Most are designed for a set number of years — roughly 5 to 15 — but the real end comes when propellant, power or a key part runs out.
Every satellite is built for a design life: the number of years its makers promise it will work. Engineers pick parts, batteries, solar panels and the amount of propellant to last that long, with margin.
The real lifetime can be much shorter or much longer.
The longest of these, GSAT-30, is a geostationary communication satellite.
Design life also sets how much propellant is loaded. The IRNSS satellites, designed for 10 years, carry 825 kg of propellant out of 1,425 kg at launch.
ISRO designed its Mars Orbiter Mission for six months as a technology demonstrator. It entered Mars orbit on 24 September 2014 and kept working for about eight years.
It survived by careful management. In 2017 the team spent about 20 kg of propellant to dodge a long eclipse, leaving 13 kg. In April 2022 contact was lost after a long eclipse, and ISRO concluded the propellant had likely run out.
Wear is built in. NASA gives lithium-ion batteries a service life of about 5 to 10 years, and says solar cells lose output over a mission from radiation, ageing and contamination, so arrays are sized for end-of-life power.
IRNSS-1F shows how close the end can be: ISRO says it completed its 10-year design life on 10 March 2026, and its atomic clock stopped three days later. It now provides one-way messaging only.
Compare the launch years in the satellite list with each status note: the older IRNSS satellites have mostly moved from navigation to messaging only. Open the NavIC tracker
Engineers estimate lifetime from consumables and wear-out, and take the shortest.
1. Propellant. If station-keeping and attitude control need Δv_year each year, and the satellite has m_p of propellant left on a dry mass m_d, the rocket equation gives the years remaining:
years ≈ v_e × ln[(m_d + m_p) ÷ m_d] ÷ Δv_year
Illustrative: m_d = 1,500 kg, m_p = 200 kg, v_e = 2,900 m/s (Isp ≈ 300 s), Δv_year = 50 m/s:
ln(1,700 ÷ 1,500) = 0.125 → 2,900 × 0.125 ÷ 50 ≈ 7.3 years.
MOM shows the same budget in action: 20 kg spent in one 97.5 m/s manoeuvre left 13 kg — much less than one more such manoeuvre.
2. Battery cycles. A low-orbit satellite at about 15 orbits a day goes through roughly 5,500 eclipse cycles a year; a geostationary one sees only two eclipse seasons. NASA lists lithium-ion cycle life of 2,000–70,000 cycles and a service life of 5–10 years, so low-orbit designs keep each discharge shallow.
3. Solar array degradation. Output drops as radiation and contamination damage the cells (NASA). Arrays are sized for end-of-life power.
4. Random failure. Parts can fail at any time; redundancy (two or three of each critical unit) raises the odds of reaching design life.
Design life is therefore a promise with margins, not an expiry date. ISRO's Mars Orbiter Mission, with a six-month requirement, lasted about sixteen times longer.
The period its makers designed it to work for, with enough propellant, power and reliable parts — for example 12 years for NVS-01.
It was designed for six months and worked for about eight years in Mars orbit, until contact was lost in April 2022.
It runs out of propellant, its power system (solar cells or batteries) degrades, or a critical component fails without a working backup.