How to Choose an Orbit for Your CubeSat
Your orbit shapes almost every other decision on the mission — how much power you generate, how often you can talk to the satellite, how long it lives, and even whether regulators will let you fly. For most CubeSats the honest answer is “wherever the rideshare is going,” but understanding the trade-offs lets you pick the right ride. This guide covers the levers that matter.
Almost everyone flies LEO
CubeSats live in Low Earth Orbit (LEO), roughly 300–600 km up. It’s cheap to reach, gives strong signals (short range), and — crucially — the thin residual atmosphere eventually drags dead satellites back down, which keeps you compliant with debris rules. Higher is not better for a CubeSat: it costs more to reach and makes deorbit harder.
Altitude: the fundamental trade-off
| Lower (~350 km) | Higher (~550 km) |
|---|---|
| Stronger link, better resolution | Weaker link, wider coverage |
| Shorter passes, more of them | Longer passes, fewer per day |
| Lifetime months to ~1 year | Lifetime several years |
| More atmospheric drag | Less drag, more stable orbit |
The ISS deploys CubeSats at around 400 km — a very common starting point because so many rideshares stage through it.
Inclination and what you can see
Inclination is the tilt of the orbit relative to the equator. It sets the range of latitudes you fly over. An ISS-inclination orbit (~51.6°) covers most populated latitudes but never the poles. A polar orbit (~90°) passes over the whole planet as the Earth rotates beneath it — ideal for global imaging or a ground station at high latitude.
Sun-synchronous orbits (SSO)
A sun-synchronous orbit is a special near-polar orbit tuned so the satellite crosses the equator at the same local solar time every day. That means consistent lighting on every pass — gold for Earth-observation missions — and predictable power, because the eclipse fraction stays roughly constant. A “dawn–dusk” SSO can even keep the satellite in near-continuous sunlight, easing the power budget dramatically.
Eclipse, coverage and revisit
The fraction of each orbit spent in the Earth’s shadow — the eclipse fraction— drives your battery sizing and is typically 30–40% in LEO. Coverage and revisit time (how long between views of the same spot) depend on altitude and inclination; higher and more inclined generally means better global revisit but weaker individual passes.
Lifetime and the deorbit rule
Regulators increasingly expect satellites to re-enter within 25 years (and newer guidance pushes toward 5). At 350–400 km, drag brings a CubeSat down naturally in months to a couple of years. Fly much above ~600 km and you may need a deorbit device (a drag sail, for example) to comply. Check this early — it can veto an otherwise attractive orbit.
Practical reality: you rarely “choose” an orbit from scratch — you choose a rideshare, which comes with a fixed altitude and inclination. Design your mission to make that orbit work.
Want to see how altitude changes your pass times, eclipse fraction and lifetime? The orbit simulator plots ground tracks and pass windows live, and feeds straight into your power and link budgets.
Design it for free in your browser
Defiant Smallsat is a free, all-in-one CubeSat & SmallSat design platform. Put this guide into practice — size your budgets, model your orbit and plan your mission without installing anything.