Orbital spaceflight - wikipedia Orbital spaceflight This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( March 2008 ) Space Shuttle Discovery rockets to orbital velocity, seen here just after booster separation An orbital spaceflight ( or orbital flight ) is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altitude at perigee ( altitude at closest approach ) above 100 kilometers ( 62 mi ) ; this is, by at least one convention, the boundary of space. To remain in orbit at this altitude requires an orbital speed of ~ 7.8 km / s. Orbital speed is slower for higher orbits, but attaining them requires greater delta - v. Due to atmospheric drag, the lowest altitude at which an object in a circular orbit can complete at least one full revolution without propulsion is approximately 150 km ( 90 mi ). The expression `` orbital spaceflight '' is mostly used to distinguish from sub-orbital spaceflights, which are flights where the apogee of a spacecraft reaches space, but the perigee is too low. Contents 1 Orbital launch 2 Stability 3 Orbits 4 Orbital maneuver 5 Deorbit and re-entry 6 History 7 See also 8 References 9 External links Orbital launch Orbital human spaceflight Name Debut Launches Vostok 1961 6 Mercury 1962 Voskhod 1964 Gemini 1965 10 Soyuz 1967 147 Apollo 1968 21 Shuttle 1981 135 Shenzhou 2003 Orbital spaceflight from Earth has only been achieved by launch vehicles that use rocket engines for propulsion. To reach orbit, the rocket must impart to the payload a delta - v of about 9.3 -- 10 km / s. This figure is mainly ( ~ 7.8 km / s ) for horizontal acceleration needed to reach orbital speed, but allows for atmospheric drag ( approximately 300 m / s with the ballistic coefficient of a 20 m long dense fueled vehicle ), gravity losses ( depending on burn time and details of the trajectory and launch vehicle ), and gaining altitude. The main proven technique involves launching nearly vertically for a few kilometers while performing a gravity turn, and then progressively flattening the trajectory out at an altitude of 170 + km and accelerating on a horizontal trajectory ( with the rocket angled upwards to fight gravity and maintain altitude ) for a 5 - 8 minute burn until orbital velocity is achieved. Currently, 2 - 4 stages are needed to achieve the required delta - v. Most launches are by expendable launch systems. The Pegasus rocket for small satellites instead launches from an aircraft at an altitude of 12 km. There have been many proposed methods for achieving orbital spaceflight that have the potential of being much more affordable than rockets. Some of these ideas such as the space elevator, and rotovator, require new materials much stronger than any currently known. Other proposed ideas include ground accelerators such as launch loops, rocket assisted aircraft / spaceplanes such as Reaction Engines Skylon, scramjet powered spaceplanes, and RBCC powered spaceplanes. Gun launch has been proposed for cargo. From 2015 SpaceX have demonstrated significant progress in their more incremental approach to reducing the cost of orbital spaceflight. Their potential for cost reduction comes mainly from pioneering propulsive landing with their reusable rocket booster stage as well as their Dragon capsule, but also includes reuse of the other components such as the payload fairings and the use of 3D printing of a superalloy to construct more efficient rocket engines, such as their SuperDraco. The initial stages of these improvements could reduce the cost of an orbital launch by an order of magnitude. Stability The International Space Station during its construction in Earth orbit in 2001. It must be periodically re-boosted to maintain its orbit Main article : Orbital decay An object in orbit at an altitude of less than roughly 200 km is considered unstable due to atmospheric drag. For a satellite to be in a stable orbit ( i.e. sustainable for more than a few months ), 350 km is a more standard altitude for low Earth orbit. For example, on 1958 - 02 - 01 the Explorer 1 satellite was launched into an orbit with a perigee of 358 kilometers ( 222 mi ). It remained in orbit for more than 12 years before its atmospheric reentry over the Pacific Ocean on 1970 - 03 - 31. However, the exact behaviour of objects in orbit depends on altitude, their ballistic coefficient, and details of space weather which can affect the height of the upper atmosphere. Orbits Main article : Geocentric orbit There are three main ' bands ' of orbit around the Earth : low Earth orbit ( LEO ), medium Earth orbit ( MEO ) and geostationary orbit ( GEO ). Due to Orbital mechanics orbits are in a particular, largely fixed plane around the Earth, which coincides with the center of the Earth, and may be tilted with respect to the equator. The Earth rotates about its axis within this orbit, and the relative motion of the spacecraft and the movement of the Earths surface determines the position that the spacecraft appears in the sky from the ground, and which parts of the Earth are visible from the spacecraft. By dropping a vertical down to the Earth 's surface it is possible to calculate a ground track which shows which part of the Earth a spacecraft is immediately above, and this is useful for helping to visualise the orbit. Orbital maneuver Main article : Orbital maneuver Skylab mission docked to the Skylab space station In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth -- for example those in orbits around the Sun -- an orbital maneuver is called a deep - space maneuver ( DSM ). Deorbit and reentry Main article : Atmospheric entry Returning spacecraft ( including all potentially manned craft ) have to find a way of slowing down as much as possible while still in higher atmospheric layers and avoid hitting the ground ( lithobraking ) or burning up. For many orbital space flights, initial deceleration is provided by the retrofiring of the craft 's rocket engines, perturbing the orbit ( by lowering perigee down into the atmosphere ) onto a suborbital trajectory. Many spacecraft in low - Earth orbit ( e.g., nanosatellites or spacecraft that have run out of station keeping fuel or are otherwise non-functional ) solve the problem of deceleration