How the Space Markets Index is counted. Version 1.0. Figures on the index come from the generated print.
What the index measures
The Space Markets Index (SMI) counts how often rockets reach orbit and how much payload they carry there, week by week. It has two parts:
- Launches. The number of orbital launch attempts in a week, and how many reached orbit, by provider and by rocket.
- Mass to orbit. The total payload mass delivered to orbit in a week, counted only where our source reports a mass.
Next to the index we show published prices: prices that companies post on their own websites for launch or in-orbit capacity. These are list prices. They are not trades, not quotes, and not SMX prices.
SMI is a data product. It is not a market, an offer, investment advice, or the price of anything you can buy or sell on SMX. SMX currently runs on testnet only (Base Sepolia).
Where the data comes from
| Source | What we use | License |
|---|---|---|
| GCAT, by Jonathan McDowell (planet4589.org/space/gcat) | Launch list, and payload mass for each object. The source of record for every SMI number | CC BY 4.0 (creativecommons.org/licenses/by/4.0). Cited as "data from GCAT (J. McDowell, planet4589.org/space/gcat)". We filter, count and sum GCAT data; the totals are ours. |
| Launch Library 2, by The Space Devs | Our own provisional count of launches since the latest GCAT update. Not used in index figures. | Not used in index figures, which use GCAT only. We use it only for our own provisional count of launches since the latest GCAT update. We do not republish Launch Library 2 records or images. Launch Library 2 by The Space Devs (thespacedevs.com). |
| SpaceX rideshare page | A published rideshare price, captured by hand | Quoted word for word, captured by hand, with a link and the date and time we read it ('as published on'). SpaceX rideshare only. |
We keep a copy of each source file we used, with the date and time we read it, so any weekly figure can be checked later.
Credit
Every SMI page and every SMI data response carries this credit: data from GCAT (J. McDowell, planet4589.org/space/gcat), licensed CC BY 4.0. SMI changes the data: we count it by week, provider and rocket, and leave out masses that GCAT marks as estimates. The pages say modified by Space Markets. GCAT does not endorse SMI. This preview's prints are GCAT only. Provisional counts of launches since the latest GCAT update are calculated by Space Markets from Launch Library 2 by The Space Devs (thespacedevs.com); they are not included in index figures, which use GCAT only.
What counts as a launch
A launch counts if it attempted to reach Earth orbit or beyond, including deep-space missions and launches that failed; suborbital flights are not counted.
- An orbital launch attempt is a launch that was meant to reach Earth orbit, as classified by GCAT. A deep-space launch is counted in its own category. Suborbital flights and tests are not counted.
- Reached orbit follows the outcome recorded by GCAT. A launch that failed, or reached a lower orbit than planned and deployed nothing usable, is listed as "did not reach orbit".
- The week runs Monday 00:00 to Sunday 23:59, UTC. A launch belongs to the week of its liftoff time in UTC.
- Provider is the organization that operated the launch, as named by GCAT. China's state launch units are grouped as CASC. Rideshare customers are not providers.
What counts as mass to orbit
- Mass to orbit is the sum of the payload masses that GCAT lists for a launch, at the moment they reached orbit. Rocket stages and debris are not counted.
- For some satellite types, such as Starlink, GCAT gives one nominal mass by bus rather than a figure weighed for each launch. We count these and label them nominal mass by bus (GCAT).
- We count a launch's mass only if every payload on it has a mass that GCAT reports as a known value. GCAT marks some masses as its own estimates; we do not count those.
- A launch that did not reach orbit adds zero to mass to orbit.
- A deep-space launch stays in its own category. It is counted in the launch total and adds nothing to mass to orbit, even when the source lists a payload mass.
- Military payloads. We leave out the mass of any payload that GCAT classes as military or intelligence (class code D) and still count the other payloads on the same launch; a launch that carries only military payloads is shown as "Military payload only" and left out of mass totals, and a launch's mass shows "Not public" only when it cannot be separated from a military payload. This applies until our legal review of these masses is complete.
When mass is unknown
We never fill a gap with a guess. If the mass for a launch is not reported, the index shows the word for why:
- Not yet reported. The launch happened, but our source has not added payload masses yet. This is normal for the first weeks after a launch.
