SpaceVPX (VITA 78) and the World of Interconnect

For many years, open techniques architectures and open requirements have helped speed up innovation to finish customers in aerospace and protection purposes via the event of interfaces which are open, key, and well-defined. Right now, area system designers and builders are actually embracing the SpaceVPX (VITA 78) normal, which leverages the OpenVPX (VITA 65.0) structure via its slot profile and module profile degree constructing blocks, which create interconnect options based mostly on the consumer’s want.

Discover the fundamentals of SpaceVPX with the designers of the VPX and SpaceVPX interconnect. Study the usual’s origin, some great benefits of SpaceVPX vs. OpenVPX, latest modifications to the usual and the significance of ordinary interconnects which drive down value, leads to a extra sturdy provide chain, and maintains a path for future growth.

SpaceVPX is an ordinary for creating plug-in playing cards (PICs) from its slot profile and module (protocol) profiles. In flip, these constructing blocks create interconnected subsystems and techniques. Developed underneath the auspices of The Subsequent Technology Area Interconnect Normal (NGSIS), it’s the results of a government-Trade collaboration. The first objective of SpaceVPX is to cost-effectively take away bandwidth as a constraint for future area techniques.

SpaceVPX is predicated on the VITA (VMEbus International Trade Association) OpenVPX normal with enhancements that reach the usual for area purposes.

The NGSIS workforce chosen the OpenVPX normal household because the bodily baseline for the brand new SpaceVPX normal as a result of VPX helps each 3U and 6U kind components with ruggedized and conduction-cooled options appropriate to be used in excessive environments. The infrastructure of OpenVPX additionally permits for prototyping and testing SpaceVPX on the bottom.

SpaceVPX is constructed upon a number of requirements, a few of that are a part of the American Nationwide Requirements Institute (ANSI)/VITA and European Cooperation for Area Standardization (ECSS) OpenVPX household:

• VITA 46 VPX and its ANSI/VITA 65.0 OpenVPX by-product – baseline normal
• ANSI/VITA 60 and ANSI/VITA 63 – suitable connectors
• ANSI/VITA 48.2[3] – mechanical extensions
• ANSI/VITA 62 – standardized energy module
• ANSI/VITA 66 and 67 – alternative {of electrical} segments with RF or optical options
• ANSI/VITA 46.11[4] – administration protocol, the premise for fault-tolerant administration of the SpaceVPX system
• ECSS – SpaceWire normal
• ECSS – Distant Reminiscence Entry Protocol (RMAP)
• ECSS – SpaceFibre normal
• Gigabit Ethernet

OpenVPX is an outlined set of system implementations inside VPX that specifies a set of system architectures. OpenVPX organizes connections in 4 main interconnect planes — knowledge, management, utility, and growth.

Knowledge Aircraft
The info aircraft incorporates high-speed multigigabit cloth connections between modules to hold payload and mission knowledge.

Management Aircraft
The management aircraft, additionally a cloth connection, usually has much less capability and is used for configuration, setup, diagnostics, and different operational management features throughout the payload and for lower-speed knowledge transfers.

Utility Aircraft
The utility aircraft offers setup and management of fundamental module features for energy sequencing, low-level diagnostics, clocks, and different base indicators wanted for system operation.

Enlargement Aircraft
The growth aircraft could also be used as a separate connection between modules utilizing comparable interfaces or to bridge heritage interfaces in a extra restricted topology comparable to a bus or ring.

Pins not outlined as a part of any of those planes are usually user-defined and can be found for pass-through from daughter or mezzanine playing cards, or to rear transition modules (RTM). For max module reuse, the user-defined pins must be configurable in order to not intrude with modules that use the identical pins another way. Seek the advice of ANSI/VITA 65.0 for extra element.

An analysis of OpenVPX for area utilization revealed a number of shortcomings. The important thing limitation was the shortage of options obtainable to assist a full, single-fault-tolerant, extremely dependable configuration. Utility indicators had been bused and, most often, supported just one set of indicators by way of sign pins to a module. In consequence, a pure OpenVPX system has alternatives for a number of failures. Moreover, a full management-control mechanism was not totally outlined with VITA 46.11.

