Document/Purpose

Identifies users and stakeholders and documents their needs/requirements for the IOR mission

Reference: Stakeholder Needs and Requirements (glossary)

Traceability (Upstream / Downstream) Documents Upstream: Mission Context
Downstream: Mission Requirements, CONOPS
Status DRAFT
Baseline Version/Date | Current Version Not yet established | v0.1 4 Mar 2026
Last Updated  7 Mar 2026
Owner / Lead  
Contributors
Reviewers
Scope / Out-Of-Scope Scope: List of users, stakeholders and their requirements.
Out-of-Scope: Operational Context, System Requirements

Users / Stakeholders

Users

Users are individuals or organizations that directly interact with the IOR system during operations.

  1. Production Teams – Personnel responsible for manufacturing and assembling the IOR system components.
  2. QA Personnel – Personnel responsible for verification, validation, and testing of the IOR system.
  3. Deployment Teams – Teams responsible for preparing and deploying the system for launch and operational use.
  4. Mission Operations Teams – Teams responsible for planning, coordinating, and executing refueling missions.
  5. Operators – Personnel responsible for operating the IOR servicing system and monitoring refueling missions.
    • IOR Mission Operators
    • IOR Mission Planners
    • Satellite Operator Coordination Teams
    • Ground System Operators
  6. Maintainers – Personnel responsible for maintaining the servicing vehicle, depot infrastructure, and associated ground systems.

Stakeholders

Stakeholders are organizations or groups that have an interest in the success, safety, or operation of the IOR system.

  1. Owner / Operating Entity – Organization responsible for operating the IOR infrastructure and ensuring its economic viability.
  2. Developers – Organizations responsible for developing the hardware, software, and infrastructure that make up the IOR system.
  3. Technology Partners – Companies providing specialized technologies such as propulsion systems, sensors, docking mechanisms, autonomy systems, or navigation technologies.
  4. Clients / Satellite Operators – Organizations that own or operate spacecraft or constellations and require in-orbit refueling services.
  5. Launch Providers – Organizations responsible for launching servicing vehicles, depots, or propellant supply missions.
  6. Space Agencies / Institutional Stakeholders – Organizations such as NASA, ESA, CSA, and other governmental bodies with interest in standards, safety, and mission coordination.

External Players and Authorities

  1. Regulatory Bodies: ITU, UNOOSA
  2. National spectrum Authorities – FCC, ISED, OfCom, country specific
  3. Space traffic management
    • US Space Command / 18th Space Defense Squadron (18 SDS)
    • EU Space Surveillance and Tracking (EU SST)
    • Space Surveillance Networks
    • Commercial space situational awareness providers
  4. Space Safety and Debris Mitigation Authorities
    • Inter-Agency Space Debris Coordination Committee (IADC)
    • United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS)
    • NASA Orbital Debris Program Office (ODPO)
    • European Space Agency Space Debris Office (ESA SD)

IOR Owner Requirements

Operations Capability Requirements

Requirement ID Summary Linked Issues Stakeholder Type
IOR-STKR-OPER-1 The Owner requires an In-Orbit Refuelling (IOR) system capable of servicing a varied number of space systems across multiple orbital regimes. MISR-3 , MISR-8 Owner
IOR-STKR-OPER-3 The IOR system shall be adaptable to service spacecraft operating in Low Earth Orbit (LEO), Geostationary Orbit (GEO), and space station orbits. Owner
IOR-STKR-OPER-4 The IOR system shall be capable of servicing spacecraft owned and operated by multiple independent commercial or governmental entities Owner
IOR-STKR-OPER-5 The IOR system shall be capable of servicing passive spacecraft equipped with a compliant and compatible refuelling interface. Owner
IOR-STKR-OPER-6 The IOR system shall be capable of servicing spacecraft across orbital altitudes ranging from 500 km to Geostationary Orbit (~35,786 km), subject to defined operational constraints. MISR-5 Owner
IOR-STKR-OPER-7 A single deployed IOR system installation shall be capable of supporting multiple client spacecraft across defined orbital regimes. MISR-6 Owner
IOR-STKR-OPER-8 The IOR system shall support customized deployment configurations for servicing large spacecraft constellations. Owner
IOR-STKR-OPER-9 The servicing capacity of an IOR installation shall be limited only by propellant availability and mission execution time constraints. MISR-3 Owner
IOR-STKR-OPER-37 The IOR system shall support servicing of the three spacecraft categories defined in the Mission Objectives: Interface-Enabled, IOR-Aware, and IOR-Cooperative spacecraft. Owner
IOR-STKR-OPER-38 The IOR system shall be capable of servicing IOR-Aware spacecraft, utilizing closed-loop operational feedback provided by the client spacecraft to enhance RPOD and refuelling operations. Owner
IOR-STKR-OPER-39 The IOR system shall be capable of servicing IOR-Cooperative spacecraft, utilizing cooperative RPOD sequences coordinated between the servicing system and the client spacecraft. Owner
IOR-STKR-OPER-40 The IOR system shall support autonomous Rendezvous, Proximity Operations and Docking (RPOD) and propellant transfer operations. Owner
IOR-STKR-OPER-41 The IOR architecture shall support multiple propellant depots deployed across different orbital regimes (e.g., LEO, GEO, Earth-Moon L1/L2, and Lunar Orbit). Owner
IOR-STKR-OPER-42 An IOR propellant depot shall be capable of being refuelled by any compatible standardized propellant delivery system. Owner
IOR-STKR-OPER-43 The IOR propellant delivery system shall be capable of refueling IOR depots as well as other depots implementing compatible standardized refueling interfaces. Owner

