Minimize ISS: Bartolomeo

ISS-Utilization: Bartolomeo - External Payload Hosting Platform

Platform System   Development Status   Launch    OSIRISv3    References

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: Artist's rendition of the Bartolomeo platform, an external payload hosting facility named after the younger brother of Christopher Columbus, it will be mounted on the forward side (ram direction) of the Columbus module. Up to 11 units will provide affordable, quick and easy access to space (image credit: Airbus DS)

Legend to Figure 2: As of 2018, a laser communication link was added to the Bartolomeo platform (Ref. 12).

ESA (European Space Agency) and Airbus DS have signed a PPP (Public Private Partnership) agreement for the construction, launch and operations of the commercial "Bartolomeo" platform — Airbus' new external payload hosting facility will be attached to the European Columbus module of the ISS (International Space Station) from mid-2019. 6)

The signing of the commercial partnership will make Bartolomeo a reality next year. While the European company funds the development and promotes commercialization, ESA will support the launch, installation and operations.

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 4 with and MUSES 7) tentatively installed in the forward Zenith-facing FRAM slot (FRAM-2). 8) 9)

All payload interfaces use the GOLD-2 (General-Purpose Oceaneering Latching Device-2) interface (Figure 3). Through the utilization of the ISS payload airlocks the Bartolomeo concept allows to return samples or entire payloads, depending on their size, back to Earth. The GOLD-2 payload interface allows to remove payloads from the platform using the ISS RMS and to put them into one of the ISS payload airlocks with appropriate counter interfaces. After having been transferred to the inside of station, samples are packed again into CTBs (Cargo Transportation Bags) for return. Payload or sample return is an optional service depending on the availability of slots in a returning vehicle. Nominally, payloads are removed from the platform at the end of the service contract and undergo destructive re- entry or return onboard a visiting vehicle.


Figure 3: Standard platform to payload interface (image credit: Oceaneering Space Systems Inc.)


Figure 4: 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 5). 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 5: 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 6 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 6: 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.


JCAP-based Payloads

FRAM Standard Payloads

Quantity of sites



Field of View

• All Nadir and Zenith view
• 4 slots Ram view

• 2 slots Zenith and Ram view
• 2 slots Nadir, Ram, Wake

• 1 slot Zenith, Ram, Starboard
• 1 slot Nadir, Ram, Starboard

Geometric envelopes

640 x 830 x 1000 mm 1)

864 x 1168 x 1245 mm

864 x 1168 x 1245 mm

Mass per payload

up to 300 kg nominal

up to 599 kg nominal 3)

up to 300 kg nominal 3)

Power per payload

up to 150 W

120 VDC operational power up to 800 W, CEPA / ExPA compatible 3)

120 VDC operational power,
ExPA compatible 4)

Data I/F to COL

up to 100 Mbit/s via
Bartolomeo wireless system

• up to 100 Mbit/s via
Bartolomeo wireless system
• Ethernet 10 Mbit/s

up to 100 Mbit/s via
Bartolomeo wireless system

Cooling capability


1 Nadir, 1 Zenith site cooled


Servicing concept

• Pressurized upload
• Transfer through JEM-A/L
• Robotic installation

• Unpressurized upload
• Robotic installation

• Unpressurized upload
• Robotic installation

Payload to platform interface

JCAP bracket and electrical

P-FRAM standard, P-FRAM
modified with fluid I/F

P-FRAM standard

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 (Flight Releasable Attachment Mechanism) 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 the 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 7). 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 7: Payload mass and volume capability of ISS external facilities












864 x 1168 x
1245 mm

up to
599 kg

750 W @ 120 VDC
500 W @ 28 VDC

10 Mbit/s






864 x 1168 x
1245 mm

370 kg


100 Mbit/s






800 x 1000 x
1850 mm

500 –
2500 kg

6 kW @ 120 VDC
1.2 kW @ 120 VDC

100 Mbit/s
TBD Mbit/s

900 W per





100 x 100
x 400 mm

4 kg

30 W @ 28 VDC

TBD Mbit/s





Very good

640 x 830 x 1000 mm

up to
100 kg

up to 100 W @ 28

100 Mbit/s





Very good

864 x 1168 x
1245 mm

300–599 kg

800 W @ 120 VDC
120 W @ 120 VDC

100 Mbit/s

1.5 kW for
2 payloads



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.

Development status:

• October 23, 2019: Quick access to space and high-speed data transfer are paving the way for competitive science on the International Space Station. The Bartolomeo external platform received a boost today as ESA and Airbus confirmed their interest in using this new space-based vantage point for several experiments. 10)

- The Bartolomeo service will provide end-to-end access for external payloads on the Station. A new community of start-ups and space entrepreneurs will benefit from an unobstructed view of Earth, direct control of experiments from the ground and the possibility of retrieving samples.


