A launch vehicle, often called a carrier rocket, is a vehicle designed to lift a payload from the surface of the Earth into outer space. The term covers machines that provide sub-orbital trajectories as well as those that place satellites, probes, or crew into stable orbits. In general usage the word "rocket" is also common: see carrier rocket for broad explanations and outer space for the destination environment.

Design, structure and principal parts

Most launch vehicles are built from a stack of major subsystems that work together from liftoff to payload separation. Key parts include:

  • Propulsion stages: independent sections, each with its own engines and propellant tanks, that fire in sequence.
  • Payload fairing: a protective shroud that shelters satellites or cargo during ascent.
  • Guidance and avionics: computers, sensors and control surfaces that steer the vehicle.
  • Structure and tanks: the airframe and containers for liquid or solid propellants.
  • Boosters: strap-on motors, often solid or liquid, that add thrust at launch.

Propulsion, fuels and performance

Different launchers use different propellant types and engine cycles. Liquid-propellant engines burn combinations such as kerosene and liquid oxygen or hydrogen and oxygen, while solid rocket motors use a cast propellant grain. The choice affects thrust, controllability, and storability. A mission’s required change in velocity (delta-v) governs how many stages and how much propellant a vehicle needs; designers calculate required delta-v using orbital mechanics and vehicle mass budgets — see delta-v for the concept.

Staging, expendability and reusability

Most traditional launch vehicles are expendable: stages are discarded after use to reduce mass and maximize payload capacity. Expendable designs are simpler but throw away costly hardware. In recent decades a push for partial and full reusability has changed the industry: for example, Falcon 9 demonstrates recoverable first-stage landings, and programs such as SpaceX’s Starship aim for fully reusable systems. Earlier attempts at reuse include components of the Space Shuttle. Reusable elements must survive reentry and be refurbished, which changes economics and design trade-offs.

History and development

Launch vehicles evolved from early experimental rockets into the sophisticated boosters used today. Cold-war era developments created families of expendable orbital launchers; later decades added commercial and private entrants that emphasized cost reduction and frequent flight rates. National space programs often develop or procure rockets as strategic capabilities, and the suitability of a particular launcher depends on the local launch site and infrastructure — the choice of a spaceport influences trajectory windows, payload limits and regulatory issues.

Uses, mission planning and notable distinctions

Launch vehicles serve a range of missions: placing communications, navigation and Earth-observation satellites into orbit, sending scientific probes beyond Earth, delivering cargo and crew to space stations, and providing sub-orbital flights for research or space tourism. When selecting a launcher engineers consider payload mass, target orbit (distinguishing orbital insertions from sub-orbital trajectories), reliability records, and cost per flight. Other practical considerations include availability of different rocket fuels, integration facilities, and political or export constraints. Together these technical and programmatic factors determine which vehicle is best for a particular mission.