Apropos of nothing, I just want to show you this amazing photo from SpaceX showing the Falcon 9 first stage booster landing on the drone ship, as seen from that ship:
There are more photos like this on the SpaceX Flickr page.
The booster successfully lofted the rest of the rocket into orbit on April 8; on top was a Dragon capsule loaded with equipment for the astronauts on the International Space Station. It berthed with ISS two days later.
Less than nine minute after launch, the booster flipped over, slowed, and descended down to the Atlantic Ocean. Waiting for it was the Of Course I Still Love You, the autonomous drone ship. The booster landing was the first successful touchdown at sea after several attempts (a landing on land was done in December).
One of the most common questions people ask is why have a ship out to sea? Why not just bring it back to the cape in Florida? The reason is sideways. Velocity, that is. The rocket doesn’t just go up, it heads east, too, so that eventually the upper stage and Dragon can achieve orbit, circling the planet.
By the time the first stage booster separates it’s moving at roughly 6,000 kph and is several hundred kilometers east of Florida. It doesn’t have much fuel left (most is used up pushing the upper stage as high and fast as it can), and going all the way back to Florida would mean slowing, stopping, reversing, going west to get to Florida, then slowing, and finally landing. That takes a lot of fuel! Instead, they put the landing platform out to sea to meet it, and then that can bring the booster back home after, saving that precious rocket fuel.
And mind you, this is all done autonomously! There’s no one on the booster, no human on the drone ship. The positions are calculated using GPS, and the rocket has enough smart software on board to find the ship, descend toward it, and even compensate for winds.
Well, almost. In this amazing video, taken from a rocketcam, you can see the booster move sideways a bit just as it makes contact:
Still, all in all, not bad! By the way, after it landed, SpaceX crew went out there to bolt it down, so that winds and rough seas didn’t knock it over on the trip back to Florida.
The question now is: Is this worth it? It costs about $60 million to build that booster, but less than a million to fuel it up (plus the costs to refurbish it and all that), so reusing it is a huge savings over building a new one each time. But did it come back in good enough shape to recycle? We’ll see; that’s the next big news I’m hoping to hear from SpaceX. Stay tuned.