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Space Technology 6: Testing Tomorrow's Technology Today!
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Abort Commands
Instructions given to the spacecraft by its computer or by ground operators to stop the current activity due to danger to the mission.

Active Pixel
A new type of imaging device that consumes a fraction of power. Active pixels are used by standard Charged Coupled Devices (CCD's).

A step-by-step procedure for solving a problem.

Unexpected behaviors of spacecraft.

Autonomous Operations
The ability of a spacecraft to make decisions without the intervention of the ground crew.

Change Detection
A technique used to recognize change in the same location between the last image and the current image, such as of floods, volcano eruptions, ice cracking, and other phenomena that are interesting to scientists.

Continuous Planning
A system that does not depend on a pre-made plans but continuously examines many operating parameters and decides on the best sequence of actions based on the current situation.

Data sent to the ground using radio communications.

A tabular statement of the assigned places of a celestial body at regular intervals.

Executive Module
The part of the software program responsible for execution of other parts of the autonomy software.

Feature Detection
Software that recognizes as interesting predefined images that have been identified by scientists. This software can be trained to recognize volcanoes, lava flows, volcano plumes, or other features.

Short for gyroscope. A gyro recognizes change in rate about an axis of rotation. In the past all gyroscopes used spinning masses. The ST6 gyro operates on the principle of a tuning fork gyro, using MEMS.

Image Formation
The ability of the spacecraft to create an image from the radar data without having to send it to the ground.

In reference to mass. The ST6 advanced avionics detects mass motion to be able to assess spacecraft movement.

Microelectromechanical System(MEMS)
Micro electro mechanical systems are a combination of electrical and mechanical devices etched in silicon much like computer chips. MEMS are tiny. The ST6 advanced avionics uses MEMS for its gyroscopes.

Performance of a function on the spacecraft rather than being conducted on the ground. In an autonomous spacecraft most of the functions are done onboard.

In space jargon "piggybacked" is a spacecraft that is not launched on its own rocket but carried as an addition to some other spacecraft. This is usually a more expensive spacecraft which has a dedicated launch vehicle.

Refers to orienting the spacecraft or its instrument such as a telescope, camera ,or a sensor towards a specific target or coordinates.

Robust Execution
Resilience of the software to unpredictable states and situations.

A system with all scientific functions and sensors highly integrated and inseparable, while most standard spacecraft have a spacecraft bus that provides a platform and resources to the scientific instruments.

Solar Arrays
Provides power to the spacecraft by converting sun light into electrical energy.

Star Camera/Tracker
Recognizes star patterns in the sky to determine the spacecraft pointing. Many star trackers look for a certain star of predetermined brightness. Any shift of this star in the field of view of the tracker registers as the spacecraft or instrument motion.

State Estimator
Function that describes the current behavior of the spacecraft including such parameters as the battery charge, instruments activated ,and other spacecraft states.

In reference to stars.

Synthetic Aperture
An aperture is the part of the sensor's collecting area, such as the telescope or antenna diameter. A filled aperture consists of just one aperture while a synthetic aperture consists of several units positioned in formation. This formation behaves as one large aperture of the total size spanned by its elements. In effect the aperture is synthesized from smaller elements.

Path on which the spacecraft flies.

Optics that are able to see a large portion of the sky.



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