Pirate 2 YesU.S.AViking developed by NASAMars probeThe second one, launched on September 9, 1975, mainly studies the temperature, magnetic field, wind speed, wind direction and X-ray spectrum of MarsAugust 7, 1976get intoMars orbit，September 3, 1976TouchdownUtopiaPlain.Accomplish the same task as its sister detector. Accidentally, the normal operation of the geophone made it record onceMarsEarthquake.The spacecraft has an artificial satellite used to photograph the surface of Mars from orbit, carry a lander and carry out communication and relay with the EarthPirate ProgramIt is the most expensive plan in the history of Mars exploration, and also the most successful and informative plan before 1990 and 2000Mars Exploration Program，
Chinese name
Pirate 2
Quality
3527 kg (including fuel)
Destination planet
Mars
Launch carrier
Hercules III E-Centaur carrier rocket
Latest information
Successful launch
Country
U.S.A
Launch time
September 9, 1975
Task duration
1975~1980
Main tasks
Study Martian temperature, magnetic field, wind speed, etc
The main function of the orbiter of NASA Viking 2 is to transport the lander to Mars, detect and locate to confirm the landing site, carry out communication relay for the lander, and carry out its own scientific research projects.Tracker based on earlierMariner 9 The spacecraft has an octagon with a cross section of about 2.5 meters.The total weight is 2328 kg, of which 1445 kg ispropellantAnd attitude control gas.The total height of the orbiter is 3.29m.FourSolar cellThe wings are symmetrically arranged along the axis of the orbiter, and the relative solar cell wings are 9.75m wide.Each wing plate is equipped with two 1.57 × 1.23m solar panels, which are composed of 34800 solar cells and can provide 620 watts of power on Mars.Electric energy is also stored in two 30 ampere hoursNickel cadmium battery。 The main thruster is a liquid rocket engine using binary propellant (methyl hydrazine and nitrogen tetroxide).The engine thrust is 1323 N, which is converted to Delta-V and 1480 m/s.The engine can swing 9 degrees with two axles.Attitude control consists of 12 small compressed nitrogen nozzles, solar search sensorsCruise sun sensor, Senegalese tracker, and six three-axis stabilized gyroscopesInertial componentAnd two accelerometers.
The communication system consists of one 20 watt S-band (2.3GHz) transmitter, two 20 wattTWT amplifier。in order toradioX-band (8.4GHz) downlink for scientific research and communication experiments.S-band (2.1GHz) uplink.1.5m dual axis stabilized paraboloid antenna, fixed low gain antenna, two 1280 megabit tape recorders and one 381MHz relay radio device.
Scientific instruments include imaging, atmospheric water vaporInfrared thermographyThe device is installed in a directional scanning platform with temperature control.The total weight of scientific instruments is 72 kg.Spacecraft transmitters also conduct radio science research.
Instruction processing passes through two independent same data processors, each with a memory capacity of 4096 words for storing uplink commands and acquired data,
Lander
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The lander is an aluminum structure with six sides, each 1.09 meters high and 0.56 meters long.Supported by three support feet.The three support feet form an equilateral triangle with a side length of 2.21 meters.The lander consists of two plutonium-238Radioactive decay cellPower supply.The batteries are installed on both sides of the lander infrastructure and areWindbreakCovering, 28cm in height and 58cm in diameter.It can provide a continuous power supply of 4.4 volts and 30 watts.Four 8 Ah 28 volt batteries provide peak load.Propulsion is provided by rocket engines using monopropellant hydrazine.There are 12 engine nozzles arranged in four groups.Three sets of nozzles can provide 32 N thrust to generate Delta-V180 m/s.These nozzles are also controlled for movement and rotation by thrust control.The descent and landing are powered by three monopropellant hydrazine propellant engines (installed on the long side of the base and arranged in a 120 degree separation) with 18 nozzles, and the thrust is adjustable between 276 N and 2667 N.Hydrazine propellant is purified to prevent contamination of the Martian surface.The lander was launched with 86kg of propellant in two titanium fuel tanks.Fuel tank
Pirate 2 detector
Installed at both ends of the radioactive decay battery windshield.The lander is controlled via inertial components, four gyroscopes, air deceleration deviceRadar altimeter, descent and landing radar and thrust control.After launch and before entering the Martian atmosphere, the lander is protected by a thermal shield.The thermal shield is used for aerodynamic deceleration when the lander enters the atmosphere, and also for preventing the microbial contamination of the Martian surface.In order to prevent microbial contamination, the lander was sterilized by 250 ° F "baking" for 7 days.During launch, a "microbial shield" was wrapped around the thermal shield until the upper stage of the Centaur launched the orbiter/lander out of Earth orbit and abandoned the one developed for VikingPlanetary protectionMethod is also used for other tasks.The communication is via a 20 watt S-band transmitter and two 20 watt TWT amplifiers, and a dual axis stabilized high gain parabolic antenna, which is installed on the suspender at one side of the base.An omnidirectional low gain S-band is installed on the base, and both can communicate directly with the earth.A UHF band (381MHz) antenna provides simplex communication relayed by the orbiter.The data is stored in a 40 megabit tape recorder.The lander computer has a 6000 word memory for command storage.The instruments carried are used for the lander's main scientific research purposes: biological research, chemical composition analysis (organic and inorganic), meteorology, seismology, geomagnetism and geomorphologyMarsSurface and atmospheric physics.The instrument includes: two 360 degree cylindrical scanning cameras installed near the long side of the base, a sampling arm with a collection probe extending from the middle, a temperature sensor, a magnet, a ground temperature sensor of the weather detector, a wind direction sensor, and a wind speed sensor installed on a support leg.Seismic sensorMagnet, camera test target and magnifying glass are installed on the back side of the camera, close to the high gain antenna.Biological experimental equipmentGas chromatograph spectroscopeAnd X-ray fluorescence spectrometer are installed in the environmental control compartment.The air pressure sensor is installed at the bottom of the lander.The total weight of scientific instruments is 91 kg,[1]
Related research
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According to CNN, Dirk Schulze Markuch, a professor of geology at Washington State University, read out his research report at the meeting of the American Astronomical Society on the 7th.He said in the report that the "Pirate 1" and "Pirate 2" probes launched by NASA in 1976 did not find any signs of life on Mars, because they were looking for life forms similar to those on Earth, but did not recognize the life forms on Mars.
Schulze Markuch believes that the characteristics of life forms on the earth are that the liquid inside living cells is saline water, but the climate conditions on Mars are dry and cold. The basic unit of life forms may contain a mixture of water and hydrogen peroxide, because this mixture can remain liquid at extremely low temperatures, and will not damage cells in the case of freezing,It can even absorb the thin water vapor in the Martian atmosphere.
Due to technical and cognitive limitations in the 1970s, the "Pirate" probe failed to identify Martian microorganisms based on hydrogen peroxide. On the contrary, these microorganisms may be "drowned" or "heated" during unintentional operation.Schulze Markuch pointed out that in the experiment of looking for signs of life, the Viking once irrigated or heated the Martian soil, which would kill Martian microorganisms.
According to the plan, NASA will launch the Phoenix Mars probe in August 2007, and in 2008 it will land in the high latitudes of the northern hemisphere of Mars, which is rich in frozen water.This will be the first probe launched by NASA's Reconnaissance Program.The plan aims to complement large-scale Mars exploration projects by launching smaller and lower cost Mars probes.Phoenix will use professional filtering instruments to carefully select and analyze the Martian soil to find traces of ancient microorganisms.At that time, it will verify the theory proposed by Schulze Markuch.[1]
