orbit

en-noun

orbit (countable and uncountable, plural orbits)

Inherited from Middle English orbite, orbita, from Latin orbita (“course, track, impression, mark”).

គន្លង

kɔɔkŭənlɔɔng

In the post WWII era, several eastern European countries came into the orbit of the Soviet Union.

The convenience store was a heavily travelled point in her daily orbit, as she purchased both cigarettes and lottery tickets there.

Bondi has been inside Trump’s orbit for some time, and is widely seen to have demonstrated her loyalty to Trump during his first term, when she helped with his impeachment defense, and more recently when she repeatedly attended Trump’s criminal trial in New York.

2024 November 22, Hugo Lowell, “Trump names Pam Bondi as attorney general pick after Gaetz steps aside”, in The Guardian, →ISSN:

So, it is clear from the consultation that while the intention is to bring track and train together under GBR, it will not escape the orbit of the government.

2025 March 5, Richard Wilcock, “DfT sets out its plans with rail reform consultation”, in RAIL, number 1030, page 28:

(figurative) A sphere of influence; an area or extent of activity, interest, or control.


trajectory

/tɹəˈd͡ʒɛktəɹi/

From New Latin trāiectōria f (“trajectory”) (used by Newton), the feminine of trāiectōrius (“of or pertaining to throwing across”), from Latin trāiectus (“thrown over or across”), past participle of trāiciō, from trans- (“across, beyond”) (see trans-) + iaciō (“to throw”) (from Proto-Indo-European *(H)yeh₁- (“to throw, impel”)). Middle French and Middle English had trajectorie (“end of a funnel”), from Latin trāiectōrium.

(cybernetics) The ordered set of intermediate states assumed by a dynamical system as a result of time evolution.


apoapsis

en-noun

apoapsis (plural apoapsides or apoapsises or apoapses)

apoapsides (plural)
apoapsises (plural)
apoapses (plural)
apapsis (alternative)

(astronomy) The point of a body's elliptical orbit about the system's centre of mass where the distance between the body and the centre of mass is at its maximum.


periapsis

periapsis (plural periapsides or periapsises or periapses)

periapsides (plural)
periapsises (plural)
periapses (plural)

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1983, Richard O. Fimmel, Laurence Colin, Eric Burgess, Pioneer Venus, NASA SP-461, page 109,
Figure 5-19. Sun-Venus-Orbiter geometry illustrates how the periapsis moves around the planet during the Venusian sidereal year to sample day and night hemispheres. Because the planet rotates in a retrograde direction, it takes more than one Venusian sidereal year for periapsis to move over all longitudes of the planet (as explained in text).

We don't always want to burn near periapsis. Suppose we want to change the height at periapsis. The most efficient place to change the radius of periapsis is at apoapsis. Consider applying #92;Deltav at some other point in the orbit. In this case both periapsis and apoapsis will change. If we apply the #92;Deltav tangentially at apoapsis, all of the #92;Deltav will go into changing periapsis, and vice versa.

2001, D. A. Vallado, Fundamentals of Astrodynamics and Applications, Springer, page 325:

2004, R. S. Saunders, et al., Mars Odyssey Mission, C. T. Russell (editor), 2001 Mars Odyssey, Kluwer Academic Publishers, page 34,
The main aerobraking phase began once the point of the spacecraft's periapsis had been lowered to within 110 km above the Martian surface.

(astronomy, astrophysics) The point of a body's (elliptical) orbit in a 2-body gravitational system such that the distance between the two bodies (measured from their respective centres of mass) is at its minimum.


perturbation

perturbation (countable and uncountable, plural perturbations)

Borrowed from Middle French perturbation, from Old French perturbacion, from Latin perturbatio.

(countable, astronomy, physics) Variation in an orbit due to the influence of external bodies


TMI

TMI (countable and uncountable, plural TMIs)

trans-Mars injection
trans-Mars injection#English

(astrodynamics) Initialism of trans-Mars injection.


escape velocity

escape velocity (plural escape velocities)

The gravitational force exerted by a planet determines its surface gravity and escape velocity.

1996, Thomas Arny, Explorations: An Introduction to Astronomy, McGraw-Hill Science, page 74:

(astrophysics) The minimum speed needed to escape the gravitational field of a planet or other body.


cubewano

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From acronym of QB1 + -o.
Derived from QB1 ("cue bee one"), short for (15760) 1992 QB1, the first such object discovered

(astronomy) Any Kuiper belt object whose orbit is not determined by resonance with Neptune (orbit ~ 40-50 AU).


epicycle

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From Latin epicyclus, from Ancient Greek ἐπίκυκλος (epíkuklos), from ἐπί (epí, “upon”) + κύκλος (kúklos, “circle”).

