To help you understand how high that is, a regular aircraft flies only about 6.2 miles (10km) above the ground.Related: What is Space?Could we take an airplane to space?There are numerous reasons we cant just use an aircraft to get into area. The hot air is then shot out the back at a really high speed– pushing the aircraft forward.An artists impression of the Stratolaunch Systems carrier aircraft. That indicates theres less space on a rocket for other freight, such as passengers and luggage.But on the bright side, being able to take oxygen along for the journey means rockets can work in space, much higher up than where most aircraft fly.How does a rocket engine work?Similar to an aircrafts jet engine, rocket engines work by shooting extremely hot gas out from the back of the rocket.
“How exactly does a spaceship enter area?”– Mathilde, age 5, SydneyHello Mathilde, thanks for this excellent question! It isnt simple to get to area, and there are a few steps to it. Lets believe about where “area” itself really begins.Well, some time back, a number of experts decided on one point above us as being the point where “area” begins. They marked it with an invisible line called the Kármán line.This line goes all around the Earth and has to do with 62 miles (100 kilometers) above us. To help you comprehend how high that is, a typical aircraft flies only about 6.2 miles (10km) above the ground.Related: What is Space?Could we take an airplane to space?There are many factors we cant just use an airplane to enter into space. A major one is that the greater up we go, the less air there is– or specifically the less “oxygen” there is in the air.The engine is what helps the airplane fly. And similar to automobile engines, airplane engines need oxygen to work. Luckily, the air we breathe is comprised of 21% oxygen (although you cant see it)! Aircraft draw air in at the front, utilizing big fans on either side. They then blend this air with jet fuel, creating a mix of fuel and oxygen which is then burned, making the air hotter. The hot air is then shot out the back at an extremely high speed– pressing the airplane forward.An artists impression of the Stratolaunch Systems provider airplane. (Image credit: Dynetics/Stratolaunch Systems)But an airplane attempting to fly too near to space, where there isnt sufficient oxygen, would resemble a person attempting to breathe in a space with no air in it.This is why we require rockets to get to area. The huge distinction between rocket engines and jet engines used in airplane is rocket engines do not need to get oxygen from the air. Rather, they carry their own oxygen with them.In some ways this is bad, since rocket engines have to bring something that an aircraft can quickly obtain from all around it. That means theres less room on a rocket for other cargo, such as guests and luggage.But on the brilliant side, being able to take oxygen along for the journey implies rockets can work in space, much greater up than where most airplane fly.How does a rocket engine work?Similar to an aircrafts jet engine, rocket engines work by shooting extremely hot gas out from the back of the rocket. As the gas is pushed backwards, the rocket is pushed forward.This is an example of a guideline in science called the Third Law of Motion, very first discovered by a popular scientist named Isaac Newton. This law says that every action has a equal and opposite reaction.You can even make a very standard “rocket” at home with some aid from an adult! If you get a balloon, blow it up, and let it go without connecting off completion, the air within will shoot out and send it flying around the space– similar to a very severely controlled rocket!This post was originally released on The Conversation.Follow us @Spacedotcom, Facebook and Google+.