EEVblog #328 - Curiosity Mars Rover Landing - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 02, 2012, 11:53:39 am
content: Dave.

author: radioman.lt
author_rank: Newbie
timestamp: August 02, 2012, 12:55:46 pm
content: more info:http://www.jpl.nasa.gov/msl/

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: August 02, 2012, 03:32:18 pm
content: Hi All,If Curiosity is running Windows There doomed.All you'll see on the live feeds will be the BSOD or 'your computer will be rebooted in 15,14,13,12 ."Mr Smiley

author: SeanB
author_rank: Super Contributor
timestamp: August 02, 2012, 04:17:02 pm
content: Somehow do not thing it runs windoze, more likely something more RTOS and a lot morre robust and able to detect and correct errors. Think BIG BLUE software, running on a space rated processor, and not likely a X86 based architecture.

author: TerminalJack505
author_rank: Super Contributor
timestamp: August 02, 2012, 04:38:14 pm
content: I just hope the software engineers remembered to enable priority inheritance this time.In 1997 the Pathfinder, running VxWorks, shortly after landing, kept resetting itself. It was eventually determined to be a priority inversion issue. Lower priority threads would grab a mutex and starve-out higher priority threads when they blocked trying to acquire the same mutex. A watchdog timer would notice that the higher priority thread wasn't running in a timely manner and reset the system.Priority inheritance would have boosted the priority of the lower priority thread to that of the higher priority thread when the OS noticed the higher priority thread was waiting on the mutex being used by the lower priority thread.It's an interesting read if you're into embedded systems.

author: lemming
author_rank: Contributor
timestamp: August 02, 2012, 04:41:59 pm
content: Computers:The two identical on-board rover computers, called "Rover Compute Element" (RCE), contain radiation-hardened memory to tolerate the extreme radiation from space and to safeguard against power-off cycles. Each computer's memory includes 256 KB of EEPROM, 256 MB of DRAM, and 2 GB of flash memory. This compares to 3 MB of EEPROM, 128 MB of DRAM, and 256 MB of flash memory used in the Mars Exploration Rovers.The RCE computers use the RAD750 CPU, which is a successor to the RAD6000 CPU used in the Mars Exploration Rovers. The RAD750 CPU is capable of up to 400 MIPS, while the RAD6000 CPU is capable of up to 35 MIPS. Of the two on-board computers, one is configured as backup, and will take over in the event of problems with the main computer.The rover has an Inertial Measurement Unit (IMU) that provides 3-axis information on its position, which is used in rover navigation. The rover's computers are constantly self-monitoring to keep the rover operational, such as by regulating the rover's temperature. Activities such as taking pictures, driving, and operating the instruments are performed in a command sequence that is sent from the flight team to the rover.http://en.wikipedia.org/wiki/Curiosity_roverAlsohttp://en.wikipedia.org/wiki/Comparison_of_embedded_computer_systems_on_board_the_Mars_roversis a good read.

author: PeteInTexas
author_rank: Frequent Contributor
timestamp: August 03, 2012, 05:34:42 am
content: I have no confidence in this sky crane thing. Too many moving parts.I find it hard to believe they could not solve the dust problem caused by the rockets. Lens cover anyone?I would have done either two parachutes- before and after the hovering rockets, or the airbag thing after hovering.

author: MikeK
author_rank: Super Contributor
timestamp: August 03, 2012, 02:02:09 pm
content: Here's a cool solar system simulator:http://eyes.nasa.gov/index.htmlYou can view the MSL spacecraft in its current position, pick a time, or run through the EDL sequence (the preview mode). As well as check out other spacecraft, planets, dwarf planets, and such.I plan on being late for work on Monday. Since I was at Cape Canaveral to watch the launch in November and have been anxious for August 5th to arrive. Cool technology, I hope it all works.

