I have never studied rocket science and am just curious about this.

I would assume one Raptor 2 engine could launch a small rocket to space. I heard they are able to make them for less than a million dollars. Wouldn't that be amazing for meteorology and weather prediction? You could launch them vertically and have them land in a desert with drogue chutes. Retrieve and repeat. This should be cheap enough to send up to look at a hurricane or something like that.

Or rocket hobbyists who might sell it after a successful launch.

These markets alone could account another 100 engines a year which could help bring down costs with scale.

Why doesn't this exist?

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    $\begingroup$ At this point Raptor is far too unreliable for commercial use - it's still heavily in development. But this question would be very valid regarding Merlin. $\endgroup$
    – SF.
    Commented Jun 2, 2023 at 13:09
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    $\begingroup$ "could account another 100 engines a year" Citation needed $\endgroup$
    – JCRM
    Commented Jun 2, 2023 at 13:17
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    $\begingroup$ You can reach space with quite a small solid fuel rocket, about the size of a telephone pole, if you don't mind coming straight back down. Orbit isn't up, it's sideways. There's no need to buy a spacex engine to merely go up. I'm not sure what the use case you're imagining is that can't be fulfilled already by sounding rockets or weather balloons. $\endgroup$ Commented Jun 2, 2023 at 15:35
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    $\begingroup$ @uhoh Elon Musk has foregone patents for SpaceX technology, He has said "We have essentially no patents. Our primary long-term competition is China. If we published patents, it would be farcical, because the Chinese would just use them as a recipe book.” $\endgroup$ Commented Jun 2, 2023 at 17:09
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    $\begingroup$ @DavidHammen Makes sense! So they have IP to protect and they are mindful to protect it, and it's of the trade secret rather than patent form. $\endgroup$
    – uhoh
    Commented Jun 2, 2023 at 21:40

5 Answers 5


Wouldn't that be amazing for meteorology and weather prediction. You could launch them vertically...

In addition to GremlinWranger's points, atmospheric science rockets don't need bleeding-edge performance. Going straight up is easy; it's the horizontal speed needed to get into orbit that requires a very efficient engine, and weather science packages tend to be lightweight compared to communications satellites, humans, and other expensive payloads. Sounding rockets, therefore, use cheap but inefficient solid rockets, which are simpler to produce as well as easy to operate at minimally equipped launch sites.

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    $\begingroup$ The low launch infrastructure is especially important when you're looking at local missions like weather studies. It does you no good to have a rocket designed to study, say, hurricanes in the Bahamas if you can't actually launch it from the Bahamas without a new billion-dollar complex. $\endgroup$
    – Cadence
    Commented Jun 2, 2023 at 18:15

In addition to the points raised by GremlinWranger and Russell Borogove, SpaceX sells launches. Why bolt whole logistics and sales and support and integration teams onto your company so somebody else can put a payload somewhere and make a middleman fee? SpaceX makes its money putting peoples' payloads up. They would prefer to keep that middleman fee for themselves, and if that payload is too small to merit buying a whole Starship ride, there's always rideshare.

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    $\begingroup$ Especially when you consider who would potentially be in the market for engines of this class. I wouldn't be surprised if the cost per engine once they added all of that overhead if they wanted to sell to someone like Boeing would be more than the cost of a falcon 9 launch. $\endgroup$ Commented Jun 3, 2023 at 22:32

There are a number of rocket science reasons why SpaceX has not tried to sell Raptor, but a practical one is simply that, with Super Heavy needing 33 engines each and ambitions to sustain launch rates of 100 per year, they need all the engines themselves.

Selling a mere 100 engines would involve adding sales, support and integration teams for an already busy company for low profit, especially where they can instead sell people a ride on a Falcon and get the money for a whole rocket.

This changes in two ways: If SpaceX is successful in the 2030s and has a factory capable of producing engines in large numbers, but only needing spares for a standing Starship fleet selling off spare capacity (and skilled staff) to third parties starts making sense.

If SpaceX is unsuccessful then there will be a large pile of engines without any rocket, and someone might choose to buy them at scrap price to re-purpose.

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    $\begingroup$ Elon Musk has recently said that they had to slow down the production line because they have more engines sitting around than they know what to do with, so technically, they already do have a "a large pile of engines without any rocket". But, of course, all the other arguments still apply. $\endgroup$ Commented Jun 4, 2023 at 8:22

In addition to the points brought up by others...

I would assume one Raptor 2 engine could launch a small rocket to space.

No. Given the size of the Raptor 2, even with a relatively high T/W ratio you'd be looking at a suborbital vehicle holding a hundred tons or so of cryogenic methane and oxygen, about the same size class as the booster of a medium orbital launcher. The engine would not be your main cost. Nor is this remotely within reach of hobbyists. Also, parachutes would probably not suffice for recovery...this rocket would have about half the liftoff thrust of the original Falcon 9 booster, which SpaceX attempted to recover this way without success.


In addition to the already present answers, rocket engine development is very "emotional" and seen by many engineers and rocket startups as the "sexy" part of the rocket. There's a lot of ego and prestige involved in making one because it's such an integral part of a launch vehicle--making a functional engine is a huge source of personal and fiscal validation. What better way to prove that you've got the engineering chops to build a rocket than designing the engine?

Further complicating the fact is ITAR. SpaceX is an American company and would not be able to sell their engines outside of the US to countries/companies/groups that might want to go cost-cutting by skipping their own R&D program.

This factor, along with the low demand for them (the launch market is basically running at capacity right now if you include Starlink) means there are hardly any customers and not much incentive find any.

Maybe, in a decade or two when the access to space, and specifically process of building rockets, becomes more commoditized, we might see a change here. This has already happened in other sections of the space industry: hardly anyone who builds a satellite nowadays builds the engine too. There is a healthy and rapidly growing boutique / cottage industry that produces ready-to-use satellite maneuvering systems and thrusters.

  • $\begingroup$ "SpaceX is an American company and [is] not be able to sell their engines outside of the US to countries/companies/groups that might want to [set the world on fire]." state.gov/… $\endgroup$
    – Mazura
    Commented Jun 4, 2023 at 20:09
  • $\begingroup$ >The MTCR seeks to limit the risks of proliferation of weapons of mass destruction (WMD) by controlling exports of goods and technologies that could make a contribution to delivery systems (other than manned aircraft) for such weapons. In this context, the Regime places particular focus on rockets and unmanned aerial vehicles capable of delivering a payload of at least 500 kg to a range of at least 300 km and on equipment, software, and technology for such systems. $\endgroup$
    – Mazura
    Commented Jun 4, 2023 at 20:09

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