Mars 2
Encyclopedia
The Mars program was a series of Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 unmanned lander
Lander (spacecraft)
A lander is a spacecraft which descends toward and comes to rest on the surface of an astronomical body. For bodies with atmospheres, the landing is called atmospheric reentry and the lander descends as a re-entry vehicle...

s and orbiter
Orbiter
An orbiter is a space probe that orbits a planet.-Asteroids:*NEAR Shoemaker...

s launched by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 in the early 1970s.

The Mars 2 and Mars 3
Mars 3
The Mars 3 was an unmanned space probe of the Mars program, a series of unmanned Mars landers and orbiters launched by the Soviet Union in the early 1970s....

 missions consisted of identical spacecraft, each with an orbiter and an attached lander; they were the first human artifacts to impact the surface of Mars. They were launched by Proton K
Proton rocket
Proton is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965 and the launch system is still in use as of 2011, which makes it one of the most successful heavy boosters in the history of spaceflight...

 heavy launch vehicle with a Block D upper stage.
  • Launch Date/Time:
    • Mars 2: 1971-05-19 at 16:22:44 UTC
  • Launch mass (including fuel):
    • Combined: 4650 kg (10,251.5 lb)
    • Orbiter: 3440 kg (7,583.9 lb)
    • Lander: 1210 kg (2,667.6 lb)
  • On-orbit dry mass: 2265 kg (4,993.5 lb)
  • Dimensions: 4.1 m (13.5 ft) tall, 2 m (6.6 ft) across (5.9 m (19.4 ft) across with solar panels deployed)

Orbiter

The orbiter engine performed a burn to put the spacecraft into a 1380 x 24,940 km, 18 hour orbit about Mars with an inclination of 48.9 degrees. Scientific instruments were generally turned on for about 30 minutes near periapsis

The orbiter primary scientific objectives were to image the Martian surface and clouds, determine the temperature on Mars, study the topography, composition and physical properties of the surface, measure properties of the atmosphere, monitor the solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...

 and the interplanetary and Martian magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...

s, and act as communications relays to send signals from the landers to Earth.

The Mars 2 orbiter sent back a large volume of data covering the period from December 1971 to March 1972, although transmissions continued through August. It was announced that Mars 2 had completed their mission by 22 August 1972, after 362 orbits. The probe, combined with Mars 3, sent back a total of 60 pictures. The images and data revealed mountains as high as 22 km, atomic hydrogen and oxygen in the upper atmosphere, surface temperatures ranging from -110 °C to +13 °C, surface pressures of 5.5 to 6 mbar (0.55 to 0.6 kPa), water vapor concentrations 5000 times less than in Earth's atmosphere, the base of the ionosphere starting at 80 to 110 km altitude, and grains from dust storms as high as 7 km in the atmosphere. The images and data enabled creation of surface relief maps, and gave information on Martian gravity and magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...

s.

Lander

The lander crashed on the Martian surface and was lost.

The Mars 2 descent module was mounted on the bus/orbiter opposite the propulsion system. It consisted of a spherical 1.2 m diameter landing capsule, a 2.9 m diameter conical aerodynamic braking shield, a parachute system and retro-rockets.

The entire descent module had a fueled mass of 1210 kg, the spherical landing capsule accounting for 358 kg of this. An automatic control system consisting of gas micro-engines and pressurized nitrogen containers provided attitude control. Four "gunpowder" engines were mounted to the outer edge of the cone to control pitch and yaw.

The main and auxiliary parachutes, the engine to initiate the landing, and the radar altimeter
Altimeter
An altimeter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth underwater.-Pressure altimeter:...

 were mounted on the top section of the lander. Foam was used to absorb shock within the descent module. The landing capsule had four triangular petals which would open after landing, righting the spacecraft and exposing the instrumentation.

The lander was equipped with two television cameras with a 360 degree view of the surface as well as a mass spectrometer to study atmospheric composition; temperature, pressure, and wind sensors; and devices to measure mechanical and chemical properties of the surface, including a mechanical scoop to search for organic materials and signs of life. It also contained a pennant with the Soviet coat of arms.

Four aerials protruded from the top of the sphere to provide communications with the orbiter via an onboard radio system. The equipment was powered by batteries which were charged by the orbiter prior to separation. Temperature control was maintained through thermal insulation and a system of radiators. The landing capsule was sterilized before launch to prevent contamination of the martian environment.

The descent module separated from the orbiter on 27 November 1971 about 4.5 hours before reaching Mars. After entering the atmosphere at approximately 6 km/s, the descent system on the module malfunctioned, possibly because the angle of entry was too steep. The descent sequence did not operate as planned and the parachute did not deploy. Mars 2 was the first manmade object to reach the surface of Mars. The landing site is unknown.

Prop-M Rover

Mars 2 lander had a small 4.5 kg Mars 'rover
Rover (space exploration)
A rover is a space exploration vehicle designed to move across the surface of a planet or other astronomical body. Some rovers have been designed to transport members of a human spaceflight crew; others have been partially or fully autonomous robots...

' on board, which would move across the surface on skis while connected to the lander with a 15-meter umbilical. Two small metal rods were used for autonomous obstacle avoidance, as radio signals from Earth would take too long to drive the rovers using remote control. The rover carried a dynamic penetrometer and a radiation densitometer.

The main PROP-M frame was a squat box with a small protrusion at the center. The frame was supported on two wide flat skis, one extending down from each side elevating the frame slightly above the surface. At the front of the box were obstacle detection bars.

The rover was planned to be placed on the surface after landing by a manipulator arm and to move in the field of view of the television cameras and stop to make measurements every 1.5 meters. The traces of movement in the Martian soil would also be recorded to determine material properties.

Because of the demise of the lander, the rover was not deployed.

See also

  • Exploration of Mars
    Exploration of Mars
    The exploration of Mars has been an important part of the space exploration programs of the Soviet Union, the United States, Europe, and Japan. Dozens of robotic spacecraft, including orbiters, landers, and rovers, have been launched toward Mars since the 1960s...

  • Space exploration
    Space exploration
    Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....

  • Unmanned space missions
  • Mars 1M
  • Mars probe program
    Mars probe program
    The Mars program was a series of unmanned spacecraft launched by the Soviet Union between 1960 and 1973. The spacecraft were intended to explore Mars, and included flyby probes, landers and orbiters....


External links

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