Search results
Results from the WOW.Com Content Network
As of January 2024, two methane-fueled rockets have reached orbit. Several others are in development and two orbital launch attempts failed: Zhuque-2 successfully reached orbit on its second flight on 12 July 2023, becoming the first methane-fueled rocket to do so. [25] It had failed to reach orbit on its maiden flight on 14 December 2022.
Rocket stages that fly through the atmosphere usually use lower performing, high molecular mass, high-density propellants due to the smaller and lighter tankage required. Upper stages, which mostly or only operate in the vacuum of space, tend to use the high energy, high performance, low density liquid hydrogen fuel.
Bipropellant liquid rockets use a liquid fuel such as liquid hydrogen or RP-1, and a liquid oxidizer such as liquid oxygen. The engine may be a cryogenic rocket engine , where the fuel and oxidizer, such as hydrogen and oxygen, are gases which have been liquefied at very low temperatures.
Furthermore, these balances in efficiency-vs-power makes methane more suitable for a single-fuel rocket, which have proven more economical than dual-fuel rockets (due to less complexity). As such, methalox has made a resurgence in popularity in 21st century rockets, at the expense of kerolox (better efficiency) and hydrolox (better handling).
Engine Origin Designer Vehicle Status Use Propellant Power cycle Specific impulse (s) [a] Thrust (N) [a] Chamber pressure (bar) Mass (kg) Thrust: weight ratio [b] Oxidiser: fuel ratio
Cryogenic fuels are fuels that require storage at extremely low temperatures in order to maintain them in a liquid state. These fuels are used in machinery that operates in space (e.g. rockets and satellites) where ordinary fuel cannot be used, due to the very low temperatures often encountered in space, and the absence of an environment that supports combustion (on Earth, oxygen is abundant ...
For rockets and space vehicles, propellants usually take up 2/3 or more of their total mass. Large upper-stage rocket engines generally use a cryogenic fuel like liquid hydrogen and liquid oxygen (LOX) as an oxidizer because of the large specific impulse possible, but must carefully consider a problem called "boil off," or the evaporation of the cryogenic propellant.
RL-10 is an early example of cryogenic rocket engine.. Rocket engines need high mass flow rates of both oxidizer and fuel to generate useful thrust. Oxygen, the simplest and most common oxidizer, is in the gas phase at standard temperature and pressure, as is hydrogen, the simplest fuel.