What Space X and its founder Elon Musk accomplished Friday by landing a reusable rocket on a moving drone ship is no small feat. So you’ll want to watch this historic moment.The crew did what it had failed to accomplish four times before by not only fulfilling its contract with NASA to transport 4,409 pounds of cargo to the International Space Station but it also stuck the landing.
And what a landing it was. Hundreds of Space X employees gathered to watch the event outside the control room while millions more tuned in to the live stream from home or at work. The launch went smoothly, quickly propelling the rocket into space. But the real fanfare was all about the landing, which happens quickly as the rocket has to slow its momentum at the last seconds before touching down.
Why does Space X keep focusing on these ocean landings? A drone ship floating on the ocean is a harder target to hit than a large expanse of ground, since it is smaller and floating on moving water. Plus, all of Space X's ocean landing attempts have resulted in the rocket exploding. Still, landing at sea can be less tricky than ground landings, and the main reason has to do with fuel. To return back to Earth, the Falcon 9 has to use the fuel leftover from takeoff to reignite its engines in a series of burns. These burns help to adjust the rocket's speed and reorient the vehicle into the right position for entering Earth's atmosphere and then landing.
Different types of landing techniques require different amounts of fuel, though, and that revolves around how the Falcon 9 launches. The rocket doesn't travel straight upward into space but follows a parabolic arc up and away from the launch pad. Because of this, the rocket has to go through a lot to conduct a ground landing. The vehicle has to slow down in the direction it's heading, completely turn around, and then retread the vertical and horizontal distance it's covered to get back to the landing site. That requires a lot of extra fuel.
The whole point of landing these rockets is to help save Space X money on launch costs. Right now, most rockets are destroyed or lost after they launch into space, meaning entirely new rockets must be built for each mission. Space X hopes to recover as many rockets as possible to cut down on cost of creating new vehicles. The Falcon 9 costs $60 million to make and only $200,000 to fuel. If a recovered rocket doesn't need too much updating and refurbishment between launches, reusability could eliminate a good chunk of that manufacturing cost.