket launch on May 11th 2018. A Falcon 9 rocket took off from Cape Canaveral, deposited Bangladesh’s first communications satellite into space, and brought the main stage back to Earth, landing neatly 9 minutes later on the drone ship “Of Course I Still Love You” about 400 kilometers from the Cape.
It’s a testament to how good SpaceX has got at this kind of thing (with the current highlight probably being the dual landing of boosters from its recent Falcon Heavy test – I mean come on, that’s just showing off, and we're not even talking about also launching a Tesla roadster into the solar system) that most of our social-media-fatigued eyes saw this touchdown as pretty routine.
But the May 11th landing was definitely special. This version of the Falcon 9 has a design, designated as “Block 5” in a nod to Soviet rocketry, that should reach a new standard in reusability.
Specifically, the goal is for the Block 5 build to be capable of 100 launches. Now that sounds impressive, but of course NASA’s Space Shuttle was also designed for re-launch. For example, the orbiter Discovery went to space an impressive 39 times, Atlantis hit 33 times, and Endeavour managed 25.
Except the Shuttle was not a simple re-use vehicle. In fact, it was only the orbiter and the solid fuel boosters that could be re-used, and then only after extensive refurbishment. Estimates of the actual cost-per-launch ranged from $450 million to as much as $1.5 billion if you include the full development and construction costs of the program. That’s not to say that it wasn’t a remarkable technological achievement – and without what was learned in the process efforts like those of SpaceX would’ve needed vastly more R&D time – but it did end up being awfully expensive.
The really special sauce for Block 5 is not so much its design goal of 100 launches (which only time will confirm), but is instead its goal of zero-refurbishment between as many as 10 separate launches. In other words, check it over, give it a polish, fuel up and launch again. As a result the cost per launch should come down to tens of millions of dollars rather than hundreds of millions.
If that works, it’ll be a major advance in launch turnaround and cost. The engineering of Block 5 includes many enhancements and tweaks from earlier versions. These include the composite overwrapped pressure vessels – carbon fiber wrapping aluminum containers for liquid helium that pressurizes the propellant tanks (you’ve got to drive those tons of propellant hard to their ignition spot). The support structure for the 9 engines (the ‘octoweb’) is bolted aluminum to enhance thermal response, the landing legs have latches to help steading drone-ship touchdowns, the avionics are upgraded, and the interstage (between the main booster and the 2nd stage) has a paint-free thermal protection so the top of the booster doesn’t get torched as the upper stage fires up.
And the icing on the cake is that Block 5 is designed to meet NASA’s requirements for human commercial spaceflight.
All of which means that the time is coming soon when we could see a transition to a new kind of relationship with space for our species. It’s going to be an interesting ride.