Due to SpaceX's recent advancements in now proven rocket tech, why does the government still fund (what some would argue to be bloated) cost-plus contracts with Boeing and Lockheed? Am I missing something?

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    $\begingroup$ Answers to "Can someone explain to me why the government..." questions are always related to getting re-elected. I've just asked How many US states receive large amounts of money due to SLS? $\endgroup$
    – uhoh
    Commented Jul 18, 2020 at 7:16
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    $\begingroup$ Which spacecraft of SpaceX has "the same capabilities or better" and has been shown to be reliable and low cost? We had three FH laucnhes with significant less capacity than SLS and zero Starship launches. Also, why would you want to have a single point of failure and only one option? $\endgroup$
    – Polygnome
    Commented Jul 18, 2020 at 8:31
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    $\begingroup$ Why would the government want to tie itself to a single provider? The Moon missions of the 1960s/70s were supposedly a government project, but the government provided nothing, only the money. Private companies built the rockets that flew. If you want value for money, it is better to put individual projects out to tender, to involve several bidders, rather than give the work to a single provider who, in effect, then does not have to bid for the work or provide value for money. $\endgroup$
    – Ed999
    Commented Jul 18, 2020 at 18:47
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    $\begingroup$ @Ed999 Are you seriously claiming that NASA is not a government agency? $\endgroup$
    – Ian Kemp
    Commented Jul 20, 2020 at 16:08
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    $\begingroup$ @Ed999 You act like the situation is exactly the same now as it was in the 60s. Stop ignoring how revolutionary SpaceX was and is for the industry. In the 60s, private companies did not build rockets with the same sort of autonomy that SpaceX does now. NASA was very heavily involved the entire time, and the projects would not have even been started without NASA, period. That's not the case with SpaceX. SpaceX said "hey, we want to build rockets." And then they did. And then NASA started using them. $\endgroup$
    – user91988
    Commented Jul 20, 2020 at 17:28

6 Answers 6


It is still way too early to make such a judgement.

It's easy to be overly optimistic about the cost of a program. The Space Shuttle was supposed to have dozens of flights each year and be super-cheap because it was reusable.

However, you simply don't know the true cost until a program has been in use for several years. After several years of the Shuttle, it was realized that the need to inspect, refurbish, and test the spacecraft increased the cost considerably, and made it impossible to meet the original schedule.

SpaceX may have successfully launched their first crewed flight, but it hasn't even landed yet. SLS hasn't launched yet. Neither program is mature enough to know what the eventual costs will be. Perhaps one or both spacecraft have a flaw which necessitates costly changes. In time, we will know.

Also, one of the goals of the Commercial Crew Program was to have more than one vehicle supplier. This could potentially lower costs through competition, and leave NASA with options in case there was a problem with one supplier. To shut down one of the vendors now would eliminate these potential benefits.

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    $\begingroup$ This got accepted?? We know the cost of zero-reuse SpaceX Falcoln hardware reasonably well, and we know the cost of the SLS first stage reasonably well (because SLS uses known engines). If SpaceX were to have a serious crew capsule weakness, you could put the Orion on SpaceX boosters and it would be still much much cheaper than SLS. This answer throws doubt where none belongs. $\endgroup$
    – Joshua
    Commented Jul 20, 2020 at 15:47
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    $\begingroup$ This answer is confusing. It's not too early to know with absolute certainty that the cost of each SLS flight will be in the billions of dollars, not counting the $15B or so in development costs already incurred, or the tens of billions more to be spent on development. That's a launch cost of at least 10 times of an expendable Falcon Heavy, which can put roughly two thirds the payload mass into orbit. $\endgroup$ Commented Jul 21, 2020 at 0:29
  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – gerrit
    Commented Jul 21, 2020 at 10:42

Eh, to begin with this statement isn't accurate.

SpaceX ... has the same capabilities if not better?

Falcon Heavy as stands can't replace SLS and launch Orion on the required orbit without significant modification. (and even if Falcon Heavy could launch Orion, it wouldn't be able to dual manifest Gateway modules) Dragon isn't comparable in capabilities to Orion and couldn't replace it without again, significant modification, despite what Zubrin may think. Starship is still very much in development phases.

