REX 1 (21527)

COSPAR: 1991-045A | Alt Name: REX

Image

Additional Sources

Launch Details

Launch Date

June 29, 1991

Launch Site

AFWTR

Launch Pad

SLC5

Launch Vehicle

Scout G-1

Orbital Elements

NORAD ID

21527

International Designator

1991-045A

Epoch

Sat, 04 Jul 2026 04:01:53 GMT

Apogee

Calculating...

Perigee

Calculating...

Inclination

89.53°

Right Ascension

259.26°

Eccentricity

Calculating...

Argument of Perigee

290.49°

Period

101.15 min

Mean Motion

14.24 rev/day

Latitude

Calculating...

Longitude

Calculating...

Altitude

Calculating...

Velocity

Calculating...

Polar Plot

3D Visualization

Basic Satellite Info

Name

REX 1

Alternative Name

REX

Type

Payload

Status

Unknown

Owner

AFROM

Country

United States

Constellation

N/A

Related Satellites

Major Events

N/A

Latest TLEs

1 21527U 91045A   26185.16798461  .00000121  00000-0  46753-4 0  9993

2 21527  89.5328 259.2586 0066212 290.4886  68.9207 14.23587128817510

Source: Celestrak

Summary

REX 1, also known as REX, is an experimental satellite owned by AFROM and operated under the Ministar BUS configuration using the GemStar Bus. Launched on June 29, 1991, from AFWTR at SLC5 using a Scout G-1 launch vehicle, it has dimensions of 0.4 meters in length, 0.6 meters in diameter, and a span of 6.1 meters. The satellite was manufactured by DSI and has a dry mass of 85 kg, matching its launch mass. It is equipped with four deployable fixed solar arrays and batteries for power generation. Its shape consists of a cylinder with an antenna. REX 1's purpose is experimental, and it carries the REX payload. The satellite's country of origin is the United States.

Physical Characteristics

Length

0.4

Diameter

0.6

Span

6.1

Dry Mass

Launch Mass

Shape

Cyl + Ant

Radar Cross Section

0.4966

Visual Magnitude

Unknown

Color

Unknown

Material Composition

Unknown

Technical Details

Payload

REX

Purpose

Experimental

Mission

Experimental

Manufacturer

DSI

Life Expectancy

Unknown

Bus

Ministar

Configuration

GemStar Bus

Motor

Equipment

Power System

4 deployable fixed solar arrays, batteries

ADCS

Unknown

Transmitter Frequency

Unknown

Map

This tool will help you track the satellite's position and predict its upcoming passes over your location. Simply input the coordinates or click the geolocation button to get started.

Latitude

Longitude

Next Pass

Azimuth Elevation Time (Local)

Start Azimuth

Max Elevation

Stop Azimuth

Time Until

Pass Duration

Satellite Articles

View All Posts »

Learn more about satellites and other related topics.

Space Brief 11 Apr 2025

Today's brief covers Millennium's milestone in missile defense, new satellite jammer for Space Force, budget increases for defense, delays in MEO satellite contracts, and potential impacts of Trump's latest order on Pentagon programs.

SpaceX Hits 50 Launches, Falcon Heavy Scrub, X Report 28 Apr 2026

SpaceX hit 50 launches in 2026 on April 26. Falcon Heavy's ViaSat-3 mission, only its 12th flight, scrubbed on weather at Kennedy; new date pending.

X Report 30 Apr 2025

SpaceX achieves a remarkable milestone with its 50th Falcon 9 launch of 2025, while Starlink continues to expand, facing competition from China's megaconstellation efforts.

Falcon 9 B1067 Targets 36th Flight Record on Starlink 10-42 | KeepTrack Space Brief

SpaceX Falcon 9 booster B1067 set for 36th flight Thursday with Starlink 10-42 mission from Cape Canaveral. Long March 10B debuts Friday in China.

Space Brief 19 Nov 2024

Today's brief covers the investigation into Musk-Putin calls, SpaceX launch restrictions impacts, Pentagon's space investment strategies, ABL Space's pivot in focus, and Israel's defense export developments.

X Report 28 Nov 2025

Today marks a significant milestone as SpaceX successfully launches another batch of Starlink satellites, boosting global connectivity efforts.

NASA Expands SpaceX Crew Contract as Boeing Stalls | KeepTrack X Report

NASA adds crew missions to SpaceX's contract as Boeing Starliner certification stalls, while Falcon 9 hits its 60th orbital launch of 2026.

Space Brief 18 Sep 2024

Today's Space Brief covers Rocket Lab's IoT satellite launch, SpaceX's European Galileo satellites, FAA's fine on SpaceX, Polaris Dawn mission achievements, and more.