
	Where results make sense

Topic: Longitude of the periapsis

Related Topics

True longitude

Mean longitude

Orbital state vectors

Orbital elements

Celestial dynamics

Astrodynamics

Mean anomaly

In the News (Tue 10 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Orbit - Wikipedia
		As an object orbits another object, periapsis is that point at which the orbiting object is closest to the object being orbited; apoapsis is that point at which the orbiting object is farthest from the object beinn orbited.
		The point where the orbiting body is closest to Earth is the perigee, called periapsis (less properly, "perifocus" or "pericentron") when the orbit is around a body other than Earth.
		The point on the orbit closest to the attracting body is the periapsis.
	wikipedia.findthelinks.com /or/Orbit.html (1445 words)

	Orbit (astronomy and physics) - MSN Encarta
		The three orbital elements that describe an orbit's orientation are the inclination (i), the longitude of the ascending node (Ω), and the argument of the periapsis (ω).
		The longitude of the ascending node is the angle in the reference plane between the equinox and the ascending node.
		The argument of the periapsis measures the angular displacement in the plane of the orbit between the ascending node and the line that passes through the center of the orbit (C) and the periapsis (P).
	encarta.msn.com /encnet/refpages/RefArticle.aspx?refid=761556131 (925 words)

	Longitude of the periapsis - Wikipedia, the free encyclopedia
		In astrodynamics, the longitude of the periapsis (symbolized
		) of an orbiting body is the longitude (measured from the point of the vernal equinox) at which the periapsis (closest approach to the central body) would occur if the body's inclination were zero.
		The longitude of periapsis is a compound angle, with part of it being measured in the plane of reference and the rest being measured in the plane of the orbit.
	en.wikipedia.org /wiki/Longitude_of_the_periapsis (154 words)

	Final Gallery
		Periapsis is the point in an orbit closest to the primary.
		Periapsis and apoapsis names are modified to apply to the body being discussed such as perilune and apolune for the moon or perihelion and aphelion for the sun.
		The argument of periapsis is the angular distance between the ascending node and the point of periapsis.
	aerospacescholars.jsc.nasa.gov /has/Students/finalGall.cfm?id=132 (705 words)

	Status Report (Site not responding. Last check: 2007-10-09)
		If you you draw a celestial sphere with the X and Z axes as described, longitude is the angle from the X axis to the projection of the pointing vector onto the ecliptic plane.
		The terms latitude and longitude are used because they are similar to how we identify the location of a point on the Earth in Spherical coordinates.
		Periapsis Altitude is the lowest point of Lunar Prospector's orbit relative to the surface of the moon.
	lunar.arc.nasa.gov /printerready/status/longer.html (940 words)

	UCLA - IGPP Space Physics Tutorial - Pioneer Venus Missions
		Periapsis altitude was controlled by the firing of gas jets for almost 600 orbits.
		Signals 'a' and 'c' are believed to be caused by natural sources whereas signals labelled 'b' are believed to be due to the interaction of the spacecraft with the ionosphere due to their extremely periodic character [Russell et al., 1988].
		Periapsis of the spacecraft is close to 15o N [Miller and Whitten, 1990].
	www-ssc.igpp.ucla.edu /ssc/tutorial/pvo_mission.html (5610 words)

	AAS 98-384
		is the density at periapsis, a and e are the orbit’s semi-major axis and eccentricity and
		Criteria for the selection of the periapsis altitude included a) consensus input by the scientists for optimal observations, b) be outside the atmosphere to avoid or minimize drag perturbations, and c) minimize the propellant required to reach this altitude.
		Due to fluctuations in the atmospheric density from periapsis to periapsis and the necessity of executing the final maneuver at a precise orbital period, a "walk-out" of the atmosphere was executed as shown in Table 5.
	mars.jpl.nasa.gov /mgs/sci/aerobrake/SFD/SFD-Paper.html (3035 words)

	Planetary Orbits
		The argument of periapsis (4) is the argument (angular distance) of periapsis from the ascending node.
		Time of periapsis passage (5) and the celestial longitude of the ascending node (6) are the remaining elements.
		Each periapsis pass, a swath of mapping data was taken, and the planet rotated so that swaths from consecutive orbits were adjacent to each other.
	www.au.af.mil /au/awc/awcgate/jplbasic/bsf5-1.htm (1003 words)

	Untitled Document
		This is of importance for MGS as the periapsis latitude is in the northern hemisphere at the beginning of aerobraking and remains in that hemisphere for a major portion of the aerobraking time period.
		At the next apoapsis (apoapsis 15) the periapsis was raised to reduce the risk to the spacecraft an a careful examination of all relevant data began.
		The longitudes of 90° and 270° in the Northern hemisphere of Mars are noticeable higher topographically than other longitudes and this suggests a coupling between the topography and the density in the lower thermosphere at 122 km which represents a new discovery.
	mars.jpl.nasa.gov /mgs/confrm/aerobexp.html (4298 words)

