
	Where results make sense

Topic: Attitude control

Related Topics

Momentum wheel

Inertial navigation

Spacecraft propulsion

Pulsed inductive thruster

Spaceship

Satellite

Magnetic field

Angular momentum

Momentum

Nozzle

Flywheel

Space colonization

Earth

Impulse

Origin

	Attitude control
		The attitude is continuously controlled by a programmed control loop: sensors measure the satellite's attitude, the onboard computer then processes these measurements and generates commands which are carried out by the actuator, to ensure correct pointing.
		The attitude is controlled by the reaction wheels and magnetic torquers (attitude is more accurate than when using thrusters); this is based on data from rate gyros which are recalibrated using STD and SSD sensor measurements.
		The attitude is controlled by means of thrusters to keep the +Z side pointed towards the Sun, with the solar array in a set position.
	spot4.cnes.fr /spot4_gb/attitude.htm (1352 words)

	Attitude Control Subsystem
		Numerous phases of the mission, from the trajectory correction manoeuvres to the flyby and data downlink to Earth involve the probe orienting itself to a new attitude and maintaining it to a fraction of a degree.
		The probe's attitude control system must also be able to carry out the trajectory correction manoeuvres required to ensure an accurate flyby of the target.
		An attitude control system consists of a feedback loop with 3 elements; a sensor (to determine attitude error), a control system to determine the required response to any error and an actuator to implement the response.
	homepage.mac.com /sjbradshaw/msc/attitude.html (2078 words)

	Attitude Instrument Flying
		The attitude indicator replaces the normal outside visual references; therefore, it is the principal attitude control instrument for the radial scan.
		Aircraft attitude control is accomplished by proper use of the attitude indicator.
		Bank attitude control is used to maintain a heading or a desired angle of bank during turns.
	www.allstar.fiu.edu /aero/AIF.htm (1919 words)

	Attitude Control System
		Simply put, the attitude control system consists of a loop of measurement and correction of the spacecraft’s attitude such that it is constantly driven into its desired nominal orientation.
		Since the attitude control system is designed to run stand-alone and a PC-based architecture which is commonly employed in a spacecraft navigation system is much to massive, the design decision fell on a microcontroller-based embedded system.
		Based on the attitude deviation, the controller drives a set of three mutually perpendicular magnetic coils, so called magnetorquers, which are used to actively stabilize the attitude of Compass-1.
	www.raumfahrt.fh-aachen.de /satellite/attitude/index.htm (1492 words)

	Spacecraft: Attitude Dynamics and Control Archives
		The attitude controller’s stability and convergence characteristics are investigated further through numeric simulation of the attitude dynamics of the spacecraft formation.
		Accurate pointing (attitude control) is required for the FUSE instrument to do its job, and the attitude control system uses magnetic coils and flywheels (momentum wheels or reaction wheels) to control the pointing direction.
		Knowing where the satellite is pointing (attitude determination) is arguably as impotant as attitude control, and FUSE has a set of six ring-laser gyros.
	www.aoe.vt.edu /~cdhall/Space/archives/cat_attitude_dynamics_and_control.html (3539 words)

	Attitude control system for three-axis stabilized satellite in near-equatorial orbit - Patent 5259577
		The attitude is stabilized in yaw by passive means in the short term, using gyroscopic techniques, and possibly complemented by the use of thrusters or magnetic coils for long-term corrections.
		For the purposes of short-term control, filtering of the roll angle is replaced by state variable techniques on estimated roll and yaw angles and angular speeds and for long-term control by state variable techniques on estimated attitude angles and external disturbances, using measurements by the Earth and Pole Star sensors.
		The main objective of the short-term control loop is to damp nutation of the pitch axis Y of the satellite by reducing to zero angular speeds about the roll axis X and the yaw axis Z and by returning the roll and yaw angles to within specified ranges.
	www.freepatentsonline.com /5259577.html (4198 words)

