> SpaceX’s president, Gwynne Shotwell, estimates that reusing these landed Falcon 9 vehicles will lead to a 30 percent reduction in launch costs, according to Space News.
Surely it will be more than a 30% reduction once they make the rocket refactoring process more efficient? I've heard Elon say that the savings would be an order of magnitude given how low the cost of fuel is relative to everything else on the rocket.
I know Elon is famously optimistic and Gwynne is probably dampening expectations on purpose but 30% doesn't seem very impressive. Is Gwynne just playing down the cost savings or is she likely to be accurate, even in the medium term (3-5 years)?
Costs per launch include fuel (trivial at < $0.5m), rocket (say $30-40m of which first stage is 3/4) and recurring costs like employee time, refurbishment, test fires, barge rental, range costs etc (significant maybe 5-10m?). Musk is prone to talking about the far future as if it were tomorrow and within our grasp today. If you count medium term as 3-5 years (I'd call that short term), there is no way they're getting an order of magnitude saving.
They charge $60m, so it's unlikely ever to come down below 20m without 2nd stage reuse, and say around 5-10m even with full re-use in a few decades. Best case they could probably get it down to 10% of current costs (90% saving) if they manage full re-use and cut down on recurring costs a lot, but for now 30% is pretty impressive.
Remember in the current Falcon 9 design, they are only reusing the first stage -- reported to account for 70% of the cost of the rocket (which is of course different to the retail price of launch service), and attempting to recover and reuse the fairing, an aluminum honeycomb core + carbon fibre sheet enclosure the size of a city bus, which is thought to add a couple million dollars per rocket including capital costs (SpaceX is thought to have limited capacity to produce fairings at a high rate, which is why they're chasing reuse).
They still need to rebuild the entire second stage each launch, and continue to pay the salaries of 4,000+ employees.
If the end-to-end launch service is priced at $60 million, 70% is $42 million, with the other 30% ($18 million) that needs to be paid each launch. Assuming the cost of all re-use is 100% free (gas and go), a full passing on of the savings would mean the second launch (which has a free first stage) could be priced at $18m + ($42m/2) = $39 million.
That's a 35% discount off $60 million. SpaceX haven't proven that reflying a returned booster is safe and reliable. It will take many relaunches to gain statistical knowledge of safety of the fleet they're building.
If SpaceX can reliably relaunch the first stage 5-10 times with minimal refurbishment costs, the amortized costs drop dramatically. During the development of the Merlin 1, testing aimed for 10 full duration (3 minute) test fires. I can see SpaceX aiming for 5-10 flights per booster with the current iteration of Falcon 9 over the longer term.
I encourage anybody interested to play around with this spreadsheet [1]. If the current design can be proven to have say 5 launches per Falcon 9 booster, that's a 65% saving to SpaceX. Falcon 9 is already the cheapest vehicle in its class (though some providers are cost competitive if doing dual launches on say, an Ariane V). The Russia's Proton rockets were reasonably cost competitive, but their reliability has proven to be very low in recent times.
As Amdahl's Law notes, as the number of reliable relaunches per rocket with minimal refurbishment costs increases towards infinity, the total cost will asymptotically approach the currently non-reusable portion of the costs (so in the current design it's the second stage, launch operations, fuel, fairings etc)
In a few decades, SpaceX wants to get airplane like re-use (fully re-usable with thousands of flights per vehicle lifetime), where each passenger pays a marginal cost of roughly the jet fuel cost and inspections and refurbishments don't happen every single flight but at set intervals. That's a probably several design generations away though (human Mars landing will certainly happen first)
What could SpaceX have learned about landing a rocket on a boat resting on waves?
It seems like the craziest idea. I would have said "No chance. Land it on land, like the word says." but they've managed the risks down to where it's not surprising that they've landed yet another one. Some special magic has gone into that and I can't even imagine what issues they've had to solve.
They mentioned on the live stream that the landing point doesn't really change the difficulty. It doesn't matter whether they land on water or on land, for the most part. What makes the landings difficult is how much propellant is left in the first stage. There's more of it left after a LEO launch, so they can do a longer landing burn and during that have more opportunity to correct, e.g. for winds. With the GTO launches there's only very little left, so the landing burn is shorter, which also stresses the vehicle more. This time they were happy to actually do a one-engine landing burn as opposed to three engines like they did with the drone ship landings so far (I think it has always been three engines at first and then one engine for the very last bit for drone ship landings until now).
They've also noted numerous times that waves don't really matter much to the landing.
My daughter and I saw a couple of strange flashes in the sky while out looking for Perseids last night. We're in the UK and the flashes were in Cassiopeia in the North Eastern sky at about 10pm BST, is possible they could have been from this rocket?
The flashes would have been Perseids. We saw a few as well, including one that flared brightly and left a short persistent trail that took about 10 seconds to disperse. If one comes directly down, or at an angle but towards you, it will just look like a flash in the sky.
