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I was doing some research about how much $/kg it costs to launch a satellite into GEO. I came across several sources that lists info for LEO:

https://ourworldindata.org/grapher/cost-space-launches-low-earth-orbit

And another source that just mention the cost (without specifying the orbit): https://spaceimpulse.com/2023/08/16/how-much-does-it-cost-to-launch-a-rocket/#How_Much_Does_It_Cost_to_Launch_a_Rocket

In SpaceX's website, the cost is listed but it does not specify what rbit exactly, it says that it is "Up to 55 mT to GTO": enter image description here

Can I just divide the STANDARD PAYMENT PLAN by the maximum payload mass to estimate the cost per kg ($/kg) for each orbit?

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    $\begingroup$ GTO (Geostationary Transfer Orbit) is used as an intermediate step to reach GEO (GEostationary Orbit). To put a satellite in LEO requires much less energy than GEO. So it is more expensive to put a satellite in GEO. If you find the same launch cost for both orbits, something must be wrong, a typo or not comparable prices. $\endgroup$
    – Uwe
    Commented Feb 27 at 13:51
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    $\begingroup$ A satellite put in a GTO needs an engine and fuel built into the satellite to reach GEO by itself. No upper stages of launch rockets should be left in GEO. Old GEO satellites going out of service should be lifted into a graveyard orbit. No old satellite or rocket stage should be left in GEO. $\endgroup$
    – Uwe
    Commented Feb 27 at 14:03
  • $\begingroup$ You're right, I will correct my question to GTO* $\endgroup$ Commented Feb 27 at 14:15
  • $\begingroup$ the launch cost for both orbits is likely to be near identical,the difference is the maximum payload $\endgroup$
    – JCRM
    Commented Mar 8 at 10:26
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    $\begingroup$ Yeah, putting a satellite into GTO just for it to remain in GTO is pointless. You put it into GTO to circularize into GEO. And to circularize it needs a lot of extra mass of fuel and propulsion systems. Meaning either you're launching a much heavier payload, or for same payload the mass of the actual satellite will be much lower. $\endgroup$
    – SF.
    Commented May 9 at 8:57

2 Answers 2

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The cost of a rocket launch is dependent on many factors. It depends what payload you are launching – some payloads require special services such as gas purges, helium or propellant top up, clean room facilities with horizontal or vertical integration all of which may (or may not) be available and may incur additional costs. Then there are range costs such as ensuring the launch site is clear and insurance costs (which can be substantial depending on the launcher).

Then there are costs dependent on the launch date. If there is an absolute requirement to launch at a specific time on a specific date then there will also likely be a premium to be paid. If there are repeated wide launch windows every day and the customer is willing to launch anytime in March 2024 (for instance) then that will be cheaper.

There are also potentially validation and documentation costs (especially NASA) and security costs (especially USAF)

Then there is the mass of the payload and the required orbit (eg altitude, inclination and eccentricity). Not all launch vehicles can launch to all orbits and some launch vehicles can fly in multiple different configurations – such as Falcon 9 with booster return to launch site, booster recovery at sea or booster expended all with different capabilities and costs. Beyond that there are complexities with ride sharing which may make it cheaper depending on circumstances.

Finally the actual cost is not usually made public and even the price, subject to all of the above, is not easy to determine.

All that being said and all other things being equal (which they probably won’t be), it should be more expensive to launch x mt to GTO than x mt to LEO because the GTO orbit is a much higher energy orbit that will leave less opportunity to use a cheaper configuration and fewer ride share options. But it really does depend on circumstances.

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  • $\begingroup$ The OP asks about cost to GTO, not GSO. $\endgroup$
    – Woody
    Commented May 2 at 2:30
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    $\begingroup$ @Woody, thanks for that I have corrected it. Although the points still stand as the energy required to transfer from an elliptical GTO a circular orbit at apogee is relatively small compared to launch mass. $\endgroup$
    – Slarty
    Commented May 2 at 16:54
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@Slarty provided an excellent answer, so please just consider this answer to be additional reading...

In principle dividing the listed price by the maximum payload to the desired orbit to arrive at a cost-per-kg is a reasonable idea and lots of articles on the Internet have done exactly that...

$${\text{\$67M}\over22,000}=\$3,045/kg$$

... except that sometimes they do not arrive at the correct answer.

enter image description here

(ref)

In this case, they probably used very out-of-date numbers and perhaps did not properly account for inflation until 2021)...

$${\text{\$2,600/kg}\times22,000}=\text{\$57.2M per launch}$$

But even if this math is done correctly with up-to-date numbers the result will differ significantly from the price that will hit a company's bank account at the end of the day.

One reason for this is that the maximum payload and the minimum price are not tied to the same configuration. The configuration that gives you the maximum payload is an expendable configuration. The configuration that gives you the minimum price is a reusable configuration.

The footnotes on SpaceX Falcon 9's Capabilities and Services page clarify the information:

$^*$ Pricing adjustments made in March 2022 to account for excessive levels of inflation. Missions purchased in 2022 but flown beyond 2023 may be subject to additional adjustments due to inflation.

$^1$ Performance represents max capability on fully expendable vehicle.

Price

The first footnote tells a potential customer that the listed price of \$67M is out of date and that the actual price is not stated. If we adjusted for 24 months of inflation (Jan 2022 CPI = 281.148, Jan 2024 CPI=308.417, ratio = 1.097) we would arrive at a value of... $$\text{\$67M}\times1.097=\text{\$73.5 M}$$

But this price is for the cheapest possible launch. This might be a flight where the booster returns to the launch site, the second stage uses the shorter engine nozzle, the destination is the lowest possible LEO orbit, no inclination changes are required, and no margins are factored in to ensure the success of the mission (see: "SpaceX loses 40 satellites to geomagnetic storm a day after launch"). It probably does not include sales tax, insurance, and various other fees, extras, etc. (see @Slarty's answer above).

Anyone who has shopped for a flight on an airline should be at least tacitly aware of how the marketing of services works. The price advertised to draw you in and the price paid at check-out can be substantially different.

Performance

Performance, on the other hand, is specified for the maximum capability of a fully expendable vehicle. So in this case SpaceX would not be able to pass on the cost savings associated with reusability.

Often people use the expendable configuration's stated 22,000 kgs capability to LEO for this. However, the performance of the reusable configuration is lower. For example, this tweet...

enter image description here

... reveals that in practice the performance of the reusable configuration might be closer to...

$$134/14 = 9.57 tons = 9570 kg$$

Summary

So we cannot simply divide the listed launch price by the maximum payload to arrive at a correct price-per-kg. This approach results in incorrect cost-per-kg information when we are given the price for the cheapest configuration and the performance of the most expensive configuration.

If you would like to arrive at a correct cost-per-kg for a given mission, I recommend that you search this site for posts with the tag and browse through the search results. Some of the posts provide detailed analyses, references to reputable sources of information, and insights from people who have decades of experience in the space industry.

However, if we divide 73.5M (2024 USD) by 9570 kg, we arrive at a baseline price of 7680 USD-per-kg, before taxes and fees. Since most of these missions were probably drone ship landings with the full-sized second-stage nozzle, this estimate is still on the low side relative to the cost a commercial customer would likely end up paying.

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