Granted Falcon Heavy can launch large scientific spacecraft like Europa Clipper, which was the other main purpose of SLS. (Stuff like an Europa Lander and the next large astrophysics mission would be outside the capabilities of Falcon Heavy and look to require SLS, but by the time they're launching in the 2030s Starship would likely be in good form)

In summary NASA pursues SLS and Orion because Falcon Heavy, Crew Dragon and Starship are currently unable to replace it for Artemis. (granted there is some congressional pressure due to SLS being a jobs program, but fundamentally, the current alternative in SpaceX isn't clearly better)

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    $\begingroup$ +1 Falcon heavy's payload fairing volume is also rather small--its the same size as the standard F9 which excludes volumetrically large payloads $\endgroup$
    – Dragongeek
    Commented Jul 18, 2020 at 11:44
  • $\begingroup$ Of course the question that immediately comes to mind is "Why would you want to launch Orion?" or other large, one piece spacecraft, instead of modular ones that are assembled in orbit? Imagine trying to launch the ISS in one piece :-) $\endgroup$
    – jamesqf
    Commented Jul 18, 2020 at 16:46
  • $\begingroup$ @jamesqf well, the more modules the more that can go wrong in orbit. And I guess building a station of the same utility as the ISS from fewer, Skylab-like modules launched on a Saturn V derivative would in hindsight have been cheaper. $\endgroup$ Commented Jul 19, 2020 at 0:20
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    $\begingroup$ but there is the "military" fairing @Dragongeek $\endgroup$
    – user20636
    Commented Jul 19, 2020 at 9:29
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    $\begingroup$ @jamesqf Every piece of equipment was built for a specific launch though. There were no backups. $\endgroup$
    – Graham
    Commented Jul 20, 2020 at 8:13

All the answers are right in their own way. One thing that is not addressed:

The Falcon Heavy is not even remotly on par with the SLS in terms of rocket diameter and payload mass.

According to Wikipedia (Falcon Heavy, SLS) the Falcon Heavy can launch 63 tonnes to LEO while SLS can deliver a whopping 95 tonnes in the Block 1 configuration which (if everthing is going according to the plans) will be raised to 130 tonnes in the Block 2 configuration

The diameter of the second stage of the falcon heavy is 3.6m with the payload fairing measuring 5.2m. The SLS has a 5m diameter second stage which will be replaced by a 8.4m one in the Block 2 configuration. I haven't found any data on fairing sizes in the SLS. This NASA fact sheet does not provide any numbers.

Of course the higher payload and diameter are bought with a lot of money. So the cost in $/kg delivered to orbit are significantly lower with the Falcon Heavy.

But for large payloads you need a large launch system.

You could of course argue that you could just launch two Falcons with lower costs than one SLS launch. Which will maybe be done in the future. But I'm not aware of a single project that will be done or is planned that uses in-orbit assembly.

So for now this will not happen. (Maybe I missed something, in this case just correct me)

  • $\begingroup$ Your second launch would just be a Centaur that docks with the first and providing boost beyond LEO. $\endgroup$
    – Joshua
    Commented Jul 20, 2020 at 15:51
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    $\begingroup$ This answer overlooks cadence, the SLS cadence will be at most once every 6 months making complex missions impossible. Also in almost every other launch system as payloads are increased, cost/KG declines, you don't pay a premium for larger launch systems, which is why cost.KG is significantly cheaper for FH over F9. Lastly, SLS launches will cost be well over a billion each (it will expend over a half billion in engines each launch), without counting the $20B or so in development costs. What extra capabilities it offers isn't worth 20 times as much per KG. $\endgroup$ Commented Jul 21, 2020 at 0:48
  • $\begingroup$ I never said that my answer is the one and only truth. It has to be viewed in the context of all the other answers which review other aspects, especially politics. $\endgroup$
    – CKA
    Commented Jul 21, 2020 at 21:18
  • $\begingroup$ Nevertheless, by pure power per launch SLS is superior. All space exploration projects take a lot of time to realize and by now there is no comparable launch alternative available. Maybe some future space project will be planned with several launches and in-orbit assembly but there is none I know of. This is not an endorsement of SLS but just a simple fact. Feel free to correct me on this $\endgroup$
    – CKA
    Commented Jul 21, 2020 at 21:28

Part of it is leveling employment. The government is fond of large projects that require multi-year ramp-up and ramp-down and massive up/down swings in employment need.

