Reprinted in Baidu Post Bar-Aerospace Bar
Original data source satellite encyclopedia -sat.huijiwiki.com
After four months of calm cruise, Venus 9 took the lead in approaching the target. 1975 65438+1October 15, Venus 9 made a course correction of 13.5 m/s one week before encountering Venus to fine-tune its trajectory. Subsequently, the orbiter fully charged the battery of the lander, advanced its internal temperature to-10℃, and then released the descent module. Go to Venus by yourself during the day.
(The picture above shows the planning process when Venus approaches. First, the lander separates, then the orbiter deflects and enters the orbit before the lander arrives. The orbiter will record data from the lander for subsequent transmission back to Earth).
Soon after, the orbiter made a deflection maneuver of 247.3 m/s as planned to adjust its orbit to the other side of Venus. 10 year 10 on October 22nd, when it was still accelerating to approach Venus, Venus 9 orbiter started the KTDU-425A engine, making a braking maneuver of 922.7m/s, with a speed of 34.150011/.
After entering the orbit, the orbiter began to receive and record the data of the lander.
65438+1At 3 o'clock on October 22, the Venus-9 lander hit the Venus atmosphere at a speed of 10.7 km per second, making an angle of 20.5 with the local horizontal plane. After the impact of about 14 seconds, the load decreased from the peak of about 170g to only 2 g, and the lander deployed a parachute of 2.8m at an altitude of 65km..
Subsequently, the spherical shell cracked with the lower part, and a larger 4.4m metal parachute was deployed. 1 1 sec later, at an altitude of 60-62 km, the speed was reduced to 50 meters per second, and the lander was released from the upper part of the shell, and then the lander deployed three 4.3-meter parachutes. The lander kept transmitting data during the descent, and finally released the parachute at a height of 50 kilometers (yes, 50 kilometers) and landed freely on the ground.
Venus 9 finally landed on the surface of Venus at 3 1.0 1 north latitude and 5: 13 east longitude. It is located in the northeast of the highland called beta zone, which is about 2500 meters higher than the "sea level" defined by the planet. The lander immediately began to measure with its various instruments and transmitted the measurement results to the orbiter far overhead.
The results show that the local ground pressure is 85 bar, the temperature is 455 degrees Fahrenheit, and the wind speed is only 0.4 to 0.7 meters per second. The photometer reading on the plane showed that a cloud of dust was raised when landing, but it quickly dispersed.
The remote camera of the lander immediately began to scan the surrounding environment continuously, and the transmitted data was mixed with other data. Disappointingly, one of the telephoto lenses failed to pop up as planned, but the other returned the data as planned.
The results show that when the sun is 54 degrees above the horizon, there is enough light for imaging. 1972, the dark situation encountered by Venus 8 was measured when the sun was only 5 degrees from the horizon. So Venus 9 finally proved that floodlights are not necessary, as long as the lander lands on Venus during the day.
Measurements from the images providing the horizon view and the inclinometer on the lander show that Venus 9 landed on a hillside with a slope of 15 to 20, and the lander itself was tilted by 10 to 15 due to the uneven surface.
Schematic diagram of how the Venus 9 lander landed on the surface of Venus.
The lander continued to emit signals from the surface until the internal temperature of the lander reached 60℃ 53 minutes after landing, and the orbiter was far away from it. Then, the orbiter turned to the earth and transmitted the recorded lander data to anxious Soviet scientists and engineers.
Panorama of Venus 9 returning from the surface of Venus. Although there was a problem with one of the telephoto cameras, the lander mission was still a great success.
When the Venus 9 orbiter is already in orbit, its sister star Venus 10 is rapidly approaching Venus to repeat the feat of its predecessor. On 1975 10 10/8, Venus 10 made a final course correction of 9.7m/s, and released its descent module five days later. Then the orbiter made a deflection combustion of 242.2m/s to make it enter the orbit around Venus.
10 year 10 On October 25th, Venus orbiter 10 made a braking maneuver of 976.5m/s and entered the initial orbit of140014000 km with an inclination of 29.50.
Venus 10 finally landed at 56438+07 of north latitude 15.42 and east longitude 2910/.5/. The landing site is about 2200 kilometers south of the landing site of Venus 9. The detector found that the atmospheric surface condition was similar to the previous landing site: atmospheric pressure was 9 1 bar, temperature was 464, and wind speed was 0.8 to 1.3 meters per second.
Unfortunately, the Venus 10 lander experienced the same failure as its sister, and the cover of one telephoto camera failed to pop out after landing. Another telephoto camera really worked, sending back a series of panoramic images, showing the completely different terrain types of the new landing site.
The lander continued to transmit data until the orbiter left after 65 minutes. In other words, the working time of Venus 10 lander exceeded 65 minutes.
