User:Marshallsumter/Radiation astronomy/Aircraft

Manned spaceflight on an individual basis has only been achieved with experimental aircraft such as the X-15. An airborne observatory is an airplane or balloon with an astronomical telescope. By carrying the telescope high, the telescope can avoid cloud cover, pollution, and carry out observations in the infrared spectrum, above water vapor in the atmosphere which absorbs infrared radiation.

Gerard P. Kuiper Airborne Observatory
The Gerard P. Kuiper Airborne Observatory (KAO) was a national facility operated by NASA to support research in infrared astronomy. The observation platform was a highly modified C-141A jet transport aircraft with a range of 6,000 nautical miles (11,000 km), capable of conducting research operations up to 48,000 feet (14 km). The KAO was based at the Ames Research Center, NAS Moffett Field, in Sunnyvale, California. It began operation in 1974 as a replacement for an earlier aircraft, the Galileo Observatory, a converted Convair CV-990 (N711NA).

Stratospheric Observatory for Infrared Astronomy
The Stratospheric Observatory for Infrared Astronomy (SOFIA) is based on a Boeing 747SP wide-body aircraft that has been modified to include a large door in the aft fuselage that can be opened in flight to allow a 2.5 meter diameter reflecting telescope access to the sky. This telescope is designed for infrared astronomy observations in the stratosphere at altitudes of about 41,000 feet (about 12 km). SOFIA's flight capability allows it to rise above almost all of the water vapor in the Earth's atmosphere, which blocks some infrared wavelengths from reaching the ground. At the aircraft's cruising altitude, 85% of the full infrared range will be available. The aircraft can also travel to almost any point on the Earth's surface, allowing observation from the northern and southern hemispheres.

"SOFIA’s primary mirror, located near the bottom of the telescope, is 2.7 meters (almost 9 feet) across. The front surface, which is highly polished and then coated with Aluminum to ensure maximum reflectivity, is deeply concave (dished inward). Incoming light rays bounce off the curved surface and are all deflected inward at the same time they are reflected back up toward the front of the telescope."

"Before the light reaches the telescope’s front end, however, it is intercepted by a small secondary mirror (about .4 meters across), which sends the light back down toward the center of the main mirror. About a meter above the center of the main mirror, a third mirror sends the light out through the side of the telescope, down a long tube which projects through the main aircraft bulkhead into the interior of the SOFIA aircraft. There, at the telescope’s focal point, the light will be recorded and analyzed by one of several different instruments."

"Astronomers tend to compare telescopes based on the diameter of their primary mirrors. SOFIA’s telescope is usually referred to as a 2.5-meter meter telescope, rather than 2.7 meters, because the optical design requires that only about 90% of the mirror’s reflecting surface (called the "effective aperture") can be used at any one time. Although SOFIA’s telescope is by far the largest ever to be placed in an aircraft, compared to normal ground-based research observatories it is only medium-sized (the world’s largest single-mirror telescope, the Subaru, is 8.2 meters across)."

ER-2 high altitude research aircraft
"ER-2 tail number 809, is one of two Airborne Science ER-2s used as science platforms by Dryden. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation."

"The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main equipment bay behind the cockpit, two wing-mounted superpods and small underbody and trailing edges. Most ER-2 missions last about six hours with ranges of about 2,200 nautical miles. The aircraft typically fly at altitudes above 65,000 feet. On November 19, 1998, the ER-2 set a world record for medium weight aircraft reaching an altitude of 68,700 feet."

"The aircraft is 63 feet long, with a wingspan of 104 feet. The top of the vertical tail is 16 feet above ground when the aircraft is on the bicycle-type landing gear. Cruising speeds are 410 knots, or 467 miles per hour, at altitude. A single General Electric F118 turbofan engine rated at 17,000 pounds thrust powers the ER-2."

