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SpaceFibre 6.25 Gbps spacecraft harnessECSS-E-ST-50-11C6.25 Gbps / Lane100 Ω Twinax

AxoMach SpaceFibre AssemblyECSS-E-ST-50-11C 6.25 Gbps/lane low-outgassing 100 Ω SpaceFibre spacecraft harness

Q: How does SpaceFibre (ECSS-E-ST-50-11C) differ electrically from legacy SpaceWire (ECSS-E-ST-50-12C)?

Legacy SpaceWire uses 2 pairs for data+strobe LVDS signalling up to 400 Mbps. SpaceFibre uses current-mode logic (CML) AC-coupled 8b/10b serial lanes over 100 Ω twinax pairs (1 TX pair + 1 RX pair per lane) operating up to 6.25 Gbps per lane, with built-in multi-lane aggregation up to 25 Gbps and Galvanic/Fibre compatibility.

Q: Why is microporous expanded PTFE (ePTFE) used instead of solid FEP for the twinax core insulation?

Microporous ePTFE has a relative permittivity of ~1.35 compared with 2.1 for solid FEP, raising the propagation velocity above 80 % of the speed of light and cutting 3.125 GHz Nyquist dielectric loss by more than 35 %, allowing 5 m copper harnesses at 6.25 Gbps.

Q: How is intra-pair phase skew kept below 5 ps/m?

Each differential pair is manufactured using dual-extruded or parallel-wrapped ePTFE twinax geometry locked under a flat silver-plated copper ribbon shield before any bundle stranding, eliminating length and dielectric asymmetry between the P and N conductors.

Q: Can you supply both laboratory EGSE test harnesses and vacuum-qualified Flight Model (FM) harnesses?

Yes. We build cost-effective EGSE test harnesses for payload testbeds as well as full ECSS-Q-ST-70-08C traceable EM/FM harnesses with lot-tested low-outgassing materials and serialized 20 GHz VNA test data.

Space-qualified AxoMach / SpaceFibre differential harness engineered to ECSS-E-ST-50-11C for 6.25 Gbps single-lane and 25 Gbps 4-lane spacecraft payload links, using microporous ePTFE dielectric and silver-plated copper.

Low-EMC design

EMC screen

Flame-retardant

Approved

SpaceFibre Harness Config

Order designation: AXM-SF-1L-26AWG-2.0M
Nominal OD: 4.8 mm
Linear mass: 38 g/m
Atten @3.1GHz: 0.82 dB/m
Min. bend R: 29 mm

All sizes (12)

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Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum

Data rate: 6.25 Gbps/lane
Impedance: 100 ± 5 Ω
Velocity (Vp): ≥ 80 % c
Intra-pair skew: ≤ 5 ps/m
Thermal range: −100 to +200 °C
Outgassing: TML < 1.0 %

Typical values for this cable type, based on ECSS-E-ST-50-11C / ESCC 3902/004 / ECSS-Q-ST-70-08C — confirmed in the datasheet and quotation for your order.

Application fit

Is AxoMach SpaceFibre Assembly right for your machine?

Designed for satellite Synthetic Aperture Radar (SAR), optical earth-observation payloads, onboard mass memory units, and launcher avionics backbones.

Switchgear & control cabinet wiring

Suitable

Dual silver-plated copper tape + braid shields achieve > 90 dB shielding effectiveness up to 6 GHz.

Fixed installation

Suitable

Vacuum-compatible fluoropolymer jacket meets ECSS-Q-ST-70-02C outgassing (TML < 1.0 %, CVCM < 0.1 %) and radiation resistance.

Free-hanging vertical run

With conditions

Engineered for spacecraft panel routing and gimbal loops; validate bend radius (≥ 6 × OD) across solar-array or antenna gimbals.

Energy chain / drag chain

Not suitable

Aerospace fluoropolymer twinax harness is not intended for heavy industrial machinery drag chains.

Use M12 X-coded 10GbE

Typical machinesEarth Observation Satellite PayloadsSynthetic Aperture Radar (SAR)Spacecraft On-Board Data HandlingLaunch Vehicle AvionicsHigh-Altitude Pseudo-Satellites (HAPS)

Construction

Layer by layer

Representative 1-lane (2 twinax pairs, TX + RX) and 4-lane (8 twinax pairs) ECSS-E-ST-50-11C SpaceFibre harness construction.

