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SpaceX Successfully Lands Its Rocket On A Floating Drone Ship For The First Time (theverge.com)
An anonymous reader quotes a report from The Verge: SpaceX has finally landed its Falcon 9 rocket on a drone ship at sea, after launching the vehicle into space this afternoon. It's the first time the company has been able to pull off an ocean landing, after four previous attempts ended in failure. This is the second time SpaceX has successfully landed one of its rockets post-launch; the first time was in December, when the company's Falcon 9 rocket touched down at a ground-based landing site in Cape Canaveral, Florida, after putting a satellite into space. Now that SpaceX has demonstrated it can do both types of landings, the company can potentially recover and reuse even more rockets in the future. And that could mean much greater cost savings for SpaceX.
. . It is not obvious that doing this risky vertical landing is going to result in any savings at all. . . This is interesting but looks like a stunt.
I'll bet on the SpaceX engineers anytime over a random commenter on /. (regardless of the UID)
Do you really think that they haven't run the sums before spending all that time and effort perfecting something that you call "a stunt"?
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During the webcast they mentioned several times that they collect tons of data for each landing attempt, so yes, I expect them to successfully land a very high number of 1st stages going forward.
Ditching it in the sea and recovering it causes too much damage to make it viable to refit. This was intended for the boosters on the space shuttle, but it ended up being cheaper to make new ones than fix the old ones.
Of course they could bring them down over land, but I think the unpredictability of exactly where they would land could be marginally terrifying.
Most of their launches don't require the full payload capabilities of the rocket. If they're not going to use the extra payload mass anyhow, how does that reduce revenue?
Because parachuting will work only on earth and similarly dense atmospheric planets. Places like Mars and others where atmosphere is very little to non-existent, you will have to land by propulsion with something as heavy as this. As Elon Musk puts it, the ultimate goal is to create a technology capable of multi-planetary traveling.
Quite true, although it should also be noted that the ratio you provide isn't going to be the ratio of savings they get. There are fixed costs associated with turning the stage around, so the cost of re-use isn't just the fuel, but it's also the labor to haul the stage back, pay the boat crews, re-inspect the engines, etc.
It's still a major win even considering those fixed costs. Many predictions are coming in around the 1/4 to 1/2 mark relative to a brand new stage. That's SpaceX's savings: they have the option to price used stages anywhere between there and full price. E.g, just to make numbers up, say their costs end up dropping to 1/3 given the number of times they launch each state. They could price used stages at 2/3 to the customer, which both gets SpaceX more profit, and gives the customer cost savings.
Blue Origin has been mocking them in the other way. "Hey, look at what we just did! What took you so long?" Sure, you had a sub-orbital launch profile (almost no horizontal velocity), popping off a tin can that came straight back down. Boy Scouts recover their Estes rockets all the time. SpaceX already did the landing thing with their Grasshopper rocket (and DC-X long before either of them), and the only reason they didn't take it higher was because they didn't have clearance to go higher at McGregor.
Falcon 9 has been on an orbital launch profile every time, sometimes even GTO, which is a lot harder to come back from. Even hitting the drone ship and falling over was harder than what Blue Origin did. A side-effect of having an actual useful launch profile is engines that can't throttle down to hover (Blue Origin can), so they have to do the much harder "hoverslam" maneuver. (zero vertical velocity at the same moment as zero altitude)
I will, however, give Blue Origin a few points for doing quick turnarounds. Their short-term objective is space tourism, and they're doing exactly what they need. It's just not nearly as hard as what SpaceX is trying to do.
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Even if they can't recover the second stage, if they can get reliable recovery/refurbishing/reuse of the first stage that'll completely change the economic equation. Say you can reduce the second stage cost by $1m by increasing the first stage cost by $1.2 million, today you won't do that because it's a net $200k loss. If you can reuse the first stage once for neglible fuel costs it becomes a (2*$1m - $1.2m)/2 = $400k profit per launch. If they can do it five or ten times, it's even more profitable. So I think there's a lot of potential improvements just redesigning to take maximum advantage of first stage reuse by making the second stage do less and cost less.
Also worth pointing out that those first-stage engines will have a limited number of flights they're good for. So on it's last flight, you stick the engine in a second stage. After all, you've got to get rid of your expired engines somewhere, so they may as well go in a second stage as a junkyard somewhere.
Each "time's up minus one" first stage yields nine expendable second stage engines, sorta kinda for free.
For the Merlin 1C, the only difference with the vacuum (second stage) version is the nozzle - a much larger expansion ratio. Other than the nozzle, they're the same engine.
The Merlin 1D variant is more deeply throttleable on the second stage, but it's unclear whether this is just a configuration setting or substantive hardware differences. I would imagine the former as much as possible.
But in any event, we concur -- lots of useful things to do with engines on their last flight.