Support
No ticket queue and no first-line script — whatever you send lands where the deck is actually built, and gets answered there. Both routes below reach the same place.
The fastest route
Ask a question, report something broken, or say what you want built next. It is a new server — you would be among the first in, which means whatever you say gets read the same day.
Join the server →The map is free and stays free. Every planet, every dwarf planet, the 6,200 catalogued small bodies, the sky view and the transfer-window solver — all of it, with no account.
Deck Pro adds the parts that cost us something to run: more than three tracked objects, calendar export and saved answers from Ask the Deck. The map is not a trial and never locks.
They are computed on your own device, not fetched from anyone. Mars Deck carries JPL’s published orbital elements and solves the positions in your browser with Kepler’s equation, which is why it opens instantly and works with no connection.
The credit for the astronomy belongs to JPL. The arithmetic is ours, and /about lists what it has been checked against.
For the eight major planets, JPL’s 1800–2050 table is good to roughly arcminutes, and our Mars oppositions land within 0.8 days of published dates.
Dwarf planets use approximate osculating elements and are marked ~ on the map, because they are not to the same standard and we would rather say so. The stars behind the sky view are procedural — a real field, correctly rotated, but not a catalogue, and no pattern in it means anything.
It is a beautiful map you can trust the figures of. It is not navigation-grade and does not claim to be.
The map does, once the page has loaded — positions are solved locally, so nothing about drawing the solar system needs a network.
Ask the Deck does not: it sends your question to a language model, so that one needs a connection. So does signing in.
⚠️ There is no app to install. Mars Deck is a website, and it is built to run well on a phone rather than to be downloaded.
Because we do not need it, and an address we hold is an address we could lose. An account is a callsign and a password.
The consequence is real and worth understanding: your recovery codes are the only way back in. There is no reset link we can send you, because there is nowhere to send it. Keep them somewhere that is not the device you signed in on.
Use /reset with your callsign and one of your recovery codes. It will set a new password and tell you how many codes you have left.
⚠️ Failed resets share a rate limit with failed sign-ins, so if you have just tried the password a few times you may need to wait fifteen minutes. That is deliberate, and it is badly timed for the person who most needs it — sorry.
If the codes are gone too, email us. We cannot recover the account — nobody can, that is the point of the design — but we can make sure nothing else is wrong.
There is a daily allowance, because every question is a real bill. Signing in raises it, and Deck Pro raises it further.
It resets each day. If Ask is answering with something about being busy rather than about your allowance, that is a global spend ceiling doing its job — the map is unaffected either way.
Email support@marsdeck.net with the order id from your PayPal receipt and we will look it up.
Every payment is confirmed with PayPal by our own server before it grants anything, and the same order can never be counted twice. If money moved and your account did not change, the order id is the thread that finds it — nothing is lost.
There is nothing to cancel. Neither plan is a subscription: Founding is bought once and is yours permanently, and Deck Pro is a thirty-day pass. No renewal, no card kept on file, nothing running on quietly in the background.
When a Deck Pro pass runs out you go back to the free deck — the map, the sky view and the transfer windows are all still there, and nothing you follow is deleted. Buy another pass whenever you want one.
You can delete your account whenever you like from /settings. It is a real deletion, not a flag.
No third-party trackers, no advertising, no consent banner to dismiss. We do set one cookie — the login session — because signing in does not work without it.
Visits are counted on our own server, and the city lookup runs against a database on that server rather than by handing your address to anyone else. /privacy says all of it plainly, including what we keep and for how long.
Screenshots, links and deep links: yes, freely, and thank you. Every object has its own shareable page and the link carries the camera, the date and the object with it.
The underlying astronomy is JPL’s published data and belongs to everyone. The engine, the renderer and the artwork are ours. If you want to build on it, ask — the answer is usually yes.
Mars Deck is not affiliated with NASA, JPL, SpaceX, xAI or Anthropic. We use JPL’s published data with gratitude, and the credit for the astronomy belongs to them.