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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.
A rock is a larger more masculine form of a rockette.
https://en.wikipedia.org/wiki/...
The smallest launch cost is fuel -- the largest is hardware. The majority of the hardware cost is for the 1st stage. So if the hardware of the 1st stage can be re-used, how is this not a win?
You are simplifying it to such an extent that you completely miss the point. The cost of the fuel is a small fraction of the cost of the launch - the cost of building the 1st stage dominates. When that stage is destroyed, it is an operational expense for that launch. When it is recovered, it is a capital expense with an additional smaller operational expense to refurbish and another expense to account for the reduced efficiency of the launch (some fuel held in reserve as you say).
Since converting the huge operating expense into a a huge capital expense that results in an asset that can continue delivering value minus some small additional operating expense, the net result is a more economic system.
All rockets fly with lots of margin (read: extra fuel) in case of unexpected anomalies during flight. The difference with SpaceX is, when the flight goes as planned, they can use that extra margin to recover an immensely expensive piece of hardware. What's more, not all payloads are using every last pound of capacity in the vehicle. If you can launch 90% of the weight at half the cost thanks to reuse, you've fundamentally changed the market.
This is like getting to reuse a Boeing 747 instead of scrapping it after a single flight. If you think that's just a stunt, you don't have much of an imagination. This is a game changer.
It's automated. No humans aboard. That fits the commonly accepted definition of drone.
1st stage is $60M. Fuel is $250K. You do the math.
The only accurate point in your post is that second stage landings may not prove practical, which is why there are no current plans to attempt that. Fortunately the second stage is a lot cheaper than the first stage, in this case the second stage is just one engine compared to 9 in the first stage.
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SpaceX calls it a drone ship as well.
. . 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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Dear lazy web, any higher quality video out there? Congrats SpaceX, this looks really impressive.
https://www.youtube.com/watch?...
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.
I was gonna mark the parent as a troll, but really it's just uninformed.
https://science.slashdot.org/s...
Elon Musk says it takes $60 million to build the Falcon 9, and $200,000 to fuel it.
Steve Poulus, a former NASA project manager, suspects final costs could be driven below a million dollars.
So it's looking like a stunt that could be worth more than 95% of the first stage's $60M. That seems like a big deal.
Anyone know why they would come in at an angle and straighten up at the last moment? Is it actually easier to control that way, or is it to protect the landing pad in case of a list-second abort?
Nope, no sig
Uh... yes. They've changed the volume of on-board hydraulic fluid, they changed the leg lock-out mechanisms, they changed the landing approach angle, and probably a billion other things. Do you even follow SpaceX bro?
I'd go out on a limb and say they will probably stick 8 out of the next 10 sea landings, and no less than 9 out of 10 RTL landings.
Which has more power: the hammer, or the anvil?
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.
Hey, that's "ASDS Of Course I Still Love You" to you, bud!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
Seawater and final impact speed are two good ones.
Seawater inside a booster makes refurbishing it MUCH harder. With parachutes, you can't control the attitude at which the booster hits the surface, and those rockets are designed to be very strong for vertical loading, but horizontal loading would destroy it... like a beer can, it can support a load at it's top, but not it's side.
Keep in mind that they have to fly with that fuel anyways... they need the margin in case of engine failure or other recoverable scenario. So all they've really done is add the weight of some landing legs, fins, a few other sundries, and some intelligent flight computers to relight the engine and bring it back down... it's not as inefficient as people are making it out to be.
Which has more power: the hammer, or the anvil?
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.
They've actually landed successfully on land prior, this was their first success on a ship at sea. The last attempt it landed, then tipped over when a support leg broke, so i'd guess they reinforced that or something. I'm sure they'll have a few more fireballs, but my money is on them getting the landing down consistently very soon.
When I first started SpaceX I wanted to land a booster in the ocean. Everyone said I was daft to try to land a booster in the ocean, but I built in all the same, just to show them. First time, it crashed into the ocean. So I built a second and third one. They sank into the ocean as well. So I built a fourth. That landed, fell over, then sank into the ocean. But the fifth one stayed up. And that's what you're going to get folks, first stages that land on autonomous barges with weird names in the middle of the ocean.
Faster! Faster! Faster would be better!
Obviously now we have to see the recovery percentage that SpaceX can achieve, especially when they start landing Falcon Heavy on three barges, the one for the center booster being much farther downrange than the others. Seeing three land, two of them simultaneously, is going to be pretty amazing. If they can recover a lot of them, this completely changes the economics of space flight beyond the 30% discount SpaceX is quoting in the short term.
