Know exactly when your satellite is overhead
Webhook alerts for AOS/LOS times, max elevation, and space weather warnings. Integrate in 5 minutes. No predict scripts, no cron jobs, no stale TLE files.
14-day free trial of the Research tier — no credit card required
±0 s
AOS / LOS timing accuracy
0+
Celestrak satellites supported
0 h
Prediction window
0 min
Space weather refresh
[ The problem ]
Satellite operations are harder than they should be
Manual tracking is error-prone
Stale TLE data, timezone bugs in predict scripts, edge cases on polar passes. One wrong epoch and your dish points at empty sky while the satellite downlinks to no one.
Missing a pass window costs money
NOAA-20 gives you 8–12 minutes of downlink every 95 minutes. Miss one unattended pass and you're waiting two orbits — or shipping a gap in your sensor archive to the customer.
Space weather can ruin your link budget
Kp ≥ 5 causes ionospheric scintillation that degrades S-band links below 15° elevation. Without a warning, you spend hours troubleshooting a hardware fault that isn't there.
[ Illumination ]
Most “great” passes are worth nothing
SGP4 is a free pip install, and it will happily tell you a satellite is about to cross your sky at 78° elevation. It will not tell you the Sun is up and there is nothing to see. Knowing which passes are worth acting on is the part that takes work — so we did it.
145
passes cleared 10° over Athens, Greece in 30 days
14
were actually observable — sunlit satellite, dark sky
1 in 10
100 lost to daylight, 31 to Earth's shadow
ISS (ZARYA) · 72 h from 2026-08-16
14 passes · 3 observable
The highlighted pass reaches 78.4° — nearly overhead, and the one any elevation-ranked tool puts at the top of the list. The Sun is 62° above the horizon at the time. You would see nothing.
Computed by the same propagator that serves the API, from the NORAD 25544 element set at epoch 2026-08-03. Observability uses a cylindrical Earth-shadow model and a civil-twilight threshold at the observer.
[ Build vs. buy ]
What would this cost your team to build in-house?
Plug in your own numbers — this isn't a fixed claim, it's your estimate.
TLE ingestion, SGP4 propagation, retry logic, an alerting pipeline — estimate your own scope.
Varies a lot by country and seniority — €65/hr is a rough EU mid-market default, not a claim about your team.
Building it yourself
€26,000
400h × €65/hr, one-time
OrbitAlert Pro
€2,988
€249/mo × 12, year one
Estimated year-one savings with OrbitAlert
€23,012
[ How it works ]
From zero to automated in three steps
STEP 01
Register your ground station
POST one JSON payload: your latitude, longitude, target satellite, elevation mask, and webhook URL. Takes 30 seconds from a terminal.
STEP 02
We compute every upcoming pass
SGP4 propagation at 10-second steps out to 24 hours, 30-second steps from there to 72. AOS, TCA, and LOS timestamps recomputed on every Celestrak TLE refresh — automatically.
STEP 03
Webhook fires before every pass
Your endpoint receives the full pass geometry — azimuth arc, peak elevation, duration, and live Kp index — N minutes before the satellite crests your horizon.
[ Features ]
Every field your system needs to act on a pass
AOS / LOS / TCA timing
Acquisition of Signal, Loss of Signal, and peak elevation moment, accurate to ±10 seconds within a 24-hour window. Feed directly into your rotator controller or scheduler.
Max elevation & azimuth arc
Rise bearing, set bearing, and peak elevation in every webhook. Everything your mount controller needs to pre-position before AOS.
Space weather (Kp index)
Live planetary K-index with severity labels — quiet, unsettled, storm, severe. Refreshed every 5 minutes from NOAA SWPC. Use it to raise your elevation cutoff automatically when Kp climbs.
Retries + email fallback
Failed deliveries are retried after 30 s and 2 min, every attempt logged with HTTP status and response time. If your endpoint stays down, we email you the pass details instead — the alert reaches you either way.
Plain REST — SDKs optional
GET /passes, POST /alerts, GET /space-weather and friends. JSON over HTTPS, standard status codes, API-key auth. Official Python & JavaScript SDKs and a CLI exist when you don't feel like hand-rolling requests.
Delivery log & dashboard
Per-alert pass history, webhook attempt details, HTTP response codes, and pass success rate. Know exactly what was delivered, when, and why it retried.
[ Webhook payload ]
Every field your controller needs
When NOAA-20 is 10 minutes from your horizon, OrbitAlert POSTs this JSON to your endpoint. AOS bearing, LOS bearing, peak elevation, duration, live Kp — everything needed to pre-position your antenna, open the recording session, and decide whether the ionosphere is cooperating.
azimuth_at_aos — pre-position your rotatormax_elevation_deg — compute your link marginkp_index — decide whether to attempt the passminutes_until_aos — schedule your countdown
[ Enterprise readiness ]
Built like infrastructure — because it is
Security, privacy, and reliability aren't a slide in a pitch deck. Every claim below links to the page where we document it.
Security practices
Hardened API surface: rate limiting, strict CORS & CSP, and SSRF protection on webhook targets. Read exactly how the platform is locked down.
Read the security pageGDPR & DPA
Privacy by design. A full Data Processing Agreement is published and available for your legal team to review before you commit to anything.
View the DPA99.9% uptime SLA
Enterprise plans carry a contractual uptime commitment — measured against deep health checks and published by us, not by marketing.
