Let's say you're standing on a train that is moving at a speed of 60 mph. This means that the train's horizontal speed is 60. Your speed relative to the ground is 60, but to the train you're having a speed of 0. When you start walking at 2 mph, your speed to the ground is 62, but the speed to the train is 2.
But there's a different problem with that idea. The speed of light is 300.000.000 meters a second. 1/3rd of that is 100.000.000 meters a second. That's the same as 360.000.000 km/h. Now let's say you can do that in about 10 minutes. So you need a runway that is 1500 times as large as the earth! So where do you find a runway for this? No, not on Jupiter because it's a gas planet (no solid surface).
Now the scientists who are working on this problem are almost all retired. Have spent their entire lives working on this problem. And even before, it was studied by others including Einstein. So you can guess that stuff like that has all been tried before