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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.
Maybe it got classified as a meteorite since it fell from the sky and survived... ;-)
- "Every demand is a prison, and wisdom is only free when it asks nothing." Sir Betrand Russell
A rock is a larger more masculine form of a rockette.
https://en.wikipedia.org/wiki/...
Elon and crew: Congrats! Can we now go to Mars?
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?
Somehow your logic does not add up. Fuel is nowadays a lot cheaper then a whole stage. Even if the payload goes down by a lot, it makes sense.
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.
Dear lazy web, any higher quality video out there?
Congrats SpaceX, this looks really impressive.
If that was the case, then why have their competitors shown interest instead of mocking it?
It's automated. No humans aboard. That fits the commonly accepted definition of drone.
True, and a jetliner could probably be considered more efficient if they cut out the landing too. If you filled every last kg on a payload to the max to get the most per dollar you argument makes sense, but once you have a payload that is less than the theoretically max then you argument breaks down rather quickly lets ignore the fact the rocket is purposely over engineered so it can land. Multi stage I would agree but when you just recovered %70 of your equipment costs, I would say thats a little more than a stunt.
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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It didn't even mention that SpaceX was launching today.
"I don't know, therefore Aliens" Wafflebox1
There are other goals than fuel efficiency. And really, given how dirt cheap kerolox is, optimizing for extreme fuel efficiency (especially on a first stage) is something of a fool's errand.
o.0
Reflying/reusing something is, with rare exceptions, always going to be cheaper than building a new something. The only real question is, how much cheaper?
After a couple hundred tries (yes, I suck), I finally got a strike! Now that I did it, I can go on to win all the bowling trophies ever!... said no sane person ever.
Sure, that's pretty impressive already, I'm not knocking them. SpaceX is awesome - I really want to see leaving earth becoming reasonably affordable in my lifetime, and SpaceX is doing a huge amount to make that a reality... but just landing a rocket once (after failing a few times), while news enough already, isn't really going to *change* anything until they can prove they can do it *consistently*. Did they actually change the *process* they use, such that they'll be able to pull it off every time by following that new process? Or are they just getting better at the process they already had, due to practice?
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"?
I am Slashdot. Are you Slashdot as well?
That's the term SpaceX uses.
The first stage costs $60 million to build.
The fuel costs $200,000 -- do the math.
I mean, if you don't mind $60 mil coming out of your pocket. The point is, re-use of the first stage enormously decreases costs per pound to orbit. If you can't figure that out, then I'm sorry, but, what are you doing on Slashdot?
If telephones are outlawed, then only outlaws will have telephones.
Efficiency is overblown as a performance metric for launch vehicles. Back in the 1950s it may have made some sense, especially if you could only make your payloads (nuclear bombs, in those days) so small, but other metrics (reliability, ease of manufacture, etc) replace that a long time ago.
You design your stage for the required orbital payload plus a few percent, which gives you margin to either (1) land and reuse the first stage, (2) launch a heavier payload and discard the stage, or (3) successfully continue to orbit even if you lose an engine or something.
Efficiency is for race cars, not cargo vans.
Or do you work for ULA?
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.
Fuel is cheap. Relatively speaking.
The only expensive part is a minor, albeit important part.
But the bulk is pretty cheap.
The rocket tech itself is the expensive part. Those are some high-quality materials needed to withstand immense forces and temperatures.
Those prices have dropped considerably in the past 3 decades, but fuel has gotten cheaper much faster.
They've been fixing technical problems that appeared in prior attempts so those problems would not re-occur. It's possible there are other lurking demons of course, but every time one occurs and they fix it, the whole endeavor becomes more reliable for the next time.
Even if they never achieve 100% stage recovery, it is still plenty worthwhile to do, and will meaningfully reduce the cost/kg to orbit. It won't reduce it as much as the ratio of stage to fuel costs, because there are fixed costs to turn the stage around for another flight (labor, etc), but even so, it might drive costs down to somewhere between 1/4 and 1/2 of what they are right now, which is significant.
Now we just order the drone ship back to port! ...
Uhh... that wasn't a story in the epic
https://www.youtube.com/watch?...
