Testing time for MetOp Second Generation

MetOp Second Technology (MetOp-SG) is a follow-on system to the profitable MetOp satellites, the final of which launched into its 800 km polar orbit in 2018.

MetOp-SG is Europe’s part of the Joint Polar System, which is a collaboration with the US.  Eumetsat, the European Organisation for the Exploitation of Meteorological Satellites, operates the MetOp satellites and is chargeable for creating the bottom phase of the system and delivering the meteorological information to the world-wide person neighborhood. ESA is chargeable for designing and manufacturing the house phase of the system – the satellites themselves.

For this marketing campaign the check merchandise was not flight however a prototype model specifically constructed for preliminary testing, generally known as the ‘structural and thermal mannequin’ (STM).

This preliminary MetOp-SG satellite tv for pc, standing 6.5m excessive and weighing in at four.four tonnes together with propellant, was shaken, shocked and positioned in extended vacuum beneath simulated daylight to show the design’s qualification for launch and readiness for house.

The MetOp Second Technology mission is definitely made up of two completely different satellites every with completely different suites of devices onboard. 

“Our STM is definitely a hybrid of those two satellite tv for pc designs,” explains Nick Goody, the mission’s propulsion and meeting integration and testing engineer.

“The 2 satellites have a standard platform, whereas the STM is supplied with the nadir-pointing devices from satellite-A plus payload unit objects from satellite-B, together with amplifiers and energy provides.  This hybrid configuration leads to the utmost mass and energy dissipation for the STM testing, meant for mechanical and thermal qualification.  These qualification goals not lined by the STM might be addressed by the SAT-A and SAT-B proto-flight fashions.”

The check marketing campaign started on the Toulouse facility of Airbus Defence and House in December 2018, the place dummy models, thermal and electrical harness was built-in, along with the propulsion module provided by Airbus’s facility in Stevenage, UK. This was adopted by integration of check fashions of the devices and the completion of its ‘harness’ – the maze of wiring connecting all the things collectively – and its multi-layer insulation wrapping.

“A micro-vibration check marketing campaign was carried out to characterise the switch features between the devices and different microvibration exporters such because the response wheels,” mentioned MetOp-SG satellite tv for pc engineering supervisor Enrico Corpaccioli.

“These measurements enable us to higher analyse the results of micro-vibrations on the devices through the operation of the satellite tv for pc when it’s in orbit.  Alignment measurements had been additionally carried out to offer a reference earlier than environmental testing started.”

Then, in June 2019, the STM was transported to the ESTEC Take a look at Centre in Noordwijk. The biggest satellite tv for pc check web site in Europe, the centre is supplied with services to simulate each side of the house setting beneath a single cleanroom roof.

Right here it was unpacked for vibration testing.  It was then crammed with 760 kg of demineralised water, instead of the hydrazine propellant it will likely be fuelled with earlier than launch, for ‘sine’ testing alongside every axis – present process a progressive sweep of frequencies and amplitudes to hunt out any doubtlessly dangerous structural resonances.

“Qualification ranges are utilized to the STM construction,” provides Nick, “which means that the amplitudes are considerably above the anticipated flight ranges and the durations are longer so as to show the mandatory margin within the design.”    

A ‘quasi-static’ load check was additionally carried out.  Satellites are uncovered to simultaneous static and dynamic masses through the launch section as a result of launcher acceleration and aerodynamics. This quasi-static load check combines static and dynamic masses into an equal load which is utilized to the satellite tv for pc in a excessive amplitude sine burst over just a few seconds.

A rocket launch is a particularly noisy occasion, so MetOp-SG was then transferred to the Massive European Acoustic Facility. Right here nitrogen is handed by large acoustic horns inside a sealed chamber, recreating the sound of a launch.

The subsequent step was a ‘match examine’ and separation check, involving mating the satellite tv for pc with a launcher adapter offered by Arianespace, to ensure the 2 designs match collectively as meant and that the ring securing the satellite tv for pc to the launcher – generally known as the clampband – operates appropriately in order that the separation can happen with none drawback.

Subsequent got here the thermal check section, which noticed MetOp-SG moved into the Massive House Simulator, the most important vacuum chamber in Europe, geared up with a photo voltaic simulator based mostly on an array of excessive energy lamps.

Numerous orbits had been simulated in varied cold and hot situations till ‘thermal stability’ was achieved inside set ranges. The outcomes from this check permits experimental correlation of the spacecraft mathematical thermal mannequin, used to confirm the thermal management design.

Testing concluded with additional alignment testing – to examine the mannequin had endured its check regime with out structural deformation – and a ‘leak examine’ involving filling the propulsion module with helium gasoline.

“This check marketing campaign has offered necessary qualification information,” provides Nick, “permitting correlation of the fashions with consultant check information and confirming the evaluation carried out through the design stage. The structural thermal mannequin has now been transported again to Toulouse in France, the place the instrument fashions, propulsion module and dummy models are being eliminated.

“The satellite tv for pc STM construction and propulsion module might be returned to their suppliers for refurbishment, as they’re destined to be employed in MetOp SG-A’s second flight mannequin.”

A story of two MetOp-SGs

The 2-satellite MetOp-SG system supplies information from polar orbit for climate forecasting and local weather monitoring and the suite of devices present data on atmospheric chemistry, air high quality, oceanography, hydrology, wind, sea ice, precipitation and temperature profiles within the environment.

MetOp SG-A hosts IASI-NG (Infrared Atmospheric Sounder Interferometer – New Technology) developed by French house company CNES; the METimage superior multispectral imaging radiometer developed by German Aerospace Heart DLR; the ESA-developed Copernicus Sentinel-5 for atmospheric sounding plus ESA’s MWS (Microwave Sounder); 3MI ((Multi-view Multi-channel Multi-polarisation Imager) and RO (Radio Occultation) devices.

MetOp SG-B consists of the identical RO devices as MetOp-SG-A plus the ESA-developed SCA (Scatterometer), ICI (Ice Cloud Imager), MWI (MicroWave Imager) and the CNES-contributed Argos Information Assortment Service, amassing data from ocean-going buoys and a House Atmosphere Monitor contributed by Thales Alenia House.

MetOp-SG is projected to enter service in 2023.