What is behind the failure of the Mars polar lander?

199865438+February 1 1 day, the United States launched the "Mars Climate" probe, followed by199965438+1October 4, and successively launched the "Mars Polar Lander". The reason is the schematic diagram of the "Mars Climate" detector.

Because they have the same task, that is to find water on Mars.

1On September 23rd, 999, the "Mars Climate" probe worth $65,438+25 million entered the atmosphere of Mars and slowly approached the fiery planet. But unfortunately, the "Mars Climate" detector suddenly turned into a big fireball and burned completely in the blink of an eye. It turned out that the units used by the staff to input data to the "Mars Climate" detector were inconsistent, which led to confusion between centimeters and inches when measuring the distance, making the orbiter fly too close to Mars. The orbiter then caught fire at high temperature and fell out of orbit into the atmosphere of Mars.

Thus, in the second millennium of the human calendar year, "Mars polar lander" became the last hope for people to explore Mars.

Mars polar landing probe

"Mars Polar Lander" used many devices similar to "Mars Pathfinder", such as its pneumatic shell, computer and parachute. But its camera system and solar panels have changed.

This time, the Mars polar lander carried a comprehensive scientific payload weighing 16 kg, including the camera and weather investigation system on Mars Pathfinder and some Russian lidar. In addition, it is equipped with a microphone, which can transmit all kinds of sounds on Mars back to Earth, so that human beings can not only see the image of Mars, but also hear the roar of the wind on Mars. This will be the first time that humans on earth have heard voices from other planets.

On this detector with a value of $65.438+65 billion, because the microphone is privately funded and has no specific scientific task, it is different from other instruments and equipment. In order to make this microphone occupy a place on the crowded lander, members of the American Planetary Society donated $50,000. The volume of this equipment is only about 1/2 of pea's, and it can record the sound with the same quality as the telephone, but the weight of the whole microphone is less than 60g.

In addition, the Mars polar lander also carries two important new systems-1.8 meter long sampling arm and high temperature gas volatilization analyzer. The sampling arm will be used to dig some trenches about 0.6 meters deep, and the camera installed on the arm will take images of the geological layer in order to reveal the history of the soil layer in the Antarctic of Mars. The sampling arm has elbow joint, which can dig the soil accurately and effectively. The camera on the arm can take high-resolution close-ups to accurately describe ice or geological crystals. The robotic arm will provide 8 samples to the gas analyzer, which will bake these substances and analyze the released gas.

It is worth mentioning that the lander carries two "Deep Space 2" micro detectors, which will stab the surface of Mars like two spears at a high speed of 650 km/h to find water. Each "Deep Space II" probe will complete 20 minutes of surface samples and water detection tests, and complete two days of soil temperature and climate monitoring tasks.

"Deep Space 2" is a part of NASA's new millennium exploration program. In fact, the New Millennium Exploration Program is a series of experimental activities carried out by NASA to prepare for the future conquest of outer space and even immigration plans. In order to ensure the success of "Deep Space II", a four-year simulation experiment was carried out in Mogavi, which is close to the terrain of Mars. The electronic equipment was launched from the high-altitude plane to the ground with a high-speed air gun, and the anti-seismic ability and feasibility of hitting the ground were tested. After 20 failed attempts, we finally designed a detector model that can withstand great impulse. According to the data of the simulation test, the impact force of these probes when they hit Mars is 60,000 times that of gravity.

The "Mars Polar Lander" started taking pictures when it was about 6.3 kilometers away from Mars. It uses a small camera. At first, it can distinguish the characteristics of an object with a size of 7.5 meters. When it descends to a height of 1 km from the ground, it can clearly distinguish the characteristics of an object with a size of 1.5 meters.

Scientists chose the landing time of the Mars polar lander in199965438+February, when the Antarctic region of Mars is in summer, which will enable the Mars polar lander to obtain continuous solar energy during its 90-day mission.

199965438+1February 3, 999 is the day when the polar lander of Mars landed on Mars. While preparing for the new millennium, people all over the world are paying attention to the news of the polar lander of Mars, hoping that it will bring a surprise to the new millennium.

The server supporting the website of NASA's Mars landing program can be said to be the most powerful website server system in the world, but it is a basic fact that when the Mars polar lander landed at the South Pole of Mars, it almost collapsed due to huge visits. Many netizens are very disappointed. They had hoped to see the live images of the surface of the red planet sent back by the Martian polar lander on the website, but they only saw the prompt that the server was too busy, or the website didn't respond at all.

