If the thought has crossed your mind, no, ordinary VoIP service does not work very well over satellite connections. Delay in satellite data transmission does not allow for VoIP transmission, but there are services available that specialize in this market:

• OptiStreams Leader in VoIP efficient satellite networking solutions and services
• Ground Control VOIP for Direcway or Galileo users
• Skycasters VOIP for Directway users
• SDN GlobalSatellite VoIP over dedicated international MPLS backbone with full QoS. Covers 85% of populated world.
• Speedway VOIP for iDirect and Linkstar users
• Transcom ISP VOIP for any high contention VSAT systems
• Agiosat Global CommunicationsVSAT/Mobile/Emergency communications, including VOIP. Global coverage.
• BusinessCom Internet via Satellite VoIP and VSAT services based on the LinkStar, iDirect and dedicated backbone channels with appropriate QoS setup. Service is offered on a unique iLBC codec which is used in Skype to achieve the best radio frequency media tolerance.
• atrexx - Global Capacity and Facility Exchange Versatile Voice-over-IP System proved with DSL type broadband connections and Internet over Satellite connections