Once there, a series of chemical reactions ( the Sabatier reaction coupled with electrolysis ) would be used to combine a small amount of hydrogen ( 8 tons ) carried by the Earth Return Vehicle with the carbon dioxide of the Martian atmosphere to create up to 112 tonnes of methane and oxygen.

Once on Mars, the crew would spend 18 months on the surface, carrying out a range of scientific research, aided by a small rover vehicle carried aboard their Mars Habitat Unit, and powered by the methane produced by the Earth Return Vehicle.

Once in the desired orbit, they often need some form of attitude control so that they are correctly pointed with respect to the Earth, the Sun, and possibly some astronomical object of interest .< ref >

Once the city captures and kills the human astronauts, the humans ' corpses are used as automatons to finalize the city's creators ' revenge ; a biological attack on the Earth.

Once operational, the aerobot will be largely on its own and will have to conduct its mission autonomously, accepting only general commands over its long link to Earth.

Once the hydrazine froze, the spacecraft would no longer be able to maneuver to keep its high gain antenna pointing towards Earth, and the downlink signal would then be lost in a matter of days.

Once a channel of ionized air is established between the cloud and ground this becomes a path of least resistance and allows for a much greater current to propagate from the Earth back up the leader into the cloud.

Once the Earth is built and realized, the Ainur move into it.

Once every 42 years, when Uranus has an equinox and its equatorial plane intersects the Earth, mutual occultations of Uranus's moons become possible.

Once launched, orbits are normally located within relatively constant flat planes at a fixed angle to the axis of the Earth, and the Earth rotates within this orbit.

Once released, the whales respond to the probe's signal, causing the object to revert its climatic effects on Earth and return to the depths of space.

Once this is accomplished, one Martian, Voldar, who strongly disagrees with the idea, repeatedly tries to kill Santa Claus along with two kidnapped Earth children.

Once a clean, smooth geopotential field has been constructed matching the known GRS80 reference ellipsoid with an equipotential surface ( we call such a field a normal potential ) we can subtract it from the true ( measured ) potential of the real Earth.

Once the city of Pinole had decided to approve the shopping center, the city relied on a relocation plan developed by Earth Metrics scientists to remove the entire colony to a nearby location immediately east of Interstate Highway 80 within the Caltrans right-of-way

Once there, he helped to create the New York Anarchist Red Cross, which included such members as Mother Earth editor Louise Berger.

Once the cores are of sufficient mass ( 5 – 10 Earth masses ), they begin to gather gas from the surrounding disk.

Once outside the ship, he discovers that Earth is now ruled by intelligent apes just like the planet from which he has fled.

Once in a while the daimyojin is distracted so Namazu moves and the Earth trembles.

Once they do, they're intercepted by the pro-war Axis faction that wishes to restart the conflict with the Earth Federation, led by one Colonel Enzo.

Once all the survivors escape Earth, the marine is the only human left on the planet.

Once functional, however, it provided satisfactory service for seven years, returning 36, 000 images of Earth and broadcasting television to thousands of remote Indian villages.

Once the Zeo Crystal is recombined in a machine devised by Billy, Earth is restored to normal.

Once the Orion spacecraft docks with the landing module and the Earth Departure Stage ( EDS ), the EDS would then fire again and propel the Orion spacecraft to a nearby near-Earth asteroid where the crew would then land and explore its surface.

Once again the Mossberg Targo outfit has appeared, but this time as a bolt-action rifle-shotgun combination.

Once she has made up her mind, the queen starts out by constructing, in her chosen abode, a small `` floor '' of dried grass or some woolly material.

Once he has been identified, however, a new melody is used to accompany his narrative, a bleak motif with barren octaves creating a rather ancient effect:

Once again what has happened is an all-consuming confabulation of the incidentals, the accidents of painting.

Once a predator has sampled one of these, it is likely to remember the colouration next time it encounters a similar animal.

Once the screen has been cleared of all asteroids and flying saucers, a new set of large asteroids appears.

Once he has received this blessing, the abbot not only becomes father of his monks in a spiritual sense, but their major superior under canon law, and has the additional authority to confer the ministries of acolyte and lector ( formerly, he could confer the minor orders, which are not sacraments, that these ministries have replaced ).

Once a node has been found in a balanced tree, the next or previous nodes can be explored in amortized constant time.

Once it has come to rest, the jack is aligned to the centre of the rink and the players take turns to roll their bowls from the mat towards the jack and thereby build up the " head ".

Once the first bowl has taken place, the other side has the opportunity to bowl.

Once a beaver has sounded the alarm, nearby beavers will dive and may not reemerge for some time.

Once the expander has reached an acceptable size, it may be removed and replaced with a more permanent implant.

Once one copy of a document has been produced, printing further copies is often quicker by means of a device called a " thermoform ", which produces copies on soft plastic.

Once published by BSI a PAS has all the functionality of a British Standard for the purposes of creating schemes such as management systems and product benchmarks as well as codes of practice.

Once a prototype has passed the tests at a certification lab, and that model is being constructed under the control of a certified quality system, the device is entitled to bear a CE mark, indicating that the device is believed to be safe and reliable when used as directed.

Once an idea has been reduced to tangible form, for example by securing it in a fixed medium ( such as a drawing, sheet music, photograph, a videotape, or a computer file ), the copyright holder is entitled to enforce his or her exclusive rights.

Once the term of a copyright has expired, the formerly copyrighted work enters the public domain and may be freely used or exploited by anyone.

Once the software has loaded, the computer is able to execute the software.

Once this islands were covered with savanna on the plains and arid shrubland on the mountainsides, but over 500 years of human habtitation, since colonisation by the Portuguese in the 15th century, nearly all the original vegetation has been cleared by widespread agriculture including the grazing of goats, sheep and cattle and the planting of imported crop species.

Once labelled by Rolling Stone as " the most controversial woman in the history of rock ", Love's sometimes outrageous behavior has given her a lasting place in pop culture, as well as a polarizing reputation in the media.

Once the virus has infected the cell, it will start replicating itself, using the mechanisms of the infected host cell.

Once the desired change in values has been brought about, the victim is expected to conform spontaneously, without any need for further coercion.

Once the ray either encounters a light source, or more probably once a set limiting number of bounces has been evaluated, then the surface illumination at that final point is evaluated using techniques described above, and the changes along the way through the various bounces evaluated to estimate a value observed at the point of view.