Is it not [Philosophie], that […] teacheth miserie, famine and sicknesse to laugh? Not by reason of some imaginarie Epicicles, but by naturall and palpable reasons.

(astronomy) A small circle whose centre is on the circumference of a larger circle; in Ptolemaic astronomy it was seen as the basis of revolution of the "seven planets", given a fixed central Earth.

فَلَك التَّدوِير

a small circle whose centre is on the circumference of a larger circle

(geometry) Any circle whose circumference rolls around that of another circle, thus creating a hypocycloid or epicycloid.

episykli

any circle whose circumference rolls around that of another circle

(organic chemistry) A ring of atoms joining parts of an already cyclic compound

If two chronicles seemed contradictory, instead of trying to choose between them, a rationalization (epicycle) was devised to cover both.

1978, The Journal of the Siam Society, volumes 66-67, page 152:

Rather than solve the theoretical problem of how to produce a method of political ethics, the contractarian device introduces an unnecessary theoretical epicycle into what is otherwise a coherent account of social justice in particular and political morality in general.

1998, Paul Joseph Kelly, Impartiality, Neutrality and Justice: Re-reading Brian Barry’s Justice as Impartiality, page 12:

(figuratively) An ad hoc complication added to a model to make it fit the known data


apsis

From Latin apsis, hapsis, from Ancient Greek ἁψίς (hapsís, “arch, vault”). See also apse.

der

(astronomy) Either of the points in the elliptical orbit of a planet, comet, or moon where it is closest or furthest from the body it orbits; examples are perihelion, aphelion, perigee, and apogee


orbiter

One day after the Hope maneuver, a Chinese spacecraft, Tianwen-1, is to also enter orbit around Mars. The Chinese mission is carrying a lander and a rover to explore a large impact basin called Utopia Planitia, but those are not to detach from the orbiter and head to the surface until May.

2021 February 9, Kenneth Chang, “Mars Mission From the U.A.E. Begins Orbit of Red Planet”, in The New York Times, →ISSN:

An object that orbits another, especially a spacecraft that orbits a planet etc. without landing on it.


resonance

en-noun

resonance (countable and uncountable, plural resonances)

From Old French resonance (French résonance), from Latin resonantia (“echo”), from resonō (“I resound”).

The leiter-wagons contained great, square boxes, with handles of thick rope; these were evidently empty by the ease with which the Slovaks handled them, and by their resonance as they were roughly moved.

1897, Bram Stoker, Dracula, New York, N.Y.: Modern Library, →OCLC:

(uncountable) The quality of being resonant.

emotional resonance

But the film is largely redeemed by an unexpected emotional resonance befitting a Steven Spielberg production.

2012 May 24, Nathan Rabin, “Film: Reviews: Men In Black 3”, in The Onion AV Club:

The whole recognition process has a deep colonial resonance. [title]

2017 October 27, Paul Daley, “The whole recognition process has a deep colonial resonance”, in The Guardian:

For audiences, all these shows mean a chance to revisit a story that still chimes loudly, and to see whether, as many suspect, it will have a more chilling resonance in the winter of 2022.

2022 November 13, Vanessa Thorpe, “‘It has added political resonance this year’: why Charles Dickens’s A Christmas Carol still strikes a chord”, in The Guardian:

(figuratively) Something that evokes an association, or a strong emotion; something that strikes a chord.

(astronomy) An influence of the gravitational forces of one orbiting object on the orbit of another, causing periodic perturbations.


perturb

en-verb

perturb (third-person singular simple present perturbs, present participle perturbing, simple past and past participle perturbed)

perturbs (present singular third-person)
perturbing (participle present)
perturbed (participle past)
perturbed (past)

From Late Middle English perturben (“to disturb (someone) mentally, disquiet; to cause disorder to (something), confuse; to hinder (something)”), from Old French perturber, and from its etymon Latin perturbāre, the present active infinitive of perturbō (“to confuse; to alarm, disturb, trouble, perturb”), from per- (intensifying prefix) + turbō (“to agitate, disturb, unsettle, perturb; to upset”) (from turba (“disorder, disturbance, turmoil”) (possibly from Ancient Greek τῠ́ρβη (tŭ́rbē, “confusion, disorder, tumult”), either from Pre-Greek, or Proto-Indo-European *(s)twerH- (“to agitate, stir up; to urge on, propel”)) + -ō (suffix forming infinitives of regular first-conjugation verbs)).

der

(astronomy) To modify the motion of a body by exerting a gravitational force.


anteorbital

(astronautics) Referring to the period before orbit is achieved.


