Early prototype · feedback wanted
Sky full of satellites over your head, in real time
All known satellites live in your browser.
Solo-developed
Result of a proof-of-concept, developed since 2023 by an amateur astronomer who has been watching this stuff since childhood.
No ads, no tracking, no sign-up
The basic functionality that needs no server is and will stay free, without ads or accounts. Later on there will be features that can't work without a server, and those will need some basic form of sign-in.
Inspired by Heavensat
Where the original had a feature, the aim is to have it here too, for free. Satellite Engine is an independent project, not affiliated with or endorsed by the original Heavensat or its developers.
Why it exists
Satellite Engine is being built to answer four questions.
What satellite did I just see?
Something crossed the sky while you were looking somewhere else. You have a rough time, a rough direction, and a memory of how fast it moved. That should be enough to put a name to it.
How do I see it again, in the same conditions?
A repeat pass is not the same thing as a repeat sighting. If it flared, what you want back is the geometry that made it flare - the same illumination and the same angles.
What interesting things are happening over me tonight?
Not a list of every catalogued object. The handful worth putting a coat on for. Distinct and rare events, from flares to lasers on science satellites firing down near you.
And can I do all of that from any device, without installing anything?
It is fully-featured in a browser. Nothing additional to install.
What it does today
It is an early prototype and it doesn't do a lot of things yet. Here is the split between what already works and what is still ahead.
Working now
- Visible 25,000 Hipparcos stars (up to mag. 8) and constellation lines
- All known satellites, drawn with the consideration of earth shadow
- Click any satellite for its COSPAR and NORAD ID and orbit data
- Filter the catalogue down by orbit properties
- Trajectory for the selected object, marked with timestamps
- Alt-azimuthal and equatorial grids
Coming next
- Solar system bodies
- Classified satellites
- Search and a sortable table of the catalogue
- Calculations: pass, flare and transit prediction
- Bigger star catalogue
- Favourites and permalinks that reproduce an exact sky
- Night mode
- Work offline
- Push notifications with customizable set of events
Who's building this
I'm Vladyslav Huba, I've been an amateur astronomer since childhood, and I still go outside and watch - for example, I've photographed CALIPSO's laser, and shot timelapses of geosynchronous satellites flaring.
I also maintain satellite.js, the SGP4 implementation this app propagates orbits with.
Satellite Engine is three years of me prototyping and my passion project.
It runs on your machine
Your location stays on your device
Free features never send it anywhere. If a future feature ever needs a server, it will say so in plain text, without hidden links, and ask for your permission before sending anything.
No cookie banner
Because there is no tracking or advertising. The app simply keeps your settings, and a cached copy of the public satellite catalogue so it isn't re-downloaded every visit.
Tell me what's wrong with it
It's a prototype and it's being shaped right now. If something is inaccurate, missing, or annoying to use, I will try to fix it.