A Design for an Orbital Assembly Facility

Simon Feast Alan Bond

Outline

• The Problems with On-Orbit Assembly

• Design Constraints / Layout and Assembly

• Why the need for it?

…Why the need for it?

An integral part of the Space Transportation Infras tructure

Function

• Vehicle Assembly and Maintenance Facility

(A Stepping Stone for High Energy Space Missions)

• Propellant Storage

• Assessment and Repair Area for Vehicle Departures/Arrivals

Ideas from the Past

The Main Problem with On-Orbit Assembly

Parallel Orbit In-Plane Orbit

Secondary Considerations with On-Orbit Vehicle Asse mbly

• Space Debris (Protection from it and minimise its creation)

• Limited Illumination (Constrained by frequent earth eclipsing)

• Payload Handling (Transfer from Delivery and Assembly)

• Habitation Modules (Used by Workforce and Vehicle Crews)

• Vehicle Propellant Storage (Required for Facility and Stages)

• Useable Power Load (Necessary for all assembly operations)

• Orbit Location (Position and Resonance with transfer orbits)

…What Influences the Layout of the Base Station Des ign?

Geometric Constraints:

• Earth to Earth-Orbit Launch Vehicle Capacity

• Workforce Habitation Facilities

• Payload Handling Requirements

• Mission Vehicle Size and Propellant Requirements

• Launch Vehicle Docking Accommodation

Maximum Payload to Orbit

12 tonnes – 300km

10 tonnes – 460km Equatorial Space station

Payload Size

4.6m Diameter

12.3m Length

200m3 Capacity

Typical Mission Vehicle Components

Individual Components are Sized to fit inside the Skylon Payload Bay

Components such as Propellant Tankage and Habitation Modules are common units

which can be expanded depending on mission requirements

Modular Arrangement of Vehicle Components

Typical Mission Vehicle Breakdown - (TROY Mars Mission)

Habitation

Earth Return Stage

Earth Departure Stage

Mars Transfer Stage

Typical Mission Vehicle Assembled

Animation

Preliminary Layout Design Sequence

Getting it up there…

Item No. Launches Cost $M

Main Structure 30 Development 8500Habitation 14 Hardware 1000Propellant Tanks 15 Launches 500Manipulators 3 Total 10,000Additional Systems 10Total 72 Maintenance 24

of which:Hardware 10Launches 14

Estimation Table

Further Considerations

• On-Orbit Manufacture

• Typical Load Cases

• Alternative Structure

• Materials / Joining

• Design Life

• Docking / Payload Handling