	Orbit - MSN Encarta
		Early in the 17th century, the German astronomer and natural philosopher Johannes Kepler propounded three laws that first described the motions of the planets about the Sun: (1) The orbit of a planet around the Sun is an ellipse.
		The argument of the periapsis is the angular displacement in the plane of the orbit between the ascending node and the line that passes through the centre of the orbit (C) and the periapsis (P).
		This axis is half the long axis (AP) of the ellipse, that is, half the distance between the periapsis (P) and apoapsis (A).
	uk.encarta.msn.com /encyclopedia_761556131/Orbit.html (842 words)

	Orbit - HorologicalWiki (Site not responding. Last check: 2007-10-09)
		At the present epoch, Mars has the next largest eccentricity while the smallest eccentricities are those of the orbits of Venus and Neptune.
		As an object orbits another object, periapsis is that point at which the orbiting object is closest to the object being orbited; apoapsis is that point at which the orbiting object is farthest from the object being orbited.
		semi-major axis for elliptic orbits; periapsis distance (in the solar system: perihelion distance) for parabolic or hyperbolic orbits.
	www.clockmakers.archivist.info /wiki/wiki.phtml?title=Orbit (1826 words)

	Basics of Space Flight Section I. The Environment of Space
		Argument of periapsis is the argument (angular distance) of the periapsis from the ascending node.
		Celestial longitude of the ascending node are the remaining elements.
		A walking orbit whose parameters are chosen such that the orbital plane precesses with nearly the same period as the planet's solar orbit period is called a sun synchronous orbit.
	www2.jpl.nasa.gov /basics/bsf5-1.html (1166 words)

	de Orbit This article is about orbits...
		As an object orbits another object, periapsis periapsis is that point point at which the orbiting object is closest to the object being orbited; apoapsis apoapsis is that point point at which the orbiting object is farthest from the object being orbited.
		The point where the orbiting body is closest to Earth is the perigee perigee, called periapsis periapsis (less properly, "perifocus" or "pericentron") when the orbit is around a body other than Earth.
		The point on the orbit closest to the attracting body is the periapsis periapsis.
	www.biodatabase.de /Orbit (1800 words)

	Final Gallery
		As a satellite orbits a planet, the point in the orbit at which the satellite is closest to the planet is called the periapsis.
		The longitude of the ascending node is similar to longitude on Earth, and it is measured in degrees counter-clockwise from zero longitude, which is in the direction of the vernal equinox.
		The angular distance between the ascending node and the point of periapsis is known as the argument of periapsis.
	aerospacescholars.jsc.nasa.gov /has/Students/finalGall.cfm?id=1061 (920 words)

	Mean longitude (via CobWeb/3.1 planetlab2.tamu.edu) (Site not responding. Last check: 2007-10-09)
		In astrodynamics or celestial dynamics mean longitude is the longitude at which an orbiting body could be found if its orbit were circular and its inclination were zero.
		The mean longitude changes at a constant rate over time.
		The only times when it is equal to the true longitude are at periapsis and apoapsis.
	www.danceage.com.cob-web.org:8888 /biography/sdmc_Mean_longitude (54 words)

	ch9
		At about one day before periapsis, a malfunction affected the stepping function of the telescope and a few images were partially lost before a work-around could be effected.
		There is still great activity in the cloud forms at high altitudes, but the banded structure of the tropics changes to a random pattern of cells and turbulence down to the limits of resolution.
		The colors are, however, probably less authentic than those of the images before periapsis because of an apparent change in the behavior of the instrument after passage through the intense radiation belts.
	www.hq.nasa.gov /pao/History/SP-349/ch9.htm (1960 words)

	Orbital Mechanics
		The longitude of the ascending node is the node's celestial longitude.
		Celestial longitude is analogous to longitude on Earth and is measured in degrees counter-clockwise from zero with zero longitude being in the direction of the vernal equinox.
		The dominant effects, however, are secular variations in longitude of the ascending node and argument of perigee because of the Earth's oblateness, represented by the J
	www.braeunig.us /space/orbmech.htm#elements (6414 words)

	Practical Astronautics (Site not responding. Last check: 2007-10-09)
		periapsis - the closest point in an orbit to the primary body.
		For earth orbits periapsis is known as perigee.
		is equal to E and M at periapsis (all equal 0 degrees) and at apoapsis (all equal 180 degrees).
	www.astronautica.com /astro (1528 words)

	[No title]
		If you select the SPICE ephemerides of the same name in Horizons, then you really should get almost identical results, because the SPICE files were generated using these exact elements.
		(2) Be aware that Saturn's moons Prometheus and Pandora are exhibiting peculiar variations in longitude that are not currently understood, probably related to interactions with the other nearby moons and rings.
		longitude of perihelion, / / and do a first-order correction to get the / / 'actual' r and true longitude values.
	www.projectpluto.com /rocks.cpp (429 words)

	Orbital Operations Manual - Aligning, Syncing, and Docking with a Space Station
		Longitude of Ascending Node is a measurement of the point at which the orbit crosses the equator when heading from South to North (ascending).
		Longitude of Ascending Node when talking about orbital planes is a more absolute measurement based on the Earth's position with the sun.
		Your periapsis is the green solid circle and your apoapsis is the green open circle.
	smithplanet.com /stuff/orbiter/orbitaloperations.htm (10596 words)

