A blogger by the name of M. Moleman, who calls himself “The Armchair Space Expert,” has published a cost analysis of NASA’s Space Launch System.
Moleman defends SLS against charges made by John Strickland, who believes it is unaffordable. Moleman’s conclusion is rather positive:
If we were to take SLS’s preliminary schedule of one cargo flight and one manned flight every other year, we get $1.2 billion for the cargo flight, and $2 billion for the manned one using Orion. A development cost of 12.6 billion dollars will have to be spread out over the total number of flights too, so if we use 30 flights like mister Strickland did we have to add $420 million to every flight. Over 30 flights, the average cost of SLS would be $2.02 billion per flight, though the number of cargo missions would probably end up dominating later on since most current Design Reference Missions would require more cargo then crewed flights. With a ratio of 2:1, we get a total of $1.89 billion per flight. If we take the costs of SLS only, not counting Orion, we get $1.6 billion per flight, which equals $18.000 per kilogram. Would this be expensive? Yes. Are there better alternatives out there? Absolutely. But it is nonetheless a huge improvement over the Space Shuttle, with payloads three to five times as big, much lower cost per kg to orbit, while eventually taking up less of the overall annual budget of NASA.
Unfortunately, his analysis contains a number of errors.
First, Moleman believes that fixed costs do not count. He argues that “adding the cost of an SLS to the annual fixed cost” is “wrong” because “the majority of fixed costs are paying the men who work in the facility.” But those facilities and men are there for a reason. If NASA were not operating a rocket program, it would not need to maintain launch pads, vehicle assembly buildings etc. The cost of maintaining those facilities and the associated workforce must be charged to the program they support.
Second, Moleman ignores the cost of money. He calculates the total development cost by simply adding up the amount of money spent each year. His method assumes that a dollar spent today has the same value as a dollar spent or received some time in the future, which is an economic fallacy. NASA is spending money to develop the Space Launch System right now, but its benefits won’t be received until some time in the future, over a period of perhaps 20 or 30 years. NASA is effectively borrowing money from the Treasury for a long-term project from with no immediate return. So, the cost of money over the next 20 or 30 years needs to be taken into account.
The Department of Defense does this with an accounting method called Life Cycle Costing, which assumes development money is “borrowed” from the Treasury at the prime rate and paid back over the expected operational lifetime of the system. This understates the true cost, since the government is giving itself an artificially low, subsidized rate — a high-risk project like most military systems would command a much higher interest rate on the free market — but DoD is at least making an attempt to account for the cost of money. Even using the prime rate, the cost of money adds greatly to the price tag for a new weapon system.
Anyone who has purchased a house knows that interest cannot simply be ignored. But for some reason, most discussions of NASA projects do just that.
Third, Moleman makes a spurious and inaccurate comparison to the Space Shuttle:
But it is nonetheless a huge improvement over the Space Shuttle, with payloads three to five times as big, much lower cost per kg to orbit, while eventually taking up less of the overall annual budget of NASA.
How is the Space Shuttle even relevant? The Shuttle is no longer flying, so it’s not an option at this point. Canceling SLS would not result in more spending on the Space Shuttle. Why does Moleman choose to beat a dead horse?
Furthermore, the Space Launch System is intended to be a system for human space exploration. The proper figure of merit is how many humans it can fly, not how many sandwiches they can bring along with them. The Space Launch System may have a payload three to five times larger, but in its planned configuration, it will launch only four astronauts at a time. That’s significantly fewer than the Space Shuttle. Moreover, it appears that two SLS launches will be required for each manned mission. Two Shuttle flights could launch 14 astronauts, while two SLS missions will only launch four. And SLS will fly less often than the Shuttle.
In reality, Moleman is calling for a slow phaseout of the NASA human space program (while maintaining the expense).
Finally, there’s this bit of silliness:
Once the ISS goes down around 2020 and even more of the budget is freed up, with enough room to allow development of a Deep Space Habitat, Solar Electric Propulsion stage and maybe even a Lunar Lander, we could finally do some real exploration. No longer shall we be restrained to going around in circles.
Where to begin? Technically, the ISS orbit isn’t circular, it’s an ellipse. We’ll assume Moleman knows that and is simply using language in a sloppy fashion. What is his point? Nearly all orbits are ellipses. When NASA sends astronauts to the Moon or Mars, they will still be traveling on an ellipse or “circle,” albeit a much bigger one. The alternative would be a parabola or hyperbola, but the energy requirements for those are prohibitive.
Moleman wants NASA to destroy a $100-billion space station so it can buy some new deep-space exploration hardware. That’s like tearing down your house so you can buy a camper and go on vacation. Destroying an existing asset is another cost that needs to be accounted for. Granted, the current value of ISS is much less than $100 billion. Depreciation must be accounted for, and frankly, ISS was probably never worth the $100 billion NASA paid for it. Still, ISS does represent an asset that would cost tens of billions of dollars to replace.
NASA is currently evaluating the possibility of extending the ISS lifetime to 2028. By the time the station reaches the end of its useful life, new 3D printing technologies will make it possible for NASA (or someone else) to disassemble its modules and reuse the materials. Throwing such a valuable asset away simply to build something new and expensive seems wasteful. Even if it’s warranted, the loss of ISS must be accounted for in the cost of the new program.
Alternatively, NASA could build a deep-space habitat, solar-electric propulsion stage, and lunar lander with the money now being spent on the Space Launch System. Such components could be launched on Delta, Atlas, or Falcon rockets that currently exist or are already in development for other programs. That would not require NASA to throw away an asset worth tens of billions of dollars, and it would allow NASA to begin deep-space exploration much sooner (assuming that’s what NASA really wants to do).