ISS-Utilization: Bartolomeo - External Payload Hosting Platform
Airbus DS together with its partner TBE (Teledyne Brown Engineering) of Huntsville, AL, USA, propose to provide, within the next two years, a new external payload platform, capable of hosting multiple external payloads on the ISS (International Space Station). This platform, named Bartolomeo, after the younger brother of Christopher Columbus, will be installed, serviced and operated in a collaborative public-private utilization scheme with ESA, NASA, and other partners in the ISS program. 1) 2) 3) 4) 5)
The ISS is a widely accepted platform for research activities in low Earth orbit which currently sees a growth in demand for external utilization. At the moment there are several unpressurized platforms used outside the ISS (Figure 1). While some of them are used only for storing items, there are a number of active sites accessible for payloads at this time. There are eight sites on the ELCs (EXPRESS Logistics Carriers) accommodated on the ITS (Integrated Truss Segment), four on the European COL-EPF (Columbus Laboratory Module Exposed Payload Facility), and ten on the JEM-EF (Japanese Experiment Module -Exposed Facility. The ELC, COL-EPF and JEM-EF positions are accessible with the station's RMS (Robotic Manipulator System), but require an unpressurized transport of payload items to the station and potentially require the installation to be supported by a costly crew EVA (Extra-Vehicular Activity), both items which are difficult to be made available to users in today's ISS operations.
Figure 1: Currently existing external payload facilities on the International Space Station (image credit: NASA)
These external facilities are well booked for the coming years. To overcome this limitation Airbus DS has proposed to provide the new Bartolomeo external payload facility to the forward-facing position of the European Columbus module (Figure 2). The new system will extend the infrastructure and capability of the ISS by 12 additional external sites fitting the expectations of the market. Bartolomeo brings features to its users which are unique for external platforms:
• Unobstructed view of Earth and space
• Unpressurized and pressurized launch of payloads
• Payload or sample return option
• Active cooling capability
• Easy access through standardized payload interfaces
• Enhanced data downlink budget for its payloads.
Figure 2: Bartolomeo external payload hosting facility installed in the Columbus Ram position (image credit: Airbus DS)
Bartolomeo is planned to be operated in a commercial end-to-end mission service enabling fast, cost-efficient and reliable access to low Earth orbit for commercial as well as institutional customers from Europe, the US and the rest of the world throughout the life of the ISS. As competitive end-to-end solution the Bartolomeo service contributes to achieving the scientific and economic goals defined in ESA's Space Exploration Strategy, responds to NASA's demand for external payload hosting on ISS, and provides a most attractive mission solution to the commercial and institutional user community of low Earth orbit.
Bartolomeo Platform System
Operational Facility Configuration: The Bartolomeo pallet structure is designed to fit into the available volume of the SpaceX Dragon Trunk for launch and will be attached on orbit to the Columbus Module Starboard Forward Trunnion with two struts to the Port and Keel trunnions. The pallet size allows for the accommodation of 6 FRAM (Flight Releasable Attachment Mechanism) Standard Payloads. Two Standard FRAM payload interfaces are available on each of the Zenith and Nadir-facing sides. Two additional FRAM interfaces are accommodated by the FRAM Extension Kit. Due to the size constraints of the Space-X Dragon trunk the FRAM Extension Kit will be launched with but not attached to the Bartolomeo pallet. The FRAM Extension Kit will be installed to the pallet structure via EVA once on orbit in concert with the installation of Bartolomeo on the Columbus Module. In addition to the FRAM capability, the pallet perimeter provides enough space to accommodate 6 JCAP (JEM Camera, Light, Pan and Tilt Assembly Adapter Plate)-based payloads. The design of the Bartolomeo platform in its fully occupied configuration is shown in Figure 3 with and MUSES 6) tentatively installed in the forward Zenith-facing FRAM slot (FRAM-2).
Figure 3: Bartolomeo base configuration with all payload slots occupied and one MUSES platform installed on each side. (a) Zenith facing side. (b) Nadir facing side (image credit: Airbus DS)
Power and Data Provision to Payloads: Bartolomeo provides an avionics system for power management, payload command and data routing, and control of the ACS (Figure 4). Power to Bartolomeo is received from COL via the PAPOS (Payload Parking Position Interface) interface at Columbus and from a dedicated NASA/USOS (United States Orbital Segment) - provided power line. All 6 FRAM-sites will nominally receive 120 VDC compatible with the ExPA (EXPRESS Pallet Adapter) as well as CEPA (Columbus Experiment Plate Assembly) standard via dedicated pin allocations in the power connectors. A total of 28 VDC to FRAM-sites can optionally be made available as required. For supplying the 6 JCAP-based payload slots, the 120 VDC power is converted to 28 VDC.
