SpainSat NG-2 launches despite NG-1 orbital control problems

A SpaceX Falcon 9v1.2 Block 5 rocket carrying Spainsat NG-2, a special Ka- and X-band communications satellite bound for Geostationary Earth Orbit (GEO) lifted off from Cape Canaveral, Florida, at 0130 GMT on 24 October.  

The launch used a super-synchronous transfer orbit with an apogee at nearly 63,000km (actual orbit: 62,984 x 409 km at 26.8 degrees inclination*). Due to an apogee that is much higher than GEO’s 36,000 km, this transfer orbit allows for a much more propellant-efficient inclination removal than required for a more usual Geosynchronous Transfer Orbit (GTO).

The B1076 booster/first stage (on its 22nd flight) was deliberately used as expendable stage since this was an ‘all out’ performance maximising launch for the Falcon 9. That is, it carried its maximum capacity of propellants, while being stripped of all unnecessary hardware, such as its landing legs, and aerodynamic control vanes. On depletion, the stage fell downrange in an uncontrolled manner into the Atlantic Ocean.

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NG-1’s control issues

The NG-2 launch was not significantly delayed, which was surprising given that its sister spacecraft, SpainSat NG-1, had suffered two recent ‘loss of control’ events, apparently due to a software issue.  

Normally when a spacecraft exhibits an anomaly, a lengthy series of tests and checks would be conducted to ensure that the next spacecraft in the series would not be afflicted by the same (or a similar) anomaly.  

SpainSat NG-1 was launched in January and experienced an incident around 19 August, when it drifted off station over 28.9 degrees east, when the spacecraft was detected by Slingshot Aerospace’s Global Sensor Network as falling into a tumble. Seradata understands that it is in the process of being recovered even though Slingshot Aerospace detects it as still tumbling. Either way, the event may have resulted in damage to the spacecraft’s electronics, induced by cold temperatures given the eclipse season.

Both SpainSat NG-1 and NG-2 use the Eurostar NEO bus platform and were built by Airbus Defence and Space and were fully insured. Thales Alenia Space in Spain was responsible for the UHF and military Ka-band payloads and the integration of the Communication Module.

*Transfer orbit from Jonathan McDowell

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