MICROSAT 4 (21583)

COSPAR: 1991-051D | Alt Name: Microsat 4

DECAYED

Image

Additional Sources

Launch Details

Launch Date

July 17, 1991

Launch Site

AFWTR

Launch Pad

RW04/22

Launch Vehicle

Pegasus/HAPS

Orbital Elements

NORAD ID

21583

International Designator

1991-051D

Decay Date

1/23/1992

Basic Satellite Info

Name

MICROSAT 4

Alternative Name

Microsat 4

Type

Payload

Status

Decayed

Owner

DARPA

Country

United States

Constellation

N/A

Related Satellites

Major Events

N/A

Summary

MICROSAT 4, also known as Microsat 4, is an experimental communication satellite launched by DARPA on July 17, 1991, from AFWTR using a Pegasus/HAPS launch vehicle from RW04/22 pad. The spacecraft is configured in a Picostar design with dimensions of 0.2 meters in length and a diameter and span of 0.5 meters each. It has a dry mass of 19 kilograms and was launched with a total mass of 21 kilograms. MICROSAT 4 uses solar cells and batteries for power, features a cold gas N2 propulsion system, and is equipped with a 1 UHF transponder digital store-and-forward communications system. The satellite's intended lifetime was planned to be four years but achieved only one year in orbit.

Physical Characteristics

Length

0.2

Diameter

0.5

Span

0.5

Dry Mass

Launch Mass

Shape

Cyl

Radar Cross Section

0.17

Visual Magnitude

Unknown

Color

Unknown

Material Composition

Unknown

Technical Details

Payload

Microsat 4

Purpose

Experimental communication

Mission

Experimental communication

Manufacturer

DSI

Life Expectancy

4 years (planned); 1 year (achieved)

Bus

Picostar

Configuration

PicoStar

Motor

Cold gas N2 propulsion

Equipment

1 UHF transponder digital store and forward communications system

Power System

Solar cellsm batteries

ADCS

Unknown

Transmitter Frequency

Unknown

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