Aircraft assisted launches
The Pegasus is carried aloft below a carrier aircraft and launched at approximately 40,000 ft (12,000 m). The carrier aircraft provides flexibility to launch the rocket from anywhere rather than just a fixed pad. A high-altitude, winged flight launch also allows the rocket to avoid flight in the densest part of the atmosphere where a larger launch vehicle, carrying much more fuel, would be needed to overcome air friction and gravity.

The Galaxy Evolution Explorer (GALEX) is an orbiting ultraviolet space telescope launched on April 28, 2003 [at 12:00 UTC]. A Pegasus rocket placed the craft into a nearly circular orbit at an altitude of 697 km and an inclination to the Earth's equator of 29 degrees.

The Array of Low Energy X-ray Imaging Sensors (ALEXIS) X-ray telescopes feature curved mirrors whose multilayer coatings reflect and focus low-energy X-rays or extreme ultraviolet light the way optical telescopes focus visible light. ... The Launch was provided by the United States Air Force Space Test Program on a Pegasus Booster on April 25, 1993.

Autonomous vehicles
“An autonomous vehicle is a virtual object, such as an elevator, which, once entered by the user, automatically moves the user to a new location in the virtual world.”

Notation: let the symbol AUV stand for autonomous underwater vehicle.

An autonomous underwater vehicle (AUV) is a robot which travels underwater without requiring input from an operator. AUVs constitute part of a larger group of undersea systems known as unmanned underwater vehicles, a classification that includes non-autonomous remotely operated underwater vehicles (ROVs) – controlled and powered from the surface by an operator/pilot via an umbilical or using remote control. In military applications AUVs more often referred to simply as unmanned undersea vehicles (UUVs).

Pilotless hovering vehicles
At right is a digitized photograph of a micro air vehicle designed to fly over a combat area during flight. As of November 14, 2006, the MAV is in the operational test phase with military Explosive Ordnance Disposal (EOD) teams to evaluate its short-range reconnaissance capabilities.

The small craft allows remote observation of hazardous environments inaccessible to ground vehicles. MAVs have been built for hobby purposes, such as aerial robotics contests and aerial photography.

The range of Reynolds numbers at which MAVs fly is similar to that of an insect or bird (103 - 105). Thus, some researchers think that understanding bird flight or insect flight will be useful to designing MAVs. The flapping motion used by birds and insects to produce lift involves aeroelasticity, which introduces structural considerations. Unsteady aerodynamics [may] also [be] present in this type of motion.

Pilotless aerial vehicles
The V-1 flying bomb the Fieseler Fi 103 is an early pulse-jet-powered predecessor of the cruise missile. In late 1936, Argus Motoren company had already developed a remote-controlled surveillance aircraft, the [Argus As 292] AS 292 (military designation FZG 43).

A culmination of the flying bomb effort is the SM-62 Snark shown in flight at right which is "an early-model intercontinental cruise missile that could carry a W39 thermonuclear warhead. The Snark has an operational range of 10,200 km.

After the successful development of the intercontinental ballistic missile (a pilotless rocket), the Snark and its kindred are replaced by the ~1,000 km ranged cruise missile.

Collision avoidances
In spaceflight, collision avoidance is the process of preventing a spacecraft from colliding with any other vehicle or object.

A launch window is said to have a [collision avoidance, or COLA] COLA blackout period during intervals when the vehicle cannot lift off to ensure its trajectory does not take it too close to another object already in space.

A collision avoidance manoeuvre  or Debris Avoidance Manoeuvre  (DAM) is an orbital manoeuvre conducted by a spacecraft to avoid colliding with another object in orbit. One is most commonly used in order to avoid a piece of space junk.

An airborne collision avoidance system (ACAS) is an aircraft system that operates independently of ground-based equipment and air traffic control in warning pilots of the presence of other aircraft that may present a threat of collision. If the risk of collision is imminent, the system indicates a manoeuvre that will reduce the risk of collision. ACAS standards and recommended practices are mainly defined in annex 10, volume IV, of the Convention on International Civil Aviation.

