Space
Selecting the right components for use in satellites or spacecraft
Decisions made by design engineers can have a critical impact on the cost and time of taking a design from bread board into Low Earth Orbit (LEO) or deep space, according to Roger Tall, director, Charcroft
T he failure of a passive
component, or a semiconductor, can be as devastating as the failure of the most sophisticated microprocessor for a satellite
in Low Earth Orbit (LEO), or for a spaceship going into deep space.
Passives in space
Space is certainly making news with images coming back from the James Webb Space Telescope and from the Solar Orbiter, in addition to the launch of the Artemis I rocket by NASA.
The passives that are being used in these spacecraft include more than 16,000 Exxelia film capacitors on the Solar Orbiter, as well as custom film capacitors on the European Ariane 6 launch system. Film capacitors, in addition to magnetics, are also integrated into the Perseverance rover which was launched in July 2020 to explore Mars.
Satellites in Low Earth Orbit (LEO) There is activity closer to home too with the highest number of Nanosat Satellite (NanoSat) launches being completed or announced for 2022.
The constellations of NanoSats, and Cube Satellites (CubeSats) which are in LEO are used for communication networks and to provide
Frequency-tuning components for high-frequency space applications
Solid body fuses are included on the QPL
Roger Tall, director, Charcroft
high-resolution imagery and mapping. The LEO satellites also contribute to ecological management by monitoring land use and natural resources, urban planning and asset tracking. According to Statistica, on January 1, 2022, there were over 4850 artificial satellites orbiting the Earth.
Strong UK space activity While the USA is leading in the number of satellites in LEO, the UK is seeing strong growth in the space sector.
Laser-based communications and power transmission for satellites are being developed by Lockheed Martin in partnership with researchers at Northumbria University, Newcastle. Lockheed Martin UK also has approval to build the SaxaVord Spaceport which will deliver the first vertical space launch from the UK.
In Edinburgh, Skyrora has applied to the UK Civil Aviation Authority for a licence to launch rockets carrying commercial satellites next year, and Virgin Orbit is looking to carry out the first satellite launch from a spaceport in Cornwall, which includes a satellite developed in Wales. There will also be collaboration between the UK Space Agency (UKSA) and the
14 October 2022 Components in Electronics
Defence Science and Technology Laboratory (Dstl) to develop new technologies and deepen specialist expertise.
A Class 7 cleanroom installed recently by Euroquartz enables customers to source UK- manufactured surface-mount oscillators which are not covered by the International Traffic in Arms Regulations (ITAR) which governs the export of some US-manufactured components.
Speeding the NanoSat design cycle The increase in the number of NanoSats, CubeSats, and other small satellites, has changed the dynamics required for designing LEO-based satellites. Unlike a spacecraft, which must operate faultlessly for years as it travels in deep space, LEO satellites are designed to fulfil commercial applications over a comparatively short life-cycle. This changes the design priorities so the engineer must deliver reliability over a shorter operational lifetime, but meet tighter cost constraints for commercial applications.
Components which have a lower level of qualification typically have a shorter lead-time as well as a lower cost. So, cost can be taken out of the design cycle by using a standard commercial off-the-shelf (COTS) version of the
passive for the early Bread Board (BB) stage of the design.
For the Flight Model (FM) of a LEO satellite, the designer will use a high-reliability COTS or AEC-Q200-qualified version of the passive. Components which are listed on the European Space Components Coordination (ESCC) Qualified Parts List (QPL), or on the European Preferred Parts List (EPPL) are typically used for spacecraft which have a longer lifetime than a LEO satellite. Moving from passives, to full space-grade qualification, allows the engineer to test the design more quickly, and to reduce the cost without compromising the final reliability.
One vital consideration is that the design engineer should check that the passive is available with the same value, voltage and case size at the levels of reliability. As the level of reliability increases, the number of capacitors or resistors is reduced. The danger is that the designer could select a part for bread board design which is not available with space-grade qualification.
The designer should therefore first select the passive from the highest reliability that will be needed for the FM design and then work back to the lower quality levels for the bread board.
www.cieonline.co.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62
