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Estimating SpaceX's Reusable Rocket Cost Savings (theverge.com)
An anonymous reader writes: On Monday, SpaceX successfully landed its Falcon 9 rocket after launching a group of satellites into orbit. It's a huge breakthrough for the commercial space industry, because reusing rockets will dramatically reduce launch costs. The question now is: by how much? Elon Musk says it takes $60 million to build the Falcon 9, and $200,000 to fuel it. That's a big difference, but we can't expect them to immediately launch the rocket again after refueling it.
"The Falcon 9 experiences major temperature changes during its flights, as well as intense pressures and vibrations from the winds in the atmosphere. These all produce wear-and-tear on the vehicle's hardware — meaning the rocket might need repairs and updates before it can launch again." This kind of refurbishing is why the Space Shuttle ended up being way more expensive than expected. Fortunately, the Falcon 9 is not nearly as complex.
This is now the true test of SpaceX's design talents; if the rocket is built to be durable, then repairs and replacements could keep relaunch costs very low indeed. Steve Poulus, a former NASA project manager, suspects final costs could be driven below a million dollars. That figure would give SpaceX the capability of easily underbidding any competitor for government contracts, not to mention bringing it into affordability for any number of companies who'd like to put a satellite in orbit.
"The Falcon 9 experiences major temperature changes during its flights, as well as intense pressures and vibrations from the winds in the atmosphere. These all produce wear-and-tear on the vehicle's hardware — meaning the rocket might need repairs and updates before it can launch again." This kind of refurbishing is why the Space Shuttle ended up being way more expensive than expected. Fortunately, the Falcon 9 is not nearly as complex.
This is now the true test of SpaceX's design talents; if the rocket is built to be durable, then repairs and replacements could keep relaunch costs very low indeed. Steve Poulus, a former NASA project manager, suspects final costs could be driven below a million dollars. That figure would give SpaceX the capability of easily underbidding any competitor for government contracts, not to mention bringing it into affordability for any number of companies who'd like to put a satellite in orbit.
Still, there are obstacles. SpaceX still needs to demonstrate the ability to consistently produce and launch rockets many times a year after the June accident caused an unexpected, six-month setback, something it will do with several flights planned for the weeks ahead.
Just because it's relatively cheap to use Space X, if I have a 50-50 ( better or worse) chance that my $100 million satellite that took several years to design and build is going to get blown up, I'll pass.
Elon Musk and company have been making huge achievements and seems one of the few people in industry to take the long view of things and it's likely to pay off in the end even though the MBAs hate him at the moment.
I, for one, welcome our new Martian overloard!
"Be particularly skeptical when presented with evidence confirming what you already believe." -
This is complicated somewhat by the fact that rocket engines have significant economy of scale in production: if you reuse each one, say, ten times, your production rate is ten times lower, so the engines are more expensive.
So it's not completely obvious how much savings you get. It seems pretty clear you get some. But how much?
A quote from an NBC News story about Blue Origin, a company founded by Amazon CEO Jeff Bezos, shows one of the differences between SpaceX rockets, which go into orbit, and Blue Origin rockets, which don't orbit:
... important to clear up the difference between 'space' and 'orbit'," Musk posted on Twitter. ... A rocket needs to be traveling about three times the speed of sound, or Mach 3, to reach space, but orbital missions require speeds about Mach 30, Musk said.
SpaceX is working to reuse rockets that are returning from the higher altitudes and faster speeds of orbital missions. "It is
The wear mechanisms are poorly understood
Yes, they are, because until Monday, we had exactly 0 (zero) first-stages that have returned from their missions. Thing will change now.
No sig today.
After decades of engineering work, heavy lift boosters still have about a 1% failure rate, If SpaceX can't beat that, then there is no glorious future for manned spacefight.
Why not? It is a 1% failure rate without reusability. A 10% failure rate but with reusability means that you beat the cost of 1% failure rate by magnitudes.
