Global Frequency is an American comic book limited series created and written by Warren Ellis and published by Wildstorm Productions, an imprint of DC Comics. It is a science-fiction series set in the present day, consisting of single-issue, standalone stories; the series of 12 issues was published between October 2002 and June 2004. Each issue was drawn by a different artist, with uniform covers by Brian Wood, interior artwork colored by David Baron; the Global Frequency is an independent, covert intelligence organization headed by a former intelligence agent who uses the alias of Miranda Zero. 1,001 people are on the Global Frequency, forming an active smart mob communicating by specially modified video mobile phones through a central dispatch system coordinated by a young woman code-named Aleph. The purpose of the organization is to protect and rescue the world from the consequences of the various secret projects that the governments or individuals of the world have established, which are unknown to the public at large.
The people on the Global Frequency are chosen and called on for their specialized skills in a variety of areas, include military personnel, intelligence agents, police detectives, scientific researchers, athletes, former criminals and assassins. The threats addressed by the organization are varied and world-threatening, including rogue military operations, paranormal phenomena, terrorist attacks and religious cults; the existence of the organization is an open secret, but its membership list is anonymous, the identities of its field agents unknown to each other before they meet on a mission. The only way to tell a member of the Global Frequency is by the phones that they carry or the Global Frequency symbol—a circle with four points on its perimeter 90°s apart that they sport somewhere on their person. Who funds the Global Frequency is not known. Zero has said that at least some of the money comes from the G8 governments that pay the Frequency for not revealing the various secret horrors that they combat.
Although the presence of an independent, unaccountable agency with strike capability makes some authorities nervous, they recognize the fact that the Frequency has the skills, the reach, more the will to act where governments cannot. As a result, the organization gets tacit approval for its activities, is sometimes called on by governments to deal with extraordinary crises; the organization acts proactively as it discovers such threats. Ellis designed the comic series like a television series with standalone "episodes", allowing the reader to begin with any issue and be able to understand what was going on; as a result, the only regular characters in the series are Miranda Zero and Aleph, with only a few other characters making a reappearance in the 12th issue of the series. This heightened the suspense for the reader, as the survival of these characters was not guaranteed; the series has been collected into two trade paperbacks. After the WildStorm imprint was discontinued, the entire series was collected under the Vertigo label in 2013.
Global Frequency Volume 1: Planet Ablaze Global Frequency Volume 2: Detonation Radio Global Frequency 2004: Nominated for "Best Limited Series" Eisner Award Mark Burnett prepared a Global Frequency television series for 2005 with Michelle Forbes as Miranda Zero, Josh Hopkins as Sean Flynn, Jenni Baird as Dr. Katrina Finch and Aimee Garcia as Aleph; the characters of Sean Flynn, an ex-policeman who accidentally stumbled on a Global Frequency mission, Katrina Finch, a brilliant scientist with expertise in multiple fields, were created for the series. Unlike the comic book, which had an ever-changing cast of field agents and Finch were to be regulars along with Zero and Aleph, with other Frequency members coming in as and when necessary in supporting roles; this would allow for the character continuity expected of a television series and yet allow other characters to be killed off as in the comic book. A pilot episode, based on the first issue of the comic book, was produced, but The WB did not commission the series.
John Rogers was the principal creative force behind the television incarnation, writing the pilot episode, with Ellis credited as producer and creator. Other writers waiting to come on board included Ben Edlund and Diego Gutierrez; the pilot was directed by Nelson McCormick. The unaired pilot was leaked onto the Internet in June 2005 and continues to be downloaded and shared via BitTorrent and other P2P networks. Although it was popular and critically acclaimed, according to Ellis himself the leaking of the pilot annoyed Warner Brothers to the extent that they killed the project. In November 2009, Production Weekly's Twitter feed revealed that a new television adaptation of Global Frequency was being worked on by The CW Television Network and writer Scott Nimerfro. In November 2014, it was announced that Fox was producing a new Global Frequency pilot, produced by Jerry Bruckheimer and written by Rockne S. O'Bannon. In February 2015, bleedingcool.com revealed that Fox will not order the pilot for Global Frequency due to problems with the script.
