Science is constantly advancing and creating new ideas for space travel. Here are a few science-based ideas for space travel that are currently being researched or developed:

1. What happens if we leave our gravity?

 Humans have built spacecraft that travel outside of Earth’s gravitational pull. In space, astronauts float around without any sense of motion. Gravity becomes less intense, making movement effortless. However, it takes some time for the body to adjust to zero-gravity conditions. After only 1 day, blood starts to pool in the legs and feet while fluid rushes out of the lungs and head. Blood vessels collapse and organs shift away from their normal positions. Astronauts lose between 2% and 5% of their bone mass per month due to the lack of gravity.

 2. How does a spaceship move?

 Astronauts use a combination of rockets and jet engines to get off the ground. A rocket launches a vehicle into orbit and propels it forward. Rocket propulsion uses fuel, and it requires a lot of force to push something that heavy off the surface of the planet. Once in orbit, astronauts turn on their jets to keep moving. Jet engines work well for short trips, but they burn a lot of fuel and require a lot of maintenance.

 3. Why do spaceships need fuel?

 The idea behind rocket propulsion is that you store potential energy in the shape of propellants and then release it at high speed. That’s how rockets shoot off into outer space. But, the amount of thrust produced by a rocket is directly proportional to the number of propellants loaded onto the ship. If you want to travel farther than 200 km, you need more fuel and larger rockets. Most current rockets are fueled by liquid oxygen (LOX) and kerosene (RP-1). LOX produces about twice the thrust of RP-1.

 4. Why doesn't a spaceship cruise in space forever?

 You need to take into account friction forces. These cause a loss of momentum over time, slowly degrading the engine and decreasing its efficiency. You can’t just power down an engine and coast indefinitely; eventually, you’d run out of fuel. To maintain a constant velocity, you’d have to replace the exhausted fuel with fresh gas periodically.

 5. Can people go faster than the speed of light?

 Yes! There are times when light moves slower than the speed of sound. Light travels 300 million meters per second. Sound travels slightly faster — about 330 kilometers per second. When light is slowed down, it reaches velocities close to the speed of sound. This means that you could theoretically make light travel faster than the speed of sound using special materials called metamaterials.

 6. Why do ships sometimes collide?

 Spacecraft are built to withstand extreme pressure. But air molecules are constantly colliding with them. Even if the ship is perfectly constructed, these collisions still happen. Collisions occur when a ship passes through an area where denser air particles are present. Because different densities of air produce different amounts of drag, heavier objects experience more drag than lighter ones. If a ship encounters a region of dense air, it may not slow down fast enough before hitting something else.

 7. How do pilots fly a plane?

 Pilots control the direction and speed of a plane by adjusting the position and rotation of the aircraft's wings. Planes rely on aerodynamics to reduce the effects of wind resistance. Aerodynamic lift occurs when air flows smoothly over a wing and creates positive pressure underneath. Drag, or negative pressure, occurs when air is forced past a curved surface and slows the plane down.