--- title: "Project CALLISTO" ocid: "ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3" canonical_url: "https://d3tenders.com/contract/?ocid=ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3" markdown_url: "https://d3tenders.com/contract/ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3.md" json_url: "https://d3tenders.com/contract/ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3.json" source: "Contracts Finder" current_stage: "Tender" buyer: "MINISTRY OF DEFENCE" published: "2026-07-06" --- # Project CALLISTO Buyer: MINISTRY OF DEFENCE Current stage: Tender OCID: ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3 [View canonical contract page](https://d3tenders.com/contract/?ocid=ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3) [Download OCDS JSON](https://d3tenders.com/contract/ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3.json) ## Summary The Ministry of Defence has initiated an active tender process entitled "Project CALLISTO," focusing on engineering design services within the aerospace sector. The procurement is structured into two distinct Lots: "CALLISTO LIGHT" for engines at 750N and "CALLISTO HEAVY" for more powerful engines between 1.8-2kN. This open procedure, valued at £750,000, seeks affordable, single-use engines for air systems, to advance beyond hobbyist-level capabilities. Interested parties must submit their Invitation to Tender (ITT) via the Defence Sourcing Portal by 27th July 2026. The contract period will commence on 16th October 2026 and conclude on 31st March 2027, with services to be delivered across diverse locations including the United Kingdom and various international territories. This tender presents robust growth opportunities for businesses specialising in aerospace engineering and design services, particularly small and medium enterprises (SMEs) capable of developing advanced, cost-effective engine technologies. Companies with the capability to design, develop, and test prototype engines will find this contract conducive to showcasing their innovations and scalability. As the procurement method is an open procedure, it offers equal competitive ground for both new entrants and established players in the defence and aerospace industries to secure government contracts and potentially establish long-term partnerships with the Ministry of Defence. ## Notice Project CALLISTO Requirement: Affordable, single use engines for current and future air systems, munitions & One Way systems, to bridge the performance gap between hobbyist, model aircraft engines and higher performance, long-life & more exquisite engines. This phase will consist of design, development and ground testing (in appropriate engine test facilities) of Qty 4 prototype engines. The engines must be affordable and scalable. Any future scaled production requirement is not included under this competition, and if required shall be subject to a separate procurement. LOTS: This procurement is split into TWO Lots: LOT 1 CALLISTO LIGHT is for a smaller, less powerful engine (750N) LOT 2 CALLISTO HEAVY is for a more powerful engine, (1.8-2kN) Tenderers are able to bid for one or both lots. Full details of the requirement and anticipated dates can be found in the linked ITT. Tenderers wishing to take part must submit an ITT on the Defence Sourcing Portal no later than the specified closing date. ## Key Details | Field | Value | | --- | --- | | Publication source | Contracts Finder | | Latest notice | https://www.contractsfinder.service.gov.uk/Notice/36585cd2-b044-47cb-81f0-e6139352fa45 | | Notice type | Tender Notice | | Procurement type | Standard | | Procurement category | Services | | Procurement method | Open | | Procurement method details | Open procedure (below threshold) | | Tender suitability | SME | | Awardee scale | Not specified | | All stages | Tender | ## Dates | Field | Value | | --- | --- | | Publication date | 6 Jul 2026 | | Submission deadline | 27 Jul 2026 | | Future notice date | Not specified | | Award date | Not specified | | Contract period | 15 Oct 2026 - 31 Mar 2027 | | Recurrence | Not specified | ## Values | Field | Value | | --- | --- | | Tender value | £750,000 | | Lots value | Not specified | | Awards value | Not specified | | Contracts value | Not specified | ## Status | Field | Value | | --- | --- | | Tender status | Active | | Lots status | Not specified | | Awards status | Not specified | | Contracts status | Not specified | ## Buyer | Field | Value | | --- | --- | | Main buyer | MINISTRY OF DEFENCE | | Locality | BRISTOL | | Post town | Bristol | | Postcode | BS34 8JH | | Country | England | | ITL 1 | TLK South West (England) | | ITL 2 | TLK5 West of England | | ITL 3 | TLK52 Bath & North East Somerset and South Gloucestershire | | Local authority | South Gloucestershire | | Electoral ward | Stoke Park & Cheswick | | Westminster constituency | Filton and Bradley Stoke | | Delivery location | Not specified | ## CPV Codes ### Divisions - 71 - Architectural, construction, engineering and inspection services ### Codes - 71320000 - Engineering design services ## Release History - 6 Jul 2026 at 16:01 - Tender - Tender Notice - https://www.contractsfinder.service.gov.uk/Notice/36585cd2-b044-47cb-81f0-e6139352fa45 ## Documents - https://www.contractsfinder.service.gov.uk/Notice/36585cd2-b044-47cb-81f0-e6139352fa45 6th July 2026 - Opportunity notice on Contracts Finder - https://contracts.mod.uk Link to eSourcing Portal - https://contracts.mod.uk/go/70568242019F381DF1EE Link to ITT ## Provenance This Markdown file is an alternate public rendering of the D3 Tenders contract record. The canonical page is https://d3tenders.com/contract/?ocid=ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3. The underlying structured data is available as OCDS JSON at https://d3tenders.com/contract/ocds-b5fd17-76761043-04d9-4843-9feb-7cc5b2b411a3.json.