A distinction is increasingly being made between ACAS and ASAS (airborne separation assurance system). ACAS is being used to describe short-range systems intended to prevent actual metal-on-metal collisions. In contrast, ASAS is being used to describe longer-range systems used to maintain standard en route separation between aircraft (5 nm {9.25 km} horizontal /1000' {305 m} vertical).

A collision avoidance system is a system of sensors that is placed within a car to warn its driver of any dangers that may lie ahead on the road. Some of the dangers that these sensors can pick up on include how close the car is to other cars surrounding it, how much its speed needs to be reduced while going around a curve, and how close the car is to going off the road. The system uses sensors that send and receive signals from things like other cars, obstacles in the road, traffic lights, and even a central database are placed within the car and tell it of any weather or traffic precautions.

Propulsion systems
A propulsion system is a machine or system of machines that produces thrust to push or pull a vehicle from a position of relative rest into motion or to provide an acceleration or deceleration for a vehicle already in motion. The objective of a propulsion system is to maintain the vehicle’s ability to propel itself and maneuver. Current propulsion systems are often some form of internal-combustion engine combined with aerodynamic lifting mechanisms.

Rocket engines such as the Pixel rocket shown at right have been developed which can hover a vehicle for brief periods.

On the ground and in the air the Waterman Aerobile at left is powered by a water-cooled 120 hp (89 kW) Tucker-Franklin engine. It can fly at 112 mph (180 km/h), cruise speed of 164 km/h, maximum speed of 193 km/h, and drive at 56 mph (90 km/h), with a maximum of approximately 113 km/h.

"Japanese electronics maker NEC Corp. on Monday showed a "flying car," a large drone-like machine with four propellers that hovered steadily for about a minute [in the second image down on the right]."

"The test flight reaching 3 meters (10 feet) high was held in a gigantic cage, as a safety precaution, at an NEC facility in a Tokyo suburb."

"The Japanese government is behind flying cars, with the goal of having people zipping around in them by the 2030s."

"Among the government-backed endeavors is a huge test course for flying cars that's built in an area devastated by the 2011 tsunami, quake and nuclear disasters in Fukushima in northeastern Japan."

"Similar projects are popping up around world, such as Uber Air of the U.S."

"The goal is to deliver a seamless transition from driving to flight like the world of "Back to the Future," although huge hurdles remain such as battery life, the need for regulations and safety concerns."

"Often called EVtol, for "electric vertical takeoff and landing" aircraft, a flying car is defined as an aircraft that's electric, or hybrid electric, with driverless capabilities, that can land and takeoff vertically."

"All of the flying car concepts, which are like drones big enough to hold humans, promise to be better than helicopters. Helicopters are expensive to maintain, noisy to fly and require trained pilots. Flying cars also are being touted as useful for disaster relief."

Magnetometric surveys
"A detailed airborne magnetometric survey [such as by the helicopters center and on the left] indicated the structure of the area was followed by a west northwest striking domal feature and the lithologies are probably siliceous, clastic sediments. The southern margin of the antiform has been transected by a west northwest striking shear, whilst the western part of the dome has undergone a later stage folding regime and the intrusion of a granitoid. [Broken Hill Type Ag-Pb-Zn (BHT) mineralisation] BHT mineralisation is predominantly hosted at a major stratigraphic break, and remobilised or offset into both the hangingwall and footwall."

Magnetometric surveys readily detect magnetic iron minerals in red or black bands within banded iron formations such as in the image on the right.

Electromagnetic surveys
"Airborne electromagnetic surveys using a grounded electric dipole source and magnetic surveys were conducted to delineate resistivity and magnetization structures".

