For astrodynamics reasons, cheap spacecraft travel to other planets is only practical within certain time windows.

For instance, the motion of a spacecraft, regarding its orbit and attitude ( rotation ), is described by the relativistic theory of classical mechanics, while the analogous movements of an atomic nucleus are described by quantum mechanics.

For instance, if limited onboard power fed to its engine was the dominant limitation on how much payload a hypothetical spacecraft could shuttle ( such as if intrinsic propellant economic cost was minor from usage of extraterrestrial soil or ice ), ideal exhaust velocity would rather be around 62. 75 % of total mission delta v if operating at constant specific impulse, except greater optimization could come from varying exhaust velocity during the mission profile ( as possible with some thruster types, including mass drivers and variable specific impulse magnetoplasma rockets ).

For example, a ramjet might collect 1 gram of incoming ions per second from interstellar space beyond the heliopause, at a velocity of 50 km / s relative to the ramjet driven spacecraft.

For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies.

For missions beyond low Earth orbit NASA is building the Space Launch System and the Orion spacecraft.

For the Mercury, Gemini, and Apollo spacecraft, such communications blackouts lasted for several minutes.

For the Apollo 13 mission, the blackout was much longer than normal because the flight path of the spacecraft was unexpectedly at a much shallower angle than normal.

For a rocket the payload can be a spacecraft launched with the rocket, or in the case of a ballistic missile, the warheads.

For spacecraft carrying instruments for which an altitude of 36000 km is suitable the Geostationary orbit is sometimes the preferred choice.

For example, nuclear pulse propulsion is a form of spacecraft propulsion that would use nuclear explosives to provide impulse to a spacecraft.

* For communications between spacecraft, including elements of a satellite constellation

For Salyut, small modifications had to be made to the docking port of the OPS to accommodate Soyuz spacecraft in addition to TKS spacecraft.

For this reason, reaction wheels are often used to aim spacecraft with cameras or telescopes.

For launches above low Earth orbit ( LEO ), the actual launch time can be somewhat flexible if a parking orbit is used, because the inclination and time the spacecraft initially spends in the parking orbit can be varied.

For example, consider a spacecraft travelling from the Earth to Mars.

For example, the capacity ( separated spacecraft mass ) of the Delta IV Heavy:

For example, if two spacecraft are in the same circular orbit and wish to dock, unless they are very close, the trailing craft cannot simply fire its engines to go faster.

For example, a dish antenna on a spacecraft is a high-gain device that must be pointed at the planet to be effective, whereas a typical Wi-Fi antenna in a laptop computer is low-gain, and as long as the base station is within range, the antenna can be in any orientation in space.

For communicating with the Deep Space Network, the spacecraft transmitted data across the x-band using a 0. 6-meter parabolic high-gain antenna, medium-gain antenna ( MGA ) and low-gain antennas ( LGA ) depending on mission phase, and a 15-watt transponder design originally intended for the Cassini spacecraft.

For storing data when the spacecraft was unable to communicate with Earth, the processor card was able to store 128-megabytes, 20 % of which was occupied by the flight system software.

For the near term, however, it must be realized that the industrial and commercial market is somewhat more sensitive to general business conditions than is the military market, and for this reason I would expect that any gain in 1961 may be somewhat smaller than those of recent years ; ;

For the boy, this epiphysis was markedly delayed at Onset but near the mean at Completion.

For centuries after the fall of the Achaemenid Empire in 331 BCE, Imperial Aramaic — or near enough for it to be recognisable — would remain an influence on the various native Iranian languages.

For the rest of the two spacecrafts ' pass over the near side of the Moon, Mattingly prepared to shift Casper to a circular orbit while Young and Duke prepared Orion for the descent to the lunar surface.

For this last case, the cohesive fracture can be said to be “ cohesive near the interface ”.

For approximately two to three weeks on either side of November 30, Antares is not visible in the night sky, because it is near conjunction with the Sun ; this period of invisibility is longer in the Northern Hemisphere than in the Southern Hemisphere, since the star's declination is significantly south of the celestial equator.

For curves given by the graph of a function, horizontal asymptotes are horizontal lines that the graph of the function approaches as x tends to Vertical asymptotes are vertical lines near which the function grows without bound.

“ For the day of the Lord upon all the nations is near … But on Mount Zion there shall be deliverance ”

For the remainder of his life he spent time between Albuquerque, New Mexico and Florida, living the last 13 years of his life in Archer, Florida, a small farming town near Gainesville.

For HTML it is possible to include this information inside the element near the top of the document:

For example, this happens for near the point.

For alternating currents, especially at higher frequencies, skin effect causes the current to spread unevenly across the conductor cross-section, with higher density near the surface, thus increasing the apparent resistance.

For Domitian, this meant that a significant part of his adolescence was spent in the absence of his near relatives.

For Golb, the amount of documents is too extensive and includes many different writing styles and calligraphies ; the ruins seem to have been a fortress, used as a military base for a very long period of timeincluding the 1st centuryso they could not have been inhabited by the Essenes ; and the large graveyard excavated in 1870, just 50 metres east of the Qumran ruins was made of over 1200 tombs that included many women and childrenPliny clearly wrote that the Essenes that lived near the Dead Sea " had not one woman, had renounced all pleasure ... and no one was born in their race ".

For the Kigensetsu celebration of 1940, according to the calculation the 2, 600th anniversary of Emperor Jimmu, the government constructed on the legendary site of Emperor Jimmu's palace, near Miyazaki, the Hakkō Tower.

For molecules of a liquid to evaporate, they must be located near the surface, be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase intermolecular forces.

For commonly used fluorescent compounds, typical excited state decay times for photon emissions with energies from the UV to near infrared are within the range of 0. 5 to 20 nanoseconds.

For instance, placing the fan near your heart meant " I love you ", while opening a fan wide meant " Wait for me ".

For example, in Shadowrun, a tactical nuclear device was detonated near FASA's offices at 1026 W. Van Buren St in Chicago, Illinois.

For death, when it stands near us, gives even to inexperienced men the courage not to seek to avoid the inevitable.

For this helium conservation program, the Bureau built a pipeline from Bushton, Kansas, to connect those plants with the government's partially depleted Cliffside gas field, near Amarillo, Texas.

For harbors near the North and South Poles, being ice-free is an important advantage, especially when it is year-round.

For instance, for genotype 1 hepatitis C treated with Pegylated interferon-alpha-2a or Pegylated interferon-alpha-2b ( brand names Pegasys or PEG-Intron ) combined with ribavirin, it has been shown that genetic polymorphisms near the human IL28B gene, encoding interferon lambda 3, are associated with significant differences in the treatment-induced clearance of the virus.

For example the system might raise an alert if someone attempted to buy components for bomb making, hired a car and rented a hotel room near the White House.

' For ' Kubla Khan ' is as near enchantment, I suppose, as we are like to come in this dull world.