From a protocol perspective, SpaceWire is the dominant medium-speed knowledge and management aircraft interface for many spacecraft, but the standard OpenVPX management planes are peripheral element interconnect categorical (PCIe) or Ethernet which aren’t usually utilized in area purposes.  (Be aware: Gigabit Ethernet was added to the 2022 revision of the SpaceVPX normal.)

The objective of SpaceVPX is to attain an appropriate degree of fault tolerance, whereas sustaining an affordable degree of compatibility with present OpenVPX parts together with connector-pin assignments for the board and the backplane (Determine 1.).

For the needs of fault tolerance, a module (outlined as a printed wire meeting which conforms to outlined mechanical and electrical specs) is taken into account the minimal redundancy aspect, or the minimal fault containment area. The utility aircraft and management aircraft inside SpaceVPX are all distributed redundantly and are organized in star topologies, dual-star topologies, partial-mesh topologies or full-mesh topologies to offer fault tolerance to the whole system.

To fulfill the specified degree of fault tolerance, the utility aircraft indicators have to be dual-redundant and switched to every SpaceVPX card operate.

A commerce research, carried out in 2010 via a authorities and business collaboration with the assist of the SpaceVPX Working Group, in contrast numerous implementations together with including the switching to every card in numerous methods and creating a singular switching card. The latter strategy was chosen so SpaceVPX playing cards can every obtain the identical utility aircraft indicators that an OpenVPX card receives with minor changes for any modifications in topology. This turned referred to as the Area Utility Administration module (SpaceUM), a significant basis of the SpaceVPX normal.

A 6U SpaceUM module comprises as much as eight units of energy and sign switches to assist eight SpaceVPX payload modules — the 3U model of the SpaceUM can assist as much as 5. It receives one energy bus from every of two energy provides and one set of utility aircraft indicators from every of two system controller features required within the SpaceVPX backplane. The assorted elements of the SpaceUM module don’t require their very own redundancy. They’re thought of extensions of the ability provide, system controller and different SpaceVPX modules for reliability calculation.

Every slot, module and backplane profile in OpenVPX is totally outlined and interlinked. Adapting these profiles to be used in area requires specification of a SpaceVPX model of every profile.

Slot Profile A slot profile offers a bodily mapping of information ports onto a slot’s backplane connector, which is agnostic to the kind of protocol used to convey knowledge from the slot to the backplane.

Module and Backplane Profiles
Module profiles are extensions of their accompanying slot profiles which allow mapping of protocols to every module port. A module profile consists of info on thermal, energy and mechanical necessities for every module. Some module profiles for SpaceVPX are much like OpenVPX which permits use of OpenVPX modules and backplanes for prototyping or testing on the bottom. Nonetheless, most module profiles for area purposes are considerably completely different from profiles for floor purposes so full specs in step with SpaceVPX are required. The part of the SpaceVPX normal that defines these profiles kinds a majority of the usual.

Interconnects are yet one more important a part of SpaceVPX. As with different components of the usual, they’re based mostly on interconnects developed for OpenVPX, however designed for the acute area setting.

Problematic temperatures, vibration, outgassing and different components can catastrophically compromise interconnect techniques in addition to sign and energy integrity. For many years, designers for area purposes have relied on personalized interconnect designs to make sure the reliability of embedded electronics uncovered to the extremes of area. The excessive value and lengthy lead occasions of a customized interconnect answer had been as soon as thought of a worthwhile funding in opposition to failures which are extraordinarily pricey or unattainable to repair in area.

Right now, the usage of normal interconnects drives down value, improves availability and maintains a path for future growth.

By leveraging the OpenVPX structure, SpaceVPX brings within the interconnect options that are outlined in VITA requirements and have gone via intensive testing to assist their use in area.

The SpaceVPX slot profiles outline the usage of VPX connectors (VITA 46 or alternate VPX connectors) and allow implementation of RF (VITA 67) and optical (VITA 66) modules on the plug-in module to backplane interface. Energy provides comply with the VITA 62 normal, which additionally defines the ability provide connector interface. For XMC mezzanine playing cards in plug-in modules, XMC 2.0 connectors per VITA 61 are beneficial. Fairly than defining new connectors with particular traits, SpaceVPX slot profiles reference the suitable VITA connector requirements that assist the OpenVPX structure.