"Airborne Electromagnetic (AEM) data [such as collected by the TEMPEST system shown on the right, the transient electromagnetic (TEM) SkyTEM system shown on the left, or the Versatile Time Domain Electromagnetics (VTEM) system in the center] are one form of the geophysical data acquired by Geoscience Australia. The data are gathered by transmitting an electromagnetic signal from a system attached to a plane or helicopter. The signal induces eddy currents in the ground which are detected by receiver coils towed below and behind the aircraft in a device called a bird. Depending on the system used and the subsurface conditions, AEM techniques can detect variations in the conductivity of the ground to a depth of several hundred metres, [sometimes up to 2000 metres in particularly favourable conditions]. The conductivity response in the ground is commonly caused by the presence of electrically conductive materials such as salt or saline water, graphite, clays and sulfide minerals."

"Since 2006, Geoscience Australia and its State and Territory partners have been collecting AEM data over large areas at broad line spacing (1000-6000 metres) to more fully survey Australia. AEM surveys also require complex processing to allow interpretation and, therefore, are usually designed to detect particular subsurface targets which are based on a perceived conductivity contrast, for example:
 * the spatial extent of geological features, such as a clay-rich unit in a sedimentary sequence or a graphite-bearing unit in a metamorphic complex
 * the depth of an unconformity between sedimentary cover and the underlying basement rock
 * the location of groundwater resources, such as fresh or saline aquifers."

Conductivity surveys
Conductivity measurements of the distribution of electrical conductivity in the ground is made aerially with a sensor suspended from the helicopter such as in the image on the right map changes in the ground water.

Hyperspectral imaging systems
"[Airborne Real-time Cueing Hyperspectral Enhanced Reconnaissance (ARCHER)] is essentially something used by the geosciences. It's pretty sophisticated stuff … beyond what the human eye can generally see."

"It might see boulders, it might see trees, it might see mountains, sagebrush, whatever, but it goes 'not that' or 'yes, that'. The amazing part of this is that it can see as little as 10 per cent of the target, and extrapolate from there."

Ground-penetrating radar
"The ability of a sophisticated radar instrument to image large regions of the world from space, using different frequencies that can penetrate dry sand cover, produced the discovery in this image: a previously unknown branch of an ancient river, buried under thousands of years of windblown sand in a region of the Sahara Desert in North Africa. This area is near the Kufra Oasis in southeast Libya, centered at 23.3 degrees north latitude, 22.9 degrees east longitude. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR- C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on its 60th orbit on October 4, 1994. This SIR-C image reveals a system of old, now inactive stream valleys, called "paleodrainage systems.""

Aerial gravity gradiometry
The aircraft imaged on the right carried-out aerial high-resolution gravity gradiometry system in combination with LIDAR digital terrain mapping, electromagnetics, digital video, and gamma-ray spectrometry over "onshore areas along the South-Eastern Tanzanian Coastal Basin and the eastern arm of the East African Rift."

Aerial induced polarization
The airplane imaged on the right is equipped with an induced polarization/resistivity device for use in time and frequency modes. Induced polarization is a reliable technique for detecting disseminated sulphides associated with base metal and gold deposits.

Aerial magnetotellurics
"Magnetotellurics (MT) is an electromagnetic method of imaging the earth's subsurface [conducted both aerially portrayed in the image on the left and through ground contact]. It uses natural variations in the earth's magnetic field to map contrasts in the electrical resistivity of the subsurface. These data [as in the image on the right] are used to image changes in the electrical resistivity over a large range of depths: from the top of the crust to the mantle. Such resistivity models are then interpreted geologically in terms of the fluid, thermal and structural evolution of the lithosphere."

Hypotheses

 * 1) The use of satellites should provide ten times the information as sounding rockets or balloons.

A control group for a radiation satellite would contain
 * 1) a radiation astronomy telescope,
 * 2) a two-way communication system,
 * 3) a positional locator,
 * 4) an orientation propulsion system, and
 * 5) power supplies and energy sources for all components.

A control group for radiation astronomy satellites may include an ideal or rigorously stable orbit so that the satellite observes the radiation at or to a much higher resolution than an Earth-based ground-level observatory is capable of.