Read the articles of the last ten years, no one thought they'd succeed. Cost of fueling 200k for one launch. Roughly Fifteen percent of the total fuel is saved for landing.
debugging complex systems doesn't really work like that
From another article it stated that refurbishing the first stage so it can be launched again would most likely cost about half a million dollars. Building a new first stage costs about $60 million and the fuel for a whole launch is only around $200k. So not using all the fuel so they can land the first stage to allow it to be refurbished and reused is more than a stunt. It makes a lot of economic sense.
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.
Drones are vehicles.
Assembly line robots are not vehicles.
The HST is a "vehicle", but a probe is already a drone, so that term is redundant.
Printers are not vehicles.
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.
They change the process after every flight, if the telemetry tells them they could have done something better. Just like they enabled the Dragon's parachutes during ascent on this flight, in case the rocket blew up. (The previous flight the 'chutes were disabled on ascent because it was assumed an explosion would be non-survivable, so when the Dragon capsude did survive the explosion, it was destroyed when it hit the water.) The odds of that making a real difference on any upcoming flight is minuscule, but it was a no-weight software change so why not? (Of course, they put considerable effort into making any software change reliable and predictable, unlike the vast majority of software out there.)
Continuous improvement. They may well change the process after this successful landing depending on telemetry, or may decide that it is good enough (for now).
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?
Honest question. Can someone explain the benefit of this vs deploying a parachute and some inflatable bumpers to protect the rocket for reuse? This seams more expensive and much more complicated. Does a controlled landing outweigh the cost of retrieval of an uncontrolled but safe landing?
To be a drone it has to be remotely piloted without requiring line of sight by the operator. Your three examples fail the "remotely piloted" requirement because they are in a fixed location.
Yes but the unused fuel represents payload mass which can't be delivered to orbit, which reduces revenue.
http://michaelsmith.id.au
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
It is a potential Mars landing technology, it makes "cents" if it enables a future contract to get people to Mars, and back. Not that sending flesh-bags to Mars 20 years from now is good economics when AI and robotics can do the job better and cheaper, but that would not be SpaceX's problem they would still get paid to deliver the tax payer funded package.
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?
A lot of good points have already been made, so I'd like to make one more note: they aren't doing second stage reuse here. There is a second stage but they are only reusing the first stage. Everyone knows second and third stage reuse has a lot of problems (more fuel required is only one of them). First stages cost more than other stages since the have the highest variability in what conditions they need to be able to function in (from near sea level pressures to near vacuum) and they are larger because they need to lift more total material. So just focusing on saving first stages already helps a lot.
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.
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.
Spoken like a pointy haired boss in training...
FWIW, I'll go out on a limb and say that that given the percentage of recovered first stages is integral to SpaceX profitability, Elon Musk probably would know better than most and he apparently has stated publicly that last time when he predicted a 50-50 chance of sticking the landing, that he pretty much made it up and he had no idea...
... not to mention that the 2nd stage isn't re-usable, so that's also a per-mission cost. S2 is much cheaper than S1, but still a significant per-mission non-recoverable cost.
First of all, they don't have to do it consistently just enough to matter. Every success is a win, every failure a cost of doing business. The real question now is, how big is the refurb effort. After all they've landed... twice. They've relaunched... zero. And if they can keep doing that, I mean once is nice but... if they can do it five times, ten times that's when you really start to spread the initial cost across lots of launches. It'll be interesting to see what's possible, also hopefully by the end of the year we'll see the Falcon Heavy launch.
Live today, because you never know what tomorrow brings
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!
which is why they're now saying it will cost 30% less, which is still disappointingly low, compared to elon's previous $60M minus $250K statements. and which is why you have to take what people say with a grain of salt (like launch timeframes!).
In a way, they (Orbital ATK, ULA) have been mocking it from day one. Whether it is whispers to Congress critters being one way, questioning NASA and Dept of Defense about opening up launch contracts to include SpaceX, etc.
Blue Origin has tried mocking it, too, after their baby steps. but that's like the teenager still at the kid's table trying to mock the adults at the grown ups table during Thanksgiving dinner...
About half their issues have been fixable engineering problems, and the other half have been bad luck, so their success rate from here on should be about 50%.
http://michaelsmith.id.au
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.
SpaceX hopes to sell used Falcon 9 boosters for as low as $40 million
https://spaceflightnow.com/2016/03/31/spacex-hopes-to-sell-used-falcon-9-boosters-for-40-million/
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.
