- Body
- Mars
#explainer
Mars has enough atmosphere to heat an arriving spacecraft intensely, but too little for a parachute to slow heavy payloads easily. Landing systems therefore combine several braking methods. They must also work autonomously because radio delay prevents real-time control from Earth.
Several different problems in sequence
A heat shield protects during high-speed entry. A parachute can reduce speed later but often cannot produce a safe touchdown alone. Engines, legs, airbags or a sky crane handle the final stage according to mission design. Curiosity and Perseverance used powered descent stages to lower the rover on cables.
Heavier payloads change the design problem
Increasing mass is not simply a matter of enlarging every part of a successful rover. Mass relative to braking area, available time and parachute capability change. Future heavy landing systems therefore require further development. Terrain selection and obstacle detection matter as much as deceleration itself.
Why mission control cannot intervene at the last moment
Signals travel between planets for minutes depending on their separation, while descent events can follow seconds apart. Ground teams therefore receive reports about events that have already happened and cannot steer every decision with a joystick. The spacecraft must use its own sensors to recognize conditions and trigger the next step correctly.
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Key points
- A heat shield protects during high-speed entry.
- Increasing mass is not simply a matter of enlarging every part of a successful rover.
- Signals travel between planets for minutes depending on their separation, while descent events can follow seconds apart.
Sources & further reading
- Entry, descent and different Mars landing architectures.
- Challenges of slowing heavy vehicles in Mars's thin atmosphere.
Spaceflightpedia. (n.d.). Why is landing on Mars so difficult?. Retrieved 17 October 2026, from https://spaceflightpedia.com/article/difficult-mars-landing
article text — CC-BY-SA · ◉ NASA photography — public domain · ✦ AI illustration — marked, generated from sources
More questions on this topic
- How long does it take to reach Mars?
- Why are Mars launches limited to launch windows?
- How would people return from Mars?
