Mars Rover Opportunity Sets Longevity Record

s31523 writes "The Mars rover Opportunity has beaten the original record of six years and 116 days operating on the surface of Mars, originally set by the Viking 1 Lander. While the Spirit rover has been on the surface longer than the Opportunity by three weeks, it has been out of communication since March 22. If Spirit comes back online, it will attain the new Martian surface longevity record. This feat, right on the heels of another longevity feat (Voyager 2 and twin on the verge of entering interstellar space and still kicking) is healing some of NASA's past black eyes. It is quite remarkable given original spec of 90 days for the mission. With the passing of the solstice, warmer temperatures and more sun will likely mean the rover will continue on."

Comments

Go technology go!

[JDSalinger]

Feats like the Mars Rovers show us that our space-engineering prowess is not only continuing to mature, but indeed getting quite robust. From this one mission alone, how much have we learned about vehicle design for dealing with the Martian environment?

And with yesterday's announcement of the creation of synthetic life, we are obviously on the edge of new breath-taking scientific ability. When will we be able to start creating custom bacteria to begin terra-forming mars? I know there is no way to predict the future, but the potential for change in our life-times is mind-blowing. As an anxious futurist, all I can say is "Go technology go!"

Re:Go technology go!

[Jarik C-Bol]

Ah, just as i suspected, the age old 'they failed, it was over engineered, it should have only lasted 95 days, blah blah blah' shtick.
For the umpteenth time, *it was deliberate* they knew they could not get approval for the budget for a rover designed to last years and years, because of the long standing 'what if it breaks early? then the money is wasted right?' attitude.
NASA knew what it would cost to build a decent rover, so they pitched it at 90 days, that way if it flakes out, it does not look like a huge failure.
They build an excellent rover on (what is thought to be) a 90 day rover budget, send it up, and 95 days later, they can say 'look! this 90 day rover we made is doing great! it well outlasted our expectations! its way cheeper for us to keep driving it around than to build a new one and send it, can we get a little more funding?' I'm confident NASA knew full well what it was doing when it built and sent these rovers. (They probably even had at least rough outlines of things to do with them in the event of an extended project life.)

Re:Go technology go!

[Morty]

In general, NASA builds most spacecraft to considerably higher spec than required to perform the primary mission. This is a basic engineering principle called safety margin. If you calculate that a bridge needs to handle a load of X, then you build it to actually handle 3X.

Spacecraft that complete their primary missions become eligible to do extended mission, usually at a reduced budget. Most spacecraft that survive their primary mission do end up going into extended mission. The primary mission is the set of scientific observations that spacecraft are funded to do. The extended mission is a collection of observations that we do given that we are already "there".

This might seem odd, but actually makes a lot of sense. A lot of the mission cost is up-front cost -- designing instruments, launch vehicle, ground systems, calibration, systems integration, etc. So build the actual spacecraft a whole lot better than spec to make sure all those other costs don't get wasted if something unexpected occurs. Then, after the primary mission, you find yourself with an incredibly expensive asset uniquely placed to do scientific observations, which has just proven itself capable of providing lots of scientific data -- so do you shut it down, or keep pulling value out of it as long as you can?

Disclaimer: I speak for myself, not my employer or work site.

Re:Mission spec too low?

[Pharmboy]

How low are the specs for these missions are set if it's been operating for 25x longer than it was designed to?

The problem is that the original specs were for U.S. standard time, and we now use metric time.

Re:Mission spec too low?

[Jeng]

No one knew if there would be enough wind to wipe the dust off of the solar panels. That was the limiting factor, it was figured it could go for 90 days before its solar panels would be too dusted to power the rover.

The specs were fine, we just under estimated the wind.

At least that is what I have been told.

Reduces black eyes, but readies 'em for a beating

[Dynedain]

This feat ... is healing some of NASA's past black eyes. It is quite remarkable given original spec of 90 days for the mission.

Until some congressional asshat takes a look and argues "NASA builds things to last 25 times longer than specified. Ergo they are spending too much and their budget is 25 times higher than it should be."

Very remarkable indeed

[digitalsushi]

It's remarkable in that M.O. Scotty tells Geordi in that novel turned episode, Relics:

from imdb:

Lt. Commander Geordi La Forge: Look, Mr. Scott, I'd love to explain everything to you. But the captain wants this spectrographic analysis done by 1300 hours.
Scotty: [thinks about it some time] You mind a little advice? Starfleet captains are like children. They want everything right now and they want it their way. But the secret is to give them only what they need, not what they want.
Lt. Commander Geordi La Forge: Yeah. Well, I told the captain I'd have this analysis done in an hour.
Scotty: How long would it really take?
Lt. Commander Geordi La Forge: [annoyed] An hour!
Scotty: [looks unbelieving] Oh. You didn't tell him how long it would REALLY take, did you?
Lt. Commander Geordi La Forge: Of course I did.
Scotty: Oh, laddie. You've got a lot to learn if you want people to think of you as a miracle worker.

NASA Young Guy: This thing should last for 6 years easy!
NASA Old Guy: Er my young peer means it should definitely last for 90 days. Anything past 90 days is amazing.

Re:Very remarkable indeed

[Chris Burke]

Haha, yeah you're so right, except for how you're totally wrong.

90 days never had anything to do with how long the rover's parts would last. Not a single damned thing. No engineer ever said "I can only guarantee this part will last for 90 days" or anything like it.

90 days was how long they thought it would be until the solar panels were too coved in dust for the rover to function. When the Martian wind turned out to be strong enough to clear the panels, NASA issued a press release and said "We were wrong; yay!" and the mission continued.

And not knowing what the environment on Mars was like is exactly why there was never any Scotty-esque sandbagging, and instead the rovers were simply designed as robustly as possible, with a hypothetical lifespan of many years, simply to ensure they worked at all.

xkcd's take on the matter

[zorro-z]

http://xkcd.com/695/

Re:Mission spec too low?

[The Grim Reefer2]

No one knew if there would be enough wind to wipe the dust off of the solar panels. That was the limiting factor, it was figured it could go for 90 days before its solar panels would be too dusted to power the rover.

That, and the homeless martians keep squeegeeing the panels.

Every frickin' time.

[CraftyJack]

Stop it. It's OK to have a story about the MER mission without a link to xkcd#695.

Re:Every frickin' time.

[blair1q]

Human beings are not connected by a hive mind. Every one of them has to be told something individually. Even in a broadcast situation, you have to put out enough photons and phonons in enough directions to get the message to all the ears. And anyone who isn't in the room when you do it will cause you or someone else (or a webserver) to repeat the message to them personally.

There. All better. Now go play.

Scotty's Rule

[0100010001010011]

Lt. Commander Geordi La Forge: Look, Mr. Scott, I'd love to explain everything to you. But the captain wants this spectrographic analysis done by 1300 hours.
Scotty: [thinks about it some time] You mind a little advice? Starfleet captains are like children. They want everything right now and they want it their way. But the secret is to give them only what they need, not what they want.
Lt. Commander Geordi La Forge: Yeah. Well, I told the captain I'd have this analysis done in an hour.
Scotty: How long would it really take?
Lt. Commander Geordi La Forge: [annoyed] An hour!
Scotty: [looks unbelieving] Oh. You didn't tell him how long it would REALLY take, did you?
Lt. Commander Geordi La Forge: Of course I did.
Scotty: Oh, laddie. You've got a lot to learn if you want people to think of you as a miracle worker.

Re:reliable tech, eh?

[CraftyJack]

Leela: Depth at 45 hundred feet, 48 hundred, 50 hundred! 5000 feet!
Farnsworth: Dear Lord, that's over 150 atmospheres of pressure.
Fry: How many atmospheres can this ship withstand?
Farnsworth: Well it's a spaceship, so I'd say anywhere between zero and one.

JPL

[poly_pusher]

http://www.jpl.nasa.gov/



This success is due to Nasa's JPL or Jet Propulsion Laboratory. The successes they have had over the past decade are astounding. I see this as more proof that remote missions are more practical in the short term as opposed to manned missions. Just give JPL some more money and let them do their thing. These are the guys that will discover what we need to know, so as to make manned spaceflight practical.

As a side note, I saw a documentary on spirit and opportunity recently. It was one of the most entertaining and surprisingly dramatic documentaries I have seen.

http://topdocumentaryfilms.com/welcome-mars/

Designed for worst case [Re:Go technology go!]

[Geoffrey.landis]

Feats like the Mars Rovers show us that our space-engineering prowess is not only continuing to mature, but indeed getting quite robust.

I don't doubt we are getting better at building equipment that can stand the rigors of space or Mars (better alloys, better lubricants, better electronics, simple design) but this also says something about our ability (or lack thereof) to estimate the durability of the things we build. Lasting twice as long as we expect is a great thing, lasting 25x as long means they were afraid to give a real estimate.

The rovers were engineered to survive 90 sols (Martian solar days) under worst-case conditions.

Turns out that the conditions they actually experience were not as bad as worst case.

Most notably, they were designed to operate in the (solar-energy-positive conditions) of Martian summer. They were definitely not designed to survive Martian winter. The fact that they were able to survive Martian winter is a tribute to, yes, the fact that the engineers overdesigned (partly, the fact that they overdesigned to withstand worst-case summer condidtions that didn't actually occur), partly that components used actually do continue to perform despite being well outside the design envelope (nobody had ever subjected the rechangable lithium batteries to these extreme cycles, until we did it on Mars), and partly by great work on the part of the operations crew. And then, after that, it was due to the fact that Mars cooperated by cleaning our solar arrays.

Kind of like how Scotty says "It will take 8 hours to get it fixed, Captain!", to which Kirk says "You have 2 hours", and yet it still gets fixed. The engineers are likely underestimating the "average" time to cover their own butts.

No, it's not a "cover your butt"-- it's the fact that if you are given a spec of, say 900 Martian days, the review board is going to require that the engineers show test results before launch proving that they will meet that spec-- on most of the components, this means testing to three times the design life. For an environment for which a lot of the conditions are not completely known, and so you'll have to test for worst case conditions. This would balloon the cost up unreasonably.

This actually makes it *harder* to get some science done, as you are scrambling to create new tasks with the extra time you weren't expecting, never knowing when it will give up the ghost.

In some ways this is true-- it would be nice to know how long the mission was going to last, if for no other reason than to know for how long I needed to rent an apartment in Pasadena. For MER, however, the team has had no problems coming up with new things to do with the extra time.