![]() Historyįurther information: Timeline of rocket and missile technology Rocket arrows depicted in the Huolongjing: "fire arrow", "dragon-shaped arrow frame", and a "complete fire arrow" However, careful design, testing, construction and use minimizes risks. Chemical rockets store a large amount of energy in an easily released form, and can be very dangerous. The stored propellant can be a simple pressurized gas or a single liquid fuel that disassociates in the presence of a catalyst ( monopropellant), two liquids that spontaneously react on contact ( hypergolic propellants), two liquids that must be ignited to react (like kerosene (RP1) and liquid oxygen, used in most liquid-propellant rockets), a solid combination of fuel with oxidizer ( solid fuel), or solid fuel with liquid or gaseous oxidizer ( hybrid propellant system). Rockets are now used for fireworks, missiles and other weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight, and space exploration.Ĭhemical rockets are the most common type of high power rocket, typically creating a high speed exhaust by the combustion of fuel with an oxidizer. Significant scientific, interplanetary and industrial use did not occur until the 20th century, when rocketry was the enabling technology for the Space Age, including setting foot on the Moon. Rockets for military and recreational uses date back to at least 13th-century China. To control their flight, rockets rely on momentum, airfoils, auxiliary reaction engines, gimballed thrust, momentum wheels, deflection of the exhaust stream, propellant flow, spin, or gravity. Compared with airbreathing engines, rockets are lightweight and powerful and capable of generating large accelerations. Multistage rockets are capable of attaining escape velocity from Earth and therefore can achieve unlimited maximum altitude. Rockets work more efficiently in a vacuum and incur a loss of thrust due to the opposing pressure of the atmosphere. Rocket engines work entirely from propellant carried within the vehicle therefore a rocket can fly in the vacuum of space. A rocket engine produces thrust by reaction to exhaust expelled at high speed. In some cases, the nature of the item means that it is non-returnable, for example, due to hygiene/health and personal care/wellness/consumable nature of the product.For other uses, see Rocket (disambiguation).Ī Soyuz-FG rocket launches from " Gagarin's Start" (Site 1/5), Baikonur CosmodromeĪ rocket (from Italian: rocchetto, lit.'bobbin/spool') is a vehicle that uses jet propulsion to accelerate without using the surrounding air. Office Products and Wireless Returns Policy New electronic items fulfilled by Amazon AU can be returned for change of mind, for a replacement or a full refund of the purchase cost of the item within 30 days of receipt of delivery.For information about returning faulty electronics please see Returning Faulty Items. ![]() Please see our Amazon Global Store Returns policy and Refunds policy for more information about returning Amazon Global Store items.Ĭamera, Electronics and PC Returns Policy ![]() Please see About Marketplace Returns & Refunds for details on Seller returns policies. To return faulty items see our Returning Faulty Items policy.įor items ordered on from a seller that fulfils and ships its own inventory (also called a third party seller), any returns will be in accordance with the returns policy set by that seller (not the Amazon AU returns policies). This change of mind return policy is in addition to, and does not affect your rights under the Australian Consumer Law including any rights you may have in respect of faulty items. Unless otherwise stated, original shipping fees for change of mind returns are not refunded. Please Contact Us and see About Items That Can’t Be Returned. In some circumstances, these items may be eligible for a refund or a replacement (for example, if you receive the wrong item due to an Amazon AU error or if the item is faulty). In some cases, the nature of the item means that it is non-returnable, for example, due to hygiene/health and personal care/wellness/consumable nature of the product. You can return most new, unopened items fulfilled by Amazon AU within 30 days of receipt of delivery for a replacement or full refund of the price you paid for the item if you change your mind - see About Replacements and About Refunds. ![]()
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