deferent

deferent (nominative singular)
deferenty (nominative plural)
deferenta (genitive singular)
deferentów (genitive plural)
deferentowi (dative singular)
deferentom (dative plural)
deferent (accusative singular)
deferenty (accusative plural)
deferentem (instrumental singular)
deferentami (instrumental plural)
deferencie (locative singular)
deferentach (locative plural)
deferencie (singular vocative)
deferenty (plural vocative)

(historical, Ptolemaic astronomy) deferent (imaginary circle surrounding the Earth, in whose periphery either the heavenly body or the center of the heavenly body's epicycle was supposed to be carried round)


eccentricity

en-noun

eccentricity (countable and uncountable, plural eccentricities)

excentricitat

a ratio between distances in a conic section

(astronomy) The eccentricity of the conic section (usually an ellipse) defined by the orbit of a given object around a reference object (such as that of a planet around the sun).


geosynchronous

Refers to the orbit of a satellite whose rate of revolution is matched to the rotation period of the Earth. A special case is the geostationary orbit which is circular and equatorial, so that the satellite appears to be fixed over a particular point on Earth's sky.

geosynkroninen

orbit whose rate of revolution is matched with Earth


geostationary

The measurement is accomplished by observing the Faraday rotation angle of signals from geostationary satellites on a continuous basis.

1971, Thomas A. Croft, Measurement of a Solar Wind Plasma Stream which Endures Several Months But is Intermittent on a Time Scale of about One Day:

At a fixed distance in three dimensions relative to a particular point on the Earth's surface; generally only possible with orbital satellites.


space velocity

space velocity (plural space velocities)

(astronomy) The velocity of a star relative to the Sun


low Earth orbit

low Earth orbit (plural low Earth orbits)

A satellite orbit around the Earth within the altitude range of ~ 200 - 2000 km, in which a satellite can communicate with Earth with a small time lag and energy consumption. Abbreviation: LEO.


plutino

From Plut(o) + -ino (“diminutive suffix”), meaning "little Pluto" (compare neutrino); coined by David C. Jewitt, et al.

We present a study of the dynamical evolution of plutinos recently escaped from the resonance through numerical simulations. It was shown in previous works the existence of weakly chaotic orbits in the plutino population that diffuse very slowly finally diving into a strong chaotic region.

2010, Romina P. Di Sisto, Adrián Brunini, Gonzalo C. de Elía, “The contribution of plutinos to the Centaur population”, in Julio A. Fernández, Daniela Lazzaro, Dina Prialnik, Rita Schulz, editors, Icy Bodies of the Solar System: IAU Symposium S263, Cambridge University Press, page 89:

This is dubbed a 3:2 resonance (with Neptune), Pluto being the largest Plutino.
About one fourth of the KBOs are Plutinos. Plutinos may be debris from the collision of another KBO with Pluto, resulting in the formation of Pluto's largest moon, Charon.

2018, C Sivaram, Kenath Arun, Kiren O V, Current Trends in Astrobiology, Cambridge Scholars Publishing, page 39:

(astronomy) Any planetoid in the Kuiper belt whose orbit, like that of Pluto, has a resonance of 3:2 with that of Neptune.

冥族小天體 /冥族小天体

planetoid in orbit with 3:2 resonance to that of Neptune


suborbital

The first rocket test was suborbital; it didn't even get off the ground but rather exploded on the launchpad.

Not reaching orbit; having a trajectory that does not reach orbital velocity and so must return to ground eventually.


twotino

This provides a possible explanation for the low fraction of twotinos compared to plutinos in the Kuiper belt.

2009, A. C. Quillen, “Resonances in Galactic and Circumstellar Disks”, in G. Contopoulos, P. A. Patsis, editors, Chaos in Astronomy: Conference 2007, Springer, page 199:

Plutinos are Kuiper belt objects in a 2:3 resonance (a = 39.4 AU) with Neptune and are named after Pluto since these bodies have orbits similar to Pluto. Twotinos are objects that are in a 1:2 resonance (a = 47.8 AU) with Neptune.

2017, Thomas H. Burbine, Asteroids, Cambridge University Press, page 234:

These objects have been given the name of twotinos (rhymes with "plutinos").
Interestingly, there are very few low-eccentricity TNOs beyond the twotinos.

2021, Barbara Ryden, Bradley M. Peterson, Foundations of Astrophysics, Cambridge University Press, page 276:

(astronomy) Any astronomical object, on the apparent outer edge of the Kuiper Belt, whose orbit has a 1:2 resonance with the planet Neptune.

Resonant trans-Neptunian object#1:2 resonance ("twotinos", period ~330 years)


orbital plane

The plane of ecliptic is the orbital plane of the earth and the other planets in the solar system.

