If a tennis ball flies at 99% of light speed, will it be in every location of its trajectory, or will it skip some on its way?

The tennis ball will not appear in every location of it’s trajectory nor will it skip some on it’s way. It will look to us that time on the tennis ball has slowed down.

Time and space are relative. What this means to your question is simply the speed of the tennis ball must be measured in relationship to something else, namely us on Earth.

If the tennis ball is launched from Earth and goes 99% the speed of light from Earth, then microbes and insects on the tennis ball would appear to be moving very slowly. But on the tennis ball, life would go on normally and life on Earth would appear to be going very quickly.

However, on the tennis ball itself, once that speed is achieved, it will appear that the tennis ball is standing still and Earth is moving away very quickly. If you were little and stood on the tennis ball and turned on a beam of light, the light would leave your flashlight at the speed of light in all directions.

Screenshot_2017-04-04_20-31-08How is that possible since light only travels the same speed in a vacuum? Because time slowed down for you, and so light always travels the speed of light, even though you seem to be normal. That’s why space and time are interwoven in the same fabric, what we call spacetime.

The same for us on Earth. We are orbiting the sun, the sun is orbiting the Milky Way center, the whole galaxy is about to collide with Andromeda, etc. etc. But as far as we’re concerned, we’re standing still and light leaves our beams of light at the speed of light.

Using the latest technologies & maneuvers, what speeds can we hope to achieve in space flight?

I’m just wondering for practical purposes. Doesn’t even have to be a manned mission, so all that extra life support weight can be dumped. Using optimal fuel mixtures, the latest technology, & as many gravity slings & other natural phenomena as possible how fast could we go?

According to Wikipedia:

New Horizons is currently making 15.73 kilometers per second on its way to a Pluto/Charon flyby in July of 2015, impressive but not the kind of speed that would get us to interstellar probe territory. Interestingly, the fastest spacecraft ever built wasn’t headed out of the Solar System at all, but in toward the Sun.

End of quote. Now let’s analyze this in terms of interstellar travel. The best candidate for possible habitable planets we know nearby are part of the TRAPPIST-1 system, which has 3 planets squarely in “the habitable zone.”

This system is very, very close compared to the rest of Milky Way and the universe: Only a mere 40 light years.

Gravity swings work great inside a solar system. Out in deep space between stars with no other planets or bodies to gravity assist, you’re just going be traveling at the fastest gravity assist you could accomplish before leaving our solar system. That would be about 15.73 km/s.

Since a light year is about 5.88 trillion miles, or about 9.5 trillion killometers and one trillion equals one thousand billion, and one billion equals one thousand million, to travel 40 light years at 15.73 kilometers would take awhile. 15.73 km per second is 56,628 km per hour. So if we divide 9.5 trillion by 56,628 km it will tell us how many hours it would take to reach TRAPPIST-1. In this way, dividing that number by 24 will tell you that it would take 1,359,072 days to reach there, or about 3,723 years.

One way. To transmit back to Earth what you found would take another 40 years at the speed of light. Would anyone still be listening?

In other words, going as fast as we can, it would take three thousand seven-hundred twenty-three years to reach that system, what to speak of any other stars further away.

We’re not going to ever go there, and nobody from space is ever going to come here.