Specific impulse is a measure of how a rocket uses propellant or a jet engine uses fuel. By definition, it is the total impulse delivered per unit of propellant consumed and is dimensionally equivalent to the generated thrust divided by the propellant mass flow rate or weight flow rate. If mass is used as the unit of propellant specific impulse has units of velocity. If weight is used instead specific impulse has units of time. Multiplying flow rate by the standard gravity converts specific impulse from the mass basis to the weight basis. A propulsion system with a higher specific impulse uses the mass of the propellant more in creating forward thrust and, in the case of a rocket, less propellant needed for a given delta-v, per the Tsiolkovsky rocket equation. In rockets, this means the engine is more effective at gaining altitude and velocity; this effectiveness is less important in jet engines that employ wings and use outside air for combustion and carry payloads that are much heavier than the propellant.
Specific impulse includes the contribution to impulse provided by external air, used for combustion and is exhausted with the spent propellant. Jet engines use outside air, therefore have a much higher specific impulse than rocket engines; the specific impulse in terms of propellant mass spent has units of distance per time, a notional velocity called the effective exhaust velocity. This is higher than the actual exhaust velocity because the mass of the combustion air is not being accounted for. Actual and effective exhaust velocity are the same in rocket engines not utilizing air or other intake propellant such as water. Specific impulse is inversely proportional to specific fuel consumption by the relationship Isp = 1/ for SFC in kg/ and Isp = 3600/SFC for SFC in lb/; the amount of propellant is measured either in units of mass or weight. If mass is used, specific impulse is an impulse per unit mass, which dimensional analysis shows to have units of speed, so specific impulses are measured in meters per second and are termed effective exhaust velocity.
However, if propellant weight is used, an impulse divided by a force turns out to be a unit of time, so specific impulses are measured in seconds. These two formulations are both used and differ from each other by a factor of g0, the dimensioned constant of gravitational acceleration at the surface of the Earth. Note that the rate of change of momentum of a rocket per unit time is equal to the thrust; the higher the specific impulse, the less propellant is needed to produce a given thrust for a given time. In this regard a propellant is more efficient the greater its specific impulse; this should not be confused with energy efficiency, which can decrease as specific impulse increases, since propulsion systems that give high specific impulse require high energy to do so. Thrust and specific impulse should not be confused; the specific impulse is the impulse produced per unit of propellant expended, while thrust is the momentary or peak force supplied by a particular engine. In many cases, propulsion systems with high specific impulse—some ion thrusters reach 10,000 seconds—produce low thrust.
When calculating specific impulse, only propellant carried with the vehicle. For a chemical rocket, the propellant mass therefore would include both oxidizer. For air-breathing engines, only the mass of the fuel is counted, not the mass of air passing through the engine. Air resistance and the engine's inability to keep a high specific impulse at a fast burn rate are why all the propellant is not used as fast as possible. A heavier engine with a higher specific impulse may not be as effective in gaining altitude, distance, or velocity as a lighter engine with a lower specific impulse. If it were not for air resistance and the reduction of propellant during flight, specific impulse would be a direct measure of the engine's effectiveness in converting propellant weight or mass into forward momentum; the most common unit for specific impulse is the second, both in SI contexts as well as where imperial or customary units are used. The advantage of seconds is that the unit and numerical value are identical across systems of measurements, universal.
Nearly all manufacturers quote their engine performance in seconds, the unit is useful for specifying aircraft engine performance. The use of metres per second to specify effective exhaust velocity is reasonably common; the unit is intuitive when describing rocket engines, although the effective exhaust speed of the engines may be different from the actual exhaust speed, which may be due to the fuel and oxidizer, dumped overboard after powering turbopumps. For airbreathing jet engines, the effective exhaust velocity is not physically meaningful, although it can be used for comparison purposes; the values expressed in N·s/kg are not uncommon and are numerically equal to the effective exhaust velocity in m/s. Specific fuel consumption is inversely proportional to specific impulse and has units of g/ or lb/. Specific fuel consumption is used extensively for describing the performance of air-breathing jet engines; the curious unit of seconds to measure the'goodness' of a fuel/engine combination can be thought of as "How many seconds this propellant can accelerate its own initial mass at 1 gee".