And don't forget that they are getting the Dragon back too, and Dragon 2 with its eventual ground-landing capability is expected to be reusable. Currently Dragon 1 lands in sea water, and the reuse they have so far is only of the pressure vessel, the capsule is stripped down to that and rebuilt.
Recovering the second stage is possible although not currently on the SpaceX roadmap. They would need to fly it with a heat shield.
Now, consider what it would take to land a Dragon on the moon and return. Not inconceivable, given Falcon Heavy and a few launches.
Bruce Perens.
60M is their entire rocket..... There are 3 parts to the rocket and their original (and still current) goal was for FULL re-usability. Since 33% of the rocket = 1/3, that completely matches up what they originally stated since you have to account for recovery, refurbish/inspection, and relaunch cost.
It's a long process and even SpaceX acknowledge early on the 2nd stage was more complex to recover and may not be possible. That said, the dragon capsule is slowly on it's way to re-usability so even if they don't accomplish that, a 50-60% cost reduction is still big considering they are currently the cheapest on the market.
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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Afaict they have attempted landings* on 6 flights of those two were successful.
Flight 14, failure due to grid fins ran out of hydralic fluid.
Flight 17, failure due to stuck valve
Flight 20, successful landing at the cape
Flight 21, failure due to landing leg issue
Flight 22, failure (and was expected to fail) due to coming in too fast due to a large payload.
Flight 23, successful landing on
So basically the devil is in the details. Each time a failure happens i'm sure they put a lot of effort into working out the details of what went wrong but what is not clear is how many iterations of failure they will have to go through before they get a reliable result.
One thing I would note is that they don't need 100% reliability. They just need sufficient reliablity to make the savings from reuse greater than the cost (payload reduction, landing location operations and repairs etc) of the landing,
* Defined here as attempting to land etiher a landing pad on land or a droneship. I don't count the drop in water tests as landing attempts.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
That's not really how rockets work. Sometimes a launch profile is compatible with secondary payloads, and so they sometimes do that. But often they're not, and so you can only launch to the one orbit. SpaceX doesn't control the satellite manufacturers operators: if the payload doesn't need the full payload, they can't just stick another satellite in there or tell them to make it bigger. If they could be putting additional payloads in the rocket to derive additional revenue, they would be. When they do the Orbcomm launches, they're launching lots of satellites at the same time, but then, those satellites all launch into very similar orbits.
Reusability on the first stage doesn't add terribly much weight anyhow: it takes a lot less fuel to decelerate a mostly empty stage than it does to accelerate the whole thing up to speed in the first place. It's also not a 1:1 relationship: 1 kilo of extra fuel does not subtract 1 kilo of mass from the potential payload. That would be true of the second stage, but not the first stage.
Since they can't really use that extra capacity anyhow, they might as well use it for cost savings, because reducing your costs is even better than increasing your revenue.
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.
SpaceX, and the people in this thread, are comparing the vehicle cost to fuel cost, which is kinda cheating. It's not the cost of the fuel that matters, it's the cost of building the vehicle larger to hold that fuel -- and the fuel needed to launch that fuel -- that matters. So let's do the math!
Most data taken from http://spaceflight101.com/spac...
Basic info:
Stage 1: 23 tonnes structure, 400 tonnes fuel
Stage 2: 4 tonnes structure, 93 tonnes fuel
Payload: 13 tonnes
When launching, the first stage burns all 9 engines at full thrust for two and a half minutes. The re-entry burn and landing happen on a single engine, and from eyeballing the videos (including this one that shows the re-entry burn) appear to take about 30 seconds total. Assuming all burns are near full thrust (which is the best way to do it), that means the landing burn takes about (1/9) * (0:30 / 2:30) = 2% of the first stage fuel. Let's double that to 4% to provide a generous safety margin: that works out to about 400 * 0.04 = 16 tons more fuel.
This fuel is carried up to the moment that the second stage separates, so it subtracts from the mass of the second stage. Second stage plus payload weighs 110 tonnes: without the landing fuel, you could have scaled that up to 126 tonnes, a 15% increase.
So, landing the first stage reduces the payload SpaceX can launch, and thus the money they earn, by about 15%. In exchange, they recover about 75% of the cost of the launch hardware. So it's worth doing, even after you subtract off the cost of recovery and refurbishing. Maybe not the game-changer Elon Musk wants it to be, but it's a win.