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Spirit Outlasts Viking 2 Lander
ScottMaxwell writes "Spirit, the Mars rover designed for a 90-day mission, has now outlasted the Viking 2 lander. Viking 2 survived until its 1281st sol (Martian day); Spirit is now on sol 1282 and counting. Assuming both rovers continue to weather the ongoing dust storms, Spirit's sister, Opportunity, will reach the same age in a few weeks. They aren't breathing down the neck of the all-time record just yet, though — the Viking 1 lander lasted 2245 sols on the surface of Mars; Spirit and Opportunity won't break that record for another 2.7 Earth years."
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Got me on Challenger, but Columbia, no. The shuttles were all designed with a 10-year lifespan in mind - they have more than outlasted that expectation
"In God we trust, all others we monitor." -- Unofficial NSA motto
that needs a big fat asterisk. Seriously, a "90-day mission" and it's still going 3 years later? Something is rotten in Mars.
Most thought that dust on the solar panels would end the missions after a few months. Turns out that whirlwinds clean them every now and then. They didn't know such would happen since long-duration solar missions hadn't been done yet.
And mechanics *are* wearing out, it is just that they find workarounds. Spirit drives backward because of a failed wheel, and Oppy holds its elbow in a single place most of the time, using wheels to maneuvor instead of bend the bad elbow. And some if it is probably luck; the electronics could snap at any time due to heat-cold cycles. (Oppy's front wheel is showing signs of wear also.)
It is also true that statistically, once missions get past the early phase, they tend to last well. The failure spots are usually early in most missions if there are failures.
Table-ized A.I.
The shuttles were designed with 100-flight airframes. The original specification called for one launch every month - per orbiter. Thus each orbiter would wear out after a decade.
As it turned out, the maximum flight rate they could get was about one launch per year - per orbiter. An order of magnitude less than the spec. Thus it is little wonder that the shuttles "lasted" longer than their design life. Each orbiter has only flown an average of 30 times.
In the ST:TNG episode Relics, Scotty criticized Geordie for giving Picard accurate repair time estimates.
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Assuming I counted correctly, there have only been 5 successful landers/rovers (Viking 1 and 2, Mars Pathfinder, Opportunity, and Spirit) and 1 partial success (Mars 6). Check the page http://en.wikipedia.org/wiki/Exploration_of_Mars. There were a lot more missions to Mars than I realized, most of them failures. Going to Mars is hard, which makes the success of Opportunity and Spirit even more amazing. It would be a mistake for us to get cocky and think we've got this mastered, just because our couple missions went really well.
The difference being that mission parts that are replaced in the orbiter's downtime are not what have an impact on the operational lifespan of the vehicle. The platform's non-replaceable parts were meant to last ten years--the time on Earth is much harder on them than a high operational tempo.
Each orbiter was only meant to last, structurally, for ten years. The number of missions it flew is largely a separate issue, given that much of the vehicle is replaced after each mission. Time was and always has been the enemy.
Since the early 70s we (NASA, its partners, and American industry) have accomplished such more than a few minor feats:
- The Shuttle program has logged almost 9 times the spaceflight of the Apollo+Skylab program
- The Shuttle program has averaged more than twice the flight rate of Apollo+Skylab
- The ISS joint-venture will triple the flight time of Shuttle by the time the station is closed in 2016, so that's approx 27-fold over Apollo+Skylab
- We since launched robotic missions to every planet (including Pluto) in the Solar System
- We have revolutionized our understanding of the cosmos using orbital telescopes (3 out of 4 Great Observatories launched by Shuttle)
- Private industry has demonstrated reusable suborbital flight with surprisingly good economics
I really hope you were joking when you asked "where are the interstellar probes." The fact is, we have made significant progress in spaceflight these last 20-30 years but those accomplishments have been overshadowed due to irrational expectations such as your own. It is inconceivable that we could have gone from Apollo to Lunar colonization, Mars missions, space industry, etc without further maturation of spaceflight technology. And as a stepping stone, the Shuttle/ISS have given us tremendous experience and capability that we did not have post-Apollo.
The greatest tragedy of all is that after debugging the Shuttle fleet of so many design issues, we are just going to retire them as soon as possible. If we were to build a new fleet of orbiters from scratch, we could implement a myriad of design improvements that would greatly lower cost and improve safety. Instead we're going to go pander to the "exploration" crowd...
They weren't nuclear reactors. They were RTGs. There was no reaction, they were powered by the heat produced by radioactive material.