Figure 8: Bartolomeo signature at IAC 2019. The European Space Agency and Airbus Defence and Space signed a Statement of Intent at the 70th annual International Astronautical Congress on their common interest to use the Bartolomeo external platform for a limited number of scientific missions on the International Space Station (image credit: Airbus)

- The International Space Station has hosted around 370 European experiments over the last two decades. However, the demand for experiment slots far outstrips supply.

- “Bartolomeo offers an attractive and competitive space platform for new users looking to reduce costs and shorten turnaround times,” said David Parker, ESA’s Director of Human and Robotic Exploration, while signing a statement of intent at the 70th annual International Astronautical Congress.

- Commercialization is part of our vision to secure the continued presence of humans on the Space Station and beyond. This innovative, cost-effective approach is key for missions to the Moon and Mars,” he added.

- In a press statement, Airbus acknowledged it is “excited about the evolving interest of European customers,” following the signature of a partnership agreement with ESA last year.

The science must go on

- The first experiment to find its science spot will be the Multi-Needle Langmuir Probe, a payload made in Norway to control the electric potential of a spacecraft or satellite platform with an electron emitter.

- New experiments such as ESA’s exobiology facility are increasing the Station’s capabilities for investigating the study of life in space.

- One of the main instruments to do this is an ultraviolet-visible spectrometer. Its technology was set to run for 75 days in the Station’s internal ICE Cubes facility to help refine the final product.

- Another experiment planned for Bartolomeo is being developed by France’s space agency CNES to investigate the ageing of new materials during spaceflight.

• December 6, 2018: UNOOSA (United Nations Office for Outer Space Affairs) is partnering with Airbus Defence and Space GmbH to offer United Nations Member States the opportunity to accommodate a payload on the Airbus Bartolomeo external platform on the International Space Station. The mission will be open to all Member States of the United Nations, and developing countries are particularly encouraged to participate. The platform will accommodate and operate payloads provided by institutions in the participating countries. 11)

- The purpose of this Call for Interest (CFI) is to provide a summary of the proposed mission opportunity and to solicit information from Member States’ entities interested in providing payloads that could be flown on this mission. The CFI also has the objective of gathering information on the interested countries so that UNOOSA may better understand the demand for this type of mission. This mission is devoted to addressing the Sustainable Development Goals (SDGs).

- The mission of UNOOSA is to promote international cooperation in the use of outer space to achieve development goals for the benefit of humankind. There is no better example of UNOOSA’s vision ‘to bring the benefits of space to humankind’ by showing space’s importance in the realization and implementation of the 17 Sustainable Development Goals shown in Figure 9.


Figure 9: Sustainable Development Goals (image credit: UNOOSA)

• March 26, 2018: The first high capacity space-to-ground laser communication system is to be installed on the Bartolomeo platform of the ISS as part of a collaboration between Airbus Defence and Space, the Institute of Communications and Navigation of DLR (German Aerospace Center) and Tesat-Spacecom GmbH & Co. KG. The system, called OSIRIS, will provide DTE (Direct To Earth) technology with a data rate of 10 Gbit/s over a range of about 1,500 km (Figure 2). 12)

- Small in seize and mass, OSIRIS will directly link to several ground stations providing unparalleled data downlink capacity to Bartolomeo and its experimental payloads. The goal is to make OSIRIS an operational system embedded in the ISS infrastructure. This new European capability will enhance the utilization opportunities on the European Columbus module and make Bartolomeo the go-to platform for data-intensive payloads on the ISS.

- ”Laser communications using Bartolomeo will pave the way for digitization of ISS operations enabling direct access to huge volumes of data to benefit customers,” said Oliver Juckenhöfel of Airbus.

- The platform hardware is in development at Airbus’ Bremen site and is currently undergoing a design review with the ESA and NASA. Bartolomeo will be operated by Airbus and attached to the outside of the Columbus European module ready for commercial operations from 2019.

- DLR and Tesat-Spacecom have entered into a long-term cooperation regarding research, development and industrialization of systems for optical space-to-ground links.

- DLR’s novel design, optimized for high performance, small size and low complexity, combined with Tesat’s long-term in orbit experience of laser communications, have resulted in OSIRIS having very high data rates and an affordable price point.

