Because failure is an option SpaceX can do stuff like land rockets on a boat | Ars Technica
After separating from the second stage and its payload, the first stage of the rocket kept coasting from the initial momentum of its launch, all the way up to 200km above the Earth. There, as it flew almost parallel to the planet, small engines turned the rocket around, so its large Merlin engines at the bottom would face the ground. They had work to do. In April the first stage hit Earth’s atmosphere at 1km/s, a speed at which one could fly from Boston to New York in about six minutes.
On Friday morning, because of the greater energy needed to deliver the heavy satellite to an orbit 90 times higher than the International Space Station, the first stage hit the atmosphere at 2km/s. That means the rocket would have to shed four times as much energy as the April landing and face eight times as much heating during the turbulent reentry to Earth’s atmosphere. So when three of the rocket’s nine engines fired for about 15 seconds during reentry, success was far from assured. But then, about a minute later, an automated camera aboard the drone ship showed a flash, and when the smoke and fire had cleared there stood a rocket that had just crashed through the sonic barrier seconds before.
What made it all so remarkable is that, in front of the world, SpaceX was willing to fail. As it had many times before. The company originally tried to land the first stage of its Falcon 9 rocket at sea in January, 2015, after delivering a Dragon spacecraft to orbit. Due to a lack of hydraulic fluid to steer its grid fins, which control the direction of the stage’s lift during reentry, the first stage came in fat and blew apart on the drone ship. The moment was captured in a memorable Vine...
Because failure is an option SpaceX can do stuff like land rockets on a boat | Ars Technica
On Friday morning, because of the greater energy needed to deliver the heavy satellite to an orbit 90 times higher than the International Space Station, the first stage hit the atmosphere at 2km/s. That means the rocket would have to shed four times as much energy as the April landing and face eight times as much heating during the turbulent reentry to Earth’s atmosphere. So when three of the rocket’s nine engines fired for about 15 seconds during reentry, success was far from assured. But then, about a minute later, an automated camera aboard the drone ship showed a flash, and when the smoke and fire had cleared there stood a rocket that had just crashed through the sonic barrier seconds before.
What made it all so remarkable is that, in front of the world, SpaceX was willing to fail. As it had many times before. The company originally tried to land the first stage of its Falcon 9 rocket at sea in January, 2015, after delivering a Dragon spacecraft to orbit. Due to a lack of hydraulic fluid to steer its grid fins, which control the direction of the stage’s lift during reentry, the first stage came in fat and blew apart on the drone ship. The moment was captured in a memorable Vine...
Because failure is an option SpaceX can do stuff like land rockets on a boat | Ars Technica