(astronomy) The surface (plane) that contains an orbit.


cycler

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The Earth-Mars cyclers could potentially be used for transporting people between the two planets.

(astronomy) An orbit that approaches two astronomical bodies on a regular basis.


astrodynamics

The study of the motion of rockets and spacecraft, usually from Newton's laws of motion, Newtonian gravity, and Kepler's laws


galactic year

(astronomy) The time taken for the Solar System to orbit around the center of the Milky Way Galaxy, estimated to be from 225 to 250 million years.

(astronomy, by extension) The time taken for a celestial body to complete a quasi-orbit in a galaxy.


LTO

LTO (countable and uncountable, plural LTOs)

lunar transfer orbit
lunar transfer orbit#English

(space science, countable) Initialism of lunar transfer orbit.


habitable zone

The zone around a star where a planet could experience temperatures like those on Earth, allowing for the possible existence of liquid water and of life.

zona d'habitabilitat

the planetary zone that could sustain life


Goldilocks zone

Goldilocks zone (plural Goldilocks zones)

So called because, like the third of the three bowls of porridge in the fairy tale Goldilocks, it is neither too hot nor too cold, but just right.

This plot may be a map of another type of Goldilocks zone for habitable ocean worlds—one base on composition.

2021, Kevin Hand, Alien Oceans: The Search for Life in the Depths of Space, Princeton University Press, →ISBN, page 43:


heliosynchronous

A heliosynchronous orbit is an orbit [around the Earth] whose plane precesses by [a little less than] one degree a day around the line of the poles, thus keeping the same position in relation to the Earth-Sun line.

1987, Pierre Lellouche, Satellite warfare: a challenge for the international community, Institut français des relations internationales, United Nations Institute for Disarmament Research, United Nations:

Describing an orbit around the Earth where each passage in the same direction along a given latitude will occur throughout the year at the same true solar time.

Describing an orbit around the Sun in which the period of revolution is the same as the Sun's period of rotation.


GEO

genetically engineered organism
genetically engineered organism#English

Initialism of genetically engineered organism.

Abbreviation of geostationary Earth orbit.

Abbreviation of geosynchronous equatorial orbit.


TLI

trans-lunar injection
trans-lunar injection#English

(space science) Initialism of trans-lunar injection.


GTO

geostationary transfer orbit
geostationary transfer orbit#English

(space science) Abbreviation of geostationary transfer orbit.


Lagrange point

Lagrange points (plural)
Lagrangian point (alternative)

Named after Joseph Louis Lagrange, who discovered the points L₄ and L₅, building on earlier work by Leonhard Euler, and in 1772 published an essay on the three-body problem.

Mathematically, the Lagrange points represent solutions to a restricted form of the three body problem in which the mass of one object is assumed negligible compared to that of the two principal bodies—as, for example, an artificial satellite and the Earth–Moon system.

Lagrange points are significant for lunar development in that raw materials, such as near-Earth objects (NEOs) can be safely stored at L-4 and L-5 prior to mining and processing.

2008, David Schrunk, Burton Sharpe, Bonnie L. Cooper, Madhu Thangavelu, The Moon: Resources, Future Development and Settlement, Springer, Praxis Publishing, page 57:

The $1.27-billion (1 billion euros) SOHO satellite was launched in 1995 and is flying a joint mission between NASA and the European Space Agency (ESA). It watches solar activity from an orbit about the Lagrange Point 1, a gravitationally stable spot between Earth and the sun that is about 932,000 miles (1.5 million kilometers) from our planet.

2013 July 28, Megan Gannon, “Spacecraft Sees Giant 'Hole' In the Sun”, in news.yahoo.com, retrieved 2013-07-29:

For science several of the Lagrange points are important. The question of access to Lagrange points or GSO slots emerges as these become congested.

2016, Francis Lyall, Paul B. Larsen, Space Law, Taylor & Francis (Routledge), page 247:

(astrophysics, orbital mechanics) A point in an orbital configuration of a two-body system where a small object affected only by gravity can theoretically be stationary relative to the two larger objects.


gravity assist

gravity assists (plural)
gravitational assist (alternative)
gravity-assist (alternative)

/ˈɡɹævɪti əˈsɪst/

After going into orbit around Jupiter with a gravity assist from the volcanic moon Io, Galileo will spend 22 months studying the planet.

1989 October 10, Warren E. Leary, “Galileo's Itinerary”, in New York Times, retrieved 2011-09-04:

Cassini is supposed to swing by Earth in 1999 for a gravity assist that would sling it out toward Saturn.

1997 September 22, Dick Thompson, Michael D. Lemonick, “Nukes in Space”, in Time:

MESSENGER successfully flew by Mercury yesterday, gaining a critical gravity assist that will enable it to enter orbit about Mercury in 2011.

