This time Phoenix stays dead…

Where the Phoenix lander is on Mars it’s winter.  Phoenix ran out of power recently.  The 2 rovers, Spirit and Opportunity, have to fight for their own survival every Martian winter.  Why?  Because they use solar arrays.  Solar arrays that degrade with time.  Solar arrays that degrade with the deposition of dust.  Solar arrays that don’t produce much power when the Sun isn’t very high in the sky.

Power constraints have hampered interplanetary probes in the past.  The problem is that once a probe gets out near Jupiter there just isn’t enough sun light to do much.  Even large arrays can’t entirely overcome the problem of “not enough light”.

We have $100 million missions that end because of power

We have missions to Mars and Jupiter and beyond.  Some like Cassini use nuclear power.  Others use solar power.  Some missions, like Phoenix, have ended not because of mechanical failure, communications failure, or a lack of good science that still needs doing but because they have too little power.

A lack of power has not stopped the Voyager missions decades after their launch.  A lack of power doesn’t need to kill or maim anymore Mars missions.  A Radioisotope Thermoelectric Generator (RTG) is the answer.

Next post: What is an RTG?

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