Facts by #JoeHansenFacts# That green flash right before a Falcon 9 lifts off is the engines being lit. The Merlin engines start with TEA-TEB, a chemical mix that bursts into flame the moment it touches oxygen. The boron in it burns green. Every start uses up a charge. At liftoff it comes from the pad, but in flight only the upper stage engine and the three landing engines carry their own. That puts a hard limit on how many times they can restart. Raptor on Starship skips the chemicals. Spark plugs light small torches, and the torches light the engine. No cartridges to run out of, and nothing extra to ship to Mars.

Facts by #JoeHansenFacts# Why does a Starmind cluster need way more laser than Starlink does? Starlink lasers pass your data along until it reaches the ground. In a compute cluster the satellites run one AI model together, so they're talking to each other nonstop. 1. SpaceX says each Starmind satellite is about one rack of compute, up to 250 kW peak. 2. A cluster is planned at "10-ish" satellites with "10 terabits or so" between them, per SpaceX VP Michael Nicolls. That's his design target, not flying hardware. 3. On the ground, Nvidia's NVL72 rack moves 130 terabytes per second between its 72 GPUs, inside one box. In orbit, the step between racks has to happen by laser. 4. Each satellite has a 75 m wingspan, and they still have to fly in tight formation so the links stay locked. SpaceX says the first thousands could start going up as soon as late 2027.

Facts by #JoeHansenFacts# Picture a 72 m Super Heavy booster, taller than a 20-story building, coming back down to the tower it launched from. Two giant steel arms, the "chopsticks", swing shut and catch it out of the air. It has no landing legs at all. SpaceX did it first on 13 October 2024, Flight 5, on the first try. They caught boosters again on Flight 7 and Flight 8 in early 2025. So why skip the legs? Earth's gravity is brutal. A rocket that flies back in one piece has very little lift left over for cargo, so every ton counts. Legs strong enough to hold a booster this size are heavy, and they ride all the way up and back down. Give that job to the tower and the weight stays on the ground. Elon says taking the legs off "greatly improves payload margin". The second reason is speed. The same arms already lift the booster onto the launch mount before every flight. When they catch it, it is right back where it started. No barge, no crane, no trip back to the pad. Elon's goal from the start: put the ship back on top, refuel, and fly again within an hour. The arms close on strong points up by the grid fins, near the top of the booster, and those carry the whole weight. Next is the ship itself. Elon hopes Flight 15 flies in 4 to 6 weeks, and he wants the tower to catch Starship too. Then both halves of the rocket come home to the same tower.

Facts by #JoeHansenFacts# A flat Starlink dish follows satellites doing over 27,000 km/h, and the dish itself never moves. So how does it keep up? Under the cover is a big grid of tiny antennas, all driven by custom chips on one thin board. If every antenna sends at the exact same moment, the signals add up straight ahead. Start each one a tiny bit later than its neighbor and the combined beam leans to one side. Change the timing and the beam points somewhere else, with nothing moving. Kind of like a stadium wave. Each person just stands up a moment after the person next to them, and the wave runs around the whole stadium. The satellites are only a few hundred km up, so each one crosses the sky in a few minutes. University measurements show the network reshuffles which satellite each dish talks to every 15 seconds, at the same seconds of every minute worldwide. The first round dish had motors to aim itself at setup. Today's Standard and Mini have none. You prop them on a kickstand and the app tells you which way to point it. After that the panel stays still and the beam does all the moving.

Facts by #JoeHansenFacts# In Pretoria, South Africa, during the apartheid era, the Musk family(@mayemusk) raised visionaries amid challenges. Elon Musk, born June 28, 1971, his brother Kimbal, born 1972, and his sister Tosca, born 1974, shared a childhood fueled by curiosity and limited technology. Their engineer father Errol provided access to early computers. At age 10, Elon received the Commodore VIC-20, one of the first affordable home computers. Lacking teachers or resources, the brothers taught themselves coding using the BASIC programming manual. Elon mastered it in three days instead of six months, igniting a passion that led to his first video game, Blastar, coded at 12 and sold for $500. This self-taught ingenuity on outdated machines in their South African home laid the foundation for their later success, including co-founding Zip2. The Musk brothers' early experiments with old computers exemplified determination, turning isolation and scarcity into skills that would revolutionize technology worldwide.