16.2K SpaceX is working towards a major milestone on their road to rapid and inexpensive reusability. The first Block 5 Falcon 9 first stage is on the test stand at their McGregor, Texas test facility as it prepares for a test fire. The booster – core 1046 – was first seen on Interstate 8 in Yuma, Arizona, being transported from the SpaceX headquarters in Hawthorne, California to their McGregor test site. It is now standing tall on the test stand ahead of a Static Fire this week. The Evolution of the Falcon 9: Ever since its debut in 2010, SpaceX’s workhorse rocket – the Falcon 9 – has had many major upgrades to its systems, most notably to its fuel tanks and engines. On its debut, the Falcon 9 looked much different than it does today. The most noticeable differences are that its engines were arranged in a 3×3 grid pattern, and its tanks were much shorter than those on today’s Falcon 9. It used nine Merlin 1C engines – their design borrowed and slightly modified from SpaceX’s early Falcon 1 – on the first stage, and one vacuum-optimized Merlin 1C engine on its second stage. This so-called Version 1.0 only flew 5 times, all carrying Dragon capsules or mockups of Dragon to Low Earth Orbit. A Falcon 9 v1.0 rocket preparing for launch at SLC-40, showing off its engine configuration. Credit: SpaceX In order to take more payload into orbit, which would make the Falcon 9 a much more attractive vehicle to potential customers, SpaceX created the new Version 1.1 of the Falcon 9 and began launching it in 2013. It featured numerous improvements over the v1.0 design, with the main changes being updating both stages’ engines from the older Merlin 1C to the newer, more powerful Merlin 1D, and stretching the fuel tanks on both stages. The v1.1 also brought a new possibility to the table for SpaceX – recovery and reusability. Thanks to the performance increases from the tank stretches and the engine upgrades, there was enough leftover propellant on some less-demanding missions to attempt to propulsively land the first stage in the open ocean, or later on an Autonomous Spaceport Drone Ship – which is essentially a strengthened barge. The Autonomous Spaceport Drone Ship “Just Read The Instructions” at sea. Credit: SpaceX SpaceX hoped to recover the second stage of the vehicle in a similar manner to the first stage, but this has been since placed on the backburner. SpaceX president Gwynne Shotwell said in late 2017 that SpaceX will attempt to “land a second stage gently in the ocean” in 2018. Ms. Shotwell later said they will not be attempting reuse on the recovered stages, saying “We will not reuse the second stages, we will try to bring them home though”. The Falcon 9 v1.0 also attempted first stage recovery on its first two flights, but with a much different approach. The stages were equipped with parachutes to attempt a landing in the Atlantic Ocean. However, these attempts ended unsuccessfully, with the parachutes being torn apart due to the stages’ mass and speed. After the v1.0 recovery failures, SpaceX decided to move to propulsive landings. In order to not damage a drone ship with early test failures, the first few landing tests occurred in the open ocean, simulating a landing on a drone ship. Rendering of an open-ocean propulsive landing of a Falcon 9 first stage. Credit: Nathan Koga NSF/L2 As was expected, the first open-ocean landing test was unsuccessful, but on the second try, SpaceX managed to land the booster softly and on-target. After more followup ocean landing tests, SpaceX moved on to testing landings on an actual drone ship. The first drone ship was named Just Read The Instructions, and the Port of Jacksonville was its home port. See Also