The more seconds it can accelerate its own mass, the more delta-V it delivers to the whole system. For all vehicles, specific impulse (impulse per unit weight-on-Earth of prope
State Space Agency of Ukraine
The State Space Agency of Ukraine is the Ukrainian government agency responsible for space policy and programs. Along with the Ukrainian Defense Industry and the Antonov Aeronautical Scientific-Technical Complex, it is a major state complex of the national defense industry of Ukraine; the State Space Agency of Ukraine does not specialize in manned astronautical programs. It is the second of two direct Soviet space program descendants; the agency does not have its own spaceport and until 2014, depended on the resources of the Russian Federal Space Agency. Until December 9, 2010, the agency was known as Національне космічне агентство України, НКАУ, the National Space Agency of Ukraine Until 2014 launches were conducted at Kazakhstan's Baikonur and Russia's Plesetsk Cosmodromes. After the Russian annexation of Crimea, launches were conducted on Sea Launch's floating platform, soon mothballed. NSAU has a control center in Dunaivtsi. Other facilities in Yevpatoria, Crimea were abandoned after the annexation by Russia.
Ukrainian spacecraft include a few kinds for international cooperation. Ukraine has supplied Russia with military satellites and their launch vehicles, a unique relationship in the world. Development of state policy concepts in the sphere of research and peaceful uses of space, as well as in the interests of national security. NSAU is a civil body in charge of co-ordinating the efforts of government installations and industrial companies. Several space-related institutes and industries are directly subordinated to NSAU. However, it is not a united and centralized system participating in all stages and details of space programs. A special space force in the military of Ukraine is absent; the agency oversees launch vehicle and satellite programs, co-operative programs with the Russian Aviation and Space Agency, the European Space Agency, NASA, commercial ventures. International participation includes the Galileo positioning system. Space activities in Ukraine have been pursued over a 10-year span in strict accordance with National Space Programs.
Each of them was intended to address the relevant current issues to preserve and further develop the space potential of Ukraine. The First Program was called upon to keep up the research and industrial space-related potentiality for the benefit of the national economy and state security as well as to be able to break into the international market of space services; the Second Program was aimed at creating an internal market of space services, conquering the international space markets by presenting in-house products and services and integrating Ukraine into the worldwide space community. The National Space Program of Ukraine for 2003-2007, adopted by the Verkhovna Rada of Ukraine on October 24, 2002, outlines the main goals, assignments and methods of maintaining space activity in Ukraine; the Ukrainian Cabinet of Ministers announced its plans on 13 April 2007 to allocate 312 million euros to the National Space Program for 2007-2011. Specific programs Scientific space research Remote sensing of the Earth Satellite telecommunication systems Development of ground-based infrastructure for navigation and special information system Space activities in the interests of national security and defense Space complexes Development of base elements and advanced space technologies Development of research and production base of the space sectorGoals of the program To develop a national system for Earth observation from outer space to meet the national demands in the social economic sphere and for security and defense purposes To introduce satellite systems and communication facilities into the telecommunication infrastructure of the state To obtain new fundamental knowledge on near-Earth outer space, the solar system, deep space and physical processes and the microgravity condition To create and develop techniques for space access with a view toward realizing national and international projects and to enable the home-made rocket to be employed on the worldwide market of space transportation services To elaborate the advanced space facilities To ensure the innovative development of the space sector in terms of improving its research and production basis The agency is a minor descendant of the Soviet space program, passed to the Russian Federal Space Agency.