See the SLAPublic status page
Deep health checks across the API, prediction worker, and webhook pipeline — with incident history out in the open, where it belongs.
Check live statusProven accuracy
Every prediction traces back to Vallado's canonical SGP4 reference vector and published GMST/geometry constants — not just our own prior output.
See the reference numbers[ Pricing ]
Straightforward. No per-pass fees.
All plans include webhook delivery, space weather, and REST API access.
14-day free trial of the Research tier — no credit card required
Free
- Pass predictions for the full active catalog
- 1 ground station
- 1 webhook alert
- 7-day webhook history
- 1,000 API calls / hour
Starter
- 3 ground stations
- Unlimited webhook history + CSV export
- Slack delivery + raw TLE access
- Unlimited API calls (fair use)
- Email support
Pro
- 15 ground stations
- Everything in Starter
- IP allowlist
- Unlimited API calls (fair use)
- Priority support
Research
- 40 ground stations — multi-site campaigns
- Everything in Pro
- Conjunction warnings + monthly PDF report
- Unlimited API calls (fair use)
- Priority support
Enterprise
- 100 ground stations
- 99.9% uptime SLA
- White-label webhooks + live TLE lookups
- Unlimited API calls (fair use)
- Dedicated support
Paid plans include unlimited API calls under fair use — we rate limit only to stop abuse, never to upsell you.
Academic pricing: sign up with a verified university email and the Research tier is free for 6 months — no card, granted automatically. After that it's 70% off any plan, so Research works out to €299/mo.
Compare plans in detail
ALL PLANS · WEBHOOKS + REST + SPACE WEATHER| Starter | ProTRIAL TIER | Research | Enterprise | |
|---|---|---|---|---|
| Monthly price | €49 | €249 | €999 | €1,499 |
| Ground stations | 3 | 15 | 40 | 100 |
| API calls Fair-use ceilings stop abuse; normal usage never reaches them. | Unlimited | Unlimited | Unlimited | Unlimited |
| Webhook history | Unlimited | Unlimited | Unlimited | Unlimited |
| CSV export | ||||
| Slack delivery | ||||
| Raw TLE API access | ||||
| Team roles (RBAC) + audit trail | ||||
| IP allowlist | — | |||
| Conjunction screening (close-approach flags) TLE-based geometric screening to flag what's worth a closer look — not a certified Pc / CDM replacement for 18 SPCS or Space-Track. | — | — | ||
| Monthly PDF mission report | — | — | ||
| White-label webhooks (custom domain) | — | — | — | |
| Live coverage view + live TLE lookups | — | — | — | |
| Uptime SLA | — | — | — | 99.9% |
| Support | Priority | Priority | Dedicated |
All prices exclude VAT. Invoice / PO and annual billing available on Research and Enterprise.Running a university lab? →Read the full API docs →
[ FAQ ]
Questions engineers actually ask
How accurate are the pass predictions?
We run SGP4 propagation at 10-second steps out to 24 hours — accurate to about ±10 seconds, precise enough to drive a rotator controller directly — and at 30-second steps for the 24-72 hour range, where timing lands within about ±20 seconds. Longer-range predictions are for planning rather than pointing anyway: the dominant error there is the age of the element set, not the step size, which is why every prediction reports its TLE epoch and freshness. AOS, TCA, and LOS are recomputed on every Celestrak TLE refresh.
Which satellites can I track?
Any of the 8,000+ objects in Celestrak's active-satellites catalogue — weather satellites like NOAA-20 and the METOP series, earth-observation missions like TERRA and AQUA, the ISS, and the large commercial constellations. If Celestrak publishes a TLE for it, you can set an alert on it.
How does the free trial work?
Every new account starts with 14 days of the Research tier — 40 ground stations, conjunction warnings, the lot — with no credit card required. Nothing is charged automatically: when the trial ends, you drop to the permanently-free tier (1 ground station, 1 alert, 1,000 API calls/hour) rather than losing access. Your alert configs and delivery history are kept, so upgrading resumes everything exactly as you left it.
What happens if my webhook endpoint is down?
Failed deliveries are retried after 30 seconds and again after 2 minutes, and every attempt is logged with its HTTP status and response time. If all three attempts fail, we email you the pass details instead, so the alert still reaches a human. The full delivery history is visible in your dashboard.
Do I need an SDK to integrate?
No — OrbitAlert is plain REST (GET /passes, POST /alerts, GET /space-weather, and more) plus a signed JSON webhook. Standard HTTPS, standard status codes, API-key auth. If you'd rather not hand-roll requests, official Python and JavaScript SDKs and a CLI are available. Most teams are live within one work session.
How does space weather affect my passes?
Every payload includes the live planetary Kp index from NOAA SWPC, refreshed every 5 minutes. When Kp climbs above 5, ionospheric scintillation can degrade low-elevation S-band links — the index lets your scheduler raise its elevation cutoff automatically.
Is there an SLA and enterprise access control?
Team roles (admin / engineer / viewer) and the audit trail are included on every plan. The Enterprise plan adds a 99.9% uptime SLA that we measure and publish ourselves, white-label webhooks on your own domain, live TLE lookups, and dedicated support. See the SLA and Security pages for the specifics.
Something else on your mind?The API docs answer the rest →
Point your dish with confidence
Production-grade pass prediction, live in five minutes. No propagation code, no TLE pipeline, no missed windows.
14-day free trial of the Research tier — no credit card required