Mania.com's main page for Global Frequency badmouth.net page on comic and pilot frequencysite.com page on original pilot, including images and plot details Global Frequency on IMDb Global Frequency at TV.com
A space vehicle or spaceship is a rocket-powered vehicle used to transport unmanned satellites or humans between the Earth's surface and outer space. The earliest space vehicles were expendable launch systems, consisting of rocket launch vehicles carrying spacecraft payloads which were small portions of the total vehicle size and mass; the single or multistage rocket without the payload is referred to as a launch vehicle. Most space vehicles in production use are expendable systems, although reusable launch systems have been envisioned since the late 1960s; the "space ship" was first envisioned in twentieth century science fiction, such as Flash Gordon, as a self-contained rocket-powered, unitized vehicle capable of reaching an extraterrestrial destination keeping its structure intact, requiring only refueling, like an airplane. Real-world rocket technology did not make this possible, it cannot use atmospheric air as its propellant. The high amount of energy required to reach at least low Earth orbital speed requires an high proportion of propellant to dry vehicle mass.
Mid-twentieth century structural technologies made it impossible to construct a single set of propellant tanks capable of holding enough mass to reach the required velocity. Thus, expendable multi-stage launch vehicles were the necessary design choice when spaceflight began in the late 1950s. A majority of launch systems in use are expendable, designed to carry a single payload into space but not for recovery and reuse, they consist of several stages which detach in sequence as the vehicle gains speed and altitude and booster propellant is exhausted. Reusable launch systems are capable of launching multiple payloads and can be recovered after each use. No reusable system is employed by any space program, reusable systems are in active development by private space enterprises such as SpaceX and Blue Origin
A sub-orbital spaceflight is a spaceflight in which the spacecraft reaches outer space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it will not complete one orbital revolution. For example, the path of an object launched from Earth that reaches the Kármán line, falls back to Earth, is considered a sub-orbital spaceflight; some sub-orbital flights have been undertaken to test spacecraft and launch vehicles intended for orbital spaceflight. Other vehicles are designed only for sub-orbital flight. Flights which attain sufficient velocity to go into low Earth orbit, de-orbit before completing their first full orbit, are not considered sub-orbital. Examples of this include Yuri Gagarin's Vostok 1, flights of the Fractional Orbital Bombardment System. A rocket is used, but experimental sub-orbital spaceflight has been achieved with a space gun. By one definition a sub-orbital spaceflight reaches an altitude higher than 100 km above sea level.
This altitude, known as the Kármán line, was chosen by the Fédération Aéronautique Internationale because it is the point where a vehicle flying fast enough to support itself with aerodynamic lift from the Earth's atmosphere would be flying faster than orbital speed. The US military and NASA award astronaut wings to those flying above 50 mi, although the U. S. State Department appears to not support a distinct boundary between atmospheric flight and spaceflight. During freefall the trajectory is part of an elliptic orbit as given by the orbit equation; the perigee distance is less than the radius of the Earth R including atmosphere, hence the ellipse intersects the Earth, hence the spacecraft will fail to complete an orbit. The major axis is vertical, the semi-major axis a is more than R/2; the specific orbital energy ϵ is given by: ε = − μ 2 a > − μ R where μ is the standard gravitational parameter. Always a < R, corresponding to a lower ϵ than the minimum for a full orbit, − μ 2 R Thus the net extra specific energy needed compared to just raising the spacecraft into space is between 0 and μ 2 R.
To minimize the required delta-v, the high-altitude part of the flight is made with the rockets off. The maximum speed in a flight is attained at the lowest altitude of this free-fall trajectory, both at the start and at the end of it. If one's goal is to "reach space", for example in competing for the Ansari X Prize, horizontal motion is not needed. In this case the lowest required delta-v, to reach 100 km altitude, is about 1.4 km/s. Moving slower, with less free-fall, would require more delta-v. Compare this with orbital spaceflights: a low Earth orbit, with an altitude of about 300 km, needs a speed around 7.7 km/s, requiring a delta-v of about 9.2 km/s. For sub-orbital spaceflights covering a horizontal distance the maximum speed and required delta-v are in between those of a vertical flight and a LEO; the maximum speed at the lower ends of the trajectory are now composed of a horizontal and a vertical component. The higher the horizontal distance covered, the greater the horizontal speed will be.