2009 Oct. 2, "MESSENGER Gains Critical Gravity Assist For Mercury Orbital Observations," spacedaily.com (retrieved 4 Sep. 2011)

(astrophysics) The favorable alteration of the speed and trajectory of a spacecraft as a result of its passing near to a celestial body.

painovoimalinko

the favorable alteration of the speed and trajectory of a spacecraft as a result of its passing near to a celestial body


gravitational slingshot

gravitational slingshot (plural gravitational slingshots)


epicykl

epicykl (nominative singular)
epicykle (nominative plural)
epicyklu (genitive singular)
epicykli (genitive plural)
epicyklów (genitive plural)
epicyklowi (dative singular)
epicyklom (dative plural)
epicykl (accusative singular)
epicykle (accusative plural)
epicyklem (instrumental singular)
epicyklami (instrumental plural)
epicyklu (locative singular)
epicyklach (locative plural)
epicyklu (singular vocative)
epicykle (plural vocative)

(historical, Ptolemaic astronomy) epicycle (small circle whose center is on the circumference of a larger circle; in Ptolemaic astronomy, it was seen as the basis of revolution of the "seven planets", given a fixed central Earth)

(geometry) epicycle (any circle whose circumference rolls around that of another circle, thus creating a hypocycloid or epicycloid)


minimoon

minimoons (plural)
mini-moon (alternative)

But weddings are stressful, and it makes sense to take a day or two after saying “I do” to relax and make mad, passionate love (read: sleep in and watch TV). So consider a minimoon: a quick two-night getaway close to home.

2008 January 16, Carolyn Ali, “Minimoons may be short, but they sure are sweet”, in The Georgia Straight:

Rachel Moschke, Editor of Wedding Ideas magazine, said: ‘Most of us worry about saving up for our wedding day, but it seems we’re reluctant to give up the quality time together that a honeymoon offers. A minimoon is the perfect way to start married life, without busting the budget.’

2009 July 1, Jo Tweedy, “After the nanobreak comes the 'minimoon' as newlyweds scrimp on honeymoon holiday”, in Daily Mail:

The couple are yet to go on their honeymoon because of their strict working schedules but did find time for a ‘minimoon’ after tying the knot.

2012 November 22, James Robertson, “Rochelle and Marvin Humes are having a baby: 'We're so excited to start a family'”, in The Mirror, UK:

A brief honeymoon or holiday taken after a wedding.


minimoon

This photo of Earth's newest minimoon was taken by the 8-meter Gemini North telescope on Hawaii's Maunakea.

2020 March 4, Theresa Machemer, “Earth's New Mini-Moon Is Leaving Soon”, in Smithsonian Magazine, archived from the original on 2022-08-20:

Earth has only had two minimoons on record – one in February 2020 and the other in 2006.

2020 September 22, Stacy Liberatore, “Earth is set to capture a minimoon in October that may stay until May 2021 – but some experts say the object could be man-made space junk”, in The Daily Mail, archived from the original on 2021-07-26:

These included a rare 'minimoon' named 2020 CD3, a tiny asteroid less than 3 metres in diameter that had been temporarily captured by Earth's gravity. The minimoon broke away from Earth's pull last April.

2021 March 11, Alexandra Witze, “Record number of asteroids seen whizzing past Earth in 2020”, in Nature, archived from the original on 2022-09-09:

(astronomy) A small asteroid captured by the Earth's gravity and temporarily acting as a second moon of Earth.

The trouble is, the difference in size between Supermoon and Minimoon, though apparent when placed side-by-side, is only 14 percent, too small to be seen with the naked eye.

2014 January 15, Geoff Gaherty, “Smallest full moon of 2014 rises tonight”, in NBC News, archived from the original on 2022-12-21:

At its closest point, perigee, the moon will obviously appear largest. Such a "maximoon" has an apparent diameter about 13% larger than a "minimoon" at its most distant point, apogee.

2018 January 29, Tim O'Brien, “'Super blue blood moon' to grace the sky – here's what we could learn from it”, in The Conversation, archived from the original on 2022-08-13:

For those interested in a longer-term project, Professor Horner said taking a photo of the supermoon and comparing it to the 'minimoon' in December can be an interesting experiment to compare the size.

2022 August 9, Rosie Bensley, “A supermoon will rise on Thursday: Here's a photographer's tips to get the best snap”, in The Canberra Times:

(astronomy, uncommon) Synonym of micromoon (“a full moon which appears unusually small due to coinciding with the Moon's apogee”).


Venus zone

Venus (planet) + zone, from being the zone where a Venus-like planet will acquire a Venus-like climate.

