- Objective: reach Mars (landing or orbit).
- Typical route: a ‘Hohmann transfer’ is generally used — the most fuel-efficient elliptical trajectory.
- Transit time: ~6 to 9 months depending on the launch window and propulsion.
- Average distance: ~225 million km (varies greatly depending on the relative positions of Earth and Mars).
- Main phases of a manned mission:
1. Launch from Earth (heavy rocket).
2. Trans-Mars injection (placement on transfer trajectory).
3. Interplanetary cruise (trajectory corrections, life support systems).
4. Entry into Martian orbit/atmospheric entry and landing.
5. Surface operations (variable duration).
6. Return (often requires rendezvous in Martian orbit + ascent vehicle).
- Possible propulsion: chemical (current), electric (ionic) for the cruise stage, or nuclear concepts (future).
- Major constraints: crew survival (radiation, microgravity), mass delivery, launch windows (approximately every 26 months), landing costs and risks.