Last Starship Flight 12 Testing in Hours, Ready to Make History Later THIS WEEK…

The warriors of Flight 12 have assembled once again. S-39 and B-19 are finally back together at the launch pad preparing for the final integration test before flight. But before this giant stainless steel skyscraper can thunder into the sky, there are still a few obstacles standing in the way. Next, vast space has officially revealed a brand new satellite bus system. Meanwhile, scientists have proposed a fascinating new navigation concept for the moon that sounds straight out of science fiction, lasers inside permanently dark lunar craters. Let's find out more on today's episode of Great SpaceX. Late May 18th and the morning of the 19th became one of the busiest periods at Starbase in recent weeks. Once again, B-19 and S-39 rolled toward the pad. This time, however, the rollout happened sequentially in the same direction instead of simultaneously. After arriving at the pad, B-19 was lifted onto the OLM at around 7AM local. Then came S-39. Fans immediately noted its serial number decal and updated markings as it slowly approached the tower. And by the afternoon of the 19th, the upper stage was successfully lifted and stacked onto B-19. The warriors of Flight 12 had reunited. Cue dramatic movie soundtrack.mp3. This marked Starship's second full stack in just 10 days after the vehicles had previously returned to the production site for additional testing. Ship 39 also completed testing at Massey's before heading back to the pad. That rapid turnaround clearly demonstrates SpaceX's effort to accelerate operations despite the frustrating delays surrounding Flight 12. And between you and me, the pressure is enormous right now. This is expected to become the first Starship flight of 2026. After months of waiting, testing, delays, and enough road closure notices to wallpaper an apartment, the company is finally approaching the finish line. Following the rollout, SpaceX released an entire set of new photos showing B-19 and S-39 moving toward the pad from angles only SpaceX seems capable of capturing. Seriously, their camera team deserves its own award category at this point. Alongside the photos, the company posted Starship and Super Heavy V3 moved to the pad at Starbase for final testing and preparations for launch. But SpaceX also included a second message that felt surprisingly emotional. They wrote, These vehicles are the first of many, made possible by the tireless effort of SpaceX engineers and technicians, and are designed to enable the core revolutionary capabilities of Starship. That statement clearly carried extra weight. Late 2025 and early 2026 were rough periods for Starship development. Delays piled up, schedules slipped, expectations grew heavier, and online speculation became, well, it's the internet, so what do you expect? But now, those long months of effort may finally be about to pay off. With the stack complete, SpaceX is preparing for one major final hurdle. For one final major hurdle before the launch. The full wet dress rehearsal. And this will actually be their second attempt. Originally, SpaceX planned testing for the 19th with the 20th serving as a backup. However, because the rollout process took longer than expected, the 19th test window became impossible. So the earlier schedule was revoked. The new primary test window now stretches from 6 in the morning to 11 at night on the 20th. And naturally, that immediately triggered new concerns inside the community. If the full wet dress rehearsal happens on the 20th, can SpaceX realistically launch the very next afternoon? Will they need an additional backup day? And perhaps most importantly, will the weather cooperate? Because according to forecasts, conditions on the 20th may not be ideal. And if the test slips again, the launch itself could slide further down the calendar. Currently, Elon Musk still maintains confidence. He stated, At the same time, the official launch window now extends all the way to May 28th. Which is SpaceX's polite way of saying, please stop asking us for an exact launch date. So even though the vehicles are fully stacked, uncertainty still hangs over the final timeline. By the time you're watching this episode, the test may have already happened. And if it succeeded, that would be extremely good news. Because the wet dress rehearsal is essentially a full trailer for launch day itself. Everything except actual engine ignition. Thousands of tons of propellant will be loaded into the tanks. And according to SpaceX's updated procedures, the goal is to complete fueling in approximately 35 minutes. That is absolutely insane when you think about the sheer amount of cryogenic fuel involved. The process also includes engine chill procedures. This is necessary because the engines must gradually cool down to match the temperature of the propellants flowing through them. Otherwise, introducing ultra cold liquid oxygen and methane too quickly could cause dangerous thermal stress. And yes, rocket engines are apparently delicate enough to need emotional preparation before launch. During the rehearsal, SpaceX will also conduct extensive checks across the entire system. Fuel tanks, pipelines, valves, ground support equipment, sensors, quick disconnect systems, software timing, pressure stabilization, basically everything that could ruin launch day if ignored. This is why wet dress rehearsals matter so much. A successful wet dress rehearsal dramatically increases confidence before flight. A failed one usually means engineers suddenly stop sleeping. Before the test even begins, Starbase itself transforms into a giant hive of activity. The chopsticks will rise into position, the QD arms will connect to the vehicle, the clamps below the booster will prepare for holddown operations, water systems and flame trench infrastructure will be activated, fuel farms will be filled, smaller pre-test activities like venting operations and detonation suppression system tests will likely occur beforehand as well. In other words, the entire launch site becomes alive, and all of it exists for one purpose, to prepare humanity's most powerful rocket for another attempt at flight. Now the big question remains, will Starship actually launch this weekend? Let me know with a yes or a no