• February 7, 2018: The platform development has recently passed the PDR (Preliminary Design Review) and is on track for launch in May 2019. First payloads are then expected to be installed in the second half of 2019. Key to offering a service for smaller payloads is the General-purpose Oceaneering Latching Device (GOLD) — a new attachment mechanism for payloads of up to 125 kg. and 0.5 m3 developed by Airbus’ partner Oceaneering Space Systems in Houston, Texas. The two companies are also working on the system to attach the platform to the Columbus module using ISS robotics. 13)

- Oliver Juckenhöfel, Head of On-Orbit Services and Exploration at Airbus, reported that the company's role is to make access to LEO as easy as it possibly can be and open up the ISS to a global user community. The company is creating a cost and time efficient way for institutional and private organizations to bring their experiments into space as external payloads that can be launched just 18 months after signing a contract. With Airbus' All-in-One Space Mission Service, Bartolomeo users can concentrate on their payload, while everything else is taken care of, from launch and installation, to in-space operations, communication links and even all the way to returning the experiment to Earth, if it is required.

Launch: A launch of the Bartolomeo platform, to be installed on the COL-EPF (Columbus Laboratory Module Exposed Payload Facility) of the ISS external facility, is set for launch in Q2 2020 on a SpaceX Dragon cargo ferry, the SpX-20 flight (Ref. 10).

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. 14)

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.”

Communication with Bartolomeo payloads

Figure 10 gives an overview of the communication architecture. For telemetry and telecommanding purposes the Bartolomeo Data Handling System (BTL-DHS) connects all payloads to the Columbus Multi-Purpose Computer Communication (MPCC) system allowing the customers to operate and control their payloads directly via Ethernet protocols and under the protection of a Virtual Private Network (VPN) between the MPCC and the Bartolomeo Control Center (BTL-CC) at Airbus (Ref. 8).

The telemetry monitoring and commanding of payloads can be done directly by each customer through an individual web console operating in the Airbus Cloud. The cloud provides state of the art security features. Different domain zones for different types of classified data including military level classifications are available. Services are deployed for public access inside the so called De-Militarized Zones (DMZ). Each DMZ is wrapped by an HTTPS-based multi-factor authentication mechanism to protect all hosted applications which are visible to the World Wide Web. On top of that, the platform provides secure multi-tenancy mechanisms by default. Every customer has his own isolated virtual environment which contains separately managed applications, e. g. the payload applications. BTL-CC has its separated additional Openshift tenant instance, which receives the telemetry of all Bartolomeo payloads.


Figure 10: Bartolomeo communication architecture (image credit: Airbus DS, DLR)

All Bartolomeo applications are hosted inside the container platform Redhat Openshift. Parts which must be visible to the public internet are hosted inside a dedicated DMZ Openshift instance. All other components are hosted inside the private Openshift instance to assure the maximum possible security. The Openshift platform provides automatic load balancing for high traffic and high performance computing scenarios. The containers healthiness and readiness will be monitored automatically by the platform. In case of unhealthy or broken services Openshift re-deploys, based on customized rules, the hosted services automatically to guarantee permanent availability and provide maximum quality of service.

The standard customer service will include one terabyte storage for each payload. Additional storage and long-term archiving solutions can be provided upon request and can be combined with in-house used big data solutions, with quasi unlimited storage capacities.

The Bartolomeo payload application provides a number of preconfigured data analytics modules (Figure 11):

- Report automation

- Trend analysis

- Planning

- Monitoring and control

- Anomaly processing efficiency

- Anomaly detection.


Figure 11: Data analytics modules available for the Bartolomeo payload application (image credit: Airbus DS)

In addition to the payload-level control through the Airbus Cloud, the Columbus Control-Center (COL-CC) controls the Bartolomeo payload power switches via the Columbus External Command & Measurement Unit (XCMU). The BTL-DHS provides three independent control layers, two commanded by the COL-XCMU and one by the COL-MPCC. This design enables safety-critical operations by protecting against payload inadvertent switch-on in a two fault tolerant way during specific ISS flight phases. Payload operations are initiated by the activation of independent power switches:

• Inhibit 1: COL PDU power outlet on/off command switch to support the platform (already on when platform is operational).

• Inhibit 2: BTL PDCU power switch to the payload within the Bartolomeo PDCU controlled by BTL DHS.

• Inhibit 3: P/L power switch within the payload operated by Bartolomeo Control Center (BTL-CC) and/or COL-CC and via COL XCMU command.

All inhibits are independent from each other. Inhibit 1 is controlled by the Columbus Flight Control Team at COL-CC or the ISS crew, Inhibit 2 is activated by the BTL-CC via MPCC and BTL -DHS, and Inhibit 3 is controlled by BTL-CC or Col-CC via XCMU discrete command. As soon as the power is provided to the payload experiment the payload user takes over the control of his payload. BTL-CC and COL-CC only manage and monitor resources and assure Safety-compliant payload operations through COL XCMU telemetry monitoring and commanding.