Suppose in 2019 you're hiring every rocket scientist in town for project X. 2023, you lay them all off because the project is done. Then project Y arrives, a modification on an existing system, and it has military urgency.

Only you go to get your rocket scientists back who really know that system, and they're gone. They didn't wait around for you to hire them back. Some went to be data scientists for Amazon and got poached by Google and live in the Bay Area. Others work for the Texas oil companies. Others for FMC in modeling geology out of Salt Lake. A few emigrated and work for ESA or Airbus, those are the only ones whose skills haven't rotted out.

The braintrust is gone. You can’t exactly draft them... so now you have to staff that department up from scratch with green weenies who don't know the systems at all.

So, you have a government project that's fairly "D-list" - that is, the government is willing to tolerate flex on the project. Now you can retain some continuity of staff and expertise, simply because you have other work to give them.

This sort of thing has been done before; this is how Boeing got into the light rail vehicle business.

  • $\begingroup$ Do you have any evidence for this? For example, that the same people might work on the SLS and ASATs? $\endgroup$ Commented Jul 18, 2020 at 12:44
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    $\begingroup$ The core idea of this answer (employment) is correct, but its supporting arguments don't help the answer. $\endgroup$
    – DrSheldon
    Commented Jul 18, 2020 at 14:54
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    $\begingroup$ @OrganicMarble They were just toss-in examples; I think they're irrelevant. I'll just remove them.. $\endgroup$ Commented Jul 18, 2020 at 16:17
  • $\begingroup$ This is just conspiracy theory masquerading as an answer. Congress designed and funded the SLS with a clear purpose is funding favored contractors. None of it has anything to do with employment or funding the 737 Max. Those engineers don't disappear, can always be re-hired, and new engineers can be poached from other aerospace projects. $\endgroup$ Commented Jul 21, 2020 at 15:27
  • $\begingroup$ @SafeFastExpressive I have promptly removed the 737 Max reference, it was never my intention to pick political fights or float particular conspiracy theories, and I apologize if my random example inadvertently did that. I didn’t say anything about favored contractors or directing the work to contractor X vs Y. However it is a genuine fact that the government does look after the corporate well-being of their defense contractors. And you arm-wave how easy/hard it is to assemble and maintain a brain-trust. People are not interchangeable cogs; institutional expertise is a thing. $\endgroup$ Commented Jul 21, 2020 at 18:00

The answer is that SLS's prime purpose isn't a launch system, it's a jobs project. NASA was required to use 45 year old engine technology to ensure that jobs and contracts were funneled to Old Space contractors. There is no way a clean sheet NASA design for a large launch system to support manned deep space missions cost effectively would ever:

• Re-use RS-25 engines costing over \$100M each (vs. Merlin engines at less than \$500k each or other available engines at less than \$20M each)

• Use $100M+ solid rocket boosters, let alone ones made in Utah by the 4th rated SRB contractor in NASA's initial bids.

• Use hydrogen as the first stage fuel, which requires heavier, more complex cryogenic tanks (which is why the SLS is so late) and while offering high ISP doesn't produce enough thrust (which is why the SLS requires SRBs).

• Build a system so complex with cadence so poor it's limited to being able to launch twice a year, which not only limits mission capabilities, but makes it much harder for NASA to use in-space refueling or assembly to dramatically reduce mission costs and increase mission capabilities even further.

The simple answer is the the head of the Senate oversight committee for space exploration is a Senator from Alabama who ensures that every budget for NASA is written very specifically to only be fulfillable by using Alabama based contractors. That Senator has never prioritized actual manned space exploration, as far as he's concerned the project is already a success and will continue to be one as long as NASA keeps funneling $2B+ a year to his constituent contractors, even if it never flies at all.