For the V-2 rocket, just reaching space but with a range of about 330 km, the maximum speed was 1.6 km/s. Scaled Composites SpaceShipTwo, under development will have a similar free-fall orbit but the announced maximum speed is 1.1 km/s. For larger ranges, due to the elliptic orbit the maximum altitude can be much more than for a LEO. On a 10,000-km intercontinental flight, such as that of an intercontinental ballistic missile or possible future commercial spaceflight, the maximum speed is about 7 km/s, the maximum altitude may be more than 1300 km. Any spaceflight that returns to the surface, including sub-orbital ones, will undergo atmospheric reentry; the speed at the start of the reentry is the maximum speed of the flight. The aerodynamic heating caused will vary accordingly: it is much less for a flight with a maximum speed of only 1 km/s than for one with a maximum speed of 7 or 8 km/s. We can calculate the minimum delta-v and the corresponding maximum altitude for a given range, d, assuming a spherical earth of circumference 40 000 km and neglecting the earth's rotation and atmosphere.
Let θ be half the angle that the projectile is to go around the earth, so in degrees it is 45°×d/10 000 km. The minimum-delta-v trajectory corresponds to an ellipse with one focus at the centre of the earth and the other at the point halfway between the launch point and the destination point. (
Robert A. Heinlein
Robert Anson Heinlein was an American science-fiction author, aeronautical engineer, retired Naval officer. Called the "dean of science fiction writers", He was among the first to emphasize scientific accuracy in his fiction, was thus a pioneer of the subgenre of hard science fiction, his work continues to have an influence on the science-fiction genre, on modern culture more generally. Heinlein became one of the first American science-fiction writers to break into mainstream magazines such as The Saturday Evening Post in the late 1940s, he was one of the best-selling science-fiction novelists for many decades, he, Isaac Asimov, Arthur C. Clarke are considered the "Big Three" of English-language science fiction authors. Notable Heinlein works include Stranger in a Strange Land, Starship Troopers and The Moon Is a Harsh Mistress, his work sometimes had controversial aspects, such as plural marriage in The Moon is a Harsh Mistress, militarism in Starship Troopers and technologically competent women characters that were strong and independent, yet stereotypically feminine – such as Friday.
A writer of numerous science-fiction short stories, Heinlein was one of a group of writers who came to prominence under the editorship of John W. Campbell at Astounding Science Fiction magazine, though Heinlein denied that Campbell influenced his writing to any great degree. Within the framework of his science-fiction stories, Heinlein addressed certain social themes: the importance of individual liberty and self-reliance, the obligation individuals owe to their societies, the influence of organized religion on culture and government, the tendency of society to repress nonconformist thought, he speculated on the influence of space travel on human cultural practices. Heinlein was named the first Science Fiction Writers Grand Master in 1974. Four of his novels won Hugo Awards. In addition, fifty years after publication, seven of his works were awarded "Retro Hugos"—awards given retrospectively for works that were published before the Hugo Awards came into existence. In his fiction, Heinlein coined terms that have become part of the English language, including "grok", "waldo", "speculative fiction", as well as popularizing existing terms like "TANSTAAFL", "pay it forward", "space marine".
He anticipated mechanical computer-aided design with "Drafting Dan" and described a modern version of a waterbed in his novel Beyond This Horizon, though he never patented nor built one. In the first chapter of the novel Space Cadet he anticipated the cell-phone, 35 years before Motorola invented the technology. Several of Heinlein's works have been adapted for television. Heinlein was born on July 7, 1907 in Butler, Missouri, he was a 6th-generation German-American: a family tradition had it that Heinleins fought in every American war starting with the War of Independence. His childhood was spent in Missouri; the outlook and values of this time and place had a definite influence on his fiction his works, as he drew upon his childhood in establishing the setting and cultural atmosphere in works like Time Enough for Love and To Sail Beyond the Sunset. Heinlein's experience in the U. S. Navy exerted a strong influence on his writing, he graduated from the U. S. Naval Academy in Annapolis, with the class of 1929.
Shortly after graduation, he was commissioned as an ensign by the U. S. Navy, he advanced to lieutenant, junior grade while serving aboard the new aircraft carrier USS Lexington in 1931, where he worked in radio communications in its earlier phases, with the carrier's aircraft. The captain of this carrier was Ernest J. King, who served as the Chief of Naval Operations and Commander-in-Chief, U. S. Fleet during World War II. Heinlein was interviewed during his years by military historians who asked him about Captain King and his service as the commander of the U. S. Navy's first modern aircraft carrier. Heinlein served as gunnery officer aboard the destroyer USS Roper in 1933 and 1934, reaching the rank of lieutenant, his brother, Lawrence Heinlein, served in the U. S. Army, the U. S. Air Force, the Missouri National Guard, reaching the rank of major general in the National Guard. In 1929, Heinlein married Elinor Curry of Kansas City. However, their marriage only lasted about a year, his second marriage in 1932 to Leslyn MacDonald lasted for 15 years.
