Nice job! The US spacecraft briefly touched an asteroid 333 million kilometers away to complete a mining mission
In the early morning of October 21, Beijing time, while we were still sleeping, the American spacecraft OSIRIS-REx was 333 million kilometers away The number performed an asteroid mining mission as scheduled, and slowly approached the asteroid Benu, and briefly touched the asteroid after more than 4 hours On the surface of the planet, dust and small rocks are quickly collected, and then the height is quickly raised. The whole process is done in one go, just like a dragonfly, it is perfect.
Good job! The U.S. spacecraft completed the asteroid mining mission, which can be described by a NASA expert:OSIRIS-REx completed an incredible feat. At 1:50 am on October 21st, OSIRIS-REx activated its chemical propulsion. Benu flew away, and in the process of approaching, he completed the extension of the 3.35-meter sampling arm by the way, placing the”take and send” sample collector (TAGSAM) at the bottom.
OSIRIS-REx is called Osiris-Rex in Chinese. OSIRIS-REx arrived at around 5:50 on the 21st At a height of 125 meters, it is very close to the asteroid. The thruster starts again to perform a”checkpoint” maneuver. The purpose is to stop the spacecraft and hover over the asteroid to facilitate horizontal movement. The purpose is to allow the sample collector (TAGSAM) Accurately align the sampling points of the”Nightingale” to prepare for the upcoming mining.
The”checkpoint” maneuver time is about 10 minutes. After 10 minutes, the thruster starts for the third time and descends at a very slow speed. To match the rotation of the asteroid, it is necessary to know that the rotation period of the asteroid Bennu is 4.29 hours. Eleven minutes later, the spacecraft passed over a two-story boulder,”Mountain of Doom”, and then successfully landed at the sampling site of the”Nightingale” that has only a small parking lot in the northern hemisphere of Benou.
According to the original plan, the contact between the American spacecraft and the asteroid Bennu was extremely short, less than 10 seconds long, including the two most important In operation, a stream of compressed nitrogen is released to hit the surface of the asteroid, causing dust and debris to fly in the sky. The sample collector takes the opportunity to collect the samples. Then, the spacecraft quickly raises the altitude according to the planned route and returns to its original orbit.
Although the whole mining process is automatically controlled by the OSIRIS-REx number, there is no live video to watch, but the real-time data shows that the sample collector has been successfully contacted Compressed nitrogen was launched on the ground. OSIRIS-REx engineers also confirmed that shortly after the spacecraft contacted the asteroid’s surface, it activated its thrusters and safely evacuated the asteroid, completing a difficult asteroid sampling mission.
Next, the OSIRIS-REx team will determine The number of samples in the sample collector was originally planned to be no less than 60 grams. It takes about a week. Since space has no weight, it cannot be weighed. However, the following two methods can be used to measure the number of samples. One measurement method is to use a SamCam camera to record the entire sample collection process to determine how much dust and stones enter the collector. However, this method also has a fatal disadvantage and requires suitable lighting conditions.
Another measurement method is to determine the amount of sample by determining the change in the spacecraft’s”moment of inertia”. In outer space, the greater the mass Larger, then its inertia is greater. This measurement method requires the sample collector to extend to the side of the spacecraft, then start the thruster, slowly rotate the spacecraft, let the sample collector rotate on a plane, and sense the quality of the sample in the sample collector through tension.
The number of samples collected by the spacecraft is directly related to, Will the spacecraft perform the second sampling mission? If it reaches 60 grams, it will be stored in the sample return cabin (SRC) together with the collector. The spacecraft will return to Earth in March 2021. If the sample is less than 60 grams , The sampling mission will be executed again on January 12, 2021, and the sampling point will be changed to”Osprey”.
p style=”text-align:justify” >The American spacecraft has completed a very difficult asteroid mining mission. In the history of human spaceflight, it has not been possible to perform such a difficult mission many times. Many, so far there are only three times. In November 2005, the Japanese Hayabusa 1 spacecraft landed on the asteroid”Itokawa” for the first time and successfully collected1500 rocks,In February 2019, the Japanese Hayabusa 2 spacecraft briefly touched the asteroid Ryugu and obtained samples. Now OSIRIS-REx has once again obtained samples of the asteroid Bennu.