Debris mitigation
Deorbit & Lifetime Compliance
The 25-year rule is dead. Check your disposal orbit against the FCC's 5-year rule and ESA's Zero Debris standard — and, if it fails, see exactly what it takes to comply.
// King-Hele atmospheric decay integrated from the disposal orbit to reentry, checked against FCC 47 CFR 25.283 / ESA Zero Debris / legacy 25-year limits. First-order screening — confirm marginal verdicts with NASA DAS at the real disposal epoch.
This orbital lifetime calculator integrates King-Hele atmospheric decay from your disposal orbit down to reentry and checks the post-mission lifetime against the regime you pick: the Federal Communications Commission (FCC) 5-year rule (47 CFR 25.283), the European Space Agency (ESA) Zero Debris standard, or the legacy 25-year guideline — the three regimes are compared side by side here. When an orbit fails, it sizes both remediations operators actually use — the deployable drag area, and the perigee-lowering disposal Δv, that bring the lifetime exactly to the limit. A first-order screen with a piecewise-exponential atmosphere at three solar-activity tiers; confirm marginal verdicts with NASA's Debris Assessment Software (DAS) at the real disposal epoch.
How this model works & what it omits
Every satellite operator now has to prove that whatever is left in orbit at end of mission comes back down promptly. The threshold tightened sharply: the FCC adopted a 5-year rule in 2022 (in force September 2024) for LEO satellites below 2,000 km — replacing the decades-old 25-year guideline — and ESA's Zero Debris standard matches it at under 5 years. Many disposal orbits that were fine under 25 years now fail. This tool tells you whether yours passes, and by how much.
The physics is atmospheric drag. A satellite with mass m, drag coefficient Cd, and cross-section A presents a ballistic coefficient BC = m/(Cd·A); the tool integrates the King-Hele simple-atmosphere decay equation da/dt = −(Cd·A/m)·ρ·√(μ·a) forward from the disposal orbit to the reentry altitude (100 km), using a piecewise-exponential atmospheric density table at three solar-activity tiers. For an elliptical disposal orbit, drag is concentrated at perigee — density is exponential in altitude — so the orbit first circularizes at perigee, then decays; that is why a low perigee is such a cheap way to shorten lifetime.
If the natural lifetime exceeds the limit, the tool solves the two remediation paths operators actually use. Required drag area — the deployable drag-sail area that would bring lifetime to exactly the limit (found by bisection, since lifetime falls monotonically with area). Disposal Δv — the perigee-lowering burn, applied at apogee, that drops the natural lifetime to the limit; from LEO this is usually only tens of m/s, and often cheaper than carrying a sail.
What this tool does not do: it is a first-order screening model, not a certified predictor. Future solar activity (the ~11-year cycle) swings thermospheric density several-fold, so real post-mission lifetime carries roughly 10–50% uncertainty — the same reason regulators accept a screening result but expect a full run of NASA DAS (Debris Assessment Software) at the actual disposal epoch for the filing. It also does not model attitude-driven area variation, geomagnetic-storm density transients, drag-sail deployment reliability, controlled-reentry targeting, or the casualty-risk / demise side of the standard (a separate assessment). A conservative compliance check uses the Low (solar-minimum) atmosphere, which gives the longest — worst-case — lifetime.
// pick a disposal scenario, or set your own orbit + regime.
Disposal orbit
// the orbit left behind at end of mission.
Spacecraft
// ballistic coefficient BC = m / (Cd·A) sets the decay rate.
Regime & atmosphere
// which limit to check, and the future-atmosphere assumption.
FCC 5-year rule (47 CFR 25.283)
Compliant
4.46 yr / 5 yr limit
0.5 yr margin
4.46 yr
Post-mission lifetime
75.8
Ballistic coeff (kg/m²)
—
Drag area to comply
—
Disposal Δv to comply
// screening only
First-order King-Hele model. Future solar activity swings atmospheric density several-fold, so real lifetime carries roughly 10–50% uncertainty. For a marginal verdict, confirm with NASA DAS (Debris Assessment Software) at the actual disposal epoch before filing. A conservative check uses the Low (solar-min) atmosphere.
// shareable URL encodes every input. no backend.
// ai-generated breakdown of what these numbers mean — with diagrams.
Common questions
How long will a satellite stay in orbit after end of mission?
Altitude dominates, and exponentially — atmospheric density falls off so steeply that 150 km changes the answer by an order of magnitude. The 550 km constellation preset (200 kg, 1.2 m² of drag area) reenters naturally in ~4.5 years, clearing the 5-year rule with about half a year of margin; a similar microsat at 700 km takes ~42 years — an 8× breach of the same limit. Ballistic coefficient (mass over drag area) matters too, but no realistic value rescues a high disposal orbit.
What is the FCC 5-year rule?
The 2022 order (Report & Order FCC-22-74, in force September 2024) requiring satellites in low Earth orbit (LEO) below 2,000 km to deorbit within 5 years of end of mission — replacing the 25-year guideline that stood for decades. ESA's Zero Debris standard sets the same under-5-year bar. The tightening reclassifies many once-fine orbits: the 600 km Earth-observation preset's 10.7-year lifetime passes the legacy 25-year check it was designed against but would fail the 5-year rule outright. Scope, effective dates, and casualty limits for all three regimes are compared in the FCC 5-year rule vs ESA Zero Debris vs 25-year guideline reference.
Drag sail or disposal burn — which fixes a failing orbit?
The tool sizes both so you can compare. For the failing 700 km microsat preset it takes either ~5.1 m² of deployed drag area (against the spacecraft's own 0.6 m²) or a ~59 m/s perigee-lowering burn at apogee. From LEO the burn is usually the cheaper option — tens of m/s is a small propellant fraction, and a sail adds deployment risk and tumbling-attitude uncertainty. Turn the Δv into propellant mass with the propulsion sizing tool.
Which solar-activity setting should I use?
For a compliance check, Low (solar minimum): the cool, contracted thermosphere gives the least drag and therefore the longest — worst-case — lifetime. The ~11-year solar cycle swings upper-atmosphere density several-fold, which is why any lifetime prediction carries roughly 10–50% uncertainty and why regulators accept a screening result but expect a NASA DAS run at the actual disposal epoch for the filing itself.
Is orbital lifetime the whole debris-compliance story?
No — it is one half. The standards also cap the ground-casualty risk from whatever survives the reentry you just scheduled, which is a separate materials-and-demise analysis: screen it with the reentry casualty risk tool. The compliance report tool composes both screens — lifetime and casualty risk — into a single orbital-debris assessment summary.
References
- // FCC (2022). Mitigation of Orbital Debris in the New Space Age, Report & Order FCC-22-74 — the "5-year rule" (47 CFR 25.283).
- // ESA (2023). Zero Debris Approach and ESSB-ST-U-007, Space Debris Mitigation Requirements (<5-year LEO clearance).
- // NASA-STD-8719.14C (2021). Process for Limiting Orbital Debris.
- // IADC-02-01 (rev. 2007). IADC Space Debris Mitigation Guidelines (the legacy 25-year guideline).
- // King-Hele, D. (1987). Satellite Orbits in an Atmosphere: Theory and Applications. Blackie.
- // Picone, J. M., et al. (2002). NRLMSISE-00 empirical model of the atmosphere. J. Geophys. Res. 107(A12).
- // NASA ODPO. Debris Assessment Software (DAS) — the reference tool for orbital-lifetime compliance.