The agency took over all the former Soviet defense industrial complex, located on the territory of Ukraine. The space industry of Ukraine started in 1937 when a group of scientists led by Heorhiy Proskura launched a large stratospheric rocket near Kharkiv. In 1954, the Soviet government transformed the car producer Yuzhmash into a rocket company. Since that time, the city of Dnipropetrovsk has been known in the Anglophone world as the Soviet Rocket City; as of April 2009, the Ukrainian National Space Agency is planning to launch a Ukrainian communications satellite by September 2011 and a Sich-2 before the end of 2011. Most of the enterprises are located in Dnipro or Kiev DniproState Enterprise Makarov Yuzhny Machine-Building
A reconnaissance satellite or intelligence satellite is an Earth observation satellite or communications satellite deployed for military or intelligence applications. The first generation type took photographs ejected canisters of photographic film which would descend to earth. Corona capsules were retrieved in mid-air. Spacecraft had digital imaging systems and downloaded the images via encrypted radio links. In the United States, most information available is on programs that existed up to 1972, as this information has been declassified due to its age; some information about programs prior to that time is still classified, a small amount of information is available on subsequent missions. A few up-to-date reconnaissance satellite images have been declassified on occasion, or leaked, as in the case of KH-11 photographs which were sent to Jane's Defence Weekly in 1984. On 16 March 1955, the United States Air Force ordered the development of an advanced reconnaissance satellite to provide continuous surveillance of "preselected areas of the Earth" in order "to determine the status of a potential enemy’s war-making capability".
There are several major types of reconnaissance satellite. Missile early warning Provides warning of an attack by detecting ballistic missile launches. Earliest known are Missile Defense Alarm System. Nuclear explosion detection characterizes nuclear explosions in space. Vela is the earliest known. Photo surveillance Provides imaging of earth from space. Images can be close-look telephoto. Corona is the earliest known. Spectral imaging is commonplace. Electronic reconnaissance Signals intelligence, intercepts stray radio waves. Samos-F is the earliest known. Radar imaging Most space-based radars use synthetic aperture radar. Can be used at night or through cloud cover. Earliest known are the Soviet US-A series. Examples of reconnaissance satellite missions: High resolution photography Measurement and Signature Intelligence Communications eavesdropping Covert communications Monitoring of nuclear test ban compliance Detection of missile launchesOn 28 August 2013, it was thought that "a $1-billion high-powered spy satellite capable of snapping pictures detailed enough to distinguish the make and model of an automobile hundreds of miles below" was launched from California's Vandenberg Air Force Base using a Delta IV Heavy launcher, America's highest-payload space launch vehicle.
On 17 February 2014, a Russian Kosmos-1220 launched in 1980 and used for naval missile targeting until 1982, made an uncontrolled atmospheric entry. Reconnaissance satellites have been used to enforce human rights, through the Satellite Sentinel Project, which monitors atrocities in Sudan and South Sudan. During his 1980 State of the Union Address, President Jimmy Carter explained how all of humanity benefited from the presence of American spy satellites:...photo-reconnaissance satellites, for example, are enormously important in stabilizing world affairs and thereby make a significant contribution to the security of all nations. Additionally, companies such as GeoEye and DigitalGlobe have provided commercial satellite imagery in support of natural disaster response and humanitarian missions. During the 1950s, a Soviet hoax had led to American fears of a bomber gap. In 1968, after gaining satellite photography, the United States' intelligence agencies were able to state with certainty that "No new ICBM complexes have been established in the USSR during the past year."
President Lyndon B. Johnson told a gathering in 1967: I wouldn't want to be quoted on this... We've spent $35 or $40 billion on the space program, and if nothing else had come out of it except the knowledge that we gained from space photography, it would be worth ten times what the whole program has cost. Because tonight we know how many missiles the enemy has and, it turned out, our guesses were way off. We were doing things. We were building things. We were harboring fears. Spy satellites are seen in spy fiction and military fiction; some works of fiction that focus on spy satellites include: The OMAC Project Enemy of the State Body of Lies Ice Station Zebra Karlsson-on-the-Roof is Sneaking Around Again Parmanu: The Story of Pokhran Defense Support Program European Union Satellite Centre List of intelligence gathering disciplines List of Kosmos satellites National Reconnaissance Office Satcom On The Move Kupperberg, Paul. Spy satellites. Rosen Publishing Group. ISBN 0-8239-3854-9 Richelson, Jeffrey.
