ISRO kept the Mars Orbiter Mission to ₹450 crore by flying a small spacecraft built on an existing design, launched on the modest PSLV and raised step by step.
The Mars Orbiter Mission, known as Mangalyaan, launched on PSLV-C25 on 5 November 2013. It entered Mars orbit on 24 September 2014, on its first attempt. ISRO says this made it the fourth space agency to reach Mars orbit, and gives the mission's cost as ₹450 crore.
It was planned as a technology demonstrator with a design life of six months. It worked for about eight years. Contact was lost during a long eclipse in April 2022, most likely because its propellant had run out.
The orbiter weighed 1,337 kg at lift-off, and 852 kg of that was propellant. Its structure was a modified version of ISRO's existing I-1K satellite bus, not a new design. It carried five science instruments.
A lighter spacecraft needs a smaller rocket. That choice shaped everything else in the mission.
PSLV could not throw the orbiter straight to Mars. Instead it placed it in a stretched Earth orbit of 250 km × 23,500 km. The rocket flew for 2,657 seconds, against about 1,200 seconds on a normal PSLV flight, with a long coast before its last stage fired.
Then the spacecraft's own engine took over. ISRO planned five orbit-raising burns, each one at the low point of the orbit. A final Trans-Mars Injection burn sent it out of Earth's sphere of influence and onto a cruise of about 300 days.
Worked example: at the 250 km low point of that orbit the spacecraft was already moving at about 9.9 km/s. From a circular 250 km orbit it would be moving at only about 7.8 km/s. PSLV had done roughly 2 km/s of the work that a bigger rocket would otherwise have had to do.
NASA's MAVEN orbiter also launched to Mars in 2013. The Planetary Society puts its total cost at $582.5 million, including $187 million for the launch and $28 million for two years of operations.
Comparisons like this need care. The two budgets are in different currencies and do not count the same things, and MAVEN carried a larger science payload. What is clear is that MOM was designed to be small and simple, and it still did its job at Mars for years.
Find the gap between the November 2013 launch and the 24 September 2014 Mars orbit insertion: that is the long cruise. Open the Mangalyaan mission timeline
Why burn at perigee? Rocket burns add the most orbital energy where the spacecraft is already fastest (the Oberth effect). Specific orbital energy is ε = v²/2 − GM/r. A small change Δv adds about v·Δv to ε, so a burn at high speed adds more energy.
Speed in PSLV's orbit. Perigee r_p = 6,378 + 250 = 6,628 km; apogee r_a = 6,378 + 23,500 = 29,878 km; semi-major axis a = 18,253 km. The vis-viva equation gives v = √(GM(2/r − 1/a)). With GM = 398,600 km³/s², v_p = √(398,600 × (2/6,628 − 1/18,253)) ≈ √98.4 ≈ 9.92 km/s.
Escape speed there. v_esc = √(2GM/r_p) = √(120.3) ≈ 10.97 km/s.
Leaving for Mars. A Hohmann transfer from Earth's orbit (1 AU) to Mars (1.524 AU) needs a speed relative to Earth, far from Earth, of about v∞ ≈ 2.9 km/s. At perigee the needed speed is √(v_esc² + v∞²) = √(120.3 + 8.6) ≈ 11.35 km/s.
From PSLV's elliptical orbit the spacecraft needed 11.35 − 9.92 ≈ 1.4 km/s. From a circular 250 km orbit, moving at √(GM/r) ≈ 7.76 km/s, it would have needed about 3.6 km/s. With 852 kg of propellant in a 1,337 kg spacecraft, that difference decides whether a mission is possible at all.
The real mission split the job into five perigee burns plus the final injection, partly so that no single long burn was critical. It also had to arrive with fuel left for Mars orbit insertion into a planned 366 km × 80,000 km orbit.
PSLV could only reach an elliptical Earth orbit. The spacecraft's own engine raised that orbit with burns at perigee before the Trans-Mars Injection burn, which is how a smaller rocket could do the job.
1,337 kg, of which 852 kg was propellant.
It was designed for six months but worked for about eight years, until contact was lost in April 2022.