Today, in 2022, "near-Earth objects", the term is no longer unfamiliar to everyone, science enthusiasts have some understanding, refers to those who have been frequently active in the vicinity of the Earth, some also have a potential threat, their nearest distance from the sun is less than or equal to 195 million kilometers.
Monitoring data from NASA show that over the years we have found many near-Earth objects, tens of thousands of them, because of the orbital relationship, they are also far away from the Earth, and the asteroid 1998KY26 is a near-Earth object, and has visited the low-Earth orbit near the Earth many times.
Asteroid 1998 KY26 orbits the Sun at a distance of 1-1.5 AU, with an orbital eccentricity of 0.2, an inclination of 1° relative to the ecliptic, and an orbital period of 500 days. Note: 1 astronomical unit is equal to about 150 million kilometers, and the average distance between the Earth and the Sun is equal to 150 million kilometers.
Through the above data, it is not difficult to find that the orbit of the asteroid 1998KY26 is on the outside of the orbit of the Earth, and there is a meeting point with the orbit of the Earth, which is exactly the case, the asteroid 1998KY26 has come to a very close position to the Earth, the distance is only 374,000 kilometers, closer than the Earth-Moon distance.
Asteroid 1998KY26 is so close to the earth that it should be one of the most accessible objects in the solar system, but the Japanese Hayabusa2 spacecraft flew for 10 years to successfully reach 1998KY26, Hayabusa2 is currently flying rapidly, flying 36.28 kilometers in 1 second, obviously so close, why did it fly so long?
In the vast space, it is not difficult for artificial spacecraft to fly over a celestial body, just calculate the speed and trajectory of the celestial body first, and then calculate the speed and trajectory of the spacecraft, during the flight, and then fine-tune the speed and trajectory of the spacecraft, you can skim from near the celestial body.
In the last century, NASA launched Voyager 1 and Voyager 2 spacecraft, both skimming over Jupiter, the first of the eight planets, borrowed Jupiter's gravity to increase speed and change the direction of flight, that is, the gravitational slingshot effect, with the help of Jupiter's gravity, the two ships rushed out of the solar system into interstellar space.
In 2019, New Horizons made an adventurous flyby in outer space 6.6 billion kilometers from Earth, skimming the Köpper Belt asteroid End of the Earth (2014MU69) at a distance of 3,500 kilometers, taking several extraordinary close-up photos and obtaining valuable scientific data.
However, the artificial spacecraft to reach an asteroid, and fly with the asteroid, this is not an easy task, first of all, to adjust their own flight trajectory step by step, and finally let their own flight trajectory coincide with the asteroid orbit, when the time is mature, you can quickly change lanes and directly cut into the asteroid orbit.
After cutting into the asteroid orbit, the spacecraft also has to constantly change the direction and speed, try to be consistent with the flight speed of the asteroid, the speed is too fast or too slow may be out of orbit, once off-orbit, the spacecraft wants to cut into the asteroid orbit to consume a lot of energy, obviously not worth the loss.
If an artificial spacecraft wants to reach an asteroid, it needs to adjust its flight trajectory many times, it needs to adjust the flight speed many times, and it needs to wait for the time to be ripe, so this is not an easy task, and the operation team behind the spacecraft needs to develop a foolproof flight plan.
In order to enter the orbit of Mercury, the Bepi Colombo spacecraft launched on October 20, 2018, ESA and JAXA made a careful plan before launch, planning to fly for 7 years, once by Earth, twice by Venus, and six times by Mercury before cutting into mercury orbit and flying with Mercury.
Now, if Hayabusa2 wants to fly with Asteroid 1998KY26, it also needs to be well planned, and since hayabusa2 spacecraft flew over Earth in December 2020 and successfully returned to the asteroid sample, it will start another "star-chasing road" to catch up with asteroid 1998KY26.
Since Hayabusa2 has little fuel left, only 30 kilograms of xenon propellant remain, so try to use the gravitational pull of the planet to increase the spacecraft's own flight speed, expand the orbital radius, fly by the Earth twice, fly over Venus once, and encounter the asteroid 2001 AV 43 when flying by Venus.
You know, Hayabusa2 needs to fly for a long time to reach 1998KY26, according to the Japan Space Agency plan, around July 2026, Hayabusa2 will fly by asteroid (98943) 2001 CC 21 at high speed, and it will not take until July 2031 for hayabusa2 spacecraft to arrive at 1998 KY26, counting the time, it will take 10 years.
Why did it take 10 years to reach the asteroid 1998 KY26? According to preliminary understanding, 1998 KY 26 is a nearly spherical sub-kilometer asteroid with a diameter of about 30 meters and rotating at a rate of 10.7 minutes per week, its orbit is in the earth-Mars transfer orbit, and it is rich in water.
The Hayabusa2 odometer shows that it has flown 6.444 billion kilometers at a speed of 36.28 kilometers per second, but it is still a long way from the asteroid 1998 KY26, and it seems that Hayabusa2 will have to continue refueling. Interesting and informative scientific content, please pay attention to the only WeChat public account: Interesting Exploration