Okay. We've seen NASA working with inflatable heat shields for probes and what have you. Making airbags pop out of things is old-hat. If this rocket can right itself, decelerate, and land on a solid surface already, wouldn't it be easier and safer to just have it deploy balloons and land directly in the water?
I'm assuming that corrosion protection has something to do with this.
After a couple hundred tries (yes, I suck), I finally got a strike! Now that I did it, I can go on to win all the bowling trophies ever!... said no sane person ever.
Yeah. Those are totally the same thing.
This is more like lining up the ball rolling thing that kids use, seeing where the ball goes, then adjusting your aim based on the result until you get a strike, at which point you screw the ball rolling thing into the floor.
Did they actually change the *process* they use
Yes. You think they just watched the others explode, shrugged, and said, "Huh. Okay, do exactly the same thing again, it might work this time"?
Or are they just getting better at the process they already had, due to practice?
Uh... I'm not sure what you think is going on here. Do you imagine there's some guy called Steve guiding the rockets in with a joystick, and he's only now got the hang of it?
systemd is Roko's Basilisk.
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
And since capital equipment /always/ has a depreciation, you can write off the depreciation instead of watching it burn up in the atmosphere.
And then you can sell the capital equipment to some other sucker.
--
BMO
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.
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.
Live today, because you never know what tomorrow brings
She's got huge.... tracts of land, perfect for landing rockets.
NASA and ESA are both mocking SpaceX.
Are you trying to spell Cthulhu? If so, back to the drawing board.
You can talk money til you're blue in the face, but watch this little spine tingler.
Happiness in intelligent people is the rarest thing I know.
Ernest Hemingway
Look, I love to mock SpaceX myself. I think it's a bunch of over inflated egos reinventing things their grandparents invented without acknowledging anything that came before that they rely on. Like all of the basic research, all of the lessons learned of things that do and don't work, and of course they don't have to invent the machines that make the machines that make the rockets, and invent the materials. Oh, and invent portable computers too. And the language to program them. And a user interface that works. . A little less ego would go a long way in other words.
Even the vertical landing concept is not new, but back then they lacked the fine control to pull it off.
Still, engineering something like that is hard even with all the modern advantages, and those who actually did the work (as opposed to their cheerleaders) should be applauded.
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.
#naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
Ignore the economics and appreciate the engineering marvel of this reusable rocket booster. Once they prove this feat can be reproduced reliably the process of designing a version 2.0 that improves the economics can begin. The fact that they are able to deliver useful payloads doing this kind of R&D is absolutely fantastic.
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
And since capital equipment /always/ has a depreciation, you can write off the depreciation instead of watching it burn up in the atmosphere.
Surely the burning-up-in-the-atmosphere approach qualifies as accelerated depreciation?
I don't care if it's 90,000 hectares. That lake was not my doing.
Do ISRO charge 1/3 as much and deliver buggy crap that blows up on launch like all the H1B shops?
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.
Elon said today in the post-launch press-conference that recovery meant a potential of 1/100 in present operating cost but that fixed cost would not change from recovery. He is trying to reduce fixed cost with additional automation and of course there are economies of scale. 30% is what they can start with and make a profit, which they have to do now. I believe they can achieve a significantly larger reduction over the long term.
Bruce Perens.
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.
While he did not mention Blue Origin by name, Elon made a point of mentioning how difficult it is to cope with high speed horizontal velocity.
Blue Origin just isn't playing in the same league yet.
Pain is merely failure leaving the body
Bitch, please; stop bitching. Nobody thanks the 1st lumberjack or the 1st carpenter or dedicates to Newton, Euler, Kepler.
Get over it.
Two obvious things here. First, who are they going to sell that capacity to? A bunch of cubesats? The income isn't necessarily there.
Second, by this particular compromise in capacity they're trying to get both lower costs per launch and higher reliability of operation. There are some very significant benefits to this, if they can get it to consistently work.
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
The second stage engine has a different design, because it's optimized for operating in vacuum. I think a better plan would be to launch the first stage as disposable when the engines are getting near the end of their life, and use that disposable launch for a heavy payload.
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.
