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We get so used to space missions outlasting their planned duration that it seems surprising when one actually ends on schedule.
by smackfu 14y ago
We get so used to space missions outlasting their planned duration that it seems surprising when one actually ends on schedule.
- jacquesm 14y agoIt actually went 11 months and 15 days beyond the planned lifespan, that's nearly 30% longer.
- gus_massa 14y agoMy impression is that it's a underpromise and overdeliver thing. For example in a Mars prove, you don't know exactly what the soil will do to your wheels, what the thermal changes will do to your cpu, what the dirt will do to your solar panels, what the wind will do to your camera support and there are even the unknown unknowns. Probably most of them can be simulated, estimated or guessed. And a 9 years mission that breaks after 8.5 years is a mayor failure that wasted millions of taxpayer's money. A 2 years mission that last 8.5 years is a successful result of good engineering practices. Probably the Helium evaporation is too easy to simulate and they only put there the right amount plus 25% just in case. The problem is that Helium is a consumable, so the tank has a finite duration. You can't try to continue until something breaks.