Orbital GEOStar Hosted Payloads User Manual

GEOStar™ Hosted Payloads

Hosted Secondary Payload Opportunities Provide Rapid/Low-Cost Access to Space

GEO

Hosted Payloads

Orbital Sciences Corporation’s Hosted Payload Interface (HPI) allows small payloads for science,

technology demonstration, and national security applications to be mounted onto Orbital’s GEOStar-2

bus GEO communications platform. This hosted payload program takes advantage of the high

frequency of commercial satellite launches and the excess resources that typically exist on a

commercial communications satellite to provide frequent and low-cost access to space.

Mission Opportunities

Hosted payloads provide a novel way to serve the needs of the science, technology demonstration,

and security and defense communities as well as the space-based commercial telecommunications

industry. Hosted payloads can be housed on spacecraft whose primary mission does not require full

use of communications payload capacity over the 15-year mission life of the commercial satellite.

The satellite owner/operator works with Orbital and the hosted payload provider to make use of the

available surplus spacecraft resources. By taking advantage of this excess, hosting can be done at a

fraction of the cost of typical science and technology demonstration satellite missions using dedicated

spacecraft.

The frequency of commercial spacecraft launches provides many opportunities for small payloads to

gain access to space. Payload hosting on Orbital’s GEOStar Bus is available on an almost yearly basis

for future launches. This robust launch pace and the quick turnaround and strict schedule requirements

of commercial spacecraft programs (typically 24-27 months) ensure efcient access to space with

minimal risk of delay.

FACTS AT A GLANCE

Programs

• Orbital integrated the Geostationary

Communication and Control

Segment onto Intelsat’s Galaxy 15

spacecraft for the Federal Aviation

Administration’s Wide Area

Augmentation System. Galaxy 15

was launched in October 2005 and

continues operation.

• The Commercially Hosted Infrared

Payload Flight Demonstration Program

(CHIRP) is for the Air Force's Third

Generation Infrared Surveillance

(3GIRS) program. The SAIC wide-eld

of view sensor was integrated onto

the Orbital-built SES-2 commercial

GEO communications satellite to

validate missile warning technologies

from geosynchronous orbit in a fast

and cost-effective manner. SES-2 was

successfully launched in September

2011.

Galaxy 15 in production. A hosted technology
demonstration payload for the FAA is
mounted on the nadir deck.

GEOStar™ Hosted Payloads

Specications

Core Features

Payload Mass Capability: < 150 kg (negotiable based on size of

primary payload)

Avail. Payload Vol.: Up to 165 x 63 x 101 cm (negotiable)

Orbit: Geosynchronous

Launch Vehicle: Ariane, Soyuz, Land Launch, Proton, and
similar

Typical Mission Life: 1-4 years

Program Schedule: 24 months from ATP to launch

Structure

Construction of

Payload Platform: Composite/aluminum facesheets over
aluminum honeycomb core

Thermal Control: Passive; payload may elect its own active
control

Power Subsystem Available

Payload Power: 500 W-1,000 W BOL (negotiable)

Bus Voltage: +36 VDC (nominal)

Attitude Control Subsystem

Stability Mode: 3-axis; zero momentum

Pointing Control: 0.01

Pointing Knowledge: <0.03
(standard Earth sensor/Sun sensor suite)

Rate/Stability: Provided upon request; dependent upon
time increment

°

granularity in maintaining pointing

°

During nominal operations

Hosted Payload Accommodation

Depending on the design of the host spacecraft, a wide variety of

hosted payload congurations can be supported. The payload is

mounted on the nadir-facing deck providing excellent eld of view

for Earth-viewing instruments and for thermal radiators. Non-

Earth-staring payloads can be accommodated on the nadir deck

as well by canting the boresight of the instrument at an angle.

Deep-space viewing instruments may also be mounted on the

zenith end of the spacecraft using a modied antenna support

bracket.

The payload panel structure consists of aluminum face-sheets

over an aluminum honeycomb core with embedded heat pipes

and conductors, providing stability and thermal control. Increased

platform stability for specic missions can be achieved by using

a mission-specic platform with quasi-kinematic mounts. A

combination of an inertial reference unit, earth sensor assembly,

and sun sensors are used to offer accurate attitude knowledge

needed to meet 0.1 degree pointing accuracy or better. Downlink

data rates of up to 75 Mbps can be provided (based on ground

station parameters). No solid state recorder is needed because,

during nominal operation, the spacecraft continually transmits

data to a known location on Earth with a pre-specied minimum

effective isotropic radiated potential.

An Earth-staring remote
sensing hosted payload
on the nadir deck of a
GEOStar-2 bus

Command and Data Handling Subsystem

Payload Interface: Independent via Orbital's HPI Modem
interface or as Remote Terminal on 1553
bus (dependent upon data rate)

Radiation Tolerance: 100 Krad for Spacecraft (15 years at

GEO) HPI Modem at 20 Krad (1 to 4
years at GEO)

RF Uplink: Up to 2 Mbps (based on ground station

parameters)

Data Downlink: Up to 75 Mbps (based on ground station
parameters)

More Information

Mr. Guy Savage

Program Director
[phone], [e-mail]

Orbital Sciences Corporation

45101 Warp Drive

•

Dulles, Virginia 20166

•

www.orbital.com

Hosted Earth Imager
Payload (Example)

A close-up view of the notional

instrument and associated

Hosted Payload

Electronics

©2014 Orbital Sciences Corporation FS001_08_2998