A theoretical orbital zone around a star that will result in an Earth-like planet existing in an orbit in the zone having a runaway greenhouse effect, similar to that found on Venus in our Solar System. The inner edge of the zone is where solar radiation is intense enough to strip the atmosphere of a planet away. The outer edge is where solar radiation is insufficient to power a runaway greenhouse.


trans-Mars injection

trans-Mars injection (plural trans-Mars injections)

(astrodynamics) an orbital burn (rocket firing) used to change orbit from local orbit, to a Mars transfer orbit (a Solar orbit that will intercept the planet Mars).


HEO

highly elliptical orbit
highly elliptical orbit#English

(space science) Initialism of highly elliptical orbit.

GEO

geostationary orbit / geostationary Earth orbit

GSO

geosynchronous orbit / geosynchronous Earth orbit


DRO

GEO

geostationary orbit/geostationary Earth orbit

GSO

geosynchronous orbit/geosynchronous Earth orbit

distant retrograde orbit
w:distant retrograde orbit

(space science) Initialism of distant retrograde orbit.


galactic habitable zone

galactic habitable zone (plural galactic habitable zones)

(astrobiology, astronomy) the zone in a disk galaxy lying within the disk which is neither too far from the core so as to be lacking in heavier elements, nor too close to the core as to experience excessive exposures to supernovae, where intelligent life may develop


JOI

orbital insertion
orbital insertion#English

(astronautics) Initialism of Jupiter orbital insertion.


GSO

geosynchronous orbit
geosynchronous orbit#English


deorbit burn

(astronautics) A firing of the engines of a spacecraft to enable it to re-enter the Earth's atmosphere.


first cosmic velocity

first cosmic velocity (plural first cosmic velocities)

From first + cosmic + velocity, from being the first velocity greater than that able to be held upon the Earth, thus entering the realm of the Cosmos.


second cosmic velocity

second cosmic velocity (plural second cosmic velocities)

From second + cosmic + velocity, from being the next threshold velocity greater than the first cosmic velocity.

(by extension) Escape velocity of the home body.


third cosmic velocity

From third + cosmic + velocity, from being the next threshold velocity greater than the second cosmic velocity.

The escape velocity of the Solar System (interstellar speed).


third cosmic velocity

third cosmic velocity (plural third cosmic velocities)

(by extension) The escape velocity of a star system.


Hohmann transfer orbit

Hohmann transfer orbit (plural Hohmann transfer orbits)

Named after German scientist Walter Hohmann, who described it in 1925.

named-after

(aerospace) An elliptical orbit used to transfer between two circular orbits of different radii in the same plane.


CHZ

Circumstellar habitable zone
w:Circumstellar habitable zone

Initialism of Circumstellar habitable zone.


quasi-satellite

quasi-satellites (plural)
quasisatellite (alternative)

(astronomy) An object in a specific type of coorbital configuration (1:1 orbital resonance) with a planet, causing it to stay close to the planet over many orbital periods, despite not being a true satellite.


photon sphere

The radius of the photon sphere is also the lower bound for any stable orbit.

For a Schwarzschild (non-spinning) black hole, the radius of the photon sphere is 1.5 times the Schwarzschild radius.

The redshift of light leaking outward from the photon sphere is #92;sqrt#123;3#125;-1#61;0.732. All light rays approaching a black hole closer than #92;sqrt#123;3#125; times the radius of the photon sphere spiral inwards and are captured (see Figure 13.5).

2000, Edward Harrison, Cosmology, 2nd edition, Cambridge University Press, page 250:

For a Kerr black hole though, one that has spin, the situation is different for the orbits near the black hole. In particular, there are two photon spheres, in contrast with the one photon sphere around a stationary Schwarzschild black hole. The outermost sphere is for photons that are orbiting oppositely to the direction of rotation of the black hole (the ones we say are on retrograde orbits). Inside this is the photon sphere for photons travelling in the same sense around the black hole as it is rotating (on prograde orbits). For a very slowly rotating black hole that isn't so very different from a Schwarzschild black hole, these two photon spheres are very nearly co-spatial. For black holes of increasing spin, these surfaces are increasingly further apart.

2015, Katherine Blundell, Black Holes: A Very Short Introduction, Oxford University Press, page 44:

2017, Lori Gardi, The Mandelbrot Set as a Quasi-Black Hole, David de Hilster (editor), John Chappell Natural Philosophy Society: 2017 Proceedings, John Chappell Natural Philosophy Society, page 65,
The lesser known region just outside the black hole is referred to as the photon sphere (outer grey region in Figure 9). The photon sphere is a region of space just outside the black hole where photons are forced to travel in complex orbits due to the extreme curvature of space within this region [2]. […] Finally, the boundary that exactly separates the black hole from the photon sphere is referred to as the event horizon (white circle surrounding the black region in Figure 9).

