>>12073355The energy you put into your rocket drive per second is the factor of your thrust and your exhaust speed. Exhaust speed limits your final speed according to Tchaikovskys equation.
At a set amount of power (we're already putting A LOT of power into our rockets, a Falcon boosters produces more power than a giant nuclear powerplant) you can either have high thrust or high final speed, not both. You need high thrust both to leave Earth in the first place and to get to your final speed quickly. It's also really hard to get to gigawatt levels of power without chemical power sources, which are similarly limited to high thrust.
But don't listen to the retards who say we don't have the capability to reach high speeds. We do. You just need nuclear propulsion. Either pulsed or thermal, or a mix of both.