The VITA 46 VPX connector is the unique VPX interconnect. It’s based mostly on TE Connectivity’s (TE) MULTIGIG RT 2 connector which was launched within the VITA 46 normal in 2006.

The MULTIGIG RT connector household offers designers an easy-to-implement, modular, standardized and cost-effective interconnect system that helps make sure the reliability of their embedded-computing purposes for area techniques.

MULTIGIG RT connectors have gone via intensive testing by TE to ascertain suitability for area, together with:

• Compliant (press-fit) pin expertise
  Testing has been carried out at min-max board gap sizes and completely different printed circuit board (PCB) platings to confirm the reliability of the compliant pin designs. Right now, quite a few area purposes use compliant pin expertise (as in comparison with conventional soldered connections), and implementation is rising.
• Vibration
  The VITA 72 research group was fashioned to handle excessive vibration purposes. The group devised a vibration take a look at that subjected a 6U VPX take a look at unit to random vibration ranges of 0.2 g2/Hz for 12 hours, a extreme requirement in comparison with the authentic VPX normal. TE’s MULTIGIG RT 2-R connector — that includes an enhanced quad-redundant backplane connector contact system and rugged information {hardware} — examined efficiently as a part of this effort and has been utilized in extremely rugged purposes since 2013.
• Excessive temperature
  MULTIGIG connectors had been subjected to a temperature vary of -55 ˚C to +105 ˚C when initially certified for VPX in 2006, which met the VITA 47 normal for plug-in modules. In direct response to necessities from space-systems builders, MULTIGIG RT connectors have since been examined and survived -55 °C to +125 °C, together with publicity to 1,000 hours of warmth at 125 °C and 100 thermal shock cycles from -55 °C to +125 °C.
• Outgassing
  In contrast to heavy polymer plug-in module connectors utilized in standard backplane connector designs, MULTIGIG RT connectors incorporate air gaps, so much less polymer is required. The polymer discount reduces weight and reduces outgassing. With MULTIGIG RT connector supplies, whole mass loss (TML) is lower than 1% and picked up risky condensable supplies (CVCM) is lower than 0.01%, which meets NASA and European Area Company (ESA) outgassing necessities.
• Present capability
  When VITA 78 was developed, there was a want for VPX connectors to assist new pinouts (not outlined in VITA 46) to assist the necessities for redundant energy distribution and redundant administration distribution. TE accomplished intensive testing for present carrying functionality on a number of adjoining MULTIGIG energy wafers inside plug-in module connectors and likewise launched new wafer configurations to assist the VITA 78 Area Utility Administration module structure.

Most area system designers use MULTIGIG RT connectors to fulfill their necessities with no bodily change to the design or supplies and finishes. If minimal modifications are required (e.g., larger lead content material [40%] within the contact tails is specified for elevated tin-whisker mitigation), further screening checks are required based mostly on the consumer or program necessities, however the connector-manufacturing processes are comparatively the identical which helps enhance value and availability.

RF and optical connector modules might be built-in inside an OpenVPX slot to hold indicators via the backplane to/from the plug-in module. These connector modules are mounted to the boards (together with normal aperture cutouts on the backplane) to accommodate a number of coaxial contacts or optical fibers. They’ll substitute choose VITA 46 connectors inside a slot. These RF and optical connector modules and contacts have been utilized in satellite tv for pc techniques and are appropriate for different purposes in area.

VITA 67 is the bottom normal for RF modules. VITA 67.3 is used for SpaceVPX structure with apertures outlined inside particular slot profiles for RF and optical connector modules.  VITA 67.3 provides coaxial contact options with the preliminary sub-miniature push-on micro (SMPM) contacts in addition to higher-density coaxial interfaces NanoRF and switched-mode energy provide (SMPS), which may improve the contact density two to 3 occasions over SMPM. A brand new revision to VITA 67.3 has begun so as to add 75 Ohm coaxial interfaces to assist larger velocity video.

VITA 66 is the bottom normal for optical modules, with MT ferrules as the first optical interface between the plug-in module and backplane. The apertures in SpaceVPX slot profiles accommodate optical and hybrid RF/optical connector modules assembly the necessities of VITA 66.5. MT interfaces might be specified for 12 or 24 fibers for highest density.