Depends on the launch. There is no remaining fuel in a second stage for any Delta v to lower its orbit into the atmosphere in most launches. A launch to GTO at 350 x 36,000 km will eventually decay. In some satellite launches there is a third stage (like a fregat, but not the same thing) which performs the final circularization of the orbit. In others the satellite itself does this. In a launch to an MEO orbit like 1500x1500 km the 2nd stage is going to stay up there pretty much forever as dead debris.
Some are deorbited immediately (such as on ISS resupply flights) others are left in orbit but so far they all have fairly low perigees so they re-enter after a few months at most.
[+] [-] davej|9 years ago|reply
Surely it will be more than a 30% reduction once they make the rocket refactoring process more efficient? I've heard Elon say that the savings would be an order of magnitude given how low the cost of fuel is relative to everything else on the rocket.
I know Elon is famously optimistic and Gwynne is probably dampening expectations on purpose but 30% doesn't seem very impressive. Is Gwynne just playing down the cost savings or is she likely to be accurate, even in the medium term (3-5 years)?
[+] [-] agildehaus|9 years ago|reply
30% reduction in launch costs will be hugely welcomed and SpaceX will be able to do lots with the additional revenue.
[+] [-] grey-area|9 years ago|reply
They charge $60m, so it's unlikely ever to come down below 20m without 2nd stage reuse, and say around 5-10m even with full re-use in a few decades. Best case they could probably get it down to 10% of current costs (90% saving) if they manage full re-use and cut down on recurring costs a lot, but for now 30% is pretty impressive.
[+] [-] JabavuAdams|9 years ago|reply
If one launch provider can send you up for $40M instead of $60M for the others, would you ever go with the others?
Suddenly SpaceX owns the launch business.
[+] [-] shasheene|9 years ago|reply
They still need to rebuild the entire second stage each launch, and continue to pay the salaries of 4,000+ employees.
If the end-to-end launch service is priced at $60 million, 70% is $42 million, with the other 30% ($18 million) that needs to be paid each launch. Assuming the cost of all re-use is 100% free (gas and go), a full passing on of the savings would mean the second launch (which has a free first stage) could be priced at $18m + ($42m/2) = $39 million.
That's a 35% discount off $60 million. SpaceX haven't proven that reflying a returned booster is safe and reliable. It will take many relaunches to gain statistical knowledge of safety of the fleet they're building.
If SpaceX can reliably relaunch the first stage 5-10 times with minimal refurbishment costs, the amortized costs drop dramatically. During the development of the Merlin 1, testing aimed for 10 full duration (3 minute) test fires. I can see SpaceX aiming for 5-10 flights per booster with the current iteration of Falcon 9 over the longer term.
I encourage anybody interested to play around with this spreadsheet [1]. If the current design can be proven to have say 5 launches per Falcon 9 booster, that's a 65% saving to SpaceX. Falcon 9 is already the cheapest vehicle in its class (though some providers are cost competitive if doing dual launches on say, an Ariane V). The Russia's Proton rockets were reasonably cost competitive, but their reliability has proven to be very low in recent times.
As Amdahl's Law notes, as the number of reliable relaunches per rocket with minimal refurbishment costs increases towards infinity, the total cost will asymptotically approach the currently non-reusable portion of the costs (so in the current design it's the second stage, launch operations, fuel, fairings etc)
In a few decades, SpaceX wants to get airplane like re-use (fully re-usable with thousands of flights per vehicle lifetime), where each passenger pays a marginal cost of roughly the jet fuel cost and inspections and refurbishments don't happen every single flight but at set intervals. That's a probably several design generations away though (human Mars landing will certainly happen first)
[1] https://docs.google.com/spreadsheets/d/144Y_OVmFFYTh_zTiV-FH...
[+] [-] cbeach|9 years ago|reply
[+] [-] richardw|9 years ago|reply
It seems like the craziest idea. I would have said "No chance. Land it on land, like the word says." but they've managed the risks down to where it's not surprising that they've landed yet another one. Some special magic has gone into that and I can't even imagine what issues they've had to solve.
[+] [-] ygra|9 years ago|reply
They've also noted numerous times that waves don't really matter much to the landing.
[+] [-] journeeman|9 years ago|reply
[+] [-] _audakel|9 years ago|reply
[+] [-] ChuckMcM|9 years ago|reply
Can't wait to see what they launch with the refurbed boosters.
[+] [-] dnautics|9 years ago|reply
[+] [-] Animats|9 years ago|reply
[+] [-] creshal|9 years ago|reply
[+] [-] patman81|9 years ago|reply
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[+] [-] david-given|9 years ago|reply
http://www.heavens-above.com/IridiumFlares.aspx?lat=53.1204&...
[+] [-] simonh|9 years ago|reply
[+] [-] DavidSJ|9 years ago|reply
[+] [-] geuis|9 years ago|reply
[+] [-] walrus01|9 years ago|reply
[+] [-] InclinedPlane|9 years ago|reply
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[+] [-] justrossthings|9 years ago|reply