Bristol Aerospace - Defence and Space

SCISAT-1

In March 1999 Bristol commenced work on the design and development of the SCISAT-1 spacecraft in support of the Atmospheric Chemistry Experiment (ACE). The mission development was led by the Canadian Space Agency and Bristol was the spacecraft prime contractor. The mission Principal Investigator is Peter Bernath at the University of Waterloo and the goal of the ACE mission goal is to take a variety of measurements in the Earth's stratosphere and troposhere to advance scientist's understanding of ozone depletion, particularly above Canada and the Arctic region. The two instruments on the ACE mission are the Fourier Transform Spectometer (ACE-FTS) developed by ABB Bomem in Quebec City and the Maestro instrument developed by EMS in Ottawa.

On August 12, 2003, the 150 Kg SCISAT-1 spacecraft was successfully launched to the desired 650 km orbit on a Pegasus-XL vehicle. The SCISAT-1 spacecraft is currently in its sixth year of highly successful mission operations and continues to high quality science data.

As the Spacecraft Prime Contractor, Bristol was responsible for the design, development, manufacture, integration, and test of the spacecraft bus. The spacecraft bus is made up of a number of subsystems; these include the Command and Data Handling (C&DH) Unit, the Attitude Control System (ACS), the Power Subsystem, the Communications and Tracking Subsystem, the Thermal Control Subsystem, the structure and the flight software. In addition to the development of this flight hardware and software, Bristol was also responsible for the definition of requirements, design, manufacture and test of all electrical and mechanical ground support equipment to support spacecraft bus integration and test and development of the real-time spacecraft simulator.

In addition to development of the spacecraft bus, Bristol was also responsible for the integration of the two science instruments and performance of all spacecraft functional and environmental testing at the CSA operated David Florida Laboratory in Ottawa. Bristol then worked closely with Orbital Sciences Corporation to integrate the spacecraft onto the Pegasus XL launcher and with CSA Satellite Operations personnel to perform LEOP (Launch and Early Operations Phase) and OOCP (On-Orbit Commissioning Phase) of the spacecraft.

SCISAT QUICK FACTS:

Spacecraft mass:	150 kg (110 kg bus, 40 kg payload)
Spacecraft power usage:	80 W orbit average, 100 W peak
Launch vehicle:	Pegasus XL
Launch interface:	3-point discrete
Orbit:	650 km, 74° inclination
Bus reliability:	87% @ 2 years
Payload data interfaces:	RS-422, CMOS/TTL, Analog
Payload data storage:	1.5 GB
Attitude knowledge:	<0.08° (pointing) <0.24° (roll)
Attitude control:	<0.05°
Position knowledge:	<100 m (S-band range rate)

An Adobe Acrobat(PDF) version of the SCISAT-1 Small Satellite Mission data sheet can be downloaded by clicking on the PDF logo to the right (2 pages/771KB)

MAC-200 Multi-Mission Smallsat Bus

Development of the Magellan Aerospace MAC-200 Multi-Mission Smallsat bus was initiated at Bristol in 2004 under contract to the Canadian Space Agency (CSA). The intent was to design a generic spacecraft platform bus platform that could be tailored to meet the requirements for a range of Canadian missions under consideration. The result would be the ability within Canada to effectively implement satellite missions using standard spacecraft bus units and interfaces to achieve minimal multi-mission life-cycle cost. The CSA in consultation with Bristol and other stakeholders in industry, academia and government established a set of requirements that bracketed the candidate missions. Since that time new missions have been identified and requirements have been refined. To date a number of variations of the generic MAC-200 have been developed.

An Adobe Acrobat(PDF) version of the MAC200 data sheet can be downloaded by clicking on the PDF logo to the right (4 pages)

An Adobe Acrobat(PDF) version of the MAC200 Control & Data Handling Unit data sheet can be downloaded by clicking on the PDF logo to the right (4 pages)

CASSIOPE The CASSIOPE mission will be the first to use the Bristol MAC-200 bus. Bristol is developing the CASSIOPE bus under contract to Macdonald Dettwiler and Associates (MDA). The Cassiope Mission is a combination space physics and communications demonstration mission. The e-POP suite of instruments is provided by the University of Calgary and the CASCADE Cx payload is provided by MDA. In addition to developing the bus, Bristol also developed elements of the e-POP payload and performed the integration of the e-POP and payloads onto the spacecraft. In parallel to the MDA contract, Bristol was contracted by the CSA to develop the real-time spacecraft simulator and ground infrastructure that will be used to support multiple missions. CASSIOPE is presently at DFL undergoing the final stages of spacecraft level testing and is scheduled for launch in 2010.
RADARSAT Constellation Mission (RCM) Bristol is teamed with MDA to provide the bus for the RADARSAT Constellation Mission (RCM). Work done in Phase A of the project confirmed that the majority of the existing MAC-200 bus subsystems are applicable to RCM. A larger bus structure and a high-capacity Power Control Unit will be developed for RCM. The mission will be the first to use a monopropellant hydrazine propulsion system. The RCM program is presently in Phase B development and the 3 RCM spacecraft and are scheduled for launch in the 2014-2016 timeframe.
ORBITALS ORBITALS is a radiation belt science mission proposed as a Canadian contribution to the International Living with a Star (ILWS) Program. Bristol has worked closely with the University of Alberta and University of Colorado in Phases 0 and A to develop a variation of the MAC-200 bus that will withstand the harsh radiation environment associated with the ORBITALS GTO-like orbit. In addition, Bristol has determined the changes to the bus ADCS needed to achieve a “sun-pointing spinning spacecraft” in a highly-elliptical orbit. The project is currently in Phase A.
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