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Universal Communication System II (SHUCS)

Problem: The SPACEHAB Universal Communication System (SHUCS) was designed and developed as an independent communications system to allow real-time voice and data transmission to and from space. SHUCS serves as the core Research Double Module communication system to ensure availability of payload uplink and downlink capabilities with ground-based laboratories.
Solution: SHUCS allows secure file transfer, commanding, up/downlink fax and voice communications globally via three ground stations and four satellites. SHUCS uses a standard TCP/IP file transfer protocol with a new Internet extension of .orb. Payload interaction during the entire mission is via the Inmarsat system of geosynchronous satellites and ground stations using the Internet navigation applications. The coverage is subject to attitude variations, but can be close to 100% in a gravity-gradient orientation. SHUCS can also be used on the Space Shuttle mid-deck, Russian Mir Space Station, International Space Station, and commercial satellites.
Initial Operation Date: May 1998, STS-91, SHUCS Phase I-64Kbs
September 1998, MIR PrirodaSHUCS Mir-64Kbs
August 1999, UDM SHUCS ISS-R,-128Kbs
May 2000, STS-107 SHUCS II-Ka Band
Beyond 2000, SHUCS Phase III-2nd Antenna
Technology Goal: The overall goal of the SPACEHAB Universal Communications System (SHUCS) is to provide reliable and Shuttle - independent data communication channel(s) that are responsive to payload user requirements. SHUCS will make use of the commercial Inmarsat geosynchronous orbit (GEO) satellite constellation and ground stations communication network operating in the L-band Radio Frequency (RF) spectrum. SHUCS will be capable of providing data from the ground operating station direct to the remote user laboratory via ISDN land lines and the Internet network system. SHUCS will consist of two assemblies an external assembly consisting of a pan and tilt unit and antenna and an internal part consisting of a terminal unit. To lower development risk and to increase the user feasibility of SHUCS, SPACEHAB has maximized the use of commercial off-the-shelf systems and procedures.

The internal terminal unit is a Lynxx unit provided by California Microwave. This unit is currently used in maritime applications and the harsh environment of the desert. The terminal will provide channel control, antenna steering, Doppler compensation, and data modulation/demodulation. The terminal will also have an internal maneuvering unit to provide solid-state inertial navigation information and a Global Positioning System (GPS) to position the antenna for maximum coverage by the satellite system. These systems are also commercial off-the-shelf systems. The terminal comes complete with a standard telephone handset that the crew can use to communicate with individuals on the ground. They also have a fax port available. This terminal will be mounted inside the SPACEHAB module with connecting cables that will be routed through a port to the external unit.

The external unit is designed for mounting on the rooftop of the aft bulkhead of the SPACEHAB module. The current design utilizes a Pan and Tilt Unit (PTU) that is currently designed for the Shuttle Closed Circuit Television (CCTV) System. The PTU will provide the positioning for the antenna. The antenna that comes standard with the California Microwave Lynxx terminal must be altered to meet the Shuttle safety requirements for launch and the space environment. This antenna will be significantly strengthened to ensure the structure can withstand launch loads and thermally conditioned to meet the extreme temperature fluctuations.

Goals Supported: 1) Fly Safely
2) Meet the Manifest
3) Improve Supportability
4) Reduce Cost
5) Support HEDS


Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 04/07/2002
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