from orbital speeds through using atmospheric drag ( aerobraking ) to provide initial deceleration. In all cases, once initial deceleration has lowered the orbital perigee into the mesosphere, all spacecraft lose most of the remaining speed, and therefore kinetic energy, through the atmospheric drag effect of aerobraking. Intentional aerobraking is achieved by orienting the returning space craft so as to present the heat shields forward toward the atmosphere to protect against the high temperatures generated by atmospheric compression and friction caused by passing through the atmosphere at hypersonic speeds. The thermal energy is dissipated mainly by compression heating the air in a shockwave ahead of the vehicle using a blunt heat shield shape, with the aim of minimising the heat entering the vehicle. Sub-orbital space flights, being at a much lower speed, do not generate anywhere near as much heat upon re-entry. Even if the orbiting objects are expendable, most space authorities are pushing toward controlled re-entries to minimize hazard to lives and property on the planet. History Sputnik 1 was the first human - made object to achieve orbital spaceflight. It was launched on 4 October 1957 by the Soviet Union. Vostok 1, launched by the Soviet Union on 12 April 1961, carrying Yuri Gagarin, was the first successful human spaceflight to reach Earth orbit. Vostok 6, launched by the Soviet Union on 16 June 1963, carrying Valentina Tereshkova, was the first successful woman carrying out a spaceflight to reach Earth orbit. See also Spaceflight portal Orbit List of orbits Ground track Orbital mechanics Project HARP was a failed attempt, and a ram accelerator is another design, to launch an object into orbit with a gun Rocket launch Non-rocket spacelaunch Spacecraft Spaceflight Spaceport, including a list of sites for orbital launches References Jump up ^ Belfiore, Michael ( December 9, 2013 ). `` The Rocketeer ''. Foreign Policy. Retrieved December 11, 2013. Jump up ^ `` Explorer 1 - NSSDC ID : 1958 - 001A ''. NASA. External links Spaceflight General Astrodynamics History Timeline Space Race Asian Space Race Records Accidents and incidents Space policy China European Union India Japan Russia Soviet Union United States Space law Outer Space Treaty Rescue Agreement Space Liability Convention Registration Convention Moon Treaty Private spaceflight Applications Astronomy Earth observation Archaeology Imagery and mapping Reconnaissance Weather and environment monitoring Satellite communications Internet Radio Telephone Television Satellite navigation Commercial use of space Space launch market competition Militarisation of space Space architecture Space exploration Space research Space technology Space weather Human spaceflight General Astronaut Life support system Animals in space Bioastronautics Space suit Extravehicular activity Weightlessness Space tourism Space colonization Programs Vostok Mercury Voskhod Gemini Soyuz Apollo Skylab Apollo -- Soyuz Space Shuttle Mir Shuttle -- Mir International Space Station Shenzhou Tiangong Health issues Effect of spaceflight on the human body Space adaptation syndrome Health threat from cosmic rays Psychological and sociological effects of spaceflight Space and survival Space medicine Space nursing Spacecraft Launch vehicle Rocket Spaceplane Robotic spacecraft Satellite Space probe Lander Rover Self - replicating spacecraft Spacecraft propulsion Rocket engine Electric propulsion Solar sail Gravity assist Destinations Sub-orbital Orbital Geocentric Geosynchronous Interplanetary Interstellar Intergalactic Space launch Direct ascent Escape velocity Expendable and reusable launch systems Launch pad Non-rocket spacelaunch Spaceport Ground segment Flight controller Ground station ( Pass ) Mission control center Space agencies CoNAE AEB CSA CNSA ESA CNES DLR ISRO LAPAN ISA ISA ASI JAXA NADA KARI SUPARCO Roscosmos SNSB SSAU UKSA NASA Portal WikiProject Gravitational orbits Types General Box Capture Circular Elliptical / Highly elliptical Escape Graveyard Hyperbolic trajectory Inclined / Non-inclined Osculating Parabolic trajectory Parking Synchronous semi sub Transfer orbit Geocentric Geosynchronous Geostationary Sun - synchronous Low Earth Medium Earth High Earth Molniya Near - equatorial Orbit of the Moon Polar Tundra About other points Areosynchronous Areostationary Halo Lissajous Lunar Heliocentric Heliosynchronous Parameters Shape Size e Eccentricity a Semi-major axis b Semi-minor axis Q, q Apsides Orientation i Inclination Ω Longitude of the ascending node ω Argument of periapsis π Longitude of the periapsis Position M Mean anomaly ν True anomaly E Eccentric anomaly L Mean longitude l True longitude Variation T Orbital period n Mean motion v Orbital speed t Epoch Maneuvers Collision avoidance ( spacecraft ) Delta - v Delta - v budget Bi-elliptic transfer Geostationary transfer Gravity assist Gravity turn Hohmann transfer Low energy transfer Oberth effect Inclination change Phasing Rocket equation Rendezvous Transposition, docking, and extraction Orbital mechanics Celestial coordinate system Characteristic energy Escape velocity Ephemeris Equatorial coordinate system Ground track Hill sphere Interplanetary Transport Network Kepler 's laws of planetary motion Lagrangian point n - body problem Orbit equation Orbital state vectors Perturbation Retrograde motion Specific orbital energy Specific relative angular momentum Two - line elements List of orbits Retrieved from `` https://en.wikipedia.org/w/index.php?title=Orbital_spaceflight&oldid=803742354 '' Categories : Spaceflight concepts Russian inventions 1957 introductions Hidden categories : Articles needing additional references from March 2008 All articles needing additional references Use dmy dates from January 2011 Talk Contents About Wikipedia Català Español Français Hrvatski Bahasa Indonesia עברית Magyar Polski Português Svenska Türkçe Edit links This page was last edited on 4 October 2017, at 10 : 09. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: speed a rocket has to be accelerated to in order to launch a satellite into orbit of the earth
Answer: the rocket must impart to the payload a delta-v of about 9.3–10 km/s