Earlier quoted context omitted.
Then that was the mother of all under-promises!
If they make it over 9000 days, they can state the just did a error on the exponent
Then the units would be time squared. That doesn’t make any sense!
Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
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Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#92Earlier quoted context omitted.
Also a testament to the value of under-promising. :)
If I remember correctly the reason they did not expect the mission to last longer than that was because they expected the solar panels to get covered with dust and thus render them useless. I don't think they had banked on martial winds to regularly clean them.
Your recollection is correct. Consider too the dust accumulation predictions for the moon landing. It would appear that we (as humans) are not very good at dust estimates (dustimates?). This is reinforced by the continuing struggle/inability to manufacture dirt. As an avid composter with a ton (lol sorry) of experience, I can make you hummus for days. I can turn 90% of your organic household waste into growth medium, bokashi tea, or pre-dirt in anywhere from 6 months to 2 years. But if you want me to make dirt? I'll need a decade to get you a production level process that requires raw stocks, pre-processing, vermiculture, aquaculture, and many rounds of late stage funding. Dirt production stymies every modern industrial process because as it stands, you cannot reduce the time necessary for conversion from hummus to dirt. I find it beautifully tragic that terraforming Mars will require mass dirt transfer from earth (consider this tonnage conundrum and revel in the irony).
Don't take my word for it. Go out and try to make earth yourself. If you can reinvent this fundamental, elementary process, you will join Jonas Salk and Fritz Haber, and very few others, in changing The Game in a fundamental way.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#93Earlier quoted context omitted.
Also a testament to the value of under-promising. :)
If I remember correctly the reason they did not expect the mission to last longer than that was because they expected the solar panels to get covered with dust and thus render them useless. I don't think they had banked on martial winds to regularly clean them.
It's also a matter of federal budgeting; when the rovers landed, NASA definitely did not have enough funds budgeted to keep tasking the rovers for 8,000 days. But as the rovers continued to operate, NASA requested more funds to continue, and Congress provided them.
Once a robotic mission accomplishes its primary objective, NASA has a great story to tell about marginal cost vs return of additional funds. It's not that uncommon; heck they still get funding to keep the Voyager program operating.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#94End of an era. We'll meet Opportunity again one day. Same thing happened with Cassini. It's kinda poetic to see these outposts of Humanity's reach fade out after a sublime performance.
More interesting would be when someone else from another species finds them in a couple of million years in the future and wonders what their purpose was all about.
If found in the current state, I'd speculate they'd conclude it's a planetary explorer:
* Lots of sensors
* Lots of communcation equipment
* No external controls
* Parts built without maitenance access
* Solar power
* Found on a mostly empty planet, with only a few other rovers around
* A planet next door littered with similar technology
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#95Opportunity's and Spirit's original missions were planned to last 90 Martian days each. They ended up lasting over 8,000 combined. That is almost as impressive as getting the rovers to Mars in the first place.
That story is very much over sold. They defiantly designed the things with a longer lifespan in mind. NASA simply had more reasonable minimum specks so if they died on day 220 nobody would call the program a failure.
Expectation management is sometimes as important as the actual delivery.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#96Was looking through Opportunity's Wikipedia page, and found this cool comparison of the embedded systems used in Mars rovers: https://en.wikipedia.org/wiki/Comparison_of_embedded_compute... That lead me to the RAD6000 page, which was new to me: https://en.wikipedia.org/wiki/IBM_RAD6000 "Reported to have a unit cost somewhere between US$200,000 and US$300,000, RAD6000 computers were released for sale in the general co…
I saw a video once saying that SpaceX uses general purpose computers on the rockets instead of specific purpose hardware. If I'm not mistaken, they amount to 6 and have a checking system to assure the output of them is the same.
Yes and a SpaceX rocket computer is not in space very long and is mostly in the low radiation environment of LEO. These Mars rovers spent years in a high radiation environment and received a large total ionizing dose of radiation. Having multiple computers doesn't do anything for total ionizing dose, they are all going to fail around the same time.
I'm not sure about the RAD6000 being discussed here, but its successor, the RAD750, is fabbed with silicon-on-sapphire to help with total ionizing dose. For single event upsets, there is triple modular redundancy for all logic in the CPU.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#97Earlier quoted context omitted.
Earth minute or Martian minute?
Excellent question. I assumed that one mars minute differs from an earth minute but I just learned that they don't. Seconds, minutes and hours are universal. Hours in a day is what varies by planets, moons etc. Funny that I never thought of that before :)
It just depends on what your definition of a Martian minute is. If you define it as 1/(24*60) of a Martian day, it is different from an Earth minute.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#98Is it possible for someone other than NASA to send a message to the rover? I'd be happy throwing a little money at a project to ping it monthly to see if there is a response.
Yes and unlikely :-) The protocols are all documented but the ability to receive signals from the rover requires a pretty sensitive receiver and antenna combination. If you have the resources to build a 10m or 15m steerable radio antenna parabolic dish then you could probably manage it.
That can't be that expensive unless you want it to be storm proofed. But it wouldn't be super cheap either, the receiver is probably going to be a bigger problem.
http://www.astrosurf.com/luxorion/dish-antenna-building.htm
Would be a good starting point. But keeping it stable under wind load is going to be the major challenge. That would be one heck of a project, it would likely take a few years of your time to pull it off.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#99Opportunity's and Spirit's original missions were planned to last 90 Martian days each. They ended up lasting over 8,000 combined. That is almost as impressive as getting the rovers to Mars in the first place.
That story is very much over sold. They defiantly designed the things with a longer lifespan in mind. NASA simply had more reasonable minimum specks so if they died on day 220 nobody would call the program a failure.
I wasn't just commenting on the physical durability of the rovers themselves although that is a huge part of it. It is also impressive from both a political and an organizational standpoint to keep a program like this running successfully for so much longer than initial plans dictated.
Re: Nasa’s Mars Rover Opportunity Concludes a 15-Year Mission
#100Seriously, what is the point of space exploration anyway? and what if we found water on Mars? shouldn't it be a huge amount of water to support life?