Space launch

Space launch is the earliest part of a flight that reaches space. Space launch involves liftoff, when a rocket or other space launch vehicle leaves the ground, floating ship or midair aircraft at the start of a flight. Liftoff is of two main types: rocket launch (the current conventional method), and non-rocket spacelaunch (where other forms of propulsion are employed, including airbreathing jet engines or other kinds).

Issues with reaching space

Definition of space

Space has no physical edge to it as the atmospheric pressure gradually reduces with altitude; instead, the edge of space is defined by convention, often the Kármán line of 100 km. Other definitions have been created as well, in the US for example space has been defined as 50 miles.

Energy

Therefore, by definition for spaceflight to occur, sufficient altitude is necessary. This implies a minimum gravitational potential energy needs to be overcome: for the Kármán line this is approximately 1 MJ/kg. W=mgh, m=1 kg, g=9.82 m/s², h=10⁵m. W=1*9.82*10⁵≈10⁶J/kg=1MJ/kg

Launch vehicle

In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad, and other infrastructure. Although a carrier rocket's payload is often an artificial satellite placed into orbit, some spaceflights, such as sounding rockets, are sub-orbital, while others enable spacecraft to escape Earth orbit entirely.

Earth orbital launch vehicles typically have at least two stages, and sometimes as many as four or more.

Types

Expendable launch vehicles are designed for one-time use. They usually separate from their payload and disintegrate during atmospheric reentry. In contrast, reusable launch vehicles are designed to be recovered intact and launched again. The Space Shuttle was the only launch vehicle with components used for multiple orbital spaceflights. SpaceX is developing a reusable rocket launching system for their Falcon 9 and Falcon Heavy launch vehicles. A second-generation VTVL design was announced in 2011. The low-altitude flight test program of an experimental technology-demonstrator launch vehicle began in 2012, with more extensive high-altitude over-water flight testing planned to begin in mid-2013, and continue on each subsequent Falcon 9 flight.Non-rocket spacelaunch alternatives are at the planning stage, although it is known that some companies are developing actual launch platforms, such as the Spanish zero2infinity with their rockoon-based launcher "bloostar".

Space Launch System

The Space Launch System (SLS) is an American Space Shuttle-derived heavy expendable launch vehicle being designed by NASA. It follows the cancellation of the Constellation program, and is to replace the retired Space Shuttle. The NASA Authorization Act of 2010 envisions the transformation of the Constellation program's Ares I and Ares V vehicle designs into a single launch vehicle usable for both crew and cargo, similar to the Ares IV. SLS will be the world's most powerful rocket with about 20% more thrust than Saturn V and a comparable payload capacity.

The SLS launch vehicle is to be upgraded over time with more powerful versions. Its initial Block 1 version is to lift a payload of 70 metric tons to low Earth orbit (LEO), which will be increased with the debut of Block 1B and the Exploration Upper Stage. Block 2 will replace the initial Shuttle-derived boosters with advanced boosters and is planned to have a LEO capability of more than 130 metric tons to meet the congressional requirement. These upgrades will allow the SLS to lift astronauts and hardware to various beyond-LEO destinations: on a circumlunar trajectory as part of Exploration Mission 1 with Block 1, to a near-Earth asteroid in Exploration Mission 2 with Block 1B, and to Mars with Block 2. The SLS will launch the Orion Crew and Service Module and may support trips to the International Space Station if necessary. SLS will use the ground operations and launch facilities at NASA's Kennedy Space Center, Florida.

Launch

Launch may refer to:

Boating

Gaming

Other uses

Space

Space is the boundless three-dimensional extent in which objects and events have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime. The concept of space is considered to be of fundamental importance to an understanding of the physical universe. However, disagreement continues between philosophers over whether it is itself an entity, a relationship between entities, or part of a conceptual framework.