Performance Requirements

Requirement ID Summary Linked Issues
IOR-STKR-PERF-10 The IOR system shall deliver a minimum lifecycle cost reduction of 60% to spacecraft owners in LEO compared to full spacecraft replacement.
IOR-STKR-PERF-11 The IOR system shall deliver a minimum lifecycle cost reduction of 60% to spacecraft owners in GEO compared to full spacecraft replacement.
IOR-STKR-PERF-12 The IOR system shall have a minimum operational mission lifespan of 15 years from first customer servicing event. MISR-4 , MISR-9
IOR-STKR-PERF-13 The SV shall provide sufficient total delta-v capability, exclusive of transferable propellant, to support all mission phases. MISR-8

Propellant Requirements

Requirement ID Summary Linked Issues
IOR-STKR-PROP-14 The IOR system architecture shall be optimized to minimize total propellant expenditure across launch, orbital transfer, local delivery, station-keeping, debris avoidance, and attitude maneuvers
IOR-STKR-PROP-15 The IOR system components shall be designed to maximize transferable propellant fraction relative to self-consumed propellant.
IOR-STKR-PROP-16 The IOR system shall be capable of servicing spacecraft utilizing multiple defined classes of propellants without requiring development of a new IOR system architecture.

Customer Requirements (LEO, GEO or ISS)

Operations Requirements

Requirement ID Summary Linked Issues Stakeholder Type
IOR-STKR-OPER-17 The IOR System mission design and CONOPS shall apply Do No Harm principles including collision avoidance, contamination control, ESD, EMI/EMC, and orbital debris mitigation practices. Customer
IOR-STKR-OPER-18 The IOR System shall support configurable CONOPS to accommodate client-specific requirements during RPOD, mated operations, and departure phases. Customer
IOR-STKR-OPER-19 The solution shall provide a nominal CONOPS describing routine execution of refuelling missions. Customer
IOR-STKR-OPER-20 The IOR System shall support sustained operations in Geostationary Earth Orbit (GEO) consistent with the defined mission design lifespan. Customer

Propellant Requirements

Requirement ID Summary Linked Issues Stakeholder Type
IOR-STKR-PROP-21 The Customer requires the IOR system to store and deliver multiple defined classes of spacecraft propellants. Customer
IOR-STKR-PROP-22 The Customer requires the IOR system to support transfer of electric propulsion propellants. Customer
IOR-STKR-PROP-23 The Customer requires the IOR system to support transfer of storable chemical propellants within the hypergolic family. Customer
IOR-STKR-PROP-24 The Customer requires the IOR system to provide a minimum transferable propellant capacity of 1000 kg per client spacecraft, which may be delivered through one or multiple Service Vehicle (SV) missions. Customer
IOR-STKR-PROP-25 The Customer requires the IOR system to support a minimum single-transfer quantity of 10 kg per refueling event. Customer
IOR-STKR-PROP-27 The Customer requires the IOR system to achieve a propellant transfer rate of not less than X kg per minute. Customer

Compliance Requirements

Requirement ID Summary Linked Issues
IOR-STKR-REGU-28 The SV shall adhere to recognized industry standards and best practices for on-orbit servicing.
IOR-STKR-REGU-29 The SV shall be manufactured and qualified in accordance with applicable National Security Space Launch Port Launch Users Guide requirements.
IOR-STKR-REGU-30 The solution shall comply with CNSSP No. 12 as applicable.
IOR-STKR-REGU-31 The IOR System shall ensure compliance with Orbital Debris Mitigation Standard Practices (ODMSP) as applicable
IOR-STKR-REGU-44 The IOR System and associated missions shall comply with national licensing and regulatory authorization requirements for launch, on-orbit operations, and space servicing activities.
IOR-STKR-REGU-45 The IOR System shall comply with applicable planetary protection and contamination control guidelines for missions operating beyond Earth orbit.

RPOD Requirements

Requirement ID Summary Linked Issues
IOR-STKR-FUNC-32 The SV shall have the capability to perform Rendezvous, Proximity Operations, and Docking (RPOD).
IOR-STKR-FUNC-33 The SV shall perform active RPOD functions to cooperative, passive client spacecraft equipped with an approved fuel interface.
IOR-STKR-FUNC-34 The IOR system shall support servicing of passive third-party spacecraft fitted with an approved fuel interface.
IOR-STKR-FUNC-35 RPOD operations including propellant transfer, detachment, and departure shall be executable through autonomous and/or ground-controlled methods.
IOR-STKR-FUNC-36 RPOD operations shall be monitorable and controllable from the owner ground station.
IOR-STKR-FUNC-46 RPOD operations shall be monitorable from the customer ground station