Radiation astronomy/Aircraft

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The image shows a North American X-15 on a test flight for the US Air Force. Credit: USAF.

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[edit | edit source]

The telescope is within the rectangular black hole on the side of the C-141A KAO aircraft. Credit: NASA.

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[edit | edit source]

The SOFIA observatory is flying with 100% open telescope door. Credit: NASA.
The image is centered on SOFIA with its telescope doors open in flight. Credit: NASA/Carla Thomas.
The diagram names the mirrors of the SOFIA telescope. Credit: Eddie Zavala (NASA Armstrong) and Erick Young (NASA Ames).
The NASA logo is reflected in SOFIAs 2.5-meter primary mirror. Credit: NASA/Tom Tschida.

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.[1] 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."[2]

"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."[2]

"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)."[2]

ER-2 high altitude research aircraft[edit | edit source]

ER-2 tail number 809, is one of two Airborne Science ER-2s used as science platforms by Dryden. Credit: NASA/Jim Ross.

"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."[3]

"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."[3]

"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."[3]

Aircraft assisted launches[edit | edit source]

Orbital Sciences' L-1011 jet aircraft releases the Pegasus rocket carrying the Space Technology 5 spacecraft with its trio of micro-satellites. Credit: NASA.
This image shows a Pegasus being carried to altitude by B-52. Credit: NASA.

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 kilometres (433 mi) 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.[4]

Autonomous vehicles[edit | edit source]

The MQ-1 Predator is an unmanned aircraft. Credit: U.S. Air Force photo/Lt Col Leslie Pratt.

“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.”[5]

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[edit | edit source]

This is an image of a micro air vehicle (MAV). Credit: United States Navy photo by Mass Communication Specialist 3rd Class Kenneth G. Takada.

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[6], 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.

Piloted hovering vehicles[edit | edit source]

CV-22 Osprey. Credit: U.S. Air Force photo/Staff Sgt. Markus Maier.

Pilotless aerial vehicles[edit | edit source]

This is an image of a V-1 flying bomb, perhaps one of the first pilotless aerial vehicle. Credit: Stahlkocher.
Perhaps the early culmination of the pilotless bomb is the Northrup SM-62 Snark shown here in flight. Credit: United States Government.
Here is a modern cruise missile on display at the United States National Air & Space Museum. Credit: Pazuzu.

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[edit | edit source]

The U.S. Air Force's F-16D is an Automatic Collision Avoidance Technology (ACAT) aircraft. Credit: NASA/Tom Tschida.

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.[7]

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.[8]

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).[9]

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[edit | edit source]

This is a captive test flight of Armadillo Aerospace's Pixel rocket. Credit: Armadillo Aerospace/Matthew C. Ross.
Completed and flown in May 1957, the Waterman Arrowbile, or Aerobile is a three-seat, roadable aircraft. Credit: Mark Pellegrini.
A "flying car," a large drone-like machine with four propellers hovered steadily for about a minute. Credit: NEC Corp..{{fairuse}}

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]."[10]

"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."[10]

"The Japanese government is behind flying cars, with the goal of having people zipping around in them by the 2030s."[10]

"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."[10]

"Similar projects are popping up around world, such as Uber Air of the U.S."[10]

"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."[10]

"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."[10]

"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."[10]

Magnetometric surveys[edit | edit source]

Banded Iron Formation is at the Fortescue Falls. Credit: Graeme Churchard from Bristol, UK.{{free media}}
This helicopter is equipped with a magnetometer array. It flies six feet above ground at speeds of 30 to 40 mph. Credit: JaxStrong.{{free media}}
Eurocopter AS350 geophysical survey helicopter is equipped with an aeromagnetic survey system. Credit: Hkeyser.{{free media}}

"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."[11]

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[edit | edit source]

Airborne Electromagnetic (AEM) data are one form of the geophysical data acquired by Geoscience Australia. Credit: R. Brodie, M. Sambridge, and A. Fisher, Commonwealth of Australia (Geoscience Australia).{{fairuse}}
SkyTEM system is operated in Australia by Geoforce Pty Ltd for Geoscience Australia. Credit: R. Brodie, M. Sambridge, and A. Fisher, Commonwealth of Australia (Geoscience Australia).{{fairuse}}
VTEM system is operated in Australia by Geoscience Australia. Credit: R. Brodie, M. Sambridge, and A. Fisher, Commonwealth of Australia (Geoscience Australia).{{fairuse}}
Helicopter conducts a time-domain electromagnetics (TDEM) Survey. Credit: United States Geological Survey.{{free media}}

"Airborne electromagnetic surveys using a grounded electric dipole source and magnetic surveys were conducted to delineate resistivity and magnetization structures".[12]

"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."[13]

"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."[13]

Conductivity surveys[edit | edit source]

Measurement of the distribution of electrical conductivity in the ground is made aerially with a sensor suspended from the helicopter. Credit: Rehli.{{free media}}

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[edit | edit source]

A U.S. Civil Air Patrol Gippsland GA8 Airvan aircraft carries the ARCHER payload. Credit: U.S. Air Force/Master Sgt. Lance Cheung.

"[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."[14]

"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."[14]

Ground-penetrating radar[edit | edit source]

A previously unknown branch of an ancient river, buried under thousands of years of windblown sand, is revealed by radar. Credit: Porao, NASA.

