The growing complexity of space systems is creating the need for high speed networking technologies to interconnect the different elements of a spacecraft. This interest has spurred initiatives by both ESA and NASA to define the next generation networking technologies for Space. In both cases, Ethernet has been the preferred choice due to its wide adoption in terrestrial applications and because it is fully specified in standards to ensure interoperability. The requirements for integrated circuits that have to operate in space are very different from those that are used in terrestrial applications. In particular, the radiation is much more intense and causes several types of effects on the devices that compromise their reliability. Therefore, special “rad-hard” design and manufacturing techniques are needed for devices that will operate in space. This means that to implement Ethernet in space systems, rad-hard Ethernet components have to be designed. The goal of this project is to design and manufacture rad-hard Ethernet PHYs. In particular a 10/100Mbps PHY is targeted as the first short term objective. This device will enable the use of Ethernet in space systems and also provide the starting point for the long term objective of implementing a Gigabit Ethernet PHY for space. To that end, the project includes a feasibility study and also contributions to the 1000BASE-T-1 Ethernet standard that is currently being developed. This standard will use just one twisted pair as opposed to four of the current 1000BASE-T standard. This makes it attractive for space systems where weight and cabling complexity are an issue. This evolutionary approach is justified by the cost of implementing 1000BASE-T and also because the new 1000BASE-T-1 standard will probably be a much better option for space systems. The Ethernet digital blocks are not available for the space technology. Special architectural techniques will be used by IHP to increase failure tolerance of digital blocks designed in 150 nm rad hard digital library. Digital blocks will be designed by IHP with the 10/100/1000 transceiver in mind so they can be re-used in the future 1Gb/s transceiver.