1. Liftoff: During the initial phase of launch, rockets accelerate rapidly to overcome Earth's gravity. This acceleration can result in speeds of several thousand miles per hour (mph) or kilometers per hour (km/h) within a few minutes. For instance, the Space Shuttle could reach a speed of approximately 1,750 mph (2,820 km/h) during its ascent.
2. Orbital Insertion: Once a rocket reaches a certain altitude, it needs to achieve orbital velocity to stay in space. Orbital velocity depends on the altitude of the orbit, but typically ranges from 17,500 mph (28,200 km/h) for low Earth orbit (LEO) to 25,000 mph (40,200 km/h) for higher orbits.
3. Interplanetary Travel: When rockets are launched on missions to other planets, they must achieve even greater speeds to overcome the gravitational pull of Earth and travel to their destinations. For example, NASA's Parker Solar Probe, designed to study the Sun, reached a speed of approximately 214,000 mph (344,000 km/h) during its closest approach to the Sun.
4. Reentry: When rockets or spacecraft return to Earth, they need to slow down significantly to avoid burning up in the atmosphere. They use various techniques, such as heat shields and parachutes, to reduce their speed. The final speed at landing or splashdown can vary greatly depending on the mission's requirements and safety considerations.
It's important to note that these are just a few examples, and specific rocket missions may have different speed profiles based on their unique objectives.