SOURCES
Where this data comes from
Distance from the Sun, speed, and one-way light time all come from NASA JPL's Horizons System — the same ephemeris service that powers most professional solar-system navigation software. No authentication required. Each probe needs two separate requests, since Horizons only accepts one observing center per call: Sun-centered for distance and speed, Earth-centered for distance and light time.
ssd.jpl.nasa.gov/api/horizons.apiSignal/contact status comes from NASA's official Deep Space Network feed — the same XML data that drives the eyes.nasa.gov DSN visualization. A probe frequently shows "not in contact"; that's real dish-scheduling behavior, not an error state.
eyes.nasa.gov/dsn/data/dsn.xmlThere's no public API that decodes actual Voyager telemetry to instrument-level status, so each probe's Instrument Health table is transcribed by hand from NASA's own status page rather than fetched live. Updated here whenever NASA's page changes.
science.nasa.gov — Where are Voyager 1 and 2 now?The Milestones timeline is hand-compiled, not fetched live. Launch dates, planetary flybys, and heliopause crossings are well-established public mission history; the more recent entries (2023 onward — comms anomalies, thruster events, and the power-conserving instrument shutdowns) are each verified against a specific NASA or JPL announcement:
- NASA — Voyager 2 enters interstellar space
- JPL — Voyager 1 resumes sending engineering updates
- JPL — Voyager 1 returns science data from all four instruments
- JPL — Voyager 1 team accomplishes tricky thruster swap
- JPL — NASA turns off science instrument to save Voyager 2 power
- JPL — NASA turns off two Voyager science instruments to extend mission
- JPL — Voyager 1 revives backup thrusters before command pause
- NASA Science — Voyager 1's last charged-particle instrument shut off
- NASA Science — Power swap prolongs Voyager 2's science mission
The Voyager illustration behind the About page text is a NASA render, with its starfield background removed by hand — not fetched live.
science.nasa.gov — Voyager illustrationLaunch date, heliopause crossing date, and constellation heading are real facts, but baked into the app rather than fetched live — they don't change often enough to need a live source.
Live figures are cached locally and refresh at most once every 15 minutes. If a refresh fails, the last known good values are shown rather than breaking the page.