For serious Mars travel, even unmanned, you want to get a big rocket into Earth orbit, then top-up the fuel tanks before accelerating towards Mars. Running fuel trips to low-Earth-orbit is going to be a large "customer", and the weight of the delivered fuel can be matched to whatever the rocket is capable off. Anything to space stations can be filled up to max payload by adding water (for drinking, oxygen extraction, and shielding). So many payloads can be adjusted to match the max payload. Satellites are a big portion of launches right now, but that will change.
SpaceX has uploaded there 4K original as well: https://www.youtube.com/watch?v=sYmQQn_ZSys
And a zoom-in of the landing "hop" https://www.youtube.com/watch?v=j3B9QElpoCk for which the jury is going to subtract points.
It is not obvious that doing this risky vertical landing is going to result in any savings at all.
It is not obvious to you, because you haven't thought the whole thing through properly.
Spend more time thinking and less time posting, and you'll be better off.
Good luck.
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.
Being able to inspect intact engines after a real mission would improve its development and refinement.
I think you're looking at it from the wrong perspective. Given some regular size of payload you need to launch, building one first stage that is 30% bigger and using it ten times, even at the cost of needing 30% more propellant, simply can't be less advantageous than building ten normal-sized stages for single use.
Ezekiel 23:20
Assuming that SpaceX can eventually deliver on their vision of 40 launches per year, cutting off another 30% out of the already quite low figure of 60M means that Ariane is getting off the market and Proton barely survives.
Ezekiel 23:20
For serious Mars travel, even unmanned, you want to get a big rocket into Earth orbit, then top-up the fuel tanks before accelerating towards Mars.
No, you wouldn't. Because now that big rocket launch is a single point of failure for your mission. Further, thrust per mass is not that important once you have a vehicle in orbit. What took a lot of thrust to lift off of Earth can be moved with a much smaller rocket engine in space, even considering the Oberth effect and crossing of the Van Allen belts.
So many payloads can be adjusted to match the max payload.
Those payloads can also be adjusted to cheapest cost per unit mass too.
Since the Dragon is volume-limited already, the only thing you gain by expending the first stage with it is more scrap at the bottom of the ocean.
Ezekiel 23:20
I would think that even considering all the differences, at least quite a few of the parts could still be reused to rebuild an upper state engine.
Ezekiel 23:20
They have at least done a test firing on the previously landed first stage. And the refurbished first stage will probably launch in Fall 2016.
Plus, now they have two to play with!
That's the analogy to think about with this. When is it best to use the artillery approach, and when is it best to use an airplane approach. An airplane approach implies refueling and re-use. You can amortize investments to improve capabilities over time. Artillery is all about cheap getting payload up there.
If you really want to get pure mass to LEO cheaply - it's hard to beat big artillery with a rocket stage. It has a few issues though.
Your payload has to be able to handle the G's from firing. The payload is probably fairly small unless you build a really big gun. If you are interested - google Gerald Bull.
Another cheapish way to get lots of mass to orbit that is mostly politically acceptable would be *really* big rockets. Some of the plans for humungous solid rocket boosters etc. Big diameter solid rockets are hard to beat for cost if you are going to throw it all away.
The truth is it's a continuum. You can plot this stuff on a graph and it's very informative. You discover the above. Artillery to LEO is very cheap - but limits you to tiny payloads. Massive throw away solids are cheap too, but if the launch vehicle fails you lose a lot. For things you value a lot (like people) you may not want to use a huge solid.
If you want to launch truly huge amounts of stuff to orbit it's very difficult to beat Orion and nuclear pulse propulsion. Politically the only way you'd see that happen would be to save the planet.
How about we put the end-of-life first stages into orbit, and lash them together into orbital fuel depots?
Mission: To provide products that consume time and energy as entertainingly as permitted by the laws of thermodynamics.
What part of fine control did they lack? Processing? Sensors? Engines?
Actually, pulling something out of orbit takes a *lot* less fuel than putting it there in the first place - you don't have to stop, you only have to include a heat shield and slow down just enough so that the opposite side of your now-elliptical orbit intersects the Earth's atmosphere. Air resistance is your friend. After a pass or two you're pretty much at first-stage velocities, and your craft is a lot lighter than the first stage as well.
Also, reentry is pretty much already standard for orbital vehicles, though not all are designed to reach the ground in one piece. The alternative is leaving huge chunks of trash in orbit to hit things you care about.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
...let me know when I can ride that first stage up and back, and do so reliably, so I can have fun watching payloads going into orbit first-hand.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
Then they should just land it with parachutes and just pay more in this supposedly cheap fuel to make up for the extra mass needed to make the structure strong enough to new forces applied to it.