author: ProBang
author_rank: Contributor
timestamp: August 03, 2012, 02:32:23 pm
content: Quote from: PeteInTexas on August 03, 2012, 05:34:42 amWith this rover? Sure.But I think, this kind of landing is a early test for a human mission to mars.At least two reasons:1. It's a very smooth landing.(After a couple of month at zero gravity the astronauts will be not the fittest.)2. The landing area is visible.(Very important, if you want to be sure, that the Habitat is landing on plain, safe ground.)

author: lewis
author_rank: Frequent Contributor
timestamp: August 03, 2012, 04:27:00 pm
content: If the dust from the descent rockets is a massive problem, which it sounds like it is because they've used the awesome sky-crane thing, why not put the rover in a bag? Descend all the way to the surface on rockets with the rover encased, then get the rover to cut its way out of the bag when all the dust has settled. Simples!Come on NASA, where's your job application form?Really REALLY looking forward to this, it will be an absolutely astonishing engineering achievement even if it doesn't work.

author: SeanB
author_rank: Super Contributor
timestamp: August 03, 2012, 05:30:03 pm
content: Remember this little rover is the size and mass of a Toyota Yaris.............

author: laborratte
author_rank: Newbie
timestamp: August 03, 2012, 06:07:29 pm
content: Curiosity landed - somehow...http://youtu.be/yjiGH9QNiU0

author: jpelczar
author_rank: Contributor
timestamp: August 03, 2012, 06:27:52 pm
content: I wonder if it would be possible to create a network of space relays, deployed in various area of our solar system, which would amplify the signal from the satellites, so we would get better data quality ? Or would it kill the entire NASA budget ?

author: SeanB
author_rank: Super Contributor
timestamp: August 03, 2012, 06:52:18 pm
content: Difficult to launch a 30m dish into space easily, as the power from the rover side is very limited. You also need a lot of power for the signals towards the probe, as again a sensitive receiver with a small antenna is limited because of space and power limits. NASA is doing well enough with what is left of the Deep Space Network dishes, even though most of them are relics from Apollo.

author: Zad
author_rank: Super Contributor
timestamp: August 03, 2012, 07:12:27 pm
content: Better to have relatively small relay spacecraft in orbit around the planet where the rover is working. You can then install sensors on the relay and do additional science. You won't get 24/7 coverage but it works out pretty well on Mars now.Incredibly, when one of the rovers had a firmware problem very early in the mission, they were able to talk to it directly via the short omni-directional vertical antenna.

author: free_electron
author_rank: Super Contributor
timestamp: August 03, 2012, 07:49:09 pm
content: Quote from: Mr Smiley on August 02, 2012, 03:32:18 pmwhy is it that invariably some moron feels the need to bring something like this up ?Serious embedded systems do not run Windows as a core os. Neither do they run botched-together and endlessly forked contraptions like linux.Serious embedded operating systems are timing accurate , fully deterministic systems like VxWorks, pSos, Nucleus or iRMX and run on rugged, hardened hardware with erro correcting memory. It is extremely hard to make a system like iRMX go tits up... We have several pieces of equipment (Eaton Ion Implanters) that run this Os. I have seen catastrophical hardware failures that wuold bring any other os to its knees. iRMX trapped the hardware failure, recovered and kept going. One such event was a failed stick of DDR memory. iRMX paused for a few seconds , interrogated the memory controller and found parity errors in a whole bank of memory. It marked the affected address blocks as 'bad' ( like it would mark a drive sector bad ) , found out what was loaded there , reloaded that from disk , and then kept going. The machine did not shut down or lock up. A log entry was made that addresses x to y were bad and should not be used with a notification that on the next planned shutdown the memory should be replaced. a couple of days later the machine scheduled for planned takedown and maintenance and that's when we replaced the failed dimm.Any single bit error in any other operating system would have catastrophical consequences. not in iRMX. it simply shrugs , and moves on

author: Unknown
author_rank: Unknown
timestamp: August 03, 2012, 08:51:54 pm
content: "The rover is powered by radioactive plutonium-238. As the plutonium undergoes decay, its heat is converted into electricity to power the rover’s electronic devices."Are you telling me that this sucker is nuclear?

