Unified Radio and Plasma Wave Investigation (URAP)

The URAP (STO) Experiment has two scientific objectives:

  1. to determine the direction and polarization of distant radio sources for remote sensing of the Heliosphere
  2. to study the local wave phenomena which determine the transport coefficients of the ambient plasma.

The URAP experiment provides electric field measurements from "DC" to 1 MHz and magnetic field measurements from 0.22 to 450 Hz. For more scientific information, visit the following URAP team websites:

URAP at the Goddard Space Flight Center

Power and Mass Properties

 The instrument consists of 7 units:

Power Dissipation

Mass
kg

Mean

Peak

Heater

mA

W

mA

W

mA

W

STO 1

Power Converters and RF Radiometer
Electronics, DPU

178.5

5.00

184.5

5.17

    

2.3754

STO 2

Plasma Wave Analyzer
Fast Wave Sampler
Fast Fourier Transform
DPU

147.5

4.13

147.5

4.13

    

3.3852

STO 3A

Dipole Antenna Preamp 1 (+X)

10.0

0.28

18.9

0.53

    

0.2232

STO 3B

Dipole Antenna Preamp 1 (-X)

10.0

0.28

18.9

0.53

    

0.2239

STO 4

Monopole Antenna Preamp (Z)

9.6

0.27

9.6

0.27

    

0.2118

STO 5

Search Coil Preamp

2.1

0.06

2.1

0.06

    

0.3447

STO 6

Search Coil Magnetometer

-

-

-

-

33.0

0.92

0.5322

 

STO 1 / STO 2 Harness

            

0.0844

Total

 

357.7

10.02

381.5

10.69

33.0

0.92

7.3808
 

 There are also 3 boom antennas:

Power Dissipation (only during deployment)

Mass
kg

Mean

Peak

Heater

mA

W

mA

W

mA

W
 

Wire Boom Drive (+X)

~430

~12

~430

~12

    

0.498
 

Wire Boom Drive (-X)

~430

~12

~430

~12

    

0.501
 

Axial Boom Drive (Z)

~250

~7

~250

~7

    

1.781
 

Wire Boom / Axial Boom Electronics
Power dissipation included in drive figures

            

0.677

Total

 

            

3.447

Operational issues

Every day, the Plasma Frequency Receiver is switched from fast-to-slow or slow-to-fast scanning. Auto-calibration, which had been performed throughout the mission, was terminated at the end of 2001. Manual calibrations are now performed on a monthly basis. STO Sounder activity also ceased at the end of 2001. The STO 6 heater will be switched off for the remainder of the mission.