After many years of effort, on 31st October 2018, the SDP Consortium submitted its design documentation for Critical Design Review (CDR). The SDP element already went through a pre-CDR review in June which included an Architecture Tradeoff Anaysis Method (ATAM) to identify risks and gaps with the architecture and examined the readiness of the System Engineering artefacts. The current documentation set addressed concerns raised in the pre-CDR and includes a new category of reports detailing the key prototyping activities that have been undertaken. Alongside the reviewable document set the Consortium have written up a lot of additional supporting material into new SDP Memos that are available for reference. A high-level overview presentation is being prepared for 9th November and a set of informal discussions will be held on 22nd/23rd November to explore the prototyping and modelling work developed up to submission. The SDP CDR meeting itself takes place in January 2019 with the Design Consortium expected to close by 31st March 2019 after which SKAO takes over managing activities (from that point until construction formally starts they are known as bridging activities) initially in support of the System Level CDR and then with a view to readying for construction.