March 3: first probe to do nothing on Mars




This was the mission that should have stolen the limelight from NASA programs to Mars. Half success despite everything, Mars 3 is the first to succeed in landing on the red planet… without succeeding in transmitting its data.

Maybe without this storm ...



Catastrophic beginnings

Tinged with ambition, the first Soviet attempts to reach Mars were sometimes bitter failures, sometimes missions flirting with success so that it escapes at the last minute ... And this despite the technique of systematically designing two identical probes to give yourself more chances of success. The first duo failed to leave Earth in 1960 (Mars 1M No.1 and 2), then a trio of probes once again fell short of success in 1962 ...

Just the vehicle '2MV-4 No.2', renamed Mars-1, he managed to hit the road, before ceasing to communicate about 100 million kilometers from Earth. Rebelote in 1964 and 1969 ... luck, on Mars, seems to turn in favor of the Americans, who succeed three flights over the red planet. But no question of giving up. The prestigious OKB-1 design office is preparing for 1971, with an offensive 'on all fronts': flyover, orbiters, landers, you have to succeed!






It's a real little armada in preparation. The 'race to the moon' being lost, the Soviets want to get ahead of their opponents, and become the first to enter orbit of Mars. However, NASA does not hide that it is preparing the Mariner 8 and 9 missions for 1971! The teams are forced to work harder, which will require some concessions to reach the launch pad in time. The onboard electronics of the three Soviet probes about to take off is their weak point. On May 10, 1971, '3MS No.170' (or Cosmos 419) took off with the hope of becoming the first vehicle to orbit Mars. But the onboard clock on the last stage of the rocket was incorrectly set: instead of turning on 1.5 hours after takeoff, it is set to 1.5 years… It will never leave Earth orbit.

9 days later, Mars 2 takes off in turn and rushes towards the red planet, followed on May 29 by Mars 3. This time, the USSR has two chances to enter orbit of Mars, and even to land there!



March 2 and March 3, ambitious technological concentrates

The two vehicles then on their way to Mars are truly equipped to revolutionize knowledge about the red planet, which comes down to a few pictures and measurements. March 2 and March 3 are twins, both weighing 4.65 tons on the day they take off with a Proton-K rocket. Each probe is broken down into two distinct parts. First, the orbiter equipped with solar panels, means to communicate with the Earth and an imposing scientific suite (radiometers, photometers, magnetometer, photo sensor, etc.), even carrying a French instrument.

STEREO-1, on board the two vehicles, will try to triangulate the source of the gamma-ray bursts in the universe, discovered in 1967. The lander on Mars 2 and Mars 3 is a robust piece of equipment weighing more than a ton, which takes on board what to get into the atmosphere, parachutes to brake and back-thrusters to land, not to mention absorbent foam for the final shock.




The landing gear is generally oval in shape, capable of opening up once placed on the ground and of deploying four petals which set it straight and put its instruments in the open air. Cameras, weather station, small mass spectrometer, the vehicles are very well equipped. The height of luxury, they take on board the very first Martian “walkers”, baptized Prop-M. Connected by a 15-meter cable to their parent vehicle, these small 4.5 kg boxes use some kind of skis to move around and must move within the camera's field of view so that mission engineers can understand the interaction with Martian soil.



That damn dust!

Without knowing it, the two Soviet missions are heading straight for a gigantic pea puree. For Mars was grappling at the end of the fall of 1971 with one of the most impressive sandstorms in its history: the entire surface was covered with thick clouds of dust from which only the highest peaks emerged. March 2 was the first to arrive, on November 27, but during the last maneuver six days earlier, his on-board computer issued a bad command: the landing gear was ejected with an angle of incidence much too high. If the orbiter comes out with a maneuver at the right time, the part that was to land crosses the atmosphere of Mars too quickly, and does not have enough time to brake or open its parachute. Mars 2 will be the first human object to touch the ground on the Red Planet… but much, much too quickly.





The Mars 2 mission orbiter will remain active for 362 orbits, performing measurements and taking dozens of photographs that will be well received on Earth. Unfortunately not only the Martian storm persists, but in addition the Soviets will not have the leisure to announce that their vehicle is the first in orbit of Mars: lighter, the NASA Mariner 9 probe has left them the priority of a few days. It's the space race ...




March 3 arises… for posterity.

On December 2, Mars 3 released its descent module, this time with the correct angle for a nominal crossing of the Martian atmosphere. Ironically, this time it is the orbital part of the mission that will have the problem: a fuel leak prevents the vehicle from completing its orbiting maneuver. It had to go around Mars in 25 hours, it will take more than 12 days ...

The lander, meanwhile, will succeed in passing to posterity. It survives its crossing of the Martian atmosphere, fine but generating prodigious heating. He opened his parachute, and to everyone's surprise, managed to land despite a relative speed estimated at almost 75 km / h! 90 seconds later, it begins to transmit its data, once its four 'petals' are deployed. The joy of the teams on the ground will be very short-lived: after the first 20 seconds of transmission of its first image (approximately 70 lines), the transmission is interrupted. Despite their best efforts, Soviet technicians, engineers and researchers failed to reconnect. Mars 3 becomes the first vehicle to have landed on Mars successfully… but without being able to carry out its mission.




Losing the race through weariness

Does the image sent by Mars 3 show something yes or not? Note that the question will be debated among researchers for several years, but that the 70 lines of data received are not considered today as usable. For some, we see the sky (because the colors are considered uniform), for others a petal of the lander or a landscape (because by increasing the contrast we believe to follow a horizon line). There is no definitive answer: the first complete photos taken from the soil of Mars will have to wait until 1976 and the landing of the American Viking probes, developed at great expense.





In the course of the 1970s, the Soviet Union will stop sending probes to Mars. There are many reasons for this, and American successes weigh heavily in the balance. But above all, there is the desire to focus exploration missions on the successes of the Venera project on Venus, rather than persevering and still failing towards the red planet. The Mars 4, 5, 6 and 7 probes, all launched in 1973 in a last-ditch effort, will not succeed in raising the bar ...



Post a Comment

Previous Post Next Post