A hardware supplier joining a C-LEO consortium needs a clear contribution to the lead’s proposal: the item it will deliver, the interfaces it depends on, the evidence it will hand over and the person who will accept it. This guide focuses on that supplier boundary. The C-LEO proposal guide covers the lead’s overall technical response and the split between Call 2 and Call 3.
Checked 8 September 2026: C-LEO Call 3 Stage One closed on 7 September. FAQ 2.26 permits new partners and limited cost changes between stages, while restricting substantial changes to the technology, overall aims or benefits. This is a conditional path within an existing proposal, not a reopened lead application. C-LEO Call 3 applicant FAQs C-LEO Call 3: national applicant guide
What is our role in the consortium?
Confirm the programme, call, lead organisation, proposal stage and proposed work package directly with the lead. A company named in a historical award is not necessarily preparing a new bid. UKSA’s FAQ 2.35 states that it does not hold a list of organisations forming consortia or primes submitting to Call 3. C-LEO Call 3 applicant FAQs
Ask the lead which technical gap your contribution closes and what information it can share. Use an agreed confidentiality boundary. You need enough host and programme context to estimate the package, but the first conversation need not expose unrelated designs or another partner’s confidential material.
What belongs in the antenna supplier handover?
Fictional example: a supplier proposes antenna control electronics for a lead’s terminal demonstration. The lead owns the terminal and integration campaign. The supplier owns the board and firmware. All allocations below are proposals requiring agreement, not a description of a real C-LEO consortium.
| Boundary | Supplier proposes to provide | Lead input / unresolved decision |
|---|---|---|
| Hardware scope | Revision B board, firmware identification and supplied-item list | Confirm quantity, representative features and excluded flight hardware. |
| Command interface | Interface response and implementation against an agreed revision | Lead supplies protocol, timing definitions and simulator access. |
| Verification | Board-level planned procedures, results and anomaly records | Agree which system-level tests the lead owns and who provides facilities. |
| Acceptance evidence | Configuration list, report references and open-item disposition | Name the accepting technical authority and review checkpoint. |
| Schedule and cost | Effort for design, integration support and evidence preparation | Confirm host availability, review turnaround and response to change. |
The output is a package the lead can place into its work plan without assuming that “electronics delivered” includes every integration or qualification activity. A useful exclusion is specific: system-level radiation assessment remains with the lead unless separately agreed. Whether that assessment is needed and how it is allocated depends on the actual application and contract.
Fictional proposed supplier handover
Handover: SUP-ANT-HO-01 v1, proposed
Item: antenna control board B, firmware FW-B v0.2
Lead input: draft terminal interface ICD-TERM-02 rev A, not agreed
Quantity: two representative boards
Excluded: flight hardware and system-level radiation assessment
Planned evidence: configuration list, board procedure, raw trace references, report and open anomalies
Evidence rights: proposed lead/customer access to named deliverables, agreement pending
Accepting role: lead technical authority, not yet named
Acceptance checkpoint/date: to agree with the lead
Open question 1: which protocol revision and simulator will the lead provide?
Open question 2: which system tests and evidence rights remain with the lead?
All allocations, rights and dates require agreement. No completed handover is claimed.How do interface changes affect the commitment?
Suppose the lead changes the host protocol after the supplier estimates firmware and test work. The supplier should identify the affected implementation, simulator, procedures and existing evidence, then return a revised impact estimate. A vague contingency percentage does not explain that dependency. The change-impact guide provides the general engineering method.
Call 3’s assessment asks for a credible technical approach, deliverables, milestone breakdown, risk register and governance. A supplier’s package should therefore let the lead reconcile evidence, ownership and schedule. C-LEO Call 3 Stage Two assessment criteria This does not mean the supplier should submit extra documents independently of the lead or bypass the official form.
What must we agree before committing?
Check the scope, assumptions, resource availability, cost basis, evidence rights and delivery responsibilities with the lead. Identify who owns foreground work and which records can be passed to the customer; obtain appropriate advice for the agreement itself. Do not infer eligibility or reimbursement of overseas work from an engineering allocation—use the current call guidance for that decision.
Use the workbook’s supplier sheet to retain the proposed boundary and outstanding questions. Review each row with an engineering owner and the bid lead. If a dependency is unresolved, carry it into the proposal through the permitted mechanism rather than silently converting an assumption into a promise. Continue with the ECSS pre-bid guide for contractual obligations and the UK route hub for other paths into space work.
Control the supplier-to-lead handover
Link the antenna board and firmware configuration to the agreed terminal interface, supplier evidence and accepting lead. If the lead changes the interface, review the affected supplier obligations and verification work before agreeing a revised handover. Arc’s connected programme model can organise that context; engineers retain the technical and approval decisions.
Frequently asked questions
Can a partner join C-LEO Call 3 after Stage One?
FAQ 2.26 permits new partners and limited cost changes between stages, while substantial changes to the technology, overall aims or benefits are restricted. Agree the proposed change with the lead and check programme instructions; this is not a new lead-application route.
Does UKSA publish a list of C-LEO bidding primes?
FAQ 2.35 says UKSA does not hold a list of organisations looking to form consortia or primes submitting to Call 3. A historical award list should not be described as a current bidder list.
What should the supplier give the lead first?
A bounded work-package description: supplied item and configuration, interfaces, assumptions, planned evidence, customer inputs, cost basis and named handover owner. Flag unresolved conditions before they become proposal commitments.
Who should own system-level qualification work in a supplier package?
Agree it explicitly with the lead. The example allocates board and firmware to the supplier and terminal integration to the lead; system-level radiation assessment is excluded unless separately agreed. Whether that work is needed and who provides facilities follows the actual application and contract.
What should change when the lead revises the host protocol?
Review the affected firmware, simulator, procedures and prior evidence, then return an explained cost and schedule impact. Preserve the former interface version and estimate so the lead can reconcile the revised commitment rather than rely on an unexplained contingency percentage.
Book a demo
See how Arc connects a bid commitment to requirements, review decisions and engineering evidence.