The region inside the photon sphere has a diameter of 1.5× Schwarzschild diameter D(s), but due to the curvature, this region gets magnified to 2.6× D(s).

2022, Wouter Schmitz, Understanding Relativity, Springer, page 277:

(of a black hole) A spherical limit around a black hole at such distance that any photon meeting it tangentially is constrained to travel in a circular orbit; (more loosely) the region between this limit and the event horizon.

sphère de photons

spherical boundary surrounding a black hole in which photons travel in circular orbits


photon circle

From the path of photon becoming circular, instead of the usual hyperbolic orbits.

(of a black hole) Synonym of photon sphere.


last photon orbit

en-noun

last photon orbit (plural last photon orbits)

From being the closest tangential approach to a black hole, where a photon's path does not eventually fall through the event horizon.


trans-lunar injection

trans-lunar injection (plural trans-lunar injections)

trans-lunar injections (plural)
TLI (alternative)

A maneuver that moves a spacecraft from orbit around the Earth onto a trajectory towards the Moon.


orbital mechanics

Astrodynamics; the study of the movement of vehicles in space.


Kessler syndrome

Proposed by NASA scientist Donald J. Kessler in 1978.

A theoretical scenario in which the density of objects in low Earth orbit due to space pollution is high enough that collisions between objects could cause a cascade in which each collision generates debris that increases the likelihood of further collisions.


ISCO

innermost stable circular orbit
innermost stable circular orbit#English

(astrophysics) Acronym of innermost stable circular orbit.


MEGA

(astronautics, space flight) Initialism of Moon-Earth gravity assist.

(astronautics, space flight) Initialism of Mars-Earth gravity assist.


lithocapture

en-verb

lithocapture (third-person singular simple present lithocaptures, present participle lithocapturing, simple past and past participle lithocaptured)

lithocaptures (present singular third-person)
lithocapturing (participle present)
lithocaptured (participle past)
lithocaptured (past)

/ˈlɪ.θoʊˌkæp.t͡ʃɚ/

/ˈlɪ.θəˌkæp.t͡ʃɚ/

/ˈlɪ.θoʊ.kæpˌt͡ʃɚ/

/ˈlɪ.θə.kæpˌt͡ʃɚ/

/ˈlɪ.θoʊˌkæp.t͡ʃə/

From litho- (“pertaining to stone”) + capture, coined as a pun on aerocapture and lithobraking.

prefix

(astronautics, humorous) To perform lithocapture.


Aldrin cycler

From Aldrin + cycler. After Buzz Aldrin, who developed the concept and its mathematical basis. From being a cycler, a space vehicle which cycles between intercepts of two celestial bodies in their own orbits, with little or no orbital adjustments needed, on as close to pure ballistics as practicable.

(astronautics) A spacecraft which cycles between Earth and Mars, in its own orbit which intercepts both their orbits at times when the planets are at those points in their orbits; which allows transport from Earth to Mars, or vice versa.


halo orbit

First used by NASA mission specialist Robert W. Farquhar in 1966 for calculated orbits around the Earth–Moon L₂ point which required the use of thrusters to be made periodic.

Due to the strong hyperbolic character of the halo orbits, the stable manifold approaches the halo orbit in a very fast way. This fact means that if we are able to put the satellite in the stable manifold of a halo orbit, it will be close to the halo orbit (say at [a] few km) in a reasonable period of time.

2001, G. Gómez, À. Jorba, J. Masdemont, C.Simó, Dynamics and Mission Design Near Libration Points, Volume III, World Scientific, page 93:

2013, Yuhui Zhao, Shoucun Hu, Xiyun Hou, Lin Liu, Chapter 39: On Nominal Formation Flying Orbit with a Small Solar System Body, Rongjun Shen, Weiping Qian (editors), Proceedings of the 26th Conference of Spacecraft TT&C Technology in China, Tsinghua University Press, Springer, Lecture Notes in Electrical Engineering 187, page 395,
If the ratio of the amplitude in x-direction to γ₁ keeps unchanged (=0.155), the periods of halo orbits are almost the same (about 190 days). As a result of the stability of CRTBP and the dynamics of halo orbit formation, nominal halo orbits do not exist if the ratio is too large or too small.

Thus, the minimum possible size for halo orbits in the Sun-Earth system is approximately (240 x 660) 10³ km at L₁ and (250 x 675) 10³ km at L₂, sizes denoting the maximum excursion from the libration point in the x and y directions respectively.