author: madworm
author_rank: Frequent Contributor
timestamp: August 03, 2012, 09:12:12 pm
content: A thermo-nuclear battery, much like on the voyager I think. Basically works as a reversed peltier element.

author: Chasm
author_rank: Regular Contributor
timestamp: August 03, 2012, 09:22:29 pm
content: Exactly. Albeit with a different design (~110W el, ~2000W thermal) and only one instead of 3 as with Voyager (~160W el, 2400W thermal - each).The Viking 1 and 2 Mars landers also used Radioisotope Thermal Generators. (2 each, ~50W el, 525W thermal)RTG are used because there is simply not enough light to power such a large rover (and energy hungry experiments). The heat can also be used to heat the rover.The other rovers also used radioactive elements to heat critical bearings like the wheels but had to use battery power to heat the rest. Small Radiothermal heating elements are quite common in space applications.

author: KTP
author_rank: Frequent Contributor
timestamp: August 03, 2012, 09:57:14 pm
content: Quote from: madworm on August 03, 2012, 09:12:12 pmVoyager is still working, sending back data so I think the nuclear battery is proven.Would be interesting if this rover is working 34 years from now. Kind of reminds me of Wall-e. Maybe it can meet up with Opportunity and go on a date.

author: free_electron
author_rank: Super Contributor
timestamp: August 03, 2012, 10:25:51 pm
content: Quote from: jucole on August 03, 2012, 08:51:54 pmno,no,no this suckers electrical, we just need the plutonium to generate the 1.21 jigawatts into the flux capacito.. oh wait.. wrong movie ...

author: Unknown
author_rank: Unknown
timestamp: August 03, 2012, 10:33:40 pm
content: Quote from: free_electron on August 03, 2012, 10:25:51 pmhehe

author: hobbs
author_rank: Contributor
timestamp: August 04, 2012, 01:23:47 am
content: Quote from: jpelczar on August 03, 2012, 06:27:52 pmCheck out George O. Smith's *Venus Equilateral* stories for pointers on how to make that work.CheersPhil Hobbs

author: dreamgame
author_rank: Newbie
timestamp: August 04, 2012, 11:06:27 pm
content: If anyone interested in details of how this will be possible. With photos and several technical details.http://danielmarin.blogspot.com.es/2012/08/asi-sera-el-descenso-de-curiosity-en.htmlSorry, is in Spanish. But some google translate will help. (a little)http://translate.google.es/translate?sl=es&tl=en&js=n&prev=_t&hl=es&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fdanielmarin.blogspot.com.es%2F2012%2F08%2Fasi-sera-el-descenso-de-curiosity-en.htmlEnjoy.

author: radioman.lt
author_rank: Newbie
timestamp: August 05, 2012, 07:19:40 pm
content: get ready for the show!

author: Mr Smiley
author_rank: Frequent Contributor
timestamp: August 05, 2012, 07:55:25 pm
content: Quote from: free_electron on August 03, 2012, 07:49:09 pm

author: G7PSK
author_rank: Super Contributor
timestamp: August 05, 2012, 08:21:44 pm
content: I read somewhere of a proposal for a solar system wide radio observatory to look into deep space. That would be some undertaking indeed but very interesting results would follow.Could even bee used to look for longer wavelengths than are possible at present.

author: MikeK
author_rank: Super Contributor
timestamp: August 05, 2012, 10:05:31 pm
content: We should start with an observatory on the moon. It's so close. Hubble has done a tremendous job by being above Earth's atmosphere. Imagine being able to carve an observatory out of the lunar surface.

author: pickle9000
author_rank: Super Contributor
timestamp: August 05, 2012, 10:31:47 pm
content: Are they planning on crashing the decent vehicle after landing the rover? I'd like to see them land it and then take it for a burn until the fuel runs out (5 seconds of fuel).Remember when they landed that satellite on the asteroid or comet (I forget which)? That was awesome....mike

author: MikeK
author_rank: Super Contributor
timestamp: August 06, 2012, 02:17:40 am
content: Just saw this:http://www.marsdaily.com/reports/Australia_is_all_ears_for_Mars_landing_999.htmlThe Canberra Deep Space Communication Complex is the main tracking station for the landing.