Some payload data can be transferred via the MPCC Ethernet connection which is established within the existing ISS Ku-band based communication link. The expected bandwidth available for Bartolomeo payloads is around 0.1 Mbit/s allowing to downlink up to 1 GB per day. The Ku-band link has a very good availability with 70 - 90% availability over the orbit which gives almost real-time data connectivity for considerable amounts of time. For broadband data needs, Bartolomeo will have its own communication system (see OSIRISv3). The Bartolomeo-provided payload resources and budgets are summarized in Table 4.


Single payload slot

Double payload slot

Field of View

• All Nadir and Zenith view
• Some slots Ram view

• 1 slot Zenith, Ram view
• 1 slot Nadir, Ram view
• 2 slots Nadir and Zenith view
• Some slots Ram view

Geometric envelope

• up to 700 x 800 x 1000 mm
(unpressurized launch)
• up to 469 x 800 x 762 mm (JEM-A/L)
• up to 551 x 800 x 1000 mm (NRAL)


up to 1000 x 800 x 1600 mm (only
unpressurized launch)


100 kg nominal (1)

• 250 kg nominal (1)
• up to 450 kg maximum capability


• 120 Vdc operational power up to 125 W, 400 W or 800 W
• 120 Vdc survival power limited to 100 W

• 120 Vdc operational power up to400+800 W (2)
• 120 Vdc survival power limited to 100+20 W

Commanding and

• Health status signal (active driver) via XCMU
• Correct mechanical engagement signal (contact status) via XCMU
• Switch off command (pulse command) via XCMU
• Temperature sensor signal via MPCC
• Current sensor signal via MPCC
• Switch on / off command (pulse command) via MPCC

Basic data downlink

0.1 Mbit/s (real time when available)

0.2 Mbit/s (real time when available)

Enhanced data downlink

Up to 2.5 TB / day (non- real time)

Robotic interface

Included in the standard payload interface

Return capability

Yes, if airlock compatible size


Table 4: Bartolomeo payload sizes, budgets and resources

Note 1: Overall payload mass budget of the platform to be taken into account
Note 2: Depending on availability

OSIRISv3 (Optical Space Infrared Downlink System version 3) Laser Communication Terminal

Next to the communication link available through the Columbus module Bartolomeo will have its own communication system to provide an independent broadband link to Earth for payload data. The communication system is the OSIRISv3 laser terminal developed by the German Aerospace Center, Institute of Communications and Navigation (DLR-IKN) and shown in Figure 12. DLR-IKN provides the laser communication device to Bartolomeo as part of the Airbus - DLR partnership for OSIRIS in-orbit testing.


Figure 12: OSIRISv3 laser communication terminal with coarse pointing assembly (image credit: DLR-IKN)

OSIRISv3 is an experimental laser communication system optimized for downlinks from small satellites. It will be demonstrated on the ISS. After a scientific phase, during which scientific channel measurements will be performed, OSIRISv3 can be used for operational data transmission as well. Furthermore, OSIRISv3 is one reference implementation of the upcoming CCSDS standard, ensuring its compatibility with world-wide optical ground station networks.

OSIRISv3 establishes a direct link to Optical Ground Stations (OGS) with a channel data rate of 10 Gbit/s.15) Link budget and availability analyses, based on cloud cover models performed by DLR-IKN estimate an expected daily throughput between 1.375 and 2.5 TB for a network of 8 Optical Ground Stations (OGS).

The laser communication terminal is accommodated on Bartolomeo on a Nadir-pointing boom enabling a good field of view independent from the Bartolomeo payload configuration. In this position, and with an additional cover to block illumination of the ISS structure, the laser may interfere only with the ISS solar arrays. With a maximum power density below 6000 W/m2 potentially being exerted, there will be no risk of damaging the ISS solar arrays. The interference between the laser beam and the arrays is avoided by the Osiris software which automatically switches off the beam based on the available ISS on-board telemetry on the solar array positions. This software safety solution enables the extension of the field of view to the areas temporarily obstructed by the arrays For ISS visiting vehicles, however, this strategy is not applicable, and a mechanical hard stop on the coarse pointing assembly is required to mechanically constrain the field of view available for laser pointing (Figure 13).


