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The Ion Propulsion System (IPS) Diagnostic Subsystem (IDS)

NSSDCA ID: 1998-061A-03

Mission Name: Deep Space 1
Principal Investigator:Prof. Karl-Heinz Glassmeier

Description

The Deep Space 1 spacecraft propulsion was provided by an ion thruster, the NASA Solar Electric Propulsion (SEP) Technology Applications Readiness (NSTAR) Ion Propulsion System (IPS), which was one of the technology evaluation components of the mission. Monitoring and characterization of the induced environment around the spacecraft created by the IPDS and its interaction with the space environment was the primary oblective of the IPS Diagnostics Subsystem (IDS). Since the measured effects of the IPS on the spacecraft environment proved to be benign, the IDS was reprogrammed during flight to collect solar induced wave data and signals caused by dust impact events during the encounter. The IPS wasmounted next to the ion engine and consisted of a suite of 12 sensors, including a plasma wave antenna and two search coil magnetometers.

The two small search coil magnetometers were mounted on the end of a 50 cm long boom. One of the magnetometers was apparently damaged at the launch site by large AC fields and was inoperable during the mission. Flight measurements were performed with the other magnetometer in 3 axes with a measurement bandwidth over 10 Hz to 50 kHz. The full-scale range at 200 Hz was 100 nT with a resolution of 1 pT. The AC magnetic fields were characterized as a discrete power spectrum with four measurement intervals per decade. The transient waveform for 'events' was also captured with a sampling rate of 20 kHz for 500-msec windows. The magnetometer was strongly influenced by components of the ion engine and magnetically activated thrusters, so analysis of the data requires extensive processing to be scientifically useful in the determination of external magnetic fields.

The dipole plasma wave antenna (PWA) is a pair of low-mass Ni-Ti shape-memory alloy (SMA) metallic strips with a tip-to-tip separation of 2 m. The PWA is connected to a low-noise, adjustable gain preamplifier. Low frequency domain (10 Hz to 100 kHz) measurements were made using a voltage-swept band pass filter with a minimum of four measurements per decade with an amplitude range of 100 micro-V/m to 1000 mV/m. High frequency (100 kHz to 30 MHz) measurements were made at a minimum of four measurements per decade with the same amplitude range as the low-frequency domain. Transient waveform measurements were performed at a 20-kHz sampling rate with a 500-msec circular buffer.

The IDS sensors were run from a common electronics unit with a Fields Measurement Processor with a spectrometer board which provided amplification and filtering of the search coil and plasma wave data. The electronics also included a Diagnostic Sensors Electronics Unit (DSEU) with two data sampling systems, a contamination monitor, and a fields monitor. The DSEU supported communication and controlled the sensors.

Alternate Names

  • DeepSpace1/IDS
  • IDS

Facts in Brief

Power (avg): 0.2 W

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Questions and comments about this experiment can be directed to: Dr. David R. Williams

 

Personnel

NameRoleOriginal AffiliationE-mail
Prof. Karl-Heinz GlassmeierPrincipal InvestigatorTechnische Universitat Braunschweigkh.glassmeier@tu-braunschweig.de
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