Then there is the way the Indian space programs does it. Cut down the cost enough to afford ten launches for the same cost as NASA has for one launch. With an 80% failure rate you still get more stuff up.
Zero-tolerance is a great way to spend a lot of money without getting the results you pay for.
I'm not saying that you want a 10% failure rate or even that 1% is good enough. But I know that the ideal failure rate you want is more than 0%. If you achieve 0% then you are not getting the most out of the money you put in.
Interesting numbers. Let's try a variant case. Suppose in addition: You're assuming that the non-reusable launch vehicle cost per launch is $60M. OK, let's start out by assuming 1/3 of that is fixed costs and operations costs, and 2/3 the vehicle cost, which is split evenly between the two stages (first stage is larger, but not proportionately more expensive). So, of the $60 million, $40 million is spent even if the vehicle first stage was free. Now assume that re-usability increases the launch cost by, say, $5 million (launch operations are expensive! and the cost is not entirely the vehicle). Assume that all the stuff needed to make the first stage reusable increases the stage cost by 25%, from $20M to $25M. And assume that the delta-V and the added mass to do the fly-back decreases payload by 10%, and that the price you sell the launch for decreases a similar percentage (some payloads won't care, but some will.)
First off, the current cost of the rocket already includes the costs to do reusibilty, so the cost of the first stage will not increase- it is designed be reused up to 10 times right now with no change in hardware.
Secondly, the cost of the 2 stages are not even remotely close to equal; the first stage has 9 Merlin engines, the second stage only has 1. An estimate of 6 to 1 (first to second) for costs would be more reasonable.
Thirdly, the payloads currently quoted already include reusability (16MT to LEO and 4.5MT to GTO). No loss of earnings there.
So none your variant assumptions are useful for this discussion.
Let's look at some other factors you haven't considered.
Like the space shuttle, SpaceX now has a rocket for examination that has flown a full mission and hasn't had a 6G salt water landing. This means that they will be able to do full engineering analysis on what stresses the rocket actually experienced during a flight event that increase all steps necessary for re-use. The results of that analysis will allow them to determine what parts of the rocket need to be enhanced or reduced to meet the 10 tens re-use goal. SpaceX has the luxury of being to make changes to their rocket without Congressional approval, so this information can be used immediately to improve the vehicle. The design goal of the Falcon is that the rocket need not be "refurbished" after every flight, just put through some standard flight maintenance tests. Having the flown stages available for analysis will help them to meet this goal.
Additionally, SpaceX currently has launch costs based on 6 launches a year. As they have already demonstrated the ability to launch with a cadence of 2 weeks several times, being able to increase their launch rate to a minimum of 1 a month will cut their overall costs per launch.
Let's assume that a slight redesign based on analysis of real-world data let's them increase reliability of the Falcon 9 to 1 in 100 and increase the payload by 1MT to GTO. At 5.5MT to GTO, this let's them handle 90% of all GTO launches (6MT is at the current top end for commercial satellites to GeoSynchronous orbits) with the reuable design. 5MT is compable to $137M Ariane 5 capbility or $132M for an Atlas 5 launch for NASA with both the throw weight and reliability requirements necessary to get these flights.
$60M to launch the current, reusable Falcon 9 1.1FT.
33% is launch cost. - $20M
56% is first stage - $34M
11% is the second stage $6M
Assumption 1: increase in flight rate reduces launch costs by 25%
Assumption 2: landing/recovery/flight readiness check costs $5M a launch
Assumption 3: 10 flights reuse of the first stage = $3.5M a launch
Under these assumptions:
Launch cost $15M
Landing/recovery/checks $5M
First stage $3.5M
Second Stage: $6M
Total: $29.5M
I'm OK with those numbers given what they can charge and how quickly they can do regular launches. Where they will really rake in the cash is for a Facon Heavy launch (same vehicle with 3 first stages instead of 1) with 56MT to LEO for an asking price of $110M and a cost, by these assumptions of $35M. They could even reduce their price after a few launches of the Heavy to $56M, and start launching bulk cargo to space at a rate of $1000/Kg
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