Scientists are more disappointed than netizens, because the Mars polar lander has not sent any information to the Earth control center after entering the thin atmosphere of Mars. The landing time of "Mars Polar Lander" is a little later than planned at 3 pm, and the first signal should be given at 3: 40 pm. When netizens vainly tried to watch the real-time images sent back by the probe through mirror websites around the world, the staff of the American Jet Propulsion Laboratory were worried to find that there was no news of the polar lander of Mars at all.

In the next few days, scientists "pricked up their ears" day and night for fear of missing the valuable signal sent back by the Mars polar lander. Some people also imagine the possibility of goodwill, suggesting that it is only a matter of time before they receive the signal and encouraging people not to give up hope.

However, with the last contact with the "Mars polar lander" on February 7, 65438, NASA scientists' efforts to find the Mars probe for five consecutive days finally failed. This means that the United States finally lost the "Mars Polar Lander" probe costing $654.38 million+$65 million and the "Deep Space 2" probe costing nearly $30 million. This is the second time that the United States has lost its Mars probe in less than three months after the Mars Climate probe burned in the Martian atmosphere.

Ironically, although there is no news of the Mars polar lander in outer space and people have generally accepted the tragic ending of "mission failure", people are surprised to find a funny farce, because people find that the Mars polar lander has been moved to the auction platform of the Internet auction website. In the introduction column of the lot, we can see the following contents: "The real Mars polar lander is in good condition and clean, running normally at a distance of 65.438+0 billion miles, and the price is 6.5438+0 million dollars." There is also a note in the remarks column: "The final price needs to be approved by NASA, and you need to go to Mars to pick up the goods yourself!"

In the subsequent accident analysis, scientists believe that there are three possibilities for detector audio:

First, the annular cruise stage connected to the solar sail may not be separated from the lander because some of the six explosive bolts have not detonated; Second, the reasons for the failure of the three detectors may be different. Scientists in charge of Deep Space 2 believe that there is a huge crater at the landing site of Deep Space 2, which may make the landing fail or the signal cannot be returned; The third possibility is that the landing process of the probe is complicated, and there may be errors in the parachute, heat shield and descending engine, which may cause the probe to crash.

However, some people accused NASA of making a series of administrative mistakes and making many wrong judgments in this incident. According to an insider, the deceleration engine of the Martian polar lander did not pass the test at all during the construction process. The test results show that the igniter used to ignite the gas fuel of the detector can not work effectively at the low temperature near Mars, which will seriously affect the ability of the deceleration engine.

Due to the high cost of redesign and reconstruction, a NASA official not only turned a blind eye to the test results, but also secretly changed the experimental data and temperature parameters, making people think that the deceleration engine can work normally. Senior officials of NASA didn't know about this problem until a few days before the Mars polar lander planned to land on1February 3, 1999, but all the remedial measures at that time were of no help.

Nasa has also been criticized by all parties. Some critics point out that the lack of manpower and funds is the main reason for the repeated setbacks of the Mars exploration program in view of the "faster, better and more economical" space policy that NASA has been proud of for many years. Some experts pointed out that the goal of "faster, better and more economical" cannot be achieved at the same time, and the three can only be regarded as the second.

After losing two Mars probes in succession, NASA plans to install black boxes for future Mars probes to collect key data as a warning when the probes crash.

This special black box being developed by the Jet Propulsion Laboratory in the United States will bear an impact force three or four times higher than that of ordinary aircraft black boxes. The black box, with a mass of no more than 7 kg, is made of superhard titanium gold and covered with a layer of material commonly used for making bulletproof vests. The electronic components inside the black box are not installed on the ordinary circuit board, but embedded in an extremely hard frame to improve the impact resistance.

Unlike the black box of an ordinary plane, after the Mars probe crashed, the staff would not look for the black box and bring it back for analysis, but sent a signal to the black box, instructing it to send the recorded data to the satellite and then to the ground control center.

The researchers will also test the impact resistance of the new black box by shooting with a cannon and observing its damage.

Man's plan to explore Mars is always alternating between success and failure. Whether it is success or failure, the cycle of each exploration is more than two years. Due to the relationship between the orbit of the Earth and Mars, the most favorable launch time will only appear once every 26 months.