It's actually saving more like 70% of the rocket (the first stage is much larger and more expensive than the second stage). It's only a 30% reduction right now to account for the fact that recovery is not guaranteed yet, plus refurbishment costs and fixed infrastructure/launch costs, and of course R&D and profit.
And in rough seas
Based (1) on some quick calculations on the video based on the speed of the exhaust traveling across the deck, (2) on the word of an experienced blue water sailor who looked at the sea state in the video, and (3) what Elon Musk said during a press conference, the cross winds for that landing were about 40 knots. That's intense!
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
Consumables for the whole thing are around $200k-$250k. By "whole thing" I mean the F9+Dragon stack, which consumes LOX, kerosene, helium, nitrogen, hydraulic fluid, Draco hypergolics, and TEA-TEB for Merlin start-ups.
A successful API design takes a mixture of software design and pedagogy.
So, when you get to your car to drive to work in the morning, you load up every last pound of unused capacity with trash and dump it at the dumpster behind your office? If you don't, you have an operational problem at the outset. You should have bought a much smaller car, and kept your weight tightly controlled.
A successful API design takes a mixture of software design and pedagogy.
It was even better: both the Dragon and the 1st stage survived the breakup of the 2nd stage. That was a sight to behold. If it wasn't for the flight termination system, the 1st stage and Dragon could have been recovered intact. If the CRS-8 kind of S2 failure happened today, and the flight rules were such that neither the range nor the automated termination system would have blown up what's left, we would have had a Dragon and S1 recovery. That's pretty amazing capability if you ask me. Sure other things could always go wrong, but I think it's quite reassuring that we have now experience with a S2 failure that leaves S1 and the payload intact!
A successful API design takes a mixture of software design and pedagogy.
I'm beginning to view any suggestion of splashing down reusable [non-SRB] stages with parachutes to be a troll nowadays.
All hail Cthulhu, may his tentacleness embrace us and usher in a thousand years of darkness!
I'm not expecting a relaunch until they've recovered three. That would give them one for destructive analysis and one to preserve.
"Lack of speed can be overcome. In the worst case by patience." --Znork
Storing cryogenic liquids is a hard problem. Even in space, they boil off.
Karma: Poor (Mostly affected by lame karma-joke sigs)
Yes but the unused fuel represents payload mass which can't be delivered to orbit, which reduces revenue.
I really think you don't know what the word revenue means.
Because this assume that the hardware will actually be reusable. Rocket engines are not like jet engines. All the data on the space shuttle has shown that its engines basically needed to be rebuilt every time, over periods of several months. This was not correctly anticipated by NASA and as far as I know, it was never solved over the entire life of the Space Shuttle. This fact was also the main reason the Space Shuttle was not able to launch sufficiently often.
This also assume that the hardware will be retrieved every time. Perhaps SpaceX will improve, but it looks as if a vertical landing is actually harder than an vertical launch, and we know those are not 100% reliable.
SpaceX believes that reusing the 1st stage could lower its launch costs by 30% ; I'm just being highly skeptical of this claim. Fortunately, it doesn't matter all that much.
What I find highly annoying is the belief that because SpaceX is a private enterprise, they will necessarily do better than a large governmental agency like NASA.
The rocket equation is highly non-linear. If you leave 30% of the fuel in the rocket for the return trip, you may lose a large proportion your final impulse and so final speed before separation with the second stage. I don't see how that could be economical.
The thing is that reusable engines have existed for a while. Solid Rocket Boosters are the simplest. They use 100% of their fuel every time, and they are retrieved by parachutes. Even under these conditions, they need significant rebuilding. SRB Rebuilding issues were a significant factor in the Challenger disaster. How economical was that?
Depends on many factor, like reliability, and how much of the retrieved engines they can actually reuse.
So you have to send to orbit a heat shield. This is not free.
Mocking is not the right term. They are skeptical because both ESA and NASA have looked at the economics and practicalities of doing the same thing, and rejected the idea.
Now if SpaceX do it, all power to them.
Not a bad comparison. Passenger planes do sometimes fly "home" empty (except for the pilots of course), and spending tons of fuel doing that is still a lot cheaper than scrapping the plane and buying a new one at the airport where it's needed.
