LeoTerra Enters Into Unique Relationship with TerreStar Networks

LeoTerra LLC, an emerging Low-Earth Orbit (LEO) satellite
communications company and TerreStar Networks Inc., a subsidiary of
Motient Corporation (MNCP), announced today their intent to explore
the feasibility of providing interoperable, advanced global mobile
broadband communication services from their respective LEO and
Geo-Stationary (GEO)-based satellite networks. The interoperability of
these LEO/GEO satellite communication systems would provide global
mobile broadband communications to support public safety and emergency
providers as well as offer rural connectivity and wholesale wireless
network extension services to retail operators.

Over the past several months, LeoTerra and TerreStar have been
working together to develop a strategy to provide previously
unavailable products and services over both networks using a common
terminal or handset device. LeoTerra and TerreStar have asked Surrey
Satellite Technology Ltd (SSTL), LeoTerra's satellite design partner,
to study these advanced services.

"Working with our leading-edge small satellite builder and
TerreStar, we hope to design an innovative platform to provide truly
mobile broadband solutions across the globe," said David Marshack, CEO
of LeoTerra LLC.

"Emerging customer requirements are compelling us to explore this
opportunity," said Robert H. Brumley, President and CEO of TerreStar
Networks Inc. "By combining our unique capabilities with LeoTerra's
and SSTL we hope to provide our government and commercial partner's
access to IP-based, global mobile broadband access anywhere."

Based on a platform designed by Surrey Satellite Technology Ltd.,
a leader in the design, manufacture and deployment of LEO satellites,
LeoTerra's network will look to employ small, high-power satellites
that will allow on-demand constellation growth while providing new,
higher levels of service. By coupling LeoTerra's scalable design with
the flexibility of TerreStar's all-IP, integrated GEO
satellite/terrestrial network, the team hopes to provide users with
previously unavailable coverage and adaptability. TerreStar plans to
launch the largest, most advanced commercial communications satellite
ever deployed.

"SSTL is very pleased to have been invited to participate in
exploring the feasibility of providing this innovative service. We
expect that SSTL's unparalleled combination of value-for-money and
extensive experience in orbit - gained through 26 satellite missions -
will provide the team with a leading edge capability," said Sir Martin
Sweeting OBE FRS, Director of the Surrey Space Centre and CEO of
Surrey Satellite Technology Ltd.

Over the coming months the team intends to work with vendor
partners, government agencies and commercial enterprises to develop a
suite of comprehensive, leading-edge products and services.

About LeoTerra LLC

LeoTerra (www.LeoTerra.com) was founded by space and broadband
veterans to develop the world's first satellite system designed to
deliver mobile broadband anywhere. The first satellites, launched into
polar orbit, are planned for a 2008 launch.

About TerreStar Networks Inc.

TerreStar (www.terrestar.com), a subsidiary of Motient Corporation
(MNCP), plans to build, own and operate North America's first
next-generation integrated mobile satellite and terrestrial
communications network that will provide universal access and tailored
applications throughout North America over conventional wireless
devices. With a first-to-market launch strategy in 2008, TerreStar
expects to offer customer-designed products and applications over a
fully optimized 4G IP network.

About Motient Corporation

Motient is the controlling shareholder of TerreStar Networks Inc.,
and a shareholder of SkyTerra Communications and Mobile Satellite
Ventures LP. For additional information on Motient, please visit the
company's website at www.motient.com.

About Surrey Satellite Technology Ltd.

Based in Guilford, England, Surrey Satellite Technology Ltd. is a
200-strong, $55M turnover private company formed in 1985 by the
University of Surrey to commercialize the results of its innovative
small satellite engineering research. The Company, majority owned by
the University and with minority holdings by its staff and SpaceX
(USA), has enjoyed steady growth in revenues of approximately 20% each
year since 2000. SSTL recently acquired the SIRA Space Optics Division
to enhance its in-house capability for satellite Earth observation
instruments.

SSTL was the first professional organization to offer low-cost
small satellites with rapid response employing advanced terrestrial
technologies.

SSTL supplies the international marketplace, with customers
including ESA, NASA, French DGA, USAF, US DOE, China and UK BNSC &
MoD.

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