Fictitious forceA fictitious force is a force that appears to act on a mass whose motion is described using a non-inertial frame of reference, such as a linearly accelerating or rotating reference frame. It is related to Newton's second law of motion, which treats forces for just one object. Passengers in a vehicle accelerating in the forward direction may perceive they are acted upon by a force moving them into the direction of the backrest of their seats for instance.
Interplanetary spaceflightInterplanetary spaceflight or interplanetary travel is the crewed or uncrewed travel between stars and planets, usually within a single planetary system. In practice, spaceflights of this type are confined to travel between the planets of the Solar System. Uncrewed space probes have flown to all the observed planets in the Solar System as well as to dwarf planets Pluto and Ceres, and several asteroids. Orbiters and landers return more information than fly-by missions.
Reliability of WikipediaThe reliability of Wikipedia concerns the validity, verifiability, and veracity of Wikipedia and its user-generated editing model, particularly its English-language edition. It is written and edited by volunteer editors who generate online content with the editorial oversight of other volunteer editors via community-generated policies and guidelines. This editing model is highly concentrated, as 77% of all articles are written by 1% of its editors, a majority of whom have chosen to remain anonymous.
Altitude sicknessAltitude sickness, the mildest form being acute mountain sickness (AMS), is a harmful effect of high altitude, caused by rapid exposure to low amounts of oxygen at high elevation. People can respond to high altitude in different ways. Symptoms may include headaches, vomiting, tiredness, confusion, trouble sleeping, and dizziness. Acute mountain sickness can progress to high-altitude pulmonary edema (HAPE) with associated shortness of breath or high-altitude cerebral edema (HACE) with associated confusion.
Launch padA launch pad is an above-ground facility from which a rocket-powered missile or space vehicle is vertically launched. The term launch pad can be used to describe just the central launch platform (mobile launcher platform), or the entire complex (launch complex). The entire complex will include a launch mount or launch platform to physically support the vehicle, a service structure with umbilicals, and the infrastructure required to provide propellants, cryogenic fluids, electrical power, communications, telemetry, rocket assembly, payload processing, storage facilities for propellants and gases, equipment, access roads, and drainage.
Sun MicrosystemsSun Microsystems, Inc. (Sun for short), was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the (NFS), and SPARC microprocessors. Sun contributed significantly to the evolution of several key computing technologies, among them Unix, RISC processors, thin client computing, and virtualized computing. Notable Sun acquisitions include Cray Business Systems Division, Storagetek, and Innotek GmbH, creators of VirtualBox.
Orbit insertionOrbit insertion is the spaceflight operation of adjusting a spacecraft’s momentum, in particular to allow for entry into a stable orbit around a planet, moon, or other celestial body. This maneuver involves either deceleration from a speed in excess of the respective body’s escape velocity, or acceleration to it from a lower speed. The result may also be a transfer orbit. There is e.g., the term descent orbit insertion. Often this is called orbit injection.
Delta-vDelta-v (more known as "change in velocity"), symbolized as ∆v and pronounced delta-vee, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of said spacecraft. A simple example might be the case of a conventional rocket-propelled spacecraft, which achieves thrust by burning fuel.
Expendable launch systemAn expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several rocket stages that are discarded sequentially as their fuel is exhausted and the vehicle gains altitude and speed. As of 2022, most satellites and human spacecraft are currently launched on ELVs. ELVs are simpler in design than reusable launch systems and therefore may have a lower production cost.
Human spaceflight programsHuman spaceflight programs have been conducted, started, or planned by multiple countries and companies. The age of manned rocket flight was initiated by Fritz von Opel who piloted the world's first rocket-propelled flight on 30 September 1929. All space flights depend on rocket technology; von Opel was the co-designer and financier of the visionary project. Until the 21st century, human spaceflight programs were sponsored exclusively by governments, through either the military or civilian space agencies.