- Unknown (source estimate only). The source gives only an estimate for at least one payload. We leave the whole launch out of the mass total.
- Unknown. The source has no mass for at least one payload. This is common for classified and some government payloads.
- Military payload only. Every payload on the launch is military or intelligence, so we show no mass for it.
- Not public. The launch's mass cannot be separated from a military payload's mass.
Every mass figure is shown with how many launches it covers, for example "reported for 39 of 84 launches". The uncounted launches are shown as unknown, never as zero.
When the index is published and revised
- Weekly print. The index for each week is first published on the following Wednesday at 12:00 PM Central Time.
- Revisions. Sources add and correct records after the fact. When they do, we publish a new revision of that week. Every revision keeps its number and time, and old revisions stay readable.
- Final. Launch counts for a week become final 14 days after the week ends. Mass to orbit becomes final 13 weeks after the week ends. After that a week changes only to fix a clear error, and each such fix is logged below.
- Current print. 2026-W39 (21–27 Sep, Monday to Sunday, UTC), revision 5, updated 26 Sep 2026, 11:51 PM CT, GCAT data to 24 Sep 2026. Launch counts for this week are not final yet: the print marks them final at 2026-10-12T00:00:00Z. Mass is not final yet: the print marks it final at 2026-12-28T00:00:00Z. Weeks with no counted launch are drawn as zero on the weekly chart.
Published prices
- We list a price only if the company itself publishes it on its own website or in its own announcement, and the site's terms allow it or the company has agreed. We record prices by hand, never by automated scraping. In this preview the only price slot is SpaceX rideshare.
- We check each price by hand once a week and keep a dated screenshot. We do not use automated tools on price pages.
- Each price shows the company, what the price buys, the date and time we read it, and a link to the page.
- We do not convert, average, or combine prices. We do not divide a rocket's price by its capacity.
- Space is reserved for prices shared directly by partners under a written data agreement. Those will be labeled with the partner's name and date.
What SMI is not
- It is not a forecast, and it does not estimate anything.
- It is not a price of any SMX market. SMX does not offer trading on SMI, and SMI is not designed or offered for settling contracts. If that ever changes, we will publish the change here in advance.
- Not affiliated with, endorsed by, or sponsored by SpaceX. SMI is not affiliated with, endorsed by, or sponsored by any other company, agency or data source named here, including GCAT and The Space Devs.
No advice
SMI is a data product. It is not a market, an offer, investment advice, or the price of anything you can buy or sell on SMX. SMX currently runs on testnet only (Base Sepolia). It is not investment, financial, legal or tax advice or a recommendation to buy, sell or hold anything.
Conflicts of interest
Space Markets also operates SMX, a testnet event-market venue. SMI is calculated from public sources under this published methodology. Changes are logged. People who run SMX markets do not decide SMI prints.
Complaints
Changes and discontinuation
We may change this methodology. Material changes are announced here at least 14 days before they apply, unless an error must be fixed sooner. If a source stops publishing, we will say so here, freeze affected prints, and may discontinue SMI.
Corrections and contact
If you see a record that looks wrong, the source link on that record shows exactly what we read and when. Corrections to the underlying data are made by the source; we pick them up in the next revision.
Change log
| Version | Date | Change |
|---|---|---|
| 0.1 | Draft | First draft, not yet published. Sources updated after the licensing check of 27 Sep 2026 |
| 1.0 | 27 Sep 2026 | Military and intelligence payload masses are left out per payload. A launch that carries only those payloads is Military payload only. Print label. |
How to reference a print
Cite the print id and the sha256 of the print file. Use the first print where the fields you need are final. A correction is a new print id. The Launch Library 2 provisional count is not part of any print.
This print is 2026-W39.r5, sha256 24f9fe11f463e10bd0f94761ac44550f6d649fc7a82ff48015bc05a1f45bd865.
SMI Launch Cadence
100 × counted launch attempts in the trailing 13 ISO weeks ending this print, divided by counted launch attempts in the same ISO weeks one year earlier. An attempt is a GCAT launch whose LaunchCode starts with O or D. The card shows the figure rounded to a whole number.