Near space
Encyclopedia
Near space is the region of Earth's atmosphere
that lies between 65,000 and 325,000–350,000 feet (20 to 100 km) above sea level
, encompassing the stratosphere
, mesosphere
, and thermosphere
. A more understandable definition would be above where a commercial airliner
flies but below the realm of an orbiting satellite
. The area is of interest for military surveillance purposes, as well as to commercial interests for communications. Currently, craft that fly in near space (nearcraft) are generally high altitude balloon
s, blimps (non-rigid airship
s) and sounding rocket
s.
Near space is also the realm of an activity known as Amateur Radio High Altitude (ARHAB
) Ballooning
. Recently, due to falling costs of GPS technology, Amateur Radio High Altitude Ballooning has become a more common hobby with many amateurs launching balloons in many different locations around the world. In the United States
, these balloons are regulated by the Federal Aviation Administration
under FAR101 restrictions.
The terms "near space" and "upper atmosphere" are generally considered synonymous. However, some sources distinguish between the two. Where such a distinction is made, only the layers closest to the Karman line
are called near space, while only the remaining layers between the lower atmosphere and near space are called the upper atmosphere.
and his wife Jeannette, on the nearcraft The Century of Progress. Later exploration was mainly carried out by unmanned nearcraft, although there have been skydiving attempts made from high altitude balloons.
to reach extreme altitudes and orbit. These are still used today for sounding rockets.
There has been a resurgence of interest in near space to launch manned spacecraft by man. Groups like ARCASPACE
, as well as the da Vinci Project
are planning on launching manned suborbital space vehicles from high altitude balloons.
JP Aerospace
has a proposal for a spaceport
in near space, as part of their Airship to Orbit program.
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
that lies between 65,000 and 325,000–350,000 feet (20 to 100 km) above sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
, encompassing the stratosphere
Stratosphere
The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...
, mesosphere
Mesosphere
The mesosphere is the layer of the Earth's atmosphere that is directly above the stratosphere and directly below the thermosphere. In the mesosphere temperature decreases with increasing height. The upper boundary of the mesosphere is the mesopause, which can be the coldest naturally occurring...
, and thermosphere
Thermosphere
The thermosphere is the biggest of all the layers of the Earth's atmosphere directly above the mesosphere and directly below the exosphere. Within this layer, ultraviolet radiation causes ionization. The International Space Station has a stable orbit within the middle of the thermosphere, between...
. A more understandable definition would be above where a commercial airliner
Airliner
An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...
flies but below the realm of an orbiting satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
. The area is of interest for military surveillance purposes, as well as to commercial interests for communications. Currently, craft that fly in near space (nearcraft) are generally high altitude balloon
High altitude balloon
High-altitude balloons are unmanned balloons, usually filled with helium or hydrogen that are released into the stratosphere, generally reaching between ....
s, blimps (non-rigid airship
Non-rigid airship
A blimp, or non-rigid airship, is a floating airship without an internal supporting framework or keel. A non-rigid airship differs from a semi-rigid airship and a rigid airship in that it does not have any rigid structure, neither a complete framework nor a partial keel, to help the airbag...
s) and sounding rocket
Sounding rocket
A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, where to sound is to throw a weighted line from a ship into...
s.
Near space is also the realm of an activity known as Amateur Radio High Altitude (ARHAB
ARHAB
Amateur Radio High Altitude Ballooning is the application of analog and digital amateur radio to weather balloons and was the name suggested by Ralph Wallio for this hobby. Often referred to as "The Poorman's Space Program", ARHAB allows amateurs to design functioning models of spacecraft and...
) Ballooning
Ballooning
Ballooning may refer to:* Hot air ballooning* Balloon * Ballooning * Ballooning degeneration...
. Recently, due to falling costs of GPS technology, Amateur Radio High Altitude Ballooning has become a more common hobby with many amateurs launching balloons in many different locations around the world. In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, these balloons are regulated by the Federal Aviation Administration
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
under FAR101 restrictions.
The terms "near space" and "upper atmosphere" are generally considered synonymous. However, some sources distinguish between the two. Where such a distinction is made, only the layers closest to the Karman line
Karman line
The Kármán line lies at an altitude of above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space...
are called near space, while only the remaining layers between the lower atmosphere and near space are called the upper atmosphere.
Exploration
Near space was first explored in the 1930s. The early flights flew to the edge of space without computers, spacesuits, and with only crude life support systems. Notable people who flew in near space were Jean PiccardJean Piccard
Jean Felix Piccard , also known as Jean Piccard, was a Swiss-born American chemist, engineer, professor and high-altitude balloonist. He invented clustered high-altitude balloons, and with his wife Jeannette, the plastic balloon...
and his wife Jeannette, on the nearcraft The Century of Progress. Later exploration was mainly carried out by unmanned nearcraft, although there have been skydiving attempts made from high altitude balloons.
Use in space travel
The region has been of interest to space travel. Early attempts used a craft known as a rockoonRockoon
A rockoon is a solid fuel sounding rocket that, rather than being immediately lit while on the ground, is first carried into the upper atmosphere by a gas-filled balloon, then separated from the balloon and automatically ignited...
to reach extreme altitudes and orbit. These are still used today for sounding rockets.
There has been a resurgence of interest in near space to launch manned spacecraft by man. Groups like ARCASPACE
ARCASPACE
Asociația Română pentru Cosmonautică și Aeronautică or Romanian Cosmonautics and Aeronautics Association is a non-governmental organization that promotes aerospace projects as well as other space-related activities...
, as well as the da Vinci Project
Da Vinci Project
The da Vinci Project was a privately funded, volunteer-staffed attempt to launch a reusable manned suborbital spacecraft. It was formed in 1996 specifically to be a contender for the Ansari X PRIZE for the first non-governmental reusable manned spacecraft. The project was based in Toronto,...
are planning on launching manned suborbital space vehicles from high altitude balloons.
JP Aerospace
JP Aerospace
JP Aerospace is a volunteer-based organization dedicated to achieving affordable access to space. They have been hired by the U.S. Air Force to provide concepts to allow rapid launch of battlefield communication and monitoring systems....
has a proposal for a spaceport
Spaceport
A spaceport or cosmodrome is a site for launching spacecraft, by analogy with seaport for ships or airport for aircraft. The word spaceport, and even more so cosmodrome, has traditionally been used for sites capable of launching spacecraft into orbit around Earth or on interplanetary trajectories...
in near space, as part of their Airship to Orbit program.