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NASA Space

Instrument and Sensing Technology

Space Instrument Size Drivers

This is an HTML version of a view graph presentation listing the major reasons why space-based remote sensing instruments are large, and what the options are for reducing the mass and/or the size of these instruments.

Presentation Outline:

• Space Instrument Size Drivers:
  • Optics Diffraction Limit
  • Faint/Weak Signal
  • Scanning/Moving Optics
  • Complex Calibration Hardware
  • Cryogenic Cooling
  • On-Board Data Handling and Link to Ground
• Mapping to Current Sensors and Instrument Technology Program

Optics Diffraction Limit

Solutions/Options:

• keep optics size, but lightweight the optics
• adaptive optics to obtain performance near limit
• use unfilled apertures (interferometry)
• obtain comparable observation at shorter wavelength
• fly closer to target (e.g., for planetary missions)

Faint/Weak Signal

Solutions/Options:

• improve detector sensitivity
• use detector arrays to increase integration/dwell time
• improve readout technology (reduce signal loss/noise between detector and electronics)
• keep optics size, but lightweight the optics

Scanning/Moving Optics

Needed to Build Up Image and/or Spectral Coverage

Solutions/Options:

• use array detectors and/or increase array size
• lightweight moving optical elements

Complex Calibration Hardware

Solutions/Options:

• develop detectors that are easier to calibrate (improved uniformity, reduced radiation and other effects)
• develop optical materials/calibration targets less susceptible to changes due to space environment
• lightweight optical elements needed for calibration

Cryogenic Cooling

Some Detectors Need Cooling to Make Them Work or Improve Sensitivity

Solutions/Options:

• develop detectors that operate at higher temperatures
• develop reliable lightweight, long-life, low-/no-vibration coolers
• reduce heat loss along readout path through improved cryogenic readout technology

On-Board Data Handling and Link to Ground

Solutions/Options:

• "smart sensors" to reduce acquisition of unwanted data
• compact, low mass/volume, low power data storage
• low power on-board processing to reduce data rate to ground
• improve communication links

Mapping to Current Sensors and Instrument Technology Program

Return to:

• Instrument and Sensing Technology Page
• Advanced Technology and Mission Studies Division Page
• Office of Space Science
• NASA Headquarters Page
• NASA Page

Created August 31, 1994. Last update: September 15, 1997. Please see my Disclaimer and Web Policy page. Originally created by Gordon Johnston. Due to changing position assignments, this page will now be maintained by Glenn Mucklow.

The world wide web uniform resource locator (URL) for this page is:

http://ranier.hq.nasa.gov/Sensors_page/SciSize.html