"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.""[15]

Aerial gravity gradiometry[edit | edit source]

Aerial high-resolution gravity gradiometry system is in combination with LIDAR digital terrain mapping, electromagnetics, digital video, and gamma-ray spectrometry. Credit: Mozambique Resources Post.{{fairuse}}

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."[16]

Aerial induced polarization[edit | edit source]

The IP method is a reliable technique for detecting disseminated sulphides associated with base metal and gold deposits. Credit: Geosan.{{fairuse}}

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[edit | edit source]

The image displays high-resolution airborne magnetotellurics results for the Gawler Craton Airborne Survey. Credit: Laszlo Katona, Geoscience Australia.{{fairuse}}
Geoscience Australia has contracted several airborne surveying companies to collect data over survey regions within the Gawler Craton. Credit: Laszlo Katona, Geoscience Australia.{{fairuse}}

"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."[17]

Hypotheses[edit | edit source]

  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.

See also[edit | edit source]

References[edit | edit source]

  1. Alfred Krabbe (March 2007). SOFIA telescope, In: ‘’Proceedings of SPIE: Astronomical Telescopes and Instrumentation’’. Munich, Germany: SPIE — The International Society for Optical Engineering. pp. 276–281. https://arxiv.org/abs/astro-ph/0004253. 
  2. 2.0 2.1 2.2 Eddie Zavala; Erick Young. SOFIA Telescope. USRA. https://www.sofia.usra.edu/Sofia/telescope/sofia_tele.html. Retrieved 2016-02-06. 
  3. 3.0 3.1 3.2 Marty Curry (October 1999). "Lockheed ER-2 #809 high altitude research aircraft in flight". Dryden Flight Research Center, NASA. Retrieved 8 June 2021.
  4. ALEXIS satellite marks fifth anniversary of launch. Los Alamos National Laboratory. 23 April 1998. http://www.fas.org/spp/military/program/masint/98-062.html. Retrieved 17 August 2011. 
  5. Mark R. Mine (May 5, 1995). Virtual Environment Interaction Techniques. Chapel Hill, NC: University of North Carolina. pp. 18. http://staffwww.itn.liu.se/~karlu/courses/TNM086/papers/VEinteractionTechniques.pdf. Retrieved 2012-03-09. 
  6. MAV multicopter hobby project "Shrediquette BOLT", http://shrediquette.blogspot.de/p/shrediquette-bolt.html
  7. Mission Status Center - Delta 313 Launch Report. Spaceflight Now. http://www.spaceflightnow.com/delta/d313/status.html. 
  8. http://www.eurocontrol.int/msa/public/standard_page/ACAS_ICAO_Provisions.html
  9. [Hoekstra, J.M. (2002). Free flight with airborne separation assurance. Report No. NLR-TP-2002-170. National Aerospace Laboratory NLR.]
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 Yuri Kageyama (4 August 2019). "Japan's NEC shows 'flying car' hovering steadily for minute". Abiko, Japan: Yahoo! News. Retrieved 5 August 2019.
  11. Malcolm Castle (3 October 2007). INDEPENDENT GEOLOGIST’S REPORT ON THE MINERAL PROJECTS in WESTERN AUSTRALIA. South Perth, WA: Agricola Mining Consultants Pty Ltd. pp. 24. http://www.aspectfinancial.com.au/asxdata/20071030/pdf/00776801.pdf. Retrieved 2017-10-01. 
  12. Kenji Okazaki; Toru Mogi; Mitsuru Utsugi; Yoshihiko Ito; Hideki Kunishima; Takashi Yamazaki; Yukitsugu Takahashi; Takeshi Hashimoto et al. (May 2011). "Airborne electromagnetic and magnetic surveys for long tunnel construction design". Physics and Chemistry of the Earth 36 (5): 1237–1246. doi:10.1016/j.pce.2011.05.008. https://www.researchgate.net/profile/Hisatoshi_Ito/publication/251679640_Airborne_electromagnetic_and_magnetic_surveys_for_long_tunnel_construction_design/links/54adbd030cf2213c5fe418bb.pdf. Retrieved 2017-10-01. 
  13. 13.0 13.1 R. Brodie; M. Sambridge; A. Fisher (May 2012). "Airborne Electromagnetics". Symonston ACT: Commonwealth of Australia (Geoscience Australia). Retrieved 2017-10-02.
  14. 14.0 14.1 Cynthia Ryan (6 September 2007). "High-tech computer joins Fossett search". Web Citation. Retrieved 2017-10-02.
  15. Porao (4 October 1994). "File:Kufra-space-radar.jpg, In: Wikimedia Commons". San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2016-09-27.
  16. Mozambique Resources Post (23 July 2015). "Africa Oil & Gas: TPDC awards CGG airborne gravity gradiometer surveys onshore Tanzania". Tanzania: Mozambique Resources Post. Retrieved 2017-10-02.
  17. Laszlo Katona (2014). "Gawler Craton Airborne Survey community information". South Australia: Geoscience Australia. Retrieved 2017-10-05.

External links[edit | edit source]

{{Radiation astronomy resources}}{{Repellor vehicle}}