European Space Agency recently announced that Europe's beleaguered Galileo satnav has suffered another setback, with clocks failing onboard a number of satellites in space. Designed to make Europe independent from America's GPS, the 10 billion-euro ($11 billion) project may experience further delays as the cause of the failure is investigated.
Eighteen orbiters have been launched for the Galileo constellation to date, a number that will ultimately be boosted to 30 operational satellites and two spares. Early, initial services were launched in December, and the failure of nine clocks out of 72 launched to date has not affected operation. As of now, no satellite has been declared "out" as a result of the glitch.
Each Galileo satellite has four ultra-accurate atomic timekeepers - two that use rubidium and two hydrogen maser. Three rubidium and six hydrogen maser clocks are not working, with one satellite sporting two failed timekeepers. Each orbiter needs just one working clock for the satnav to work - the rest are spares.
The question now is should thjey postpone the next launch until they find the root cause? The next four satellites are scheduled to be launched in to space in the second half of 2017.
People are suggesting that they wait until they find a solution, but that means if more clocks are failing then they are reducing the capability of Galileo. If ESA launches on time, they will at least sustain if not increase the possibility of Galileo, but they might be taking the risk (of) a systematic problem. Its also not known whether the broken clocks can be fixed or not.
ESA boasts that Galileo has the most accurate atomic clocks ever flown for geolocalisation. Similar to traditional clocks relying on the tick of a pendulum, atomic timekeepers also count regular oscillations, in this case switches between energy states of atoms stimulated by heat or light. The project has already experienced many setbacks, taking 17 years and more than triple the original budget before going live last month.
In August 2014, after a more than year-long delay over "technical difficulties", satellites number five and six were placed into a lopsided, elliptical orbit - delaying subsequent launches. The civilian-controlled service is seen as strategically important for Europe, which relies on two military-run rivals - GPS and Russia's GLONASS. Neither providing a guarantee of uninterrupted service.
ESA director general Jan Woerner also defended the decision to create an autonomous European satnav system based on European technology. He said - If you want to be competitive in the global market you should not rely in too many aspects on the technology of others. If you only use proven technology, you have no further development. We ought to take risks in order to learn, in order to be competitive in the future.
Last October, ESA's Mars lander Schiaparelli, designed to test technology for a future rover, also crashed into the Red Planet. It had been Europe's second failed attempt to reach the Martian surface.