XMC mezzanine playing cards might be applied on SpaceVPX plug-in modules so as to add I/O and different options. VITA 61 XMC 2.0, the usual based mostly on TE’s Mezalok connector, is the beneficial XMC connector within the SpaceVPX normal. The Mezalok connector options a number of factors of contact per pin, supporting the redundancy required for area purposes. The connector meets outgassing necessities and has been examined to excessive environments — together with 2000 thermal cycles from -55 ºC to +125 ºC with no solder joint failures.

By leveraging the OpenVPX structure, SpaceVPX also can leverage the OpenVPX interconnect roadmap which addresses options having sooner speeds, larger density, smaller measurement, and lighter weight. There may be important exercise with new and revised VITA requirements to outline applied sciences supporting next-generation embedded computing.

Increased knowledge price MULTIGIG RT 3 connectors can be found and standardized in VITA 46.30 (compliant pin) and 46.31 (solder tail) to assist channels to 25-32 Gigabits per second, supporting 100G Ethernet and PCI Gen 4 and 5. These might be integrated in a SpaceVPX slot changing VITA 46.0 connectors.

The newest revision of the VITA 67.3 normal consists of higher-density RF interfaces NanoRF and SMPS, lowering measurement and weight — each of that are important for area techniques — and accommodating larger frequencies to 70 GHz. A brand new revision to VITA 67.3 has begun so as to add 75 Ohm coaxial interfaces inside a connector module to assist larger velocity video protocols.

The VITA 66.5 normal will likely be launched in 2022, documenting higher-density optical interfaces, bringing as much as three MT interfaces right into a half-module and enabling integration of a hard and fast edge-mount transceiver. As well as, VITA 66.5 offers options with NanoRF contacts and optical MTs built-in into a typical connector module, offering unprecedented density inside an OpenVPX slot.

New VITA 62 energy provide requirements have addressed three-phase energy (VITA 62.1) and better 270VDC enter voltages (VITA 62.2). New MULTIBEAM XLE connectors from TE with isolating fins present this improve for larger voltage ranges whereas sustaining the identical VITA 62.0 interface.

• SpaceVPX is a set of requirements for interconnects between area system parts developed to cost-effectively take away bandwidth as a constraint for future area techniques.
• The objective of SpaceVPX is to attain an appropriate degree of fault tolerance whereas sustaining an affordable degree of compatibility with present OpenVPX parts.
• SpaceVPX interconnect are based mostly on interconnects developed for OpenVPX, tailored for the acute area setting.
• TE connectors have gone via intensive testing to ascertain suitability for area and have been utilized in satellite tv for pc techniques and different area purposes.
• New and revised VITA requirements proceed to outline applied sciences that assist the following technology of embedded computing whereas lowering prices, bettering availability of parts, and sustaining a path for future growth.

Patrick Collier is Open Programs Architect and lead techniques engineer at Aspen Consulting Group. He focuses on the event and use of open architectures for each area and nonspace purposes. Previous to this, Patrick was an Open Programs Architect and Programs Engineer at L3Harris. Beforehand he was a lead {hardware} engineer at PMA-209 NAVAIR, the place he centered on the event of the {Hardware} Open Programs Know-how (HOST) set of requirements. His first task was as a senior electrical analysis engineer with the Air Power Analysis Laboratory Area Autos Directorate. Whereas at AFRL, he based the Subsequent Technology Area Interconnect Normal (NGSIS) with Raphael Some (NASA JPL). Patrick additionally based and is presently chair for the VITA 78 (SpaceVPX) and VITA 78.1 (SpaceVPXLite) efforts. He’s additionally a cofounder of the Sensor Open System Structure (SOSA) and chair of its {Hardware} Working Group. Moreover, he was a lead for the Area Common Modular Structure (SUMO), the place he labored to include present space-related requirements and architectures into SUMO.

Michael Walmsley, world product supervisor for TE Connectivity, has greater than 40 years of expertise with interconnects, primarily in engineering and product handle­ment roles. His areas of experience embody interconnect options for embedding computing, rugged high-speed board-level, and RF connectors. Michael is a board member for the VITA Requirements Group (www.vita.org), which drives expertise and requirements for the bus and board business. He’s additionally actively concerned in each VITA and Sensor Open System Structure (SOSA). Michael holds a bachelor’s diploma in mechanical engineering from the College of Rochester and an MBA from Penn State.