	Attitude Control - Politecnico di Milano - Palamede Program
		The attitude determination and control subsystem (ADCS) stabilises the vehicle and orients it in desired directions during the mission despite the external disturbance torques acting on it.
		The control objective of this mode is not only to eliminate all spacecraft rates relative to the measured B-field, but also to stabilise the pitch axis, by a large slew manoeuvre, reaching the desired orientation normal to the orbit plane.
		An attitude sensor, developed by Maurizio Vanotti, based on GPS signals acquisition has been studied in alternative to the magnetometers and sun sensors attitude determination but it will not be implemented on the first of Palamede.
	www.aero.polimi.it /~palamede/docs/attitudecont1.htm (1137 words)

	Cassini-Huygens: Spacecraft-Orbiter Engineering Subsystems
		Its first responsibility is to maintain attitude control of the spacecraft, which means its position along three axes.
		This is called attitude determination and is achieved in the Attitude and Articulation Control Subsystem by three Inertial Reference Units (IRUSs) and a Stellar Reference Unit (SRU), or star tracker.
		To shield the harmful hot rays of the sun from the spacecraft's instruments during most of the early portion of the long journey to Saturn, the high-gain antenna was positioned toward the sun, functioning as an umbrella.
	saturn.jpl.nasa.gov /spacecraft/subsystems-cassini.cfm (1452 words)

	Attitude Control
		Spacecraft stability and control is a must so that sensors, solar panels, antennas and other hardware are properly oriented to perform their functions.
		This highly reliable hardware for reaction torque and angular momentum storage for attitude control is built for use on medium to large spacecraft.
		New and innovative attitude determination and control hardware includes a lunar horizon crossing indicator and an Earth sensor for geosynchronous applications.
	www.sti.nasa.gov /tto/spinoff1997/t2.html (653 words)

	FLIGHT PATH AND ORIENTATION CONTROL
		Control ceases and the body is stabilized when sensing instruments, usually gyroscopic devices, indicate that the proper attitude has been achieved.
		Regardless of the details of mechanism, the magnitude of the control torque produced by the ejection of mass from the vehicle is equal to the sideward reaction force multiplied by the perpendicular distance from the center of gravity to the line of action of the sideward force.
		In unpowered flight in space the principal control problem is that of controlling the attitude or orientation of the vehicle with respect to a specified reference system.
	www.hq.nasa.gov /office/pao/History/conghand/orient.htm (2275 words)

	5.4 Attitude Sensors (Site not responding. Last check: )
		Attitude control of a satellite is classified by two methods ; spin control and three axis control.
		The spin control is rather simple but has a low S/N ratio, while the three axis control is more complex, but has a high S/N. Figure 5.4.1 shows the typical types of attitude measurement sensors, which are used for different purposes.
		Earth sensor detects the radiation of CO with in the wavelength range of 14 - 16 mm emitted from the rim of the earth, from which two axis attitude of roll and pitch can be measured with an accuracy of 0.3 - 1 degree, as shown in Figure 5.4.2.
	www.profc.udec.cl /~gabriel/tutoriales/rsnote/cp5/cp5-4.htm (373 words)

	Attitude Determination and Control Progress Report 2
		The attitude of a spacecraft, or its orientation, is determined by position, velocity, attitude and attitude motion.
		Will be necessary for momentum dumping if reaction wheels or gyroscopic control is used in the Odysseus II, although they probably use too much fuel to be the primary source of attitude control on an interplanetary mission.
		Attitude determination will likely be a combination of gyroscopic response and star sensors or sun sensors.
	mmae.iit.edu /~MAE442/adacprg2.htm (1318 words)

	Two Gyro. Mode Handbook (Site not responding. Last check: )
		Attitude is estimated in M2G mode through a combination of rates provided by the two gyros and the attitude derived from the cross product of the magnetic field model and the magnetic field measured by the MSS.
		Attitude Hold Mode: This mode is used when gyro plane errors are expected to be small (e.g., after two successful onboard attitude determinations).
		This onboard attitude determination may be followed by a maneuver to correct the pointing, and a second OBAD is performed to ensure that the pointing has been refined sufficiently.
	www.stsci.edu:8083 /hst/HST_overview/TwoGyroMode/handbook/c04_slewing4.html (1573 words)