America's Secret Eyes in Space: the U. S. Keyhole Spy Satellite Program. Harper & Row. ISBN 0-88730-285-8 Norris, Pat. "Spies in the Sky: Surveillance Satellites in War and Peace". Berlin. Retrieved 15 February 2012. FAS Intelligence Resource Program – Imagery Intelligence GlobalSecurity.org: Imagery Intelligence Iran to Launch first spy satellite Egyptsat1 Spaceports Around the World: Iraq's Al-Anbar Space Research Center Military Intelligence Satellites
Soviet space program
The Soviet space program comprised several of the rocket and space exploration programs conducted by the Soviet Union from the 1930s until its collapse in 1991. Over its 60-year history, this classified military program was responsible for a number of pioneering accomplishments in space flight, including the first intercontinental ballistic missile, first satellite, first animal in Earth orbit, first human in space and Earth orbit, first woman in space and Earth orbit, first spacewalk, first Moon impact, first image of the far side of the Moon and unmanned lunar soft landing, first space rover, first sample of lunar soil automatically extracted and brought to Earth, first space station. Further notable records included the first interplanetary probes: Venera 1 and Mars 1 to fly by Venus and Mars Venera 3 and Mars 2 to impact the respective planet surface, Venera 7 and Mars 3 to make soft landings on these planets; the rocket and space program of the USSR boosted by the assistance of captured scientists from the advanced German rocket program, was performed by Soviet engineers and scientists after 1955, was based on some unique Soviet and Imperial Russian theoretical developments, many derived by Konstantin Tsiolkovsky, sometimes known as the father of theoretical astronautics.
Sergey Korolev was the head of the principal design group. Unlike its American competitor in the "Space Race", which had NASA as a single coordinating agency, the USSR's program was split among several competing design bureaus led by Korolev, Mikhail Yangel, Valentin Glushko, Vladimir Chelomei; because of the program's classified status, for propaganda value, announcements of the outcomes of missions were delayed until success was certain, failures were sometimes kept secret. As a result of Mikhail Gorbachev's policy of glasnost in the 1980s, many facts about the space program were declassified. Notable setbacks included the deaths of Korolev, Vladimir Komarov, Yuri Gagarin between 1966 and 1968, development failure of the huge N-1 rocket intended to power a manned lunar landing, which exploded shortly after lift-off on four unmanned tests. With the collapse of the Soviet Union and Ukraine inherited the program. Russia created the Russian Aviation and Space Agency, now known as the Roscosmos State Corporation, while Ukraine created the National Space Agency of Ukraine.
The theory of space exploration had a solid basis in the Russian Empire before the First World War with the writings of Konstantin Tsiolkovsky, who published pioneering papers in the late 19th and early 20th centuries and in 1929 introduced the concept of the multistaged rocket. Practical aspects built on early experiments carried out by members of the reactive propulsion study group, GIRD in the 1920s and 1930s, where such pioneers as Sergey Korolev—who dreamed of traveling to Mars—and the German-Russian engineer Friedrich Zander worked. On August 18, 1933, GIRD launched the first Soviet liquid-fueled rocket Gird-09, on November 25, 1933, the first hybrid-fueled rocket GIRD-X. In 1940-41 another advance in the reactive propulsion field took place: the development and serial production of the Katyusha multiple rocket launcher. During the 1930s Soviet rocket technology was comparable to Germany's, but Joseph Stalin's Great Purge damaged its progress. Many leading engineers were killed, Korolev and others were imprisoned in the Gulag.
