Proton | Mars-2d
A Proton rocket launched Proton | Mars-2d from Baikonur Cosmodrome, Republic of Kazakhstan, targeting Mars.
- Launch time
- Status
- FAILED
- Operator
- Soviet Space Program
- Mission type
- Robotic Exploration
- Rocket
- Proton
- Launch site
- Baikonur Cosmodrome, Republic of Kazakhstan
- Launch pad
- 81/23 (81L)
- Payload
- —
- Target orbit
- Mars

Mission timeline
- 1971-05-10T16:58:42.000ZProton roars off the pad at Baikonur Cosmodrome, Republic of Kazakhstan.
- The vehicle reaches Max Q, the highest aerodynamic load of the flight.
- Flight anomaly — the mission is unsuccessful.