MacDonald was, according to the testimony of Heinlein's Navy friend, Rear Admiral Cal Laning, "astonishingly intelligent read, liberal, though a registered Republican," while Isaac Asimov recalled that Heinlein was, at the time, "a flaming liberal". At the Philadelphia Naval Shipyard Heinlein met and befriended a chemical engineer named Virginia "Ginny" Gerstenfeld. After the war, her engagement having fallen through, she moved to UCLA for doctoral studies in chemistry and made contact again; as his second wife's alcoholism spun out of control, Heinlein moved out and the couple filed for divorce. Heinlein's friendship with Virginia turned into a relationship and on October 21, 1948 — shortly after the decree nisi came through — they married in the town of Raton, New Mexico, shortly after setting up housekeeping in Colorado, they remained married until Heinlein's death. As Heinlein's increasing success as a writer resolved their initial financial woes, they had a house custom built with various innovative features described in an article in Popular Mechanics.
In 1965, after various chronic health problems of
An anti-ballistic missile is a surface-to-air missile designed to counter ballistic missiles. Ballistic missiles are used to deliver nuclear, biological, or conventional warheads in a ballistic flight trajectory; the term "anti-ballistic missile" is a generic term conveying a system designed to intercept and destroy any type of ballistic threat, however it is used for systems designed to counter intercontinental ballistic missiles. There are only three systems in the world. Besides them, some smaller systems exist, that cannot intercept intercontinental strategic missiles if within range—an incoming ICBM moves too fast for these systems; the Russian A-135 anti-ballistic missile system is used for the defense of Moscow. It was preceded by the A-35 anti-ballistic missile system; the system uses Gazelle missiles with nuclear warheads to intercept incoming ICBMs. The U. S. Ground-Based Midcourse Defense System known as National Missile Defense, was first tested in 1997 and had its first successful intercept test in 1999.
Instead of using an explosive charge, it launches a hit-to-kill kinetic projectile to intercept an ICBM. The current GMD system is intended to shield the United States mainland against a limited nuclear attack by a rogue state such as North Korea. GMD does not have the ability to protect against an all-out nuclear attack from Russia, as there are 44 ground-based interceptors deployed against crossing projectiles headed toward the homeland; the Israeli Arrow 3 system entered operational service in 2017. It is designed for exo-atmosphere interception of ballistic missiles during the spaceflight portion of their trajectory, including those of ICBMs, it may act as an anti-satellite weapon. During 1993, a symposium was held by western European nations to discuss potential future ballistic missile defence programs. In the end, the council recommended deployment of early warning and surveillance systems as well as regionally controlled defence systems. During spring 2006 reports about negotiations between the United States and Poland as well as the Czech Republic were published.
The plans propose the installation of a latest generation ABM system with a radar site in the Czech Republic and the launch site in Poland. The system was announced to be aimed against ICBMs from North Korea; this caused harsh comments by Russian President Vladimir Putin at the Organization for Security and Co-operation in Europe security conference during spring 2007 in Munich. Other European ministers commented that any change of strategic weapons should be negotiated on NATO level and not'unilaterally' between the U. S. and other states. German foreign minister Frank-Walter Steinmeier expressed severe concerns about the way in which the U. S. had conveyed its plans to its European partners and criticised the U. S. administration for not having consulted Russia prior to announcing its endeavours to deploy a new missile defence system in Central Europe. As of July 2007, a majority of Poles were opposed to hosting a component of the system in Poland. By 28 July 2016 Missile Defense Agency planning and agreements had clarified enough to give more details about the Aegis Ashore sites in Romania and Poland.
Project 640 had been the PRC's indigenous effort. The Academy of Anti-Ballistic Missile & Anti-Satellite was established from 1969 for the purpose of developing Project 640; the project was to involve at least three elements, including the necessary sensors and guidance/command systems, the Fan Ji missile interceptor, the XianFeng missile-intercepting cannon. The FJ-1 had completed two successful flight tests during 1979, while the low-altitude interceptor FJ-2 completed some successful flight tests using scaled prototypes. A high altitude FJ-3 interceptor was proposed. Despite the development of missiles, the programme was slowed down due to financial and political reasons, it was closed down during 1980 under a new leadership of Deng Xiaoping as it was deemed unnecessary after the 1972 Anti-Ballistic Missile Treaty between the Soviet Union and the United States and the closure of the US Safeguard ABM system. In March 2006, China tested an interceptor system comparable to the U. S. Patriot missiles.