Although the Katyusha was effective on the Eastern Front during World War II, the advanced state of the German rocket program amazed Soviet engineers who inspected its remains at Peenemünde and Mittelwerk after the end of the war in Europe. The Americans had secretly moved most leading German scientists and 100 V-2 rockets to the United States in Operation Paperclip, but the Soviet program benefited from captured German records and scientists, in particular drawings obtained from the V-2 production sites. Under the direction of Dimitri Ustinov and others inspected the drawings. Helped by rocket scientist Helmut Gröttrup and other captured Germans until the early 1950s, they built a replica of the V-2 called the R-1, although the weight of Soviet nuclear warheads required a more powerful booster. Korolev's OKB-1 design bureau was dedicated to the liquid-fueled cryogenic rockets he had been experimenting with in the late 1930s; this work resulted in the design of the R-7 Semyorka intercontinental ballistic missile, tested in August 1957.
The Soviet space program was tied to the USSR's Five-Year Plans and from the start was reliant on support from the Soviet military. Although he was "single-mindedly driven by the dream of space travel", Korolev kept this a secret while working on military projects—especially, after the Soviet Union's first atomic bomb test in 1949, a missile capable of carrying a nuclear warhead to the United States—as many mocked the idea of launching satellites and manned spacecraft. Nonetheless, the first Soviet rocket with animals aboard launched in July 1951. Two months ahead of America's first such achievement and subsequent flights gave the Soviets valuable experience with space medicine; because of its global range and large payl
Gagarin's Start is a launch site at Baikonur Cosmodrome in Kazakhstan, used for the Soviet space program and now managed by Roscosmos. The launchpad for the world's first human spaceflight made by Yuri Gagarin on Vostok 1 in 1961, the site was referred to as Site No.1 as the first one of its kind. It is sometimes referred to as NIIP-5 LC1, Baikonur LC1 or GIK-5 LC1. On 17 March 1954 the Council of Ministers ordered several ministries to select a site for a proving ground to test the R-7 rocket by 1 January 1955. A special reconnaissance commission considered several possible geographic regions and selected Tyuratam in the Kazakh SSR; this selection was approved on 12 February 1955 by the Council of Ministers, with a completion of construction targeted for 1958. Work on the construction of Site No.1 began on 20 July 1955 by military engineers. Day and night more than 60 powerful trucks worked at the site. During winter explosives were utilized. By the end of October 1956 all primary building and installation of infrastructure for R-7 tests was completed.
The Installation and Testing Building named "Site No.2" was built and a special railway completed from there to Site No.1 where the launch pad for the rocket was located. By April 1957 all remaining work was completed and the site was ready for launches; the R-7 missile made its maiden voyage from LC-1 on 15 May 1957. On 4 October 1957 the pad was used to launch the world's first artificial satellite, Sputnik 1. Manned spaceflights launched from the site include Yuri Gagarin's flight, Valentina Tereshkova's flight, numerous other human spaceflight missions, including all Soviet and Russian manned spaceflights to Mir; the pad was used to launch Luna program spacecraft, Mars probe program spacecraft, Venera program spacecraft, many Cosmos satellites and others. From 1957 through 1966 the site hosted ready-to-launch strategic nuclear ICBMs in addition to spacecraft launches; the 500th launch from this site was of Soyuz TMA-18M on 2 September 2015. In 1961, the growing launch schedule of the Soviet space program resulted in the opening of a sister pad at Baikonur, LC-31/6.
LC-1 has been the primary facility for manned launches, with occasional Soyuz flights from LC-31/6. LC-1 was damaged several times by booster explosions during the early years; as of 2016, the most recent accident to occur on or around the pad was the attempted launch of Soyuz T-10-1 in September 1983 ended disastrously when the booster caught fire during prelaunch preparations and exploded, causing severe damage that left LC-1 inoperable for a year. According to the Russian State Owned Sputnik, Gagarin's Start is supposed to be decommissioned by the end of 2019 due to the upcoming decommission of the Soyuz-FG Launch Vehicle, but again according to the same article there could be some difficulties with the decommission, because LC-31/6 might not be able to handle all planned launches in 2020. Baikonur Cosmodrome Site 31 Cape Canaveral Air Force Station Launch Complex 14, the equivalent for the United States' first manned spaceflights J. K. Golovanov, M. "Korolev: Facts and myths", Nauka, 1994, ISBN 5-02-000822-2.