The image returned by the Venus 9 lander shows a rocky landscape full of edges and corners, with almost no signs of dust or erosion. Obviously, this is a young mountainous area with active geology. The measurement of rock density and composition shows that they are basalt, which is the most common rock type on the earth.
The photos taken by Venus 10 lander show that the lander landed on the undulating plain, the bedrock was exposed on the ground, and weathered particles were visible on the ground. The lander itself landed on a 3-meter-long board, which tilted the lander backward by 8 degrees. Although the analysis of existing rocks shows that the albedo of basalt composition is about 0.06, which is similar to that observed by Venus 9, it is obviously an older eroded landscape.
The Venus orbiter continues to study Venus from above. Venus 9 finally entered the orbit with a period of 48 hours 18 minutes and an inclination of 34.15, and the orbit was adjusted to1012200 km. It began a long-term study of Venus. Venus orbiter 10 enters1620113900 km orbit with an inclination of 29.5 and a period of 49 hours and 23 minutes.
Both orbiters continued to observe Venus until about three months after entering orbit, and the transmitter failure prevented them from observing again.
The two missions were officially announced on March 26th, 1976. Although Venus -9 and Venus-10 may not run as long as some people hope, they provide the first long-term observation of Venus and its surrounding environment, rather than the short-term flight snapshots provided by Venus missions before the United States and the Soviet Union.
Combined with the achievements of the lander, Venus 9 and 10 missions are obviously the most successful planetary exploration missions ever performed by the Soviet Union. It provides valuable data about our sister planet, and it has achieved two historical firsts ahead of American pirates 1.
The two "firsts" are:
The first orbiter to successfully orbit another planet, and the first lander to send back images of the surface of another planet.
A small part of the image of Venus surface drawn by Venus orbiter 10.
The pictures sent back by the Venus 9 orbiter show the clouds of Venus under ultraviolet light and ultraviolet light.
About the 50-kilometer free fall of Venus 9 yesterday.
I found an article by an expert in space history, which said:
At 3: 58 EST1October 22nd, Venera 9 lander hit Venus' atmosphere at a speed of 10.7 km per second, making an angle of 20.5 with the local horizontal line. After about 654 38+04 seconds, the load dropped from the peak value 170 G to only 2 G, and the 2.8-meter parachute was deployed at the height of 65 km. Then the spherical air shell cracked, the lower part was allowed to fall, and a larger 4.4-meter metal parachute was deployed. After 65438 +0 1 s, at an altitude of 60 to 62 kilometers, the speed now drops to 50 meters per second, the upper part of the aeroshell releases the lander, and then the lander deploys three 4.3-meter parachutes. The lander continued to transmit data when descending, and finally cut off the parachute at a height of 50 kilometers and landed freely on the surface.
The last sentence is crucial: "The lander continued to transmit data when descending, and finally cut off the parachute at a height of 50 kilometers and reached the surface in a free fall." The lander kept transmitting data during the descent, and finally cut the parachute at a height of 50 kilometers and landed freely on the ground.
What's fascinating is that according to the article, three parachutes with a height of 4.3 meters are deployed at a height of 60 kilometers, and then there are no parachutes for free fall, so I extremely doubt that the author has any misunderstanding about the height.
Link to the article:/2015/10/22/venera-9-and-10-to-venus/
Let's start with Venus 1 1 and 12.
Most of the successes of Venus 9 and 10 have proved the superiority of 4V- 1 detector. While enjoying themselves, the engineers of Lavochkin Scientific Research and Production Consortium began to fix the last two problems, so as to take more photos of the surface of Venus and make the lander work on the surface for a longer time.
Compared with the Soviets, Americans are like frogs when exploring Venus. When the Soviet Union pokes it, it moves. Don't poke, don't move. For example, the Soviet Union failed to launch five or six times in a row, and the Americans issued Mariner 2 skimmer, and the mission was successful. After that, the Soviet Union finally got rid of the curse of failure. Venus 4 succeeded for the first time, and the United States issued Mariner 5, which succeeded again. Now, Venus 9 and Venus 10 of the Soviet Union circled Venus for the first time and took photos on the surface for the first time. Americans carried out two missions in 1978: Venus-Pioneer 1 and No.2, 1 aimed at the orbit, and No.2 aimed at landing.
On May 20th 1978, Venus-Pioneer 1 was successfully launched, and in July 1980 was inserted into Venus orbit.
1On August 8, 978, Venus-Pioneer 2 was successfully launched. It carries a big detector and three small detectors, which are separated and penetrate the atmosphere of Venus from different positions. Although it can only hit the surface of Venus, it also sends back useful data.
