Could someone explain to me why they attempt this? Wouldn't inflating a set of floating devices when it goes down the ocean an easier way of retrieving it? Or something other than this REALLY HARD TO PULL OFF maneuver? Genuinely interested.
Any type of lateral forces will irreversibly damage the rocket. As an illustration, extreme care is taken when the rocket needs to be transported on its side. Some rockets, not the Falcon 9, can't even be transported on their side without being pressurized.
So pretty much anything other than a perfect soft touch landing would leave the rocket unable to fly again. Anything touching the 3/16" thick skin of the Falcon 9, would cause the very least extensive refurbishment at the least, but more likely irreversibly damage the frame of the 15 stories tall 1st stage. So this rules out every alternative that has been suggested in this thread.
2) Flotation devices attached to the booster = extra payload. It would be the canvas/dinghys AND compressed gas canisters for inflating them. This is arguably (a lot?) more weight than just landing struts + fins. Any extra payload on a rocket represents a massive cost and means less stuff you can haul for paying customers.
Actually parachuting and fishing the stage from the sea was their first idea, but they never recovered a single stage that way, and moved to active controlled recovery, which is much much much better in my opinion.
Yes, but how much extra fuel does the rocket have to carry to land? That's a ton of extra payload as well.
Any ideas why it's higher on land? Seems like it wouldn't differ that much.
Musk has stated in the past that they're looking to eventually use this tech to create rockets which can be used on Mars, hence why parachutes and inflatables are out of the question.
Further, the ocean platform it was landing on was built to sustain heavy seas and stay relatively flat. Recovering a rocket bobbing in the waves could be much harder than this. Also a challenge: quenching a very hot engine in cold ocean water.
No, this platform-landing is probably one of the simplest, safest ways to recover/reuse a stage.
Of course, you could just try to land it vertically on the water on some cushion and have more cushions deploy to make it tip over horizontally and float (all the time staying above the surface of the ocean). Such a solution isn't as compatible with recovery on dry land. If you want to do e.g. space tourism missions and land on dry land, the vertical landing seems better.
No they haven't. SpaceX started doing that in 2013 before the barge landings. I don't think anyone had ever even tried to land(sea?) a liquid fuel booster before that.
You may be thinking of the STS solid boosters, but solid boosters are really a different game. They can be built sturdy enough to hit the ocean at 60mph, but they couldn't possibly be simply refueled and reflown.
Landing in the ocean is only done for certain types of missions, where its not possible to carry enough fuel to turn the first stand around a fly it all the way back to the launch site. Instead, they can carry just enough fuel to land wherever they are finished boosting the 2nd stage, to put it simply.
I'd imagine that the barge landings introduce a lot of uncertainty and complicating factors that are impossible to completely nullify. High waves and (comparatively) strong open-ocean winds seem (to me at least) to make consistently successful lands much harder.
For American launch sites, you have KSC for launching east, and Vandenberg for launching south. (North and south are equivalent in terms of which orbits they can reach, so you don't need both.) Vandenberg can be used for launching west, but pretty much never is, unless you count ICBM tests and the like.
Hacker News has officially become a parody of itself.
But some rocket launches come form the west coast, not all are Florida.
No one else lands first stages. SpaceX is the first to do it.
Nobody else does this. I have absolutely no idea what you could possibly be referring to. SpaceX lands on land preferably when it is an option.
> I don't understand why they won't keep landing them on the ground ... It's not like there's not enough space on Earth
As a general rule, you not understanding the reason for something does not mean there is not a good reason. For reference, see the Dunning-Kruger effect. Furthermore, I honestly do not understand how you could even contemplate "SpaceX does not think there is enough space on land" as a serious argument and treat its dismissal as legitimate support for your beliefs. This is some of the most egregiously lazy reasoning I have ever seen on the internet.
SpaceX launches rockets in the direction of water so that an accident won't threaten property or people on land. To return to land after staging the first stage of the Falcon 9 must perform a burn—the "boost back"—to point its lateral velocity back to land; this is the first of three burns required for landing and the most expensive in fuel by a considerable margin. If the first stage is travelling too quickly (greater than approximately 1.6 km/s lateral velocity) it does not physically have enough fuel to return to the launch site and perform the landing. In this case, a far more mild burn can put the booster on a re-entry trajectory and it can land on an autonomous barge in the ocean. As the rocket trajectory is chosen to put the ground path well away from land, the choice is between either returning to the launch site or landing in the ocean. If a return to the launch site is prohibited by the rocket's capabilites and physics then an ocean landing is the only option.
In the case of Jason-3 a barge landing was the only option as SpaceX does not yet have permission to use their landing facility at Vandenberg Air Force Base. In the future, the central core of the Falcon Heavy will almost certainly have to land in the ocean due to its velocity at separation.
Believe it or not, we've been landing spacecraft for decades. Does "space shuttle" ring a bell?
Apollo Lunar Module, if Moon counts.
Lunar module doesn't count, the reduced gravity makes everything a hundred times simpler.