Satellite statistics, Page 1


Active Payloads

Here is a summary of active satellite payloads versus time.

Active Payloads: Annual totals


Space Debris Population

Here I show the cataloged orbiting satellite population. In low orbit, most objects larger than 10 cm are cataloged; in high orbit only larger objects are tracked. Objects are added to the total based on my estimate of their time of separation from the parent satellite, rather than on their date of being added to the catalog (so all of the FY-1C debris is added on the same day). I distinguish between `inert parts' jettisoned from satellites (sometimes called `operational debris') and objects resulting from major disintegrations, collisions or explosion (which I label as `debris'). The two major recent debris events, the Chinese antisatellite test which destroyed their FY-1C satellite, and the accidental collision of Iridium 33 and Kosmos-2251, are treated separately so that their huge effect can be more readily appreciated.

The data are shown as both individual line graphs and as a cumulative sand chart.

The mass of individual pieces of debris is not known, but is small compared to that of payloads and rocket stages. For example, all of the FY-1C debris totals roughly 1000 kg, the mass of the original satellite. Here is an attempt at estimating the mass of the orbiting satellite population; dry masses are used - i.e. liquid propellant mass is omitted. The y axis of the graph is in (metric) tonnes. The expert reader will spot the Mir and Skylab reentries.


Launches

Orbital launches, including Earth orbit and deep space launches. Launch vehicle failures that reached orbit are included; marginal orbit cases are included.

Note that for 2011, US launches exceed those of China only because the Sea Launch partnership is considered to be a US-based launch system.

Below, launch failures are also included, and the data are also shown as percentages.


Suborbital launches. The mesospheric launches (green) are mostly weather rockets; NOAA and NASA databases ended in the 1980s so recent decades are missing. The suborbital launches (apogee above 80 km) include science sounding rockets and missile tests. Data on Russian and Chinese missile tests and Scud-class launches in developing-world conflicts are still significantly incomplete. The spike in the 1940s represents WWII V-2 launches with known dates.


Orbital launch attempts. This figure is in 'sand chart' style where the height of the histogram bins is the sum of all the categories, so that the different categories don't overlap each other. Note that it took humanity about 5 years to figure out the orbital launch trick and reduce failures from an initial 50 percent to a few percent. The same data is also shown as a percentage of the total.