	Speakers Platform: Attitude Control: The Key to Lasting Success
		This highly elusive state, however, is nearly impossible to achieve when your supplier fails to meet a deadline, when a strike keeps you from arriving on time for a meeting, or when venture capitalists withdraw their interest as the stock market turns bearish.
		Attitude control involves the practice and application of three peak performance skills.
		When we’re in charge of our attitude we don’t use the victim’s inner dialogue: "I have to show up but I don’t want to." Instead we speak about "choosing to show up to do our best." Choice is an executive function that involves considering the risks, consequences, and one’s commitments before deciding how to act.
	www.speaking.com /articles_html/NeilFiore,Ph.D._716.html (852 words)

	Ulysses Attitude and Orbit Control Subsystem (Site not responding. Last check: )
		The Attitude and Orbit Control Electronics uses inputs from the spacecraft receivers, decoders, Sun Sensors, and ground commands to control the spacecraft spin rate, attitude, and manoeuvres.
		The Reaction Control Subsystem consists of the tank, pipes, valves and thrusters that contain and regulate the flow of hydrazine rocket fuel from the spacecraft.
		Routine attitude manoeuvres consist of pulsing an axial thruster at the correct phase in the spin cycle to slew the spin axis across the Earth path.
	ulysses-ops.jpl.esa.int /ulsfct/spacecraft/AOCS.html (704 words)

	SCT Attitude Control Module (Site not responding. Last check: )
		Magnetic control algorithms for instantaneous two-axis and average three axis control.
		Sun nadir pointing control is used on numerous spacecraft, such as GPS II and Topex.
		A low-cost approach to geosynchronous spacecraft control system design is to use a fixed momentum wheel for pitch control, magnetic torquers for roll yaw control, and monopropellant thrusters for 3-axis control during stationkeeping.
	www.psatellite.com /products/html/SCT_AttitudeControl.php (413 words)

	Navigation, Guidance & Control Specification Sheet
		The attitude control effectors chosen in the preliminary WORLD-M design were momentum wheels for fine attitude control, and a Reaction Control System (RCS) for coarse attitude control and momentum dumping.
		Fine control requirements are primarily driven by communications antenna pointing requirements, solar panel alignment, and DV maneuver alignment.
		The RCS is used for large attitude corrections which must be accomplished quickly, for dumping the excess momentum of the fine control system, and to provide authoritative landing phase attitude control.
	www.tsgc.utexas.edu /tadp/1995/spects/ngc.html (1738 words)

	The Ørsted Satellite Project
		The control system must be able to handle different operational phases, reconfigure between several sensor and actuator configurations, and close down in case of severe faults.
		The Ørsted attitude estimation approach is based on extended Kalman filtering of magnetometer and sun sensor readings in combination with a star camera filter.
		The attitude is estimated for onboard attitude control purposes and the precision requirements are limited.
	www.control.auc.dk /projects/satellites/orsted.html (1136 words)

	Attitude Control System (Site not responding. Last check: )
		Controls orientation of the Single Access antennas to slew between user satellites and track user satellites in response to ground commands.
		Controls the orientation of the Space to Ground Link antenna to point at the ground terminal in response to ground command.
		Provides attitude sensor data and solar array angles for actuation of thrusters, solar array drives and momentum wheels by direct ground control.
	msp.gsfc.nasa.gov /tdrss/attitude.html (148 words)

	Wolfe Self-Propelled Trenchless Drainage Plows
		Accuracy is the key, and the extra long beam parallel linkage on Wolfe plows controls the mole blade for exacting precision on smooth tile or tubing installations.
		An added measure of control from a special back-pressure variable system transfers more weight to the tracks under hard conditions.
		Highly accessible controls monitor the depth, grade and attitude of the shoe through your choice of laser of electronic tracking systems.
	www.wolfeequipment.com /drainage.htm (596 words)