2013, Daniel García Yárnoz, Joan-Pau Sanchez, Colin R. McInnes, “Chapter 21: Opportunities for Asteroid Retrieval Missions”, in Viorel Badescu, editor, Asteroids: Prospective Energy and Material Resources, Springer, page 486:

(orbital mechanics) A periodic, three-dimensional orbit about any one of the Lagrange points L₁, L₂ or L₃ of a two-body gravitational system.


bi-elliptic transfer

en-noun

bi-elliptic transfer (plural bi-elliptic transfers)

(astronautics) A type of movement of a spacecraft from one orbit to another, in which the spacecraft first raises its apoapsis to an extremely high altitude, then, at the new, higher, apoapsis, performs an engine burn to change its periapsis to that of the desired orbit, and, finally, upon reaching the new periapsis, performs a third burn to lower the eccentricity of its orbit and circularize in the desired orbit, or performs these steps in reverse to move from a higher to a lower orbit.


Oberth effect

(astronautics) The concept that the most efficient place for spacecraft to change velocity is at the periapsis (the lowest point of an orbit).


circumtriple

(astrophysics) orbiting around three stars or other centers.


quasi-moon

quasi-moons (plural)
quasimoon (alternative)

From quasi- + moon, modeled after quasi-satellite.


clear the neighborhood

en-verb

clear the neighborhood (third-person singular simple present clears the neighborhood, present participle clearing the neighborhood, simple past and past participle cleared the neighborhood)

clears the neighborhood (present singular third-person)
clearing the neighborhood (participle present)
cleared the neighborhood (participle past)
cleared the neighborhood (past)
clear the neighbourhood (alternative)

Clearing the neighborhood is one of three necessary criteria for a celestial body to be considered a planet in the Solar System, according to the definition adopted in 2006 by the International Astronomical Union.

(astronomy, of a celestial body) To become gravitationally dominant, such that there are no other bodies of comparable size within its orbit, other than its natural satellites or those otherwise under its gravitational influence.


Hohmann transfer

en-noun

Hohmann transfer (plural Hohmann transfers)

Named after Walter Hohmann, the German engineer who described it.

(astronautics) An elliptical orbit used to transfer a spacecraft between two circular orbits of different altitudes in the same plane, with the periapsis of the orbit being tangent to the smaller circular orbit and its apoapsis being tangent to the larger circular orbit.

(astronautics) The process of using such an orbit to transfer between two other orbits.


sun-synchronous orbit

sun-synchronous orbit (plural sun-synchronous orbits)

(astrodynamics) A nearly polar orbit in which a satellite passes over the surface of a planet maintaining the same local mean solar time.


heliosynchronous orbit

heliosynchronous orbit (plural heliosynchronous orbits)

sun-synchronous orbit
sun-synchronous orbit

(astrodynamics) A sun-synchronous orbit.


геостационарный

ru-adj

геостациона́рный

геостациона́рный • (geostacionárnyj)

геостациона́рный (canonical)
geostacionárnyj (romanization)
геостациона́рный (masculine nominative)
геостациона́рное (neuter nominative)
геостациона́рная (feminine nominative)
геостациона́рные (nominative plural)
геостациона́рного (genitive masculine neuter)
геостациона́рной (feminine genitive)
геостациона́рных (genitive plural)
геостациона́рному (dative masculine neuter)
геостациона́рной (dative feminine)
геостациона́рным (dative plural)
геостациона́рного (accusative animate masculine)
геостациона́рное (accusative neuter)
геостациона́рную (accusative feminine)
геостациона́рных (accusative animate plural)
геостациона́рный (accusative inanimate masculine)
геостациона́рные (accusative inanimate plural)
геостациона́рным (instrumental masculine neuter)
геостациона́рной (feminine instrumental)
геостациона́рною (feminine instrumental)
геостациона́рными (instrumental plural)
геостациона́рном (masculine neuter prepositional)
геостациона́рной (feminine prepositional)
геостациона́рных (plural prepositional)
геостациона́рен (masculine short-form)
геостациона́рно (neuter short-form)
геостациона́рна (feminine short-form)
геостациона́рны (plural short-form)

ru-decl-adj

геостациона́рный

Умеща́ющийся в ра́нец ко́мплекс «Тень-С» мо́жет передава́ть цифровы́е да́нные и го́лос че́рез росси́йские спу́тники на геостациона́рной орби́те.

2025 April 23, Дмитрий Сотак, “В России разработана защищенная от помех переносная станция спутниковой связи”, in Коммерсантъ [Kommersant]:

Umeščájuščijsja v ránec kómpleks «Tenʹ-S» móžet peredavátʹ cifrovýje dánnyje i gólos čérez rossíjskije spútniki na geostacionárnoj orbíte.


zona laik huni

id-noun

zona laik huni (plural zona-zona laik huni)