	Planetary Orbits
		and the periapsis measured from the centre and is related to the mean and true anomalies by the set of equations:
		of the orbital plane, the longitude of the ascending node
		The perifocal coordinate system has its X-axis from the focus to the periapsis, and its Z-axis right-handed perpendicular to the orbital plane in the sense of orbital motion.
	www.mps.mpg.de /homes/fraenz/systems/systems2art/node15.html (468 words)

	argument_of_the_perihelion
		The argument of periapsis (Ï) is the orbital element describing the angle between an orbiting body's ascending node (the point where the body crosses the plane of reference from South to North) and its periapsis (the point of closest approach to the central body), measured in the orbital plane and in the direction of motion.
		An argument of periapsis of 0Â° means that the orbiting body will be at its closest approach to the central body at the same moment that it crosses the plane of reference from South to North.
		An argument of periapsis of 90Â° means that the orbiting body will reach periapsis at its northmost distance from the plane of reference.
	www.hondparts.com /wiki/?title=Argument_of_the_perihelion (255 words)

	Glossary of Aerospace Terms
		In an orbit, the angular distance between the point of periapsis and the ascending node.
		In an orbit, the celestial longitude of the ascending node.
		The study of the motions of artificial satellites and space vehicles moving under the influence of forces such as gravity, drag, and thrust.
	www.geocities.com /jpadfield13/terms.html (10376 words)

	Explanations of Ancillary Data for MOC Images
		During the Aerobraking and Science Phasing Orbits portion of the mission in 1997 and 1998, the 5-digit numerical identifier was based upon orbit number (defined by periapsis point) and numerical sequence of image commanded for that orbit.
		For example, an image identified as AB1-10905 was taken during the Aerobraking-1 Subphase on orbit 109 and it was the 5th image taken by MOC during that orbit.
		This is the approximate longitude location of the image center on the planet, Mars.
	www.msss.com /moc_gallery/ab1_m04/explain.html (1951 words)

	5 Mission Technologies
		The periapsis is affected by yaw and pitch angle and by timing, while longitude of periapsis is affected mostly by timing.
		Obviously, the characteristics of the orbit prior to the deorbit maneuver have an influence.
		The satellite is usually a few degress out of longitude after this initial insertion, and the last few small maneuvers to get it on station are analogous to the docking maneuvers for a station rendezvous...although there is probably nothing to collide with.
	aftercolumbia.tripod.com /deltasprint/id5.html (3816 words)

	Apollo Lunar Landing Mission Tutorial (Site not responding. Last check: 2007-10-09)
		The maneuver is timed such that periapsis occurs approximately 250 nm (463.2 km) up-range or east of the landing site, establishing optimum range and altitude conditions for the LM Powered Descent Initiate (PDI) maneuver later in the flight.
		This presupposes that the longitude of the apoapsis thus established was reasonably close to the longitude of the landing site...
		The benefit in first performing an Orbit Circ maneuver is that longitude of apoapsis becomes basically irrelevant when eccentricity is near zero, making accurate positioning of the Descent Orbit periapsis a relatively simple task.
	www.jdkbph.com /ALMT/07DOI.htm (844 words)

	Relativity and the Separation Formula
		The periapsis (q) and semi-latus rectum (d) are physical dimensions of any conic section, not just ellipses-- though a hyperbola might be thought of as an ellipse with a negative major axis and an imaginary minor axis.
		The point where the Sun crosses the celestial equator and enters the northern hemisphere is the Vernal Equinox, providing the benchmark to celestial longitude, which is then measured along the ecliptic to the East, the direction in which the Sun and planets move against the background of the stars.
		Once on the plane of the orbit, the angle of longitude is measured to the East until the perihelion (perigee, etc.) point is reached.
	www.friesian.com /separat.htm (4782 words)

	MASL IORB FLAG
		Classical orbital elements (semi-major axis, eccentricity, inclination, longitude of the ascending node, argument of periapsis, and mean anomaly), are an example of such a set, as are the six elements of a Cartesian state vector (x, y, z, vx, vy, and vz).
		A "frozen" orbit is one where J3 acts to cancel the precession of periapsis due to J2.
		When A=5 (Ground Station Elements) and C=2, then Element (1) is the magnitude of the radius projected into the XY-plane, Element (2) is the Z position, and Element (3) is the associated longitude.
	roger.ecn.purdue.edu /~masl/documents/masl/iorb.html (1237 words)

	True longitude - Wikipedia, the free encyclopedia
		In astrodynamics true longitude is the longitude at which an orbiting body could actually be found if its inclination were zero.
		Together with the inclination and the ascending node, the true longitude can tell us the precise direction from the central object at which the body would be located at a particular time.
		This page was last modified 01:54, 16 September 2005.
	en.wikipedia.org /wiki/True_longitude (98 words)

Try your search on: Qwika (all wikis)