Block 5 rocket launch marks the end of the beginning for SpaceX

Less than eight years after its maiden launch, the Falcon 9 booster has become the most dominant rocket in the world. Modern and efficient, no rocket launched more than the 70m Falcon 9 booster launched last year. Barring catastrophe, no rocket seems likely to launch more this year.
In part, SpaceX has achieved this level of efficiency by bringing a Silicon Valley mindset to the aerospace industry. The company seeks to disrupt, take chances, and, like so many relentless start-up companies, drive employees to work long hours to meet demanding engineering goals.
While founder Elon Musk’s ambitions to settle Mars get most of the public’s attention, the company’s workhorse Falcon 9 rocket, which almost never leaves Earth orbit, is the reason SpaceX has soared to date. And on this vehicle, Musk’s company has imprinted its ethos of disruption and innovation by seeking every opportunity to improve the rocket.
Although this has caused headaches for customers like NASA and some suppliers, constant tinkering has allowed SpaceX to maximize performance of this rocket. By regularly upgrading the Merlin engines, shedding weight with lighter materials, and using super-chilled rocket fuel to maximize density, the Falcon 9 rocket now is about twice as powerful as it was during its initial flight. Rarely during its more than 50 launches since June 2010 has a Falcon 9 rocket not had a handful or more changes from the previous edition.
All the while, SpaceX has had a singular goal for the Falcon 9 rocket: to build the most perfect and efficient orbital rocket it could. Now, finally, the company seems close to taking a final step toward that goal by closing the loop on first-stage reusability.
As soon as next Monday, but more likely a bit later this month, SpaceX intends to launch the “Block 5” variant of the Falcon 9 rocket for the first time. Musk has said this fifth revision of the Falcon 9 should mark the final major change for the booster.