	SPACE.com -- Shuttle Astronauts Repair ISS Gyroscope in Second Spacewalk
		The news was so good to flight controllers it prompted lead spacewalk officer Cindy Begley to jump out of her chair in applause.
		Control moment gyroscopes are vital components for the International Space Station (ISS), allowing the orbital laboratory the ability to change its orientation while conserving propellant by not firing its Russian-built thrusters.
		Flight controllers powered down one of the station’s working gyroscopes, CMG-3, while Discovery is docked at the ISS after some abnormal vibrations led them to suspect the massive load was putting too much of a strain on it.
	www.space.com /missionlaunches/050801_sts114_eva2.html (1081 words)

	Orbital Maneuvering and Attitude Control Device (Site not responding. Last check: )
		The device is used for attitude control of the spacecraft and for small maneuvers.
		Fig.1 illustrates locations of OMACD and controlling nozzles on a subsatellite with respect to its axes.
		Two pairs of the thrusters control spin rate of the spacecraft (to spin up and to despin it).
	www.iki.rssi.ru /interball/omacd.html (160 words)

	CSER Attitude Control and Navigation Group
		The group covers attitude determination and control, in-orbit navigation; and in-orbit control and propulsion.
		In attitude control: a novel and low cost combination of active magnetorquing (switched currents under algorithmic computer control) and passive gravity gradient stabilisation has been developed.
		In attitude control the gravity gradient effect is exploited where a tip mass is deployed at the end of boom.
	www.ee.surrey.ac.uk /SSC/CSER/AnnualReport/AttitudeControl.html (390 words)

	Attitude Control of Space Platform Based Tethered Satellite System (Site not responding. Last check: )
		Using an order N Lagrangian formulation, the paper studies attitude control of a rigid platform supporting a flexible tether connected to a rigid satellite.
		The control is achieved through time dependent offset of the tether attachment point, as determined through the Liapunov method, thus providing regulated amount of tether tension induced damping moment.
		Results suggest that the controller is quite successful in stabilizing the platform about its nominal equilibrium position in a few orbits, even in the presence of relatively large disturbances.
	www.pubs.asce.org /WWWdisplay.cgi?9801061 (226 words)

	Inspiring Solutions provides you with DiSC profiles, assessments, book, training kits and videos they can use to ...
		Written by Michele Matt, CSP, Attitude: The Choice is Yours helps people to tap into their personal attitudes to better understand, analyze, adjust, and maintain the right frame of mind at work and at home.
		We have created and selected products that are easy to use, comprehensive and invaluable for giving people a deeper understanding of themselves and other people.
		For more than 50 years, individuals have raved about the positive effects that Adventures in Attitudes® has had on their lives.
	www.inspiringsolutions.com (473 words)

	Linda Coleman Willis - Attitude Makes The Difference
		Attitudes are formed by the thoughts we hold in our minds over a period of time.
		But the joy and success we experience when we act instead of react, when we see opportunity instead of problems, when we see possibility instead of impossibilities, is the greatest gift we can give ourselves and the people around us.
		There is no negative attitude that the human mind cannot justify as being right.
	www.lindaspeak.com /Attitude.htm (413 words)

	Basics of Space Flight Section II. Space Flight Projects
		Thus the term guidance and control has become associated with attitude control during the powered ascent phase of a spacecraft's mission.
		Three-axis controlled craft can point optical instruments and antennas without having to de-spin them, but they may have to carry out special rotating maneuvers to best utilize their fields and particle instruments.
		Reaction wheels are fairly massive attitude control devices at the output of AACS computers.
	www2.jpl.nasa.gov /basics/bsf11-2.html (2509 words)

Try your search on: Qwika (all wikis)