ISBN 5-217-02942-0. I. Ostashev, Korolyov, 2001.. Korolev. Yangel." - M. I. Kuznetsk, Voronezh: IPF "Voronezh", 1997, ISBN 5-89981-117-X. Notes of a military engineer" - Rjazhsky A. A. 2004, SC. first, the publishing house of the "Heroes of the Fatherland" ISBN 5-91017-018-X. "Rocket and space feat Baikonur" - Vladimir Порошков, the "Patriot" publishers 2007. ISBN 5-7030-0969-3 "Unknown Baikonur" - edited by B. I. Posysaeva, M.: "globe", 2001. ISBN 5-8155-0051-8 "Bank of the Universe" - edited by Boltenko A. C. Kiev, 2014. Publishing house "Phoenix", ISBN 978-966-136-169-9
A payload fairing is a nose cone used to protect a spacecraft against the impact of dynamic pressure and aerodynamic heating during launch through an atmosphere. More an additional function on some flights has been to maintain the cleanroom environment for precision instruments. Once outside the atmosphere the fairing is jettisoned, exposing the payload to the space environment; the standard payload fairing is a cone-cylinder combination, due to aerodynamic considerations. The type of fairing which separates into two halves upon jettisoning is called a clamshell fairing by way of analogy to the bifurcating shell of a clam. In some cases the fairing may enclose both the payload and the upper stage of the rocket, such as on Atlas V and Proton M. If the payload is attached both to the booster's core structures and to the fairing, the payload may still be affected by the fairing's bending loads, as well as inertia loads due to vibrations caused by gusts and buffeting. Traditionally, fairings either burned up in the atmosphere or were destroyed upon impacting the ocean.
On March 30, 2017, SpaceX retrieved a fairing intact for the first time in history. In some cases, the fairing is planned to separate after cutoff of the upper stage, in others, the separation is to occur before a cutoff, but after the vehicle has transcended the densest part of the atmosphere. Failure of the fairing to separate in these cases may cause the craft to fail to reach orbit, due to the extra mass; the Augmented Target Docking Adapter, to be used for the Gemini 9A manned mission, was placed into orbit by an Atlas SLV-3 in June 1966. But when the Gemini crew rendezvoused with it, they discovered the fairing had failed to open and separate, making docking impossible. Two lanyards, which should have been removed before flight, were still in place; the cause was determined to be a launch crew error. In 1999, the launch of the IKONOS-1 Earth observation satellite failed after the payload fairing of the Athena II rocket did not open properly, preventing the satellite from reaching orbit.
On February 24, 2009, NASA's Orbiting Carbon Observatory satellite failed to reach orbit after liftoff because the fairing on the Taurus XL launch vehicle failed to separate, causing the vehicle to retain too much mass and subsequently fall back to Earth and land in the Indian Ocean near Antarctica. The same happened to the Naro-1, South Korea's first carrier rocket, launched on August 25, 2009. During the launch half of the payload's fairing failed to separate, as a result, the rocket was thrown off course; the satellite did not reach a stable orbit. On March 4, 2011, NASA's Glory satellite launch failed to reach orbit after liftoff due to a fairing separation failure on the Orbital Sciences Taurus XL launch vehicle, ending up in the Indian Ocean; this failure represented the second consecutive failure of a fairing on an Orbital Sciences Taurus XL vehicle. NASA subsequently decided to switch the launch vehicle for the Orbiting Carbon Observatory's replacement, OCO-2, from a Taurus to a Delta II rocket.
On August 31, 2017, ISRO's IRNSS-1H satellite failed to deploy after the payload fairing of the rocket PSLV-C39 failed to separate. As a result of extra mass, the rocket could not reach the desired orbit despite each stage's performance being nominal; the payload got stuck within the heat shield. RUAG Space, a Zurich-based Swiss company, is the manufacturer of fairings for Ariane, as part of the cooperation within the European space programme, produces the 5m fairings for the Atlas V. SpaceX manufactures the fairings used on its Falcon 9 family of rockets. Sabot