I am writing a scenario for a game that I am a fan of. It involves an asteroid heading for impact with the Earth in 2027. This asteroid's initial diameter is about 1km, but it is slowly disintegrating (breaking apart into smaller pieces) due to the YORP effect. It is moving at ## Km/s.
After the asteroid has broken apart there is still a mass of rocks heading towards Earth. Instead of it being just a 1km asteroid hitting earth, it has now split up into several rocks with the largest (main part) being 300m in diameter.
Humanity detected the asteroid in 2021 and realise it is will hit the earth in 2027.
In the story, the humans lie to the world to cover up the fact that this asteroid is heading directly towards earth. Only in 2024 does news reach the public that the asteroid will hit Earth. This reasults in theories but no solutions to redirect the asteroid. In my scenario, the asteroid will hit the earth so these humans will ultimately fail to redirect the asteroid.
Info: The speed of the asteroid would be around 31 km/s (want it to be super fast to punch through atmosphere). Also this is just a bit more than the average speed of asteroids.
Question: I want my scenario, requiring the asteriod to hit Earth, to be believable. Given the trends in current technology, would it be possible to divert this asteroid between 2024 and 2027?