China has acquired and is license-producing the S-300PMU-2/S-300PMU-1 series of terminal ABM-capable SAMs. China-produced HQ-9 SAM system may possess terminal ABM capabilities. PRC Navy's operating modern air-defense destroyers known as the Type 052C Destroyer and Type 051C Destroyer are armed with naval HHQ-9 missiles; the HQ-19, similar to the THAAD, was first tested in 2003, subsequently a few more times, including in November 2015. The HQ-29, a counterpart to the MIM-104F PAC-3, was first tested in 2011. Surface-to-air missiles that have some terminal ABM capability: HQ-29 HQ-19 HQ-9 FK-3 HQ-18 HQ-10 HQ-16 HQ-15 The technology and experience from the successful anti-satellite test using a ground-launched interceptor during January 2007 was applied to current ABM efforts and development. China carried out a land-based anti-ballistic missile test on 11 January 2010; the test was exoatmospheric and done with a kinetic kill vehicle. China is the second country after US that demonstrated intercepting ballistic missile with a kinetic kill vehicle, the interceptor missile was a SC-19.
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Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system; the force applied on a surface in a direction perpendicular or normal to the surface is called thrust. Force, thus thrust, is measured using the International System of Units in newtons, represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load is referred to as thrust. A fixed-wing aircraft generates forward thrust when air is pushed in the direction opposite to flight; this can be done in several ways including by the spinning blades of a propeller, or a rotating fan pushing air out from the back of a jet engine, or by ejecting hot gases from a rocket engine. The forward thrust is proportional to the mass of the airstream multiplied by the difference in velocity of the airstream.
Reverse thrust can be generated to aid braking after landing by reversing the pitch of variable-pitch propeller blades, or using a thrust reverser on a jet engine. Rotary wing aircraft and thrust vectoring V/STOL aircraft use engine thrust to support the weight of the aircraft, vector sum of this thrust fore and aft to control forward speed. A motorboat generates thrust; the resulting thrust pushes the boat in the opposite direction to the sum of the momentum change in the water flowing through the propeller. A rocket is propelled forward by a thrust force equal in magnitude, but opposite in direction, to the time-rate of momentum change of the exhaust gas accelerated from the combustion chamber through the rocket engine nozzle; this is the exhaust velocity with respect to the rocket, times the time-rate at which the mass is expelled, or in mathematical terms: T = v d m d t Where T is the thrust generated, d m d t is the rate of change of mass with respect to time, v is the speed of the exhaust gases measured relative to the rocket.
For vertical launch of a rocket the initial thrust at liftoff must be more than the weight. Each of the three Space Shuttle Main Engines could produce a thrust of 1.8 MN, each of the Space Shuttle's two Solid Rocket Boosters 14.7 MN, together 29.4 MN. By contrast, the simplified Aid For EVA Rescue has 24 thrusters of 3.56 N each. In the air-breathing category, the AMT-USA AT-180 jet engine developed for radio-controlled aircraft produce 90 N of thrust; the GE90-115B engine fitted on the Boeing 777-300ER, recognized by the Guinness Book of World Records as the "World's Most Powerful Commercial Jet Engine," has a thrust of 569 kN. The power needed to generate thrust and the force of the thrust can be related in a non-linear way. In general, P 2 ∝ T 3; the proportionality constant varies, can be solved for a uniform flow: d m d t = ρ A v T = d m d t v, P = 1 2 d m d t v 2 T = ρ A v 2, P = 1 2 ρ A v 3 P 2 = T 3 4 ρ A Note that these calculations are only valid for when the incoming air is accelerated from a standstill – for example when hovering.