The Bartolomeo command and data routing provisions are connected to the Columbus data management system, which provides hardwired connections via the Columbus External Command & Measurement Unit. In addition it is intended to provide access to the ISS external wireless system, as well as to a Bartolomeo-provided wireless provision supporting Internet Packet based communication with end users.
Figure 4: Data routing from Bartolomeo to Columbus and USOS (image credit: Airbus DS)
Payload Viewing Conditions: The position of the Bartolomeo platform on COL facing forward provides very good viewing conditions in the Zenith, Nadir and Forward direction, reduced viewing sideward and some limited viewing in the Wake direction. The results of a field of view analysis for representative payloads on the pallet are presented in Figure 5 for the Zenith-, Nadir-, Ram-, and Wake-oriented half spheres. In this stereographic projection the light red areas indicate the approximate temporary obscuration of the payload view towards space or Earth.
Figure 5: Payload fields of view from Bartolomeo in stereographic projection with regions of temporary obscuration by ISS solar arrays indicated in red, (a) Zenith, (b) Nadir, (c) Ram, and (d) Wake direction (image credit: Airbus DS)
The total obscuration maxima and minima over one orbit are summarized in Table 1 for all viewing directions. This analysis does not consider visiting vehicles docked to Node 2.
Table 1: Minima and maxima of the payload field of view obscuration
Bartolomeo Platform Servicing Concept:
Platform Servicing Concept: During the utilization phase the Bartolomeo platform concept is fully robotically serviceable. All payloads will be installed using the ISS RMS (Robotic Manipulator System) only. Two different payload sizes are foreseen in the design, an airlock-compatible size suitable for pressurized transport using JCAP brackets as payload to platform interface, and the FRAM-based standard size for unpressurized transport. The payload slot features, interfaces, budgets and servicing concepts are summarized in Table 2.
Table 2: Bartolomeo payload sizes, budgets and resources
Legend to Table 2:
1) Geometric envelope constrained by JEM airlock dimensions, envelope can be extended if payload is launched unpressurized.
2) FRAM capability depends on payload center of gravity
3) Power routed from Columbus
4) Power routed from ISS US Segment
Pressurized Transport Opportunity: The launch of payloads to the ISS is a resource that is very well available for payloads transported in a pressurized environment among other resupply items required by the station operations. With the aim of providing a reliable and easy to prepare way of transportation to ISS, payloads may be launched pressurized to the station and are installed into the Bartolomeo platform using the JEM (Japanese Experiment Module) airlock. Due to the high frequency of flights and the flexibility of the vehicle manifests the risk of a delay in the payload readiness can be mitigated by delaying to the next flight opportunity which on average is available not more than two months later. The launch within the system of ISS resupply flights introduces an unparalleled reliability of the access to LEO (Low Earth Orbit) for small size payloads. The size of the payload items is limited by the envelope of the JEM airlock. This limitation, however, may be mitigated by the potential availability of the NanoRacks airlock in the near future.
Another attractive feature of the pressurized launch option is the relaxed vibrational environment experienced by the payload during launch, due to the transportation of payloads packed in foam inside the standardized Cargo Transfer Bags.
Payload or Sample Return Option: Through the utilization of the Japanese airlock the Bartolomeo concept allows to return samples or entire payloads, depending on their size, back to Earth. The JCAP payload interface allows to remove payloads from the platform using the ISS robotic manipulator system and to put them onto the extended Japanese airlock slide table which needs to be equipped with the available counter interface. After having been transferred to the inside of station, payloads are packed again for return.
