Method
This page is the contract. Numbers on the other screens are only as good as the definitions below.
Unofficial status
This is an unofficial public calculator. It is not a Bureau 1440 product, not a government product, and not affiliated with any ministry, armed force, or operator. Catalog names such as RASSVET-3 are transcribed from public NORAD / CelesTrak listings.
Data source and refresh
Orbital data are public general-perturbations (GP) element sets from CelesTrak (JSON GP). The server fetches them about every ten minutes and caches the result. If the live fetch fails, a dated checked-in snapshot is used and labelled as such. This site does not invent ephemeris and does not fit custom orbits.
The user-agent on catalog requests identifies this app as an unofficial geometric coverage tracker. No Space-Track credentials are shipped to the browser.
Propagation and Earth model
Positions are propagated with SGP4/SDP4 as implemented by satellite.js from the published element set. Elevation, footprints, and the altitude proxy use a spherical Earth with Re = 6371 km. That is good enough for an MVP coverage clock; it is not a precision orbit determination.
Sampling step is 30 seconds. Displayed AOS/LOS are linearly interpolated between steps and should be read as ±30 s. Passes shorter than 60 seconds after interpolation are discarded.
Coverage (this site)
Coverage (this site): at least one catalogued Rassvet object is above elevation E over point P, using public TLEs.
That is the only definition used for the Now tile, the Today minutes, the city chips, the map footprints, and the next-window countdown.
What the numbers are not
Not “a terminal has a lock”.
Not “capacity for N users”.
Not “24-hour service”.
Not “the constellation is operational at 800 km”.
Not proof of encryption, inter-satellite links, gateway routing, or any military function. Geometric line-of-sight is a necessary condition for a link, not a sufficient one.
Why 10° / 25° / 40°
10° is near-horizon geometric visibility. 25° is a conservative comms-like mask and the default. 40° is a stricter mask. None of these is a measured Bureau 1440 requirement. They exist so a reader can see how sensitive the minutes are to the assumed minimum elevation.
Why 480 km is the Raised gate
Public reporting on the first production batch describes flattening near about 500–550 km, not the 800 km figure that appears in filings and brochures. This site treats 480 km as a product constant for “raised”: catalogued, not decayed, with an approximate altitude from the latest element set of at least 480 km. The 800 km figure is not used as an operational gate.
Approximate altitude is a − Re from mean motion (semi-major axis minus 6371 km), labelled approx. Perigee and apogee use the same a with the published eccentricity.
Window versus pass
A pass is one object above the mask. A window is the union of all such intervals: overlapping satellites do not double-count minutes. The Today tile and city chips use windows. The pass list is per-object so an analyst can see who is contributing. That split is deliberate.
Stale element sets
If the newest GP epoch for an object is older than 72 hours, the object is marked stale and still propagated, with a warning. Missing IDs that remain in the curated list but have no TLE are marked missing and are omitted from Now / Today / footprints. Decayed IDs on the manual override list (and any object whose perigee is persistently below 150 km) are excluded from coverage.
Public program figures (claims, not this site’s measurements)
Operator / state figures often cited: on the order of 250–292 satellites by 2027 for an initial operational constellation, later growth toward ~700–900.
Analyst figures often cited: continuous service (not mere line-of-sight) discussed in the 200–250 satellite range.
Reporting through mid/late 2026: production batches of 16, orbit raise to ~500 km rather than the 800 km filing, roughly two longer geometric windows per day over Ukraine once the first batch flattened, four line-of-sight passes of which only some are high elevation.
Those sentences belong here, not on the homepage, unless the live calculator currently agrees.
What this site will never show
Unit positions, front lines, frequencies, waveforms, terminal installation guides, jamming recipes, or any targeting language. The curated NORAD list lives in a config file so a new launch group can be added without rewriting the app.