Schematic, not to scale — generated from the layer data

#	Layer	Material & reference
1	Silver-plated copper / SPCW signal conductors	26 AWG or 24 AWG stranded or solid silver-plated copper / high-strength silver-plated copper alloy (≥ 2.0 μm Ag per ASTM B298)Minimises high-frequency skin-effect attenuation up to 6.25 GHz
2	Microporous expanded PTFE (ePTFE) dielectric	Low-dielectric-constant (εr ≈ 1.35) microporous ePTFE tape-wrapped insulationAchieves ≥ 80 % velocity of propagation and ultra-low insertion loss
3	Individual twinax pair shield	Helical silver-plated copper flat-ribbon wrap + polyimide containment tape on each 100 Ω differential pairProvides ≤ 5 ps/m intra-pair skew and ≥ 75 dB near-end crosstalk isolation between TX and RX lanes
4	Overall spacecraft EMC braid	≥ 90 % coverage silver-plated copper braided outer shield terminated 360° to the connector EMI backshellGuarantees ECSS spacecraft Radiated Susceptibility and Emissions compliance
5	Space-grade FEP / PFA outer jacket	Extruded thin-wall fluorinated ethylene propylene (FEP) or PFA jacket (atomic-oxygen & radiation resistant, TML < 1.0 %)Withstands −100 °C to +200 °C thermal vacuum cycling

SF-1L (Single-Lane 6.25 Gbps)

2 × 100 Ω shielded twinax pairs (1 TX + 1 RX) in 26 AWG or 24 AWG for point-to-point payload links up to 5 m

SF-2L / SF-4L (Multi-Lane 12.5 / 25 Gbps)

4 or 8 × 100 Ω shielded twinax pairs in a bundled low-outgassing harness for multi-lane SpaceFibre mass-memory trunks

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on ECSS-E-ST-50-11C / ESCC 3902/004 / ECSS-Q-ST-70-08C. Values for your order are confirmed in the datasheet and quotation.

Electrical

Protocol standard: ECSS-E-ST-50-11C SpaceFibre (up to 6.25 Gbps/lane)
Differential impedance: 100 ± 5 Ω at TDR 50 ps rise time
Insertion loss at 3.125 GHz: ≤ 0.85 dB/m (26 AWG) · ≤ 0.65 dB/m (24 AWG)
Intra-pair skew: ≤ 5.0 ps/m
NEXT (TX to RX pair): ≥ 65 dB up to 3.125 GHz
Shielding effectiveness: ≥ 90 dB (100 MHz to 6 GHz)

Thermal

Operating thermal vacuum: −100 °C to +200 °C
Outgassing (ECSS-Q-ST-70-02C): TML < 1.0 % · CVCM < 0.1 % · RML < 1.0 %
Radiation resistance: ≥ 100 Mrad (1 MGy) total ionizing dose

Mechanical

Min. bend radius (static): 5 × OD (single-lane) · 6 × OD (multi-lane)
Min. bend radius (dynamic): 10 × OD
Random vibration: Qualified to 25 g rms launch vibration profile
Mating durability: ≥ 500 cycles (space-grade micro-D / AxoMach)

Resistance

Flammability: Non-flammable in vacuum & atmosphere per ECSS-Q-ST-70-29C
Atomic oxygen & UV: Fluoropolymer FEP/PFA jacket + optional silver braid

Reference standards

Data link standard: ECSS-E-ST-50-11C SpaceFibre
Cable specification: ESCC 3902/004 / ESCC 3902/003
Workmanship standard: ECSS-Q-ST-70-08C / IPC/WHMA-A-620 Space Addendum

Identification

Jacket colour: Translucent Blue, White or Metallic Silver
Serialization: Individual laser-etched serial & lot traceability sleeve
Customs tariff (HS): 8544.42 / 8807.90

Sizes

12 standard AxoMach / SpaceFibre 6.25 Gbps aerospace harness configurations

Covers 1-lane (6.25 Gbps), 2-lane (12.5 Gbps) and 4-lane (25 Gbps) 100 Ω twinax harnesses in 26 AWG and 24 AWG.

Lane configs, insertion loss & mass
Order designation	Lanes (Pairs)	Gauge AWG	Aggregate Gbps	Atten @3.1GHz dB/m	Nominal OD mm	Linear Mass g/m	Min. bend R mm
Single-Lane SpaceFibre Harnesses (6.25 Gbps, 1 TX + 1 RX Twinax)
AXM-SF-1L-26AWG-0.5M	1 Lane (2×100Ω)	26	6.25	0.82	4.8	38	29
AXM-SF-1L-26AWG-1.0M	1 Lane (2×100Ω)	26	6.25	0.82	4.8	38	29
AXM-SF-1L-26AWG-2.0M	1 Lane (2×100Ω)	26	6.25	0.82	4.8	38	29
AXM-SF-1L-26AWG-3.0M	1 Lane (2×100Ω)	26	6.25	0.82	4.8	38	29
AXM-SF-1L-24AWG-3.0M	1 Lane (2×100Ω)	24	6.25	0.62	5.6	52	34
AXM-SF-1L-24AWG-5.0M	1 Lane (2×100Ω)	24	6.25	0.62	5.6	52	34
Multi-Lane SpaceFibre Harnesses (12.5 Gbps 2-Lane & 25 Gbps 4-Lane)
AXM-SF-2L-26AWG-1.0M	2 Lanes (4×100Ω)	26	12.5	0.84	6.8	74	41
AXM-SF-2L-26AWG-2.5M	2 Lanes (4×100Ω)	26	12.5	0.84	6.8	74	41
AXM-SF-2L-24AWG-4.0M	2 Lanes (4×100Ω)	24	12.5	0.64	7.8	98	47
AXM-SF-4L-26AWG-1.0M	4 Lanes (8×100Ω)	26	25.0	0.85	9.2	142	55
AXM-SF-4L-26AWG-2.5M	4 Lanes (8×100Ω)	26	25.0	0.85	9.2	142	55
AXM-SF-4L-24AWG-4.0M	4 Lanes (8×100Ω)	24	25.0	0.65	10.6	188	64

Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
Every flight or engineering-model assembly is supplied with a 20 GHz Vector Network Analyzer (VNA) S-parameter & TDR test report (Sdd21, Sdd11, intra-pair skew, and NEXT).

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

ConductorClass 5 stranding
Spark test100 % in-line
Lay-upCores, earth, fillers
SheathingInner, braid / screen, outer
Electrical testsAC voltage, resistance
DimensionsOD, wall thickness
Inspection documents & dispatchDrum & dispatch

Testing & inspection	Test value / reference	Frequency
Routine tests
20 GHz VNA S-parameter & TDR characterization	Differential impedance 100 ± 5 Ω, Sdd21 insertion loss, Sdd11 return loss & ≤ 5 ps/m skew	100 % of assemblies
Dielectric withstand & insulation resistance	500 Vrms AC for 1 min and ≥ 5,000 MΩ·km at 500 V DC	100 % of assemblies
Sample tests
Thermal vacuum & outgassing verification	TML < 1.0 % and CVCM < 0.1 % per ECSS-Q-ST-70-02C	Material qualification lot
Eye-diagram & Bit Error Rate (BER < 10⁻¹²) at 6.25 Gbps	PRBS-31 pattern testing across 5 m harness assembly	Type approval

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

ECSS-E-ST-50-11C SpaceFibre Link CompliantESCC 3902/004 & ECSS-Q-ST-70-02C Outgassing

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX AXM-SF ECSS-E-ST-50-11C 100 OHM SPACEFIBRE [LOT/SN]

Cleanroom packaging: ISO Class 7 cleanroom double-bagged under dry nitrogen with VNA plots
Model grades: Electrical Ground Support Equipment (EGSE), Engineering Model (EM) & Flight Model (FM)
Connector options: AxoMach, SpaceFibre Micro-D, eSATA-Space & MIL-DTL-38999 Twinax
Lead time: 4–6 weeks (EGSE/EM) · 8–10 weeks (FM)

Technical documents

Downloads

PDFAxoMach SpaceFibre Assembly – technical datasheet12 sizes · construction, technical data, approvals XLSXAxoMach SpaceFibre Assembly spec data (Excel)All 12 sizes with dimensions and data, for your BOM or quotation

Revision: 2026-10-20
Updated: 2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

How does SpaceFibre (ECSS-E-ST-50-11C) differ electrically from legacy SpaceWire (ECSS-E-ST-50-12C)?

Legacy SpaceWire uses 2 pairs for data+strobe LVDS signalling up to 400 Mbps. SpaceFibre uses current-mode logic (CML) AC-coupled 8b/10b serial lanes over 100 Ω twinax pairs (1 TX pair + 1 RX pair per lane) operating up to 6.25 Gbps per lane, with built-in multi-lane aggregation up to 25 Gbps and Galvanic/Fibre compatibility.

Why is microporous expanded PTFE (ePTFE) used instead of solid FEP for the twinax core insulation?

Microporous ePTFE has a relative permittivity of ~1.35 compared with 2.1 for solid FEP, raising the propagation velocity above 80 % of the speed of light and cutting 3.125 GHz Nyquist dielectric loss by more than 35 %, allowing 5 m copper harnesses at 6.25 Gbps.

How is intra-pair phase skew kept below 5 ps/m?

Each differential pair is manufactured using dual-extruded or parallel-wrapped ePTFE twinax geometry locked under a flat silver-plated copper ribbon shield before any bundle stranding, eliminating length and dielectric asymmetry between the P and N conductors.

Can you supply both laboratory EGSE test harnesses and vacuum-qualified Flight Model (FM) harnesses?

Yes. We build cost-effective EGSE test harnesses for payload testbeds as well as full ECSS-Q-ST-70-08C traceable EM/FM harnesses with lot-tested low-outgassing materials and serialized 20 GHz VNA test data.

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