in the comment section down below to tell me what you think. Then don't forget to like the video and subscribe to the channel to continue following SpaceX's development journey. Next, let's shift gears and talk about Vast Space, because this company just made a very interesting move. Most people know Vast for its ambitious commercial space station plans, so now they're entering the satellite business too. On May 19, Vast officially announced a new product line called Vast Satellite. The company stated, Vast is expanding into high-power satellites, introducing our new line of high-power satellite buses that leverage the technologies we've developed in-house for our Haven 1 space station and validated with the success of the Haven demo mission. According to Vast, the new satellite line is intended for operators working in communications, Earth observation, national security, and orbital data center infrastructure. And yes, orbital data centers are apparently becoming a real thing now. Humanity truly looked at Earth's electricity bill and decided, what if we moved the servers into space? What makes Vast's announcement more credible than the average startup promise is that they already possess actual flight heritage. Last November, the company launched Haven demo aboard a SpaceX Falcon 9 rocket. The mission successfully tested key systems that will eventually support the Haven space station program. Propulsion, power systems, avionics, core spacecraft operations, everything reportedly performed successfully. The spacecraft later completed a controlled deorbit in February. And importantly, Vast builds many of these systems internally. That means the technologies proven during Haven demo can now directly support the newly announced satellite program. Vast CEO Max Haut stated, We believe Vast is uniquely positioned to compete in the high-power satellite market through the combination of our world-class engineering team, large-scale manufacturing capabilities, and the on-orbit success of Haven demo. He also added, Customers can benefit from our experience designing, building, and operating flight-proven large-scale spacecraft while gaining access to highly capable, flexible spacecraft platforms backed by operational expertise. And perhaps the most surprising part, they already have a customer. A confidential buyer has reportedly committed to purchasing four satellites with options up to 200 more. That's not a small contract. That's the kind of number that immediately gets investors sitting up straighter in their chairs. The first spacecraft in the Vast satellite lineup will reportedly be a 15-kilowatt-class satellite bus. It'll weigh around 700 kilograms with fuel and carry over 350 kilograms of payload. The satellites are designed for at least five years of operation in LEO, and Vast plans to launch the first batch of 10 satellites in late 2027. They want launch systems, stations, satellites, infrastructure, services, entire ecosystems. And I've got to say, that shift is making the space industry far more competitive and fascinating than ever before. And finally, let's head to the moon. Because scientists may have just proposed one of the coolest lunar navigation ideas we've heard in years. We all know navigation on Earth is relatively easy thanks to GPS satellites. But navigation on the moon is a completely different challenge, especially if humanity wants permanent lunar settlements in the future. That means astronauts, rovers, spacecraft, and cargo systems will eventually require their own lunar positioning infrastructure. And scientists now believe the answer may involve lasers hidden inside permanently shadowed craters near the moon's south pole. Which sounds less like navigation research and more like the setup for a 007 movie. According to researchers from the National Institute of Standards and Technology, ultra-stable lasers placed inside these craters could potentially serve as the foundation for a future lunar GPS system. The idea builds on previous concepts involving navigation satellites, radio beacons, and atomic clock systems. But this new proposal takes advantage of something unique about the moon itself. Because of the moon's tiny axial tilt, certain craters near the poles never receive sunlight, ever. These regions remain in permanent darkness and temperatures there can plunge to negative 370 degrees Fahrenheit or negative 223 degrees Celsius. Scientists have long viewed these craters as potential reservoirs of frozen water ice that could support future lunar bases. But now, researchers believe those same extreme conditions could also create the perfect environment for highly stable laser systems. The proposal centers around silicon optical cavities. These devices stabilize laser frequencies by bouncing light between mirrors separated by an extremely precise distance. On Earth, maintaining that level of stability requires expensive cryogenic cooling systems and vibration isolation equipment. But inside a permanently shadowed lunar crater, nature might already provide those conditions automatically. Extreme cold, near perfect vacuum, low vibration levels, it's basically the universe handing scientists a naturally built laboratory. That stability could eventually allow lunar navigation systems to measure positions and spacecraft movement with extraordinary precision. Study lead author Jun Ye explained, As soon as I understood what the permanently shadowed regions could offer, I felt that this would be the most ideal environment for a super-stable laser. And to be fair, this idea could become incredibly important in the future. Because long-term lunar settlement isn't just about landing astronauts anymore. It's about building sustainable infrastructure, navigation, communication, power, transportation, habitats, supply chains. The moon is gradually transforming from a destination into an ecosystem. And while laser-filled frozen craters may sound bizarre today, so did reusable rockets not very long ago. Now, SpaceX lands them routinely while people casually watch from livestreams eating pizza on their couch. The future gets weird pretty fast. And that brings us to the end of today's episode. Thank you so much for tuning in. As always, this has been Kevin from GreatSpaceX. Until next time, keep looking up!