author: DrGeoff
author_rank: Frequent Contributor
timestamp: August 06, 2012, 03:55:14 am
content: I think this one is running RTEMS, at least in parts, which is a realtime executive that was developed for military systems initially and is now public domain. Very robust and ported to quite a few systems now.RTEMS.org for more details.http://www.rtems.org/pipermail/rtems-users/2012-August/010316.html

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:05:09 am
content: 26 minutes to landing. Here is the countdown clock:http://www.nasa.gov/mission_pages/msl/index.htmlThe live stream is here:http://www.ustream.tv/nasajpl

author: nitro2k01
author_rank: Frequent Contributor
timestamp: August 06, 2012, 05:19:45 am
content: Or if you want to listen to mission control with ambient music:http://somafm.com/missioncontrol/

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:30:19 am
content: Down to 90m/sec

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:31:32 am
content: in powered flight now. 500m altitude

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:32:15 am
content: skycrane has started

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:32:48 am
content: touchdown confirmed

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:35:08 am
content: Communication from Curiosity to Oddessy is strong. First thumbnail images just coming through now.

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:38:57 am
content: First 256x256 pixel image has just come through showing the rover wheel on Mars. The camera still has its dustcovers on the lense. Oddessy is just about to go out of range.

author: MikeK
author_rank: Super Contributor
timestamp: August 06, 2012, 05:39:25 am
content: Engineering kicks ass again!

author: amspire
author_rank: Super Contributor
timestamp: August 06, 2012, 05:48:35 am
content: Here are the two 256x256 pixel photos. You can see the dust on the lens dust cover:140Kg from 400kG of fuel left after touchdown.

author: MikeK
author_rank: Super Contributor
timestamp: August 06, 2012, 05:52:05 am
content: Lots of raw images here:http://mars.jpl.nasa.gov/msl/multimedia/raw/

author: Things
author_rank: Regular Contributor
timestamp: August 06, 2012, 06:51:36 am
content: Bloody incredible it worked so well, hugely impressed!

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 06, 2012, 07:33:41 am
content: Nice that it worked, I would like to see the sensor data about what really happened.I wish they stopped calling that picture "High Res"

author: radioman.lt
author_rank: Newbie
timestamp: August 06, 2012, 07:52:25 am
content: i wonder is it real or they faked it ;/ ..you never know

author: EEVblog
author_rank: Unknown
timestamp: August 06, 2012, 07:57:10 am
content: Freak'n awesome!But I'm pissed!I was one of few people who didn't see it "live", and actually got a spoiler that it had landed, ruining the entire thing.I went to the Sydney Observatory to see it as they advertised a live feed and figured it would be cool to hand out with the pro crowd watching this.But it was a debacle.Was supposed to happen at 3:30pm Syd time of course, and they announced they would start the live feed at 3pm. Ok, fair enough. Then we just watched videos until about 3:25pm when they decided to turn the live feed on. Great, at least I'll get to watch it...No Wifi, so I wasn't able to see anything much on my phone apart from Twitter.Then things just seemed a bit strange, I heard one announcer on the feed say 22min until entry and figured the timeline got screwed by some issue or something.Then decided to check twitter to see what's happening and I see the NASA tweet that it had landed! and twitter melted down.So I and a guy next to me who was doing the same thing looked at each other whispering WTF just happened?And then we realised the "live" feed we were watching was massively delayed, by at least 20min it turns out, so we had to sit there deflated and watch he "live" feed knowing the ending. I have no idea how it was delayed or where they were getting their feed from.Experience totally ruined.Then we got a tap on the shoulder to keep our mouth shut, and they admitted they knew it was already down.I should have stay home.Thumbs down to the Sydney Observatory, what a bunch of dickheads.Dave.