Comparison with Existing External ISS Sites:
The Bartolomeo system is very much competitive in comparison to the other existing external payload sites on ISS:
• ELCs (Express Logistics Carriers) with FRAM payload slots
• JEM-EF (Japanese Experiment Module Exposed Facility)
• COL-EPF (Columbus External Payload Facility)
• NREP (NanoRacks External Platform) for very small size payloads
Bartolomeo offers a payload mass and volume capability similar to the ELCs and COL-EPF, whereas the JEM-EF offers much larger payload accommodation (Figure 6). Bartolomeo is very competitive regarding the viewing conditions and the power and data resources available. Bartolomeo payloads can use up to 800 W of power which the other platforms except JEM-EF are unable to provide. Bartolomeo will provide active cooling capability to its payloads as well as the option to choose between unpressurized and pressurized launch and to return samples or the entire payload back to Earth (Table 3)
Figure 6: Payload mass and volume capability of ISS external facilities
Table 3: Comparison of ISS external facilities payload resources
In summary, the Bartolomeo platform will provide an end-to-end service that offers fast, cost-efficient and reliable access to the ISS for private and institutional users on commercial terms. Its all-in-one payload mission service will attract customers from areas including Earth observation, technology demonstrators, astro- and heliophysics, material science and new space flight applications.
Launch: A launch of the Bartolomeo external facility is expexted for 2018 to be installed on the COL-EPF (Columbus Laboratory Module Exposed Payload Facility) of the ISS.
Orbit: Near circular orbit, altitude of ~ 400 km, inclination = 51.6º.
First customer: In September 2016, Neumann Space, an Australian Space technology company, and Airbus DS signed an agreement for a hosted payload aboard the new Bartolomeo platform of the ISS (International Space Station).
Named after the younger brother of Christopher Columbus, the Bartolomeo platform will be attached to the European Columbus Module and operated by Airbus DS starting in 2018. With its All-in-One Mission Service, Airbus DS provides all mission-related elements and can even assist when it comes to building the actual payload. 7)
Neumann Space will use their 50+ liters of payload space on Bartolomeo for their FAST (Facility for Australian Space Testing) program. Patrick Neumann, Chief Scientist and co-founder of Neumann Space stated, "The FAST program provides a unique opportunity for the in-orbit demonstration of technology for small and medium enterprises, schools and universities filling a gap in the current market. With FAST, a collection of payloads starting at just 1 kg mass will be sent together with our Neumann Drive to be operated in space for up to 12 months. We are glad to rely on Airbus Defence and Space to handle launch, power, in-orbit installation, communications down from the ISS and all the other bits and pieces needed to make this program a success."
1) Christian Steimle, Ron E. Dunklee, Bill Corley, Bartolomeo - Commercial External Payload Hosting Facility on ISS," Proceedings of the 67th IAC (International Astronautical Congress), Guadalajara, Mexico, Sept. 26-30, 2016, paper: IAC-16-B.3.4-B.6.5.1
2) "Airbus Defence and Space and the European Space Agency (ESA) launch Bartolomeo, an innovative external commercial payload platform for the ISS," Airbus DS, June 2, 2016, URL: https://airbusdefenceandspace.com/newsroom/news-and-features/airbus-defence-and-space-and-the-european-space-agency-esa-launch-bartolomeo-an-innovative-external-commercial-payload-platform-for-the-iss/
3) "Christopher Columbus' Brother's Space Journey With Airbus Defence and Space & Neumann Space," Satnews Daily, Sept. 29, 2016, URL: http://www.satnews.com/story.php?number=1169213776
4) Christiam Steimle, Uwe Pape, Ronald Dunklee,Bill Corley, "Bartolomeo - Multi-purpose Payload Hosting Facility on Columbus," November 30, 2015, URL: http://nanoracks.com/wp-content/uploads/15-Christian-Steimle-Bartolomeo-Concept-Airbus.pdf
5) Hauke Ernst, Christian Steimle, Luca Briganti, Ron E. Dunklee, "Commercial Utilization of European ISS Elements," Proceedings of the 67th IAC (International Astronautical Congress), Guadalajara, Mexico, Sept. 26-30, 2016, paper: IAC-16-B.3.4-B.6.5.5
6) M. Whorton, O. Adetona, "Earth Observation from the International Space Station: The Teledyne "Multiple User System for Earth Sensing" (MUSES)," Advances in the Astronautical Sciences Guidance, Navigation and Control, Vol. 151, 2014
7) "Airbus Defence and Space and Australia's Neumann Space Sign First Payload Agreement for the New Bartolomeo Platform on ISS," Airbus DS News, Sept. 29, 2016, URL: https://airbusdefenceandspace.com/newsroom/news-and-features/airbus-defence-and-space-and-australias-neumann-space-sign-first-payload-agreement-for-the-new-bartolomeo-platform-on-iss/
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).