Exhibit 99.1

High Stakes for Mobile Satellite Systems

World Satellite Business Week

September 10, 2009

Safe Harbor

“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995:

This presentation includes “forward looking statements.” All statements other than
statements of historical facts included in this presentation regarding the prospects of our
industry and our prospects, plans, financial position and business strategy, may
constitute forward looking statements. These statements are based on the beliefs and
assumptions of our management and on the information currently available to our
management at the time of such statements. Forward looking statements generally can
be identified by the words “believes,” “expects,” “anticipates,” “intends,” “plans,”
“estimates” or similar expressions that indicate future events and trends. Although we
believe that the expectations reflected in these forward-looking statements are
reasonable, these expectations may not prove to be correct. Important factors that could
cause actual results to differ materially from our expectations are disclosed in our filings
with the United States Securities and Exchange Commission (“SEC”). All subsequent
written and oral forward-looking statements attributable to us or persons acting on our
behalf are expressly qualified in their entirety by the cautionary statements included our
SEC filings. Factors, risks and uncertainties that could cause actual outcomes and
results to be materially different from those projected include, but are not limited to, our
ability to obtain financing, obtain and maintain regulatory approvals, generate sufficient
cash flows, develop our universal chipset architecture, achieve market acceptance for our
services, develop our network and generate technological innovations.

The forward-looking statements in this presentation are made only as of the date of this
presentation.

We undertake no obligation to update or revise the forward-looking statements, whether
as a result of new information, future events or otherwise.

TerreStar Networks

•Owned by U.S. publicly-traded TerreStar Corporation

–(NASDAQ: TSTR)

•Funded into 2010

–Viable, stable and innovating

•Unique spectrum position

–20 MHz of spectrum in 2.0 GHz range (ATC eligible)

– 8 MHz of nationwide 1.4 spectrum

•Most advanced, powerful commercial communications satellite

–Launched July 1, 2009

–First call over satellite using smartphones with no external antennas completed July 19,
2009

•Channel partners in place

•Holistic Technology Ecosystem

–Integrated satellite/ ground-based design

–Flexible device form factors

•Handsets similar to today’s cellular devices

•Mobile data modems

•Chipsets for OEM integration

•Typical mobile devices can be enabled

Integrated Network Architecture

First Phase Satellite Coverage

•Orbital slot 111° West

•Beam coverage: Continental United States, Canada, Puerto
Rico, Hawaii and Alaska

Significant Development Progress

TerreStar Networks Strategy

Spectrum Perfected, License Secured

üSuccessful Satellite Launch

üCall Completed Over Satellite with Integrated Satellite-
Terrestrial Devices

ü All FCC and IC Milestones Achieved

Minimize Risk

ü Experienced Management

ü Market-Defining Technology

ü Tier 1 Partners and Suppliers

Prudent Capital Plan

üTargeted and Prioritized Technology Spend

ü Aggressive Operating Expense Reduction

ü Restructured Agreements with Partners and Suppliers

World’s First Satellite-Terrestrial Smartphone

User Interface

Windows Mobile Professional

Touch Screen

QWERTY Keyboard

Terrestrial

Dual-band WCDMA (850 and
1900)

Quad-band GSM/EGPRS
(850,900,1800,1900)

Wi-Fi

Bluetooth

Satellite

2.x GHz GMR-3G

No External Antenna

Industry-Leading Partners and Suppliers

Critical Partner Ecosystem is in Place and Executing to Plan

Satellite

OSS/BSS

Devices

Network

Thank You.