In
spacecraft
A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...
operations, Launch and Early Operations (LEOP) is one of the most critical phases of a mission. Spacecraft operations
engineers
Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the ...
take control of the
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...
after it separates from the
launch vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and ...
. LEOP generally concludes once the satellite is safely positioned in its final
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
.
During this period, operations staff work typically 24 hours a day to activate, monitor and control the various
subsystems of the satellite, including the deployment of any satellite appendages (such as
antennas
In radio engineering, an antenna or aerial is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an ...
,
solar arrays
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and c ...
,
reflectors, and
radiators), and undertake critical orbit and
attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
manoeuvres. Extra support staff are typically on hand and
on-call
On-call scheduling, sometimes referred to as on-call shifts, are processes used in business where employee work schedules are intentionally unpredictable. Employees who work on-call are expected to be available at any time during their shift, usu ...
during LEOP, relative to staffing during normal operations.
For
geostationary satellites
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitude ...
, the launch vehicle typically carries the spacecraft to
Geostationary Transfer Orbit, or GTO. From this
elliptical
Elliptical may mean:
* having the shape of an ellipse, or more broadly, any oval shape
** in botany, having an elliptic leaf shape
** of aircraft wings, having an elliptical planform
* characterised by ellipsis (the omission of words), or by conc ...
orbit, the LEOP generally includes a sequence of
apogee engine
An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final (most commonly circular) orbit. For a satellite laun ...
firings to reach the circular
geostationary orbit.
See also
*
Ground segment
A ground segment consists of all the ground-based elements of a space system used by operators and support personnel, as opposed to the space segment and user segment. The ground segment enables management of a spacecraft, and distribution of pay ...
*
Satellite space segment
References
ESA Spacecraft Operations website
Spaceflight concepts
Spaceflight