Science Observations with the IUE Using the One Gyro Mode

AbstractThe International Ultraviolet Explorer (IUE) is a geosynchronous orbiting telescope launched by the National Aeronautics and Space Administration (NASA) on January 26, 1978, and operated jointly by NASA and the European Space Agency. The science instrument consists of two spectrographs which span the wavelength range of 1150 to 3200 Å and offer two dispersions with resolutions of 6 Å and 0.2 Å. The spacecraft’s attitude control system originally included an inertial reference package containing 6 gyroscopes for 3-axis stabilization. The science instrument includes a prime and redundant Field Error Sensor (FES) camera for target aquisition and offset guiding. Since launch, 4 of the 6 gyroscopes have failed. The current attitude control system utilizes the remaining 2 gyros and a Fine Sun Sensor (FSS) for 3-axis stabilization. When the next gyro fails, a new attitude control system will be uplinked which will rely on the remaining gyro and the FSS for general 3-axis stabilzation. In addition to the FSS, the FES cameras will be required to assist in maintaining fine attitude control during target aquisition. This has required thoroughly determining the characteristics of the FES cameras and the spectrograph aperture plate as well as devising new target acquisition procedures. The results of this work are presented.

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Design, Ground Testing and On-Orbit Performance of a Sun Sensor Based on COTS Photodiodes for the UPMSat-2 Satellite

Sensors ◽

10.3390/s21144905 ◽

2021 ◽

Vol 21 (14) ◽

pp. 4905

Author(s):

Angel Porras-Hermoso ◽

Daniel Alfonso-Corcuera ◽

Javier Piqueras ◽

Elena Roibás-Millán ◽

Javier Cubas ◽

...

Keyword(s):

Control System ◽

Attitude Control ◽

Response Curve ◽

The Sun ◽

Space Systems ◽

Attitude Control System ◽

Ground Testing ◽

Sun Sensor ◽

Early Results ◽

Red Leds

This paper presents the development of the UPMSat-2 sun sensor, from the design to on-orbit operation. It also includes the testing of the instrument, one of the most important tasks that needs to be performed to operate a sensor with precision. The UPMSat-2 solar sensor has been designed, tested, and manufactured at the Universidad Politécnica de Madrid (UPM) using 3D printing and COTS (photodiodes). The work described in this paper was carried out by students and teachers of the Master in Space Systems (Máster Universitario en Sistemas Espaciales—MUSE). The solar sensor is composed of six photodiodes that are divided into two sets; each set is held and oriented on the satellite by its corresponding support printed in Delrin. The paper describes the choice of components, the electrical diagram, and the manufacture of the supports. The methodology followed to obtain the response curve of each photodiode is simple and inexpensive, as it requires a limited number of instruments and tools. The selected irradiance source was a set of red LEDs and halogen instead of an AM0 spectrum irradiance simulator. Some early results from the UPMSat-2 mission have been analyzed in the present paper. Data from magnetometers and the attitude control system have been used to validate the data obtained from the sun sensor. The results indicate a good performance of the sensors during flight, in accordance with the data from the ground tests.

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Assessment of the Quality of the IDT Elemental Observations

Highlights of Astronomy ◽

10.1017/s1539299600009345 ◽

1992 ◽

Vol 9 ◽

pp. 414-414

Author(s):

M.A.C. Perryman

Keyword(s):

Control System ◽

Data Analysis ◽

Attitude Control ◽

Angular Separation ◽

Attitude Control System ◽

Phase Measurements ◽

One Dimensional ◽

The One ◽

Comparison Of The Results

AbstractThe quasi-simultaneous measurement of the one-dimensional angular separation of stars on the sky, on both small and large angular scales, rely on the measurements made by the IDT detector, as well as on inputs from the star mapper and attitude control system. This presentation will concentrate on the results of a comparison of the results of the IDT data processing carried out by the FAST and NDAC data analysis teams. The extent to which the intensity and phase measurements agree between the two reductions, and the extent to which the differences are consistent with expected photon noise errors, will be illustrated.

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A Novel Approach for Satellite Attitude Control by Using Solar Sailing

Volume 1: Advances in Aerospace Technology ◽

10.1115/imece2018-88311 ◽

2018 ◽

Author(s):

Ni Li ◽

Paolo Arguelles ◽

Kevin Chaput ◽

Stephen L. Kenan ◽

Salla Kim ◽

...

Keyword(s):

Attitude Control ◽

European Space Agency ◽

Solar Sail ◽

Attitude Control System ◽

Solar Sailing ◽

Satellite Attitude ◽

Space Agency ◽

Novel Approach ◽

Satellite Attitude Control ◽

Orientation System

Solar sailing is a new satellite propulsion technology using radiation pressure exerted by sunlight on a large mirrored surface. Since it does not need propellants, it is increasingly being considered by both the European Space Agency and the National Aeronautics and Space Administration for future science missions. An attitude control system is essential for a sail craft to maintain a desired orientation. IKAROS, launched in 2010, practically proved the possibility of using a solar sail as a propulsion system. However, it also showed the current sail orientation system could change the attitude very slowly, about 1 degree per day. In contrast to the existing single solar sail design, a new distributed four-sail configuration is proposed in this paper and the coordinated motion of the four sails is used to control the attitude pointing of a satellite. The feasibility and efficiency of this proposed design were assessed and concluded that it is possible to steer a CubeSat up to 1 degree in 60 seconds for either the roll or pitch axes.

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Flueric Sun Sensor-Actuator, A Solar Attitude Control System

10.4271/670553 ◽

1967 ◽

Author(s):

Lawrence S. Galowin ◽

Albertus E. Schmidlin

Keyword(s):

Control System ◽

Attitude Control ◽

Attitude Control System ◽

Sensor Actuator ◽

Sun Sensor

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Geometric Adaptive Controls of a Quadrotor UAV with Decoupled Attitude Dynamics

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4052714 ◽

2021 ◽

Author(s):

Kanishke Gamagedara ◽

Taeyoung Lee

Keyword(s):

Control System ◽

Attitude Control ◽

Position Tracking ◽

Control Input ◽

Attitude Dynamics ◽

Attitude Control System ◽

Adaptive Controls ◽

Local Coordinates ◽

Aerial Vehicle ◽

The One

Abstract This paper presents a geometric adaptive position tracking control system for a quadrotor unmanned aerial vehicle. In particular, the attitude control system is designed on the product of the two-dimensional unit sphere and the one-dimensional circle such that the direction of the thrust that is critical for position tracking is controlled independently from the yawing direction that is irrelevant to the position dynamics. Compared against the prior work with coupled attitude controls on the special orthogonal group, the proposed controller prevents large yaw errors from causing an undesirable performance degradation in tracking a position command. Further, the control input is augmented with adaptive control terms to mitigate the effects of disturbances, and it is formulated globally on the spheres to avoid singularities and complexities of local coordinates. The efficacy of the proposed control system is illustrated by both numerical examples and indoor/outdoor flight experiments.

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