Inmarsat and ViaSat to Develop New Broadband Global Area Network (BGAN) Terminal for Defense Sector.

Collaboration to Deliver Unparalleled Mobile Voice and Broadband IP Data to Tactical Warfighters

CARLSBAD, Calif. -- Inmarsat (LSE:ISAT), the leading provider of global mobile satellite communications, and ViaSat Inc. (Nasdaq:VSAT), a provider of digital communications for commercial and military applications, have announced a co-funded project to develop a new mobile satellite communications terminal for the defense sector. The collaboration will provide secure, reliable and highly mobile voice and high-speed data communications to the armed forces.

Targeted specifically at the U.S. and NATO markets, the ViaSat Integrated Terminal will combine Inmarsat's IP-based Broadband Global Area Network (BGAN) technology with ViaSat AltaSec([R]) IP inline encryption equipment to create a portable, ruggedized BGAN user terminal capable of uplinking IP data fully compliant with HAIPE[TM] version 1.3.5 Type 1 security standards. The new terminal takes advantage of ViaSat's long history of supplying ruggedized equipment to tactical warfighters in the Army, Navy, Air Force, and Marines.

"ViaSat's leadership in manpack MILSATCOM terminal equipment makes them a natural partner to manufacture BGAN terminals that can meet the demanding requirements of defense agencies and military services worldwide," said Perry Melton, vice president of sales & marketing for Inmarsat.

BGAN is the world's first mobile communications service to deliver simultaneous voice and broadband IP data to a highly portable device on a global basis. It supports mobile broadband data at speeds up to half-a-megabit per second, as well as guaranteed IP data rates up to 256 kbps. Engineers from both companies have already successfully demonstrated the compatibility of using the BGAN service with ViaSat KG-250 Type-1 High Assurance Internet Protocol Encryptor Interoperability Standard (HAIPE IS) compliant encryption products over the new constellation of Inmarsat advanced broadband satellites, the Inmarsat-4s.

"We know that the BGAN capabilities are highly attractive to a variety of military users, and this agreement with ViaSat will provide enhanced hardware to maximize its potential in that sector," said Melton. "ViaSat has the expertise and insight into U.S., NATO and Allied military needs to develop a BGAN terminal that is a viable augmentation to existing military satcom services."

"This terminal will combine BGAN's unprecedented levels of broadband connectivity for Communications on the Move and other high mobility requirements, with the military's needs for a hardware platform that meets the ruggedness and security needs of IP-centric, tactical users," said Phil Berry, vice president and general manager of Government SATCOM Systems for ViaSat. "By developing a BGAN terminal integrated with HAIPE IS security, we create a near term secure connectivity capability needed by today's warfighters. We look forward to further exciting developments through our strategic partnership with Inmarsat."

HAIPE is a trademark of the National Security Agency. ViaSat and AltaSec are registered trademarks of ViaSat, Inc.

Forward-looking Statements

Certain statements in this announcement constitute "forward-looking statements" within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements involve risks, uncertainties and other factors that may cause our actual results, performance or achievements, or industry results, to be materially different from those projected in the forward-looking statements. These factors include: general economic and business conditions; changes in technology; timing or delay in signing, commencement, implementation and performance of programmes, or the delivery of products or services under them; structural change in the satellite industry; relationships with customers; competition; and ability to attract personnel. You are cautioned not to rely on these forward-looking statements, which speak only as of the date of this announcement. We undertake no obligation to update or revise any forward-looking statement to reflect any change in our expectations or any change in events, conditions or circumstances.

About ViaSat (www.viasat.com)

ViaSat produces innovative satellite and other communication products that enable fast, secure, and efficient communications to any location. The Company provides networking products and managed network services for enterprise IP applications; is a key supplier of network-centric military communications and encryption technologies to the U.S. government; and is the primary technology partner for gateway and customer-premises equipment for consumer and mobile satellite broadband services. The company's three wholly owned subsidiaries, US Monolithics, Efficient Channel Coding, and Enerdyne Technologies Inc., design and produce complimentary products such as monolithic microwave integrated circuits, DVB-S2 satellite communication components, and video data link systems. ViaSat has locations in Carlsbad, CA, and Duluth, GA, along with its Comsat Laboratories division in Germantown, MD. Additional field offices are located in Boston, MA, Baltimore, MD, Washington DC, Australia, China, India, Italy, and Spain.

About Inmarsat

Inmarsat plc (LSE:ISAT) is the leading provider of global mobile satellite communications. Since 1979, Inmarsat has been providing reliable voice and high-speed data communications to governments, enterprises and other organisations, with a range of services that can be used on land, at sea or in the air. The company's services are delivered through a global network of partners, including the world's leading telecoms groups. For the year ended 31 December 2005, Inmarsat plc had total revenue of US$491.1 million and profit before tax of US$95.5 million. More information can be found at www.inmarsat.com.