Processing, presumably.
The engines can't throttle down to hover, so they have to come down at speed, brake at exactly the last moment, and then cut off just as the rocket would otherwise start lifting off again.
Nope, but it's a hell of a lot lighter than the amount of fuel it replaces, which is all that's important.
As others have pointed out in regards to the first stage recovery - the point is not necessarily to eliminate as much mass as possible from every launch, but to maximize the economic return on the launch - because right now the cost of a launch is basically fixed at slightly more than the cost of the vehicle, regardless of payload size. The rocket is also built to the most extreme payloads it can service, resulting in lots of excess capacity for the average launch, and it's unlikely that that excess capacity can be sold effectively since that would require that other payloads need to be delivered to basically the same narrow range of orbits AND be capable of being physically squeezed into the remaining cowling volume without throwing off the center of gravity or risking damage to the primary payload.
Fuel is typically less than 5% of the launch cost, with 90+% being the vehicle itself. I've heard numbers in the 60-70% range for the cost recovery of the Falcon 9R first stage, so maybe 20-30% for the second stage. A launch currently costs $61.2M, so we could conservatively say that landing the first stage for reuse is worth about $36M, and the second stage about $12M, leaving an extra 10% for refitting costs. Those costs may prove higher than that, especially before reuse is mastered, but even if you're only recovering 70%or even only 50% of your launch costs, it's extremely unlikely that you could arrange for secondary payloads that are anywhere near as lucrative.
As others have probably pointed out - the current state of affairs is akin to requiring 747s to be completely scrapped after every flight. It's incredibly wasteful, and causes the ticket price to be so high that only the most economically valuable payloads are even considered.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
$60 million to build a rocket, vs. $200k to fuel it. Even if (and I do stress IF) half the fuel cost was to account for inefficiency in carrying extra fuel and landing the rocket, that's still a heck of a lot cheaper than a 1-shot $60m rocket every time you launch.
Even if they reuse the rocket only once before having to scrap it, that halves the mission cost of each launch.
I might suck at math, but even I'm not that bad at it. And de-orbiting something isn't remotely as costly in terms of fuel as you imply, but that's also why the first and primary stage don't actually achieve orbit in a multi-stage vehicle, which, in the history of rocketry, is not something that happens... pretty much ever. As for the later stages, either leave them in orbit, or leave them with just enough fuel to deorbit, but since those upper stages are insignificant in terms of cost as compared to the main launch vehicle, you don't bother landing them, and just let them burn up on re-entry, if you're that concerned about creating space junk.
"Inveniemus Viam Aut Faciemus" 'We will find a way... Or we will make one!' --Hannibal of Carthage
Before you lecture, research.
SSME is staged combustion vs gas-generator on the Merlin 1D which is a world of difference.
SpaceX has done quite a bit endurance testing on it's engines and they are absolutely able to fly multiple missions without complete rebuilding. Their design lifetime is 25 missions if memory serves. Maintenance? Yes. Rebuild? Certainly not.
Be ask skeptical as you like but even if they stick 50% of launches, it's a major savings. I'd venture to guess the reason they aren't showing more than 30% savings is to not set investor expectations too high. New rocket = $60mil, refuel = $200K. Do the math even if you factor in maintenance.
SpaceX will (and is) doing far better privately than NASA has publicly. They're not rife with corruption, bribery, and general governmental BS that NASA was and is.
You can get rich if you own a politician, but you have to be rich to buy one in the first place.
What you claim as research is simply company communication. They have no duty of public disclosure unlike NASA. There are many other cost factors in engine reuse than fuel cost, like others have said on this very thread.
Right now SpaceX is riding off the back of NASA. We'll see how this pan out in the long run. Private enterprise is not able to rewrite the laws of physics. NASA may be rife with corruption and top-heavy with management, its engineers are still top-notch, and they are skeptical as well.
There was a proposal to do this with the shuttle's main fuel tank. Vented, scrubbed, and repressurized they would have made massive space habitats, far larger than the ISS. The downside was that they weren't designed for it, and a bunch of stuff would have been a PITA with them.
I wish this had been pursued. The dregs from a single launch could have kept MIR in orbit for another decade. That was a lot of kit to drop into the ocean.