The inverse of the proportionality constant, the "efficiency" of an otherwise-perfect thruster, is proportional to the area of the cross section of the propelled volume of fluid and the density of the fluid. This helps to explain why moving through water is easier and why aircraft have much larger propellers than watercraft. A common question is how to contrast the thrust rating of a jet engine with the power rating of a piston engine; such comparison is difficult. A piston engine does not move the aircraft by itself, so piston engines are rated by how much power they deliver to the propeller. Except for changes in temperature and air pressure, this quantity depends on the throttle setting. A jet engine has no propeller, so the propulsive power of a jet engine is determined from its thrust as follows. Power is the force it takes to move something over some distance divided by the time it takes to move that distance: P = F d t In case of
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: uncontrolled entry, such as the entry of astronomical objects, space debris, or bolides. Technologies and procedures allowing the controlled atmospheric entry and landing of spacecraft are collectively termed as EDL. Atmospheric drag and aerodynamic heating can cause atmospheric breakup capable of disintegrating smaller objects; these forces may cause objects with lower compressive strength to explode. Crewed space vehicles must be slowed to subsonic speeds before parachutes or air brakes may be deployed; such vehicles have kinetic energies between 50 and 1,800 megajoules, atmospheric dissipation is the only way of expending the kinetic energy. The amount of rocket fuel required to slow the vehicle would be nearly equal to the amount used to accelerate it and it is thus impractical to use retro rockets for the entire Earth reentry procedure.
While the high temperature generated at the surface of the heat shield is due to adiabatic compression, the vehicle's kinetic energy is lost to gas friction after the vehicle has passed by. Other smaller energy losses include black-body radiation directly from the hot gases and chemical reactions between ionized gases. Ballistic warheads and expendable vehicles do not require slowing at reentry, in fact, are made streamlined so as to maintain their speed. Furthermore, slow-speed returns to Earth from near-space such as parachute jumps from balloons do not require heat shielding because the gravitational acceleration of an object starting at relative rest from within the atmosphere itself cannot create enough velocity to cause significant atmospheric heating. For Earth, atmospheric entry occurs at the Kármán line at an altitude of 100 km above the surface, while at Venus atmospheric entry occurs at 250 km and at Mars atmospheric entry at about 80 km. Uncontrolled, objects reach high velocities while accelerating through space toward the Earth under the influence of Earth's gravity, are slowed by friction upon encountering Earth's atmosphere.
Meteors are often travelling quite fast relative to the Earth because their own orbital path is different from that of the Earth before they encounter Earth's gravity well. Most controlled objects enter at hypersonic speeds due to their suborbital, orbital, or unbounded trajectories. Various advanced technologies have been developed to enable atmospheric reentry and flight at extreme velocities. An alternative low velocity method of controlled atmospheric entry is buoyancy, suitable for planetary entry where thick atmospheres, strong gravity, or both factors complicate high-velocity hyperbolic entry, such as the atmospheres of Venus and the gas giants; the concept of the ablative heat shield was described as early as 1920 by Robert Goddard: "In the case of meteors, which enter the atmosphere with speeds as high as 30 miles per second, the interior of the meteors remains cold, the erosion is due, to a large extent, to chipping or cracking of the heated surface. For this reason, if the outer surface of the apparatus were to consist of layers of a infusible hard substance with layers of a poor heat conductor between, the surface would not be eroded to any considerable extent as the velocity of the apparatus would not be nearly so great as that of the average meteor."Practical development of reentry systems began as the range and reentry velocity of ballistic missiles increased.
For early short-range missiles, like the V-2, stabilization and aerodynamic stress were important issues, but heating was not a serious problem. Medium-range missiles like the Soviet R-5, with a 1,200-kilometer range, required ceramic composite heat shielding on separable reentry vehicles; the first ICBMs, with ranges of 8,000 to 12,000 kilometers, were only possible with the development of modern ablative heat shields and blunt-shaped vehicles. In the United States, this technology was pioneered by H. Julian Allen and A. J. Eggers Jr. of the National Advisory Committee for Aeronautics at Ames Research Center. In 1951, they made the counterintuitive discovery that a blunt shape made the most effective heat shield. From simple engineering principles and Eggers showed that the heat load experienced by an entry vehicle was inversely proportional to the drag coefficient. If the reentry vehicle is made blunt, air cannot "get out of the way" enough, acts as an air cushion to push the shock wave and heated shock layer forward.
Since most of the hot gases are no longer in direct contact with the vehicle, the heat energy would stay in the shocked gas and move around the vehicle to dissipate into the atmosphere. The Allen and Eggers discovery, though treated as a military secret, was published in 1958. Over the decades since the 1950s, a rich technical jargon has grown around the engineering of vehicles designed to enter planetary atmospheres, it is recommended that the reader review the jargon glossary before continuing with this article on atmospheric reentry. When atmospheric entry is pa