Figure 13: Usable field of view for the OSIRISv3 terminal with areas of temporal obstruction by the ISS solar arrays indicated in blue (image credit: DLR-IKN)

The OSIRISv3 terminal will be launched in soft-stowed configuration separately from the Bartolomeo platform. The soft-stowed launch significantly reduces the mechanical loads experienced by the payload. Thereby, a launch lock securing the coarse pointing assembly can be avoided. This launch lock would have been difficult to remove robotically on orbit. After having been launched pressurized OSIRISv3 will be installed on its accommodation boom like a standard Bartolomeo payload.

ArgUS Multi-Payload Frame

Bartolomeo is designed host payloads of sizes in the 100 - 450 kg range in either a "Single" or "Double" payload configuration. However, also smaller than Single payloads can be accommodated in an efficient way. The smaller payloads will share a Single slot using the ArgUS multi-payload frame with an own sub-avionics capable of monitoring and controlling the sub-payloads, their power consumption and data flows. This multi-payload frame is compatible with all Bartolomeo payload slots except of Slot 7 and Slot 8. ArgUS provides for internal ISS payload removal and replacement, transfer of the integrated payload through one of the ISS payload airlocks. ArgUS will then operate payloads in the open space environment while attached to the Bartolomeo platform. The ArgUS platform allows for various configurations with different standard sizes of payloads. An example is shown in Figure 14.


Figure 14: ArgUS multi-payload frame for Bartolomeo (image credit: DLR-IKN)

Payloads are typically oriented in the Nadir-Zenith line. The Argus plate can accommodate sideward placement for limited payload slots. Payloads with nonstandard sizes may either use the available attachment interfaces and volume on the experiment base plate or, in case of large payloads they may use the entire available volume.

ArgUS has its own avionics and power supply to enable the operations of up to 10 active payloads in parallel. ArgUS also features the OTCM / SPDM umbilical interface required to provide heater power through the ISS robotic system during installation. The ArgUS capabilities are summarized in Table 5.



Slot compatibility

Slot 1, 2, 3, 4, 5, 6

Airlock compatibility

JEM-A/L (Airlock), NRAL (NanoRacks Airlock)

Sub-payload mass

4 - 100 kg

Sub-payload volume

3U up to Single payload maximum volume

Nominal voltage range

28 V ± 2 V

Nominal power

140 W

Maximum current

5 A

Table 5: ArgUS standard power characteristics

In summary, Bartolomeo is a competitive system, embedded in an end-to-end service. Bartolomeo contributes by achieving the scientific and economic goals defined in the strategy of the ISS program partners, responds to the demand for additional external payload hosting sites on ISS, and provides a most attractive mission solution to the commercial and institutional user community in LEO (Low Earth Orbit). The Bartolomeo payload hosting service is available on commercial terms and conditions and will significantly reduce the cost of a space mission in LEO.

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:

3) ”Christopher Columbus' Brother's Space Journey With Airbus Defence and Space & Neumann Space,” Satnews Daily, Sept. 29, 2016, URL:

4) Christiam Steimle, Uwe Pape, Ronald Dunklee,Bill Corley, ”Bartolomeo - Multi-purpose Payload Hosting Facility on Columbus,” November 30, 2015, URL:

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) ”All-in-one service for the Space Station,” ESA, 7 Feb. 2018, URL:

7) 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

8) Christian Steimle, Carl Walz, Christian Fuchs, Don Pedersen, Chiara M. Lombardi, ”Bartolomeo External Platform Entering Into Commercial Service,” Proceedings of the 70th IAC (International Astronautical Congress), Washington DC, USA, 21-25 October 2019, paper: IAC-19.B3.3, URL:

9) Christian Steimle, Bill Corley, ”New Bartolomeo External Platform on its Pathway to Space,” 8th Annual International Space Station Research and Development Conference, July 29- August 1, 2019, Atlanta, GA, USA, URL:

10) ”European boost to the all-in-one Bartolomeo service for the Space Station,” ESA / Science & Exploration / Human and Robotic Exploration, 23 October 2019, URL:

11) ”Accessing Space with the ISS Bartolomeo Platform UNOOSA Call for Interest,” UNOOSA, 6 December 2018, URL:

12) ”First high capacity space-to-ground laser communications system for the European external ISS platform,” Geospatial World, 26 March 2018, URL:

13) ”Bartolomeo Platform Partnership Agreement Signed Between ESA and Airbus,” Satnews, Daily, 7 Feb. 2018, URL:

14) ”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:

15) Christian Fuchs, Christopher Schmidt, ”Update on DLR's OSIRIS program,” International Conference on Space Optics—ICSO 2018, Chania, Greece, 9–12 October 2018, Edited by Zoran Sodnik, Nikos Karafolas, and Bruno Cugny, URL:

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 (

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