Frequently Asked Questions

General Questions

ESA stands for "European Space Agency"

NAVISP stands for "Navigation Innovation and Support Programme"

ARTES stands for "Advanced Research in Telecommunications Systems"

ITT stands for "Invitations To Tender"

PNT stands for "positioning, navigation and timing"

Questions About ITTs

External services cover services such as hire of facilities, computer services, manpower services (e.g. consultancy), plating of parts, services for procurement of HIREL parts etc. The costs for these should be shown on the PSS A2 form of the Prime Contractor under Other Cost Elements Point 3.7 and further detailed on Exhibit. A Third Party should be involved as subcontractor (not as external services) when they are contributing to the development work of the project, when they are responsible for the realisation of specific work packages. To include a Third Party as Subcontractor also involves a firm commitment by the Third Party (contract between Prime contractor and Subcontractor) and is especially recommended when this Third Party is essential to carry out the activity.

In principle, the first (advance) payment and the final payment are fixed. The remaining payments can be proposed by the Tenderer with respect to dates and amounts, but should take into account a balance between expenditures and payments and should be related to achievements (conclusion of work packages, development of hardware/software, reviews, etc).

Payment milestones have to be invoiced when reaching the achievements related to the specific milestones and as defined in the Milestone Payment Plan included in the contract. Each payment milestone is broken down to the amounts that pertain to each member of the Project team. Project Team members have to issue a specific invoice for the part of their competence. Subcontractors have to submit their invoices to the Prime contractor. The Prime contractor approves the invoices and submits them to ESA as specified in the contract. ESA checks if the required milestone achievements have been reached and payments will be made within one month directly to all contractors.
For example, if the payment plan agreed in the contract foresees the following breakdown:
Milestone M Amount

  • Company A (prime) 25 kEuro
  • Company B (subcontractor) 12 kEuro
  • Company C (subcontractor) 0 kEuro
  • Company D (subcontractor) 18 kEuro

Company A will have to issue an invoice for 25 k EUR directly to ESA. Company B and D will have to issue an invoice of 12 and 18 k EUR respectively to Company A for approval and forwarding to ESA. When ESA receives the invoices of Company B and D endorsed by Company A, ESA will proceed with the payment of the invoice directly to the accounts of Company B and D.