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    $\begingroup$ This is the correct answer. SLS is a creature of politics, not engineering. It's meant to keep as much of the old Shuttle workforce employed as possible. Which, in and of itself, is not a bad reason - there's a lot of institutional knowledge and skill that's worth preserving. The main problem with SLS/Orion has been shoddy project management on both NASA's and Boeing/LockMart's parts. It was always going to be expensive, but poor management and cost tracking has made it worse. $\endgroup$
    – John Bode
    Commented Jul 22, 2020 at 15:33
  • $\begingroup$ The other answers all tend to the same implied conclusion: if you spend a billion dollars on launch vehicles, when you might have spent less, that money is wasted. That is a naive argument. That billion dollars is spent in the US, providing jobs for US technicians. The arguments for spending less are, in effect, saying: let's provide fewer jobs in the vehicle manufacturing and/or servicing sectors. Every tax dollar spent is supporting American jobs. That is, in itself, a sufficient justification for this type of project - even if most of the jobs are in Alabama! $\endgroup$
    – Ed999
    Commented Aug 1, 2020 at 0:59

The answer is: to avoid a complete space shutdown like occurred from 2003 - 2006.

After the Columbia shuttle disaster, the space shuttle program was suspended from Feb 1 2003 to July 4 2006. By having its only means of getting a man to space suspended, the USA had to rely on other countries. And dependence on other countries is one of those things America hates more than anything. But with multiple options, even if one is ground space is still accessible.

SLS is expensive, but space is expensive.

The shuttle was costing $450M per launch.

SLS is set to cost from $500M per launch.

With the costs comparable, remember that that the shuttle had a 27.5t payload, SLS' payload is 70t.

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    $\begingroup$ The SLS is going to burn up over \$500M in first stage engines alone (SRBs and RS-25s) per launch, not counting the cost of the massive first stage and it's cryogenic tanks, the second stage, assembly, ground crew, etc. The cost of each launch is going to be roughly \$2B, and that doesn't count developmental costs approaching \$20B already. And the total cost of the Space Shuttle program was \$196B for 134 flights, or \$1.5B per launch in 1990s dollars. en.wikipedia.org/wiki/Space_Shuttle_program $\endgroup$ Commented Jul 21, 2020 at 15:20
  • $\begingroup$ @SafeFastExpressive Your numbers are different but still comparable. 1.5B compared to 2B is negligible considering the performance differences. It's just a shame to waste those beautiful RS-25s... $\endgroup$
    – Coomie
    Commented Jul 28, 2020 at 2:33
  • $\begingroup$ That was 1990 dollars, in today’s dollars Shuttle cost over \$2B per launch. Which is ridiculous now and then. Re-using \$100M RS-25s is like rebuilding junked 40 year old Ferrari engines. Hugely expensive to refurb and build new ones. RS-25 is a bad 1st stage engine. Requiring Hydrogen significantly increases first stage mass/ complexity, requiring expensive solid rocket boosters. SpaceX Merlins cost $500k each, and Raptors likely less than \$1M each. Both use dense fuels perfect for first stages, and have high thrust to weight performance obviating the need for costly SRBs. $\endgroup$ Commented Jul 28, 2020 at 18:38
  • $\begingroup$ And billion dollar launches should be long gone in this day and age. Falcon 9 costs \$1,500/lb to LEO, a Falcon Heavy \$1,100/lb. The Shuttle cost \$30,000/lb in 1990s dollars. The SLS will cost \$10,000/lb per launch, with development costs north of \$30,000/lb. SLS is based on a 50 year old tech that massively failed at providing cost effective launches. It’s clear that similar sized launch systems can be built today using common launch technologies to launch at 1/10th the SLS cost or less. $\endgroup$ Commented Jul 28, 2020 at 18:44
  • $\begingroup$ Starship/SuperHeavy will lift larger payloads than SLS and will be significantly cheaper per pound than SLS, Falcon 9, or Heavy. In fact, an expendable Starship 2nd stage at \$100M and a launch cost of \$150M is under \$750/lb. If SS/SH reusable over tens of trips the cost drops as low as \$100 per pound. The gating factor for space exploration is launch costs. We will never make manned deep space exploration common or have large space stations at payload costs over \$1,000 per lb. SLS is a massive step backwards in that. $\endgroup$ Commented Jul 28, 2020 at 18:46

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