Orbital 499 User Manual

Wire Antenna

Wire Antenna

Deployment

Deployment

Assembly

Assembly

Model 499

Model 499

Introduction

Wire Antenna Deployment Assembly (WADA) Model
499 was developed for the Combined Release and
Radiation Effects Satellite (CRRES) as part of the Passive
Plasma Sounder experiment to study near vehicle
thermal plasma characteristics. This motorized
mechanism is capable of extending and retracting a wire
antenna, up to 360.8 feet (110 meters) long,
perpendicular to the satellite spin-axis. The antenna is a
stranded beryllium-copper wire measuring 0.015 inch
(0.038 cm) diameter, with a tensioning tip mass attached
to the outer end. Either bare or insulated wire may be
used. The deployer features electrical and mechanical

stops at both full-extension and –retraction. A
potentiometer, driven by the moving antenna wire,
provides a continuous indication of the deployed length.
This deployment mechanism is designed to meet the
requirements of document MIL-A-083577A (USAF) for
Moving Mechanical Assemblies for Space and Launch
Vehicles. Similar units were used on Dynamics
Explorer-1 & -2, International Sun-Earth Explorer,
San Marco D/L and ISTP-WIND satellites. This unit can
be deployed or retracted in orbit.

Typical Technical Specifications:

Antenna Wire

Deployed Length: Up to 360.8 ft

(110 meters)
Diameter —
W/out insulation: 0.015 in

(0.038 cm)
With insulation: 0.032in

(0.081 cm)
Material &
Construction: Beryllium Copper
Insulation Material: Teflon

(per MIL-W-16878)
Weight: —
W/out insulation: 0.361 gr/ft

(1.184 gr/m)
With insulation: 0.605 gr/ft

(1.985 gr/m)

Height: 7.21 in (18.31 cm)
Length: 10.27 in

Width: 7.50 in (19.05 cm)
Total Unit Weight: 5.51 lbs (2.5 kg)
Drive Motor: Brushless D.C.
Power: 14 Watts maximum
Voltage: 28 Vdc Nominal
Deployment Rate: Approximately

Tip Mass Weight: 0.073 lbs

Operating
Temperature Range: -10°C to +50°C
Qualification
Temperature Range: -20°C to +60°C
Survival
Temperature Range: -25°C to +65°C

Deployer

(26.09 cm)

0.6 in/sec
(15 mm/sec)

(33±.01 gram)

Features

■ Automatic full-extend and -retract motor power cut-off

■ Full-extend and -retract flags

■ Deployed length indicator

■ Minimal magnetic materials

Deployed length

up to 360.8 ft.

(110 meters)

3.50

9.77

5.50

1.25

7.21

4.54

7.50

Wire Antenna Deployment Assembly

Orbital Technical Services Division
5010 Herzel Place
Beltsville, MD 20705
Phone: [phone] FAX: [phone]
www.orbital.com

5.11

5.25

4.02

1.25

Model 499

7500 Greenway Ctr. Dr.,
Ste. 700 Greenbelt, MD 20770
Phone: [phone] FAX: [phone]