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USSR's 5M project:
The first effort to return soil from Mars!

In the 1970s, the Soviet space industry made the first serious attempt to develop spacecraft capable of bringing a piece of Mars back to Earth. After several years of intensive efforts, the top-secret 5M project was abandoned in the face of numerous technical challenges and, like many other unrealized Soviet space dreams, it had remained under wraps for decades. This section will re-tell the story of the 5M project in unprecedented detail.


The 5M project envisioned an unprecedented salvo launch of two Proton rockets within seconds of each other.

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Origin of the 5M project

The successful Soviet effort to return soil samples from the Moon with robotic spacecraft at the beginning of the 1970s, inspired the nation's engineers to take on the much bigger challenge of getting a piece of Mars. According to the 5NM concept, the N1 or N-1M super-heavy rocket would launch a 98-ton behemoth in September 1975.

Retailoring 5M from the N1 rocket to Proton

After the cancellation of the N1 development in 1974, the Mars sample return mission had to be downsized to fit onto the much smaller Proton rocket. To make it possible, the mission was initially split among three Proton boosters...


Final design of the 5M mission

When the three-launch scenario proved to be too complicated, the 5M mission was drastically re-designed to work with just two Protons. The resulting two-spacecraft 5M complex consisted of the "passive" 11S824M space tug carrying the Martian vehicle and the 11S86 "active" space tug.

Development and cancellation (INSIDER CONTENT)

From the outset, the 5M project faced multiple technical challenges. The dismal success rate of early Soviet Mars probes left little hope that a far more complex two-way mission to the Red Planet had a realistic chance to succeed. After a huge expense of funds and engineering effort, the 5M project was cancelled on Nov. 17, 1977.


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Launch and rendezvous

The extremely complex flight scenario for the 5M mission was unlike anything else attempted in the space exploration history. The dual mission would begin with a salvo launch of two Proton rockets from adjoining launch pads in Tyuratam.


Cruising to Mars

The 5M spacecraft would spend between 10 and 11 months cruising from the Earth to Mars. Nearly 30 days before approaching the Red Planet, all the batteries of the cruise module, the landing platform and the return vehicle would be fully charged and ready for the ultimate action.


How 5M was expected to land on Mars (INSIDER CONTENT)

On its approach to Mars, the lander would separate from the cruise module and hit the thin atmosphere of the Red Planet, braking with an umbrella-like heat shield, followed by a rocket-assisted descent. No parachute system, typical for most previous and subsequent Mars landings, would be employed in the 5M mission scenario.


Operations on the surface (INSIDER CONTENT)

Once on the surface, the lander would have to conduct the drilling and gathering of samples, followed by the even more complex task of determining its position on the planet, in order to chart its journey back to Earth.


UPDATE, March 20: Return to Earth (INSIDER CONTENT)

The final but untried leg of the Soviet 5M mission included a blastoff from the surface of Mars, followed by an orbital flight around the Red Planet and concluded with a cruise back to Earth. At the time, when Soviet engineers began tackling the problem of the return from Mars, no spacecraft had ever attempted a landing on the planet's surface.

All articles and illustrations inside this section by Anatoly Zak unless stated otherwise. All rights reserved

Last update: March 19, 2023

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