When Americans "touched the bear across the river", the Soviet Union decided to launch two more Venus probes when the 1978 Venus window was about to close. I'm afraid I was stimulated by Americans this time. Because the conditions for the transfer of Venus were not good at that time-according to the orbital calculation, this launch window is not a good opportunity to orbit Venus, because the kinetic energy of these aircraft will be three times that of Venus 10 when they arrive.
In order to reduce the extra fuel consumption caused by deceleration, Soviet engineers decided not to adopt the orbiter-lander scheme, but to turn the orbiter into a flight platform.
The flight platform first separated from the lander, and then flew over Venus in a hyperbolic orbit. Near the designated position, the flying platform can receive the signal of the lander, and the flying platform will send the signal back to Earth.
The flight platform is equipped with instruments for deep space and Venus flying over;
(1)30- 166 nanometer extreme ultraviolet spectrometer
(2) Composite plasma spectrometer
(3) Konus gamma ray burst detector
(4) Sneg gamma ray burst detector
(5) Magnetometer
(6)4 semiconductor counters
(7)2 gas emission counters
(8)4 flicker counters
(9) Hemispherical Proton Telescope
It can be seen that the flight platform is also designed for space observation. It will continue its scientific research mission after flying over Venus.
(stamps of that year)
Because the structure of the flight platform is consistent with Venus 9 and 10, engineers need not work too hard on the flight platform. The real big head is still on the lander.
The basic design of the lander is similar to that of Venus 9 and Venus 10: spherical fuselage with a series of pillars installed on the annular landing platform. There is a disc pneumatic brake and a cylindrical tower at the top.
The lander is equipped with a panoramic color imaging system. Other instruments include a gas chromatograph for measuring the atmospheric composition of Venus, an instrument for studying scattered solar radiation and soil composition, a soil penetrator, temperature, pressure and wind sensors, an accelerometer and a Groza device for measuring atmospheric emissions.
The outer ball covers the whole lander and consists of two materials: KG-25 is high-temperature polyurethane foam, and PTKV-260 is a high-temperature heat shield with unknown composition (probably honeycomb composite material, which is unknown to outsiders now).
In order to leave more space for ground experiments, the parachute system is simplified into a flight guide parachute, a single-layer descending parachute cut off at the bottom of the cloud (49 km) and a supersonic braking parachute finally used.
Specifically, the descent module and the lander inside include experiments to study clouds, atmosphere and the surface of Venus:
(1) backscattering turbidimeter
(2) Mass spectrometer
(3) Gas chromatograph
(4)X-ray fluorescence spectrometer
(5) 360 scanning photometer
(6) Spectrometer (430- 1 170 nm)
(7) Microphone/anemometer
(8) kilohertz radio sensor
(9)4 thermometers
(10)3 barometers
(1 1) accelerometer
(12)PROP-V penetrometer
(13) soil analysis device
(14)2 color cameras
There are many new musical instruments in 4V- 1 this time. For example, the soil sampling and analysis device installed on the landing ring (that is, the soil drill summary in the picture).
It will drill samples at the landing site and send soil samples to the analysis room for analysis.
Another example is a mass spectrometer:
It has a complicated one-meter air intake system to avoid being polluted by cloud materials like the mass spectrometer of Venus 9. It uses an air inlet valve to open a large area in a short time and suck the cloud material into the mass analyzer. Moreover, it will be activated far below the clouds and sub-clouds.
The photometry results of Venus 9 and 10 show that Venus has strong light in the daytime and does not need a searchlight, so the searchlight is deleted in the new 4V- 1.
In addition, it is a great pity that the lens cover of Venus 9 10 camera is not completely opened. To this end, the engineers thought of various ways, and finally used the means of initiating explosive device. That is, after landing, the lens cover will be exploded by explosives instead of being ejected by the spring mechanism as before. In the ground test, this lens cover release mechanism performs well.
The descent module also carries a mission commemorative badge-the same as the last mission.
Venus 1 1 was launched at 03:25:39 UTC on September 9, 0978. After two revisions in September 16 and February 17, the descent module was separated from its flight platform on February 23rd 1978.
12 On February 23rd, after the lander was released, the flight platform continued to pass Venus along the heliocentric orbit. 1978 65438+February 25th, with an altitude of about 34,000 kilometers. The flight platform is closest to Venus. This flight platform acts as a data relay for the lander for 95 minutes until it flies out of sight of the lander.
On February 25th, 1 1.2km/s, the lander entered the atmosphere of Venus at night. In the descent process, it first uses aerodynamic braking, then uses parachute braking, and finally uses atmospheric braking. With the increase of atmospheric depth, the landing speed of the spacecraft decelerated from 50m/s to 8m/s.
Finally, at 03: 24 on February 25th at 1 hour, it made a soft landing on the ground without any dust. Landing point south latitude 14, east longitude 299. The information is transmitted to the flight platform as planned.
Sometimes, success is so boring …
(To be continued)