Science & Research

Even if you don’t keep up with developments in space propulsion technology, you’ve still probably heard about the EmDrive.  You’ve probably seen headlines declaring it  the key to interstellar travel , and claims that it will drastically reduce travel time across our solar system, making our dreams of people walking on other planets even more of a reality. There have even been claims that this highly controversial technology is the key to creating warp drives . Simply put, the EmDrive is a conundrum. First designed in 2001 by aerospace engineer Roger Shawyer, the technology can be summed up as a propellant less propulsion system, meaning the engine doesn’t use fuel to cause a reaction. Removing the need for fuel makes a craft substantially lighter, and therefore easier to move (and cheaper to make, theoretically). In addition, the hypothetical drive is able to reach extremely high speeds — we’re talking potentially getting humans to the outer reaches of th...

This article is part of the  NASA Knows! (Grades 5-8)  series.   What Shape Is an Orbit? Orbits come in different shapes. All orbits are elliptical, which means they are an  ellipse , similar to an oval. For the planets, the orbits are almost circular. The orbits of comets have a different shape. They are highly eccentric or "squashed." They look more like thin ellipses than circles. How Do Objects Stay in Orbit? An object in motion will stay in motion unless something pushes or pulls on it. This statement is called Newton's first law of motion. Without gravity, an Earth-orbiting satellite would go off into space along a straight line. With gravity, it is pulled back toward Earth. A constant tug-of-war takes place between the satellite's tendency to move in a straight line, or momentum, and the tug of gravity pulling the satellite back. Where Do Satellites Orbit Earth? The International Space Station is in low Earth orbit, or LEO. LEO is the first 100 to 20...

Missile is a weapon that is self-propelled or directed by remote control, carrying conventional or nuclear explosive.  There are three broad types of missiles Conventional guided missiles Cruise missiles Ballistic missiles Difference between cruise and ballistic missile  A Cruise Missile is a guided missile that flies with constant speed to deliver a warhead at specified target over long distance with high accuracy. A Ballistic Missile is launched directly into the high layers of the earth’s atmosphere. Cruise missile is classified by size, range, speed and launch type. Ballistic missile is classified based on its range, maximum distance measured along the earth’s ellipsoid from point of launch to point of impact of last element of their payload. Cruise missile flies with in earth’s atmosphere and use jet engine technology. Cruise missiles are known specifically for low-level flight which is staying relatively close to the surfa...