author: radioman.lt
author_rank: Newbie
timestamp: August 06, 2012, 08:10:35 am
content: yeah, a bit of shame ;/

author: djsb
author_rank: Super Contributor
timestamp: August 06, 2012, 08:17:48 am
content: Just went on YouTube NASATelevision and some news company has blocked a video that NASA uploaded for copyright reasons.Mean spirited b******s. I'll just have to watch the BBC later.David.

author: radioman.lt
author_rank: Newbie
timestamp: August 06, 2012, 08:29:43 am
content: Quote from: djsb on August 06, 2012, 08:17:48 amridiculous

author: Things
author_rank: Regular Contributor
timestamp: August 06, 2012, 08:48:30 am
content: That sucks bigtime Dave.I got my scare too as my internet started dropping out 20 mins before the landing, bloody Telstra at it again!But hey, at least it's worked successfully, it's a pretty awesome event to witness.

author: analogueground
author_rank: Newbie
timestamp: August 06, 2012, 09:06:27 am
content: I'm in the UK and I set my alarm early and watched the whole thing using the NASA TV app without a glitch, which was a surprise as I expected the bandwidth to be hammered.What an unbelievable achievement! The whole project was inspirational from a technical point of view and shows that you only push the boundaries when you take risks. From his comments, I felt Dave wanted this to fail so he could say 'I told you so'That's the attitude you get from being immersed in too much systems engineering without looking out of the window.NASA JPL employ the daring, the visionaries and the engineers - you need them all to do what they have just achieved. Incredible stuff.Steve

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 06, 2012, 09:24:04 am
content: I did turn on the internet live feed but I checked CNN an they were also broadcasting it. I missed the beginning though I started seeing it at about mach 3.They should have kept this real time sensor data on the screen though for the viewers, looked nice. Sensor screen example:https://www.youtube.com/NASATelevisionEdit(incl. funny transcript!)They had quite a safety margin on the fuel, 35% of fuel left.Dave, maybe it helps thinking that even the best seat to witness it had a 14min delay

author: EEVblog
author_rank: Unknown
timestamp: August 06, 2012, 10:25:03 am
content: Quote from: analogueground on August 06, 2012, 09:06:27 amI predicted it would work!Dave.

author: IanJ
author_rank: Unknown
timestamp: August 06, 2012, 11:01:27 am
content: Quote from: analogueground on August 06, 2012, 09:06:27 amAm a bit surprised some folks in UK couldn't get the feed.........I got up early and straight to NASA TV website.......very clean, un-interrupted live feed......perfect!It all happened so fast.....and how the guy who announced touchdown managed it without screaming I'll never know.Would love to be involved in a project like Curiosity.............!Ian.

author: EEVblog
author_rank: Unknown
timestamp: August 06, 2012, 11:48:56 am
content: Have been thinking about trying to get one of the systems designers on the AmpHour show.Would be good to get an electronics perspective of such a project. I need a name though so I can harass themDave.

author: Things
author_rank: Regular Contributor
timestamp: August 06, 2012, 11:54:52 am
content: Quote from: EEVblog on August 06, 2012, 11:48:56 amThey were all probably waiting to see if it worked or not before putting their names out in public. Would hate to be the guy that screwed up and created a $2.4bil crater on Mars

author: EEVblog
author_rank: Unknown
timestamp: August 06, 2012, 12:06:46 pm
content: Quote from: Things on August 06, 2012, 11:54:52 amThe Big Bang Theory - Plan AAADave.

author: firewalker
author_rank: Super Contributor
timestamp: August 06, 2012, 12:53:42 pm
content: Quote from: EEVblog on August 06, 2012, 07:57:10 amIt seems that someone made a click on the time line of Nasa's feed. It would automatically drop the live feed and start playing back from the point of the click (~130 hours of video).Alexander.

author: EEVblog
author_rank: Unknown
timestamp: August 06, 2012, 01:55:42 pm
content: Quote from: firewalker on August 06, 2012, 12:53:42 pmAh, that would explain it!Dave.

author: Mechatrommer
author_rank: Super Contributor
timestamp: August 06, 2012, 02:08:15 pm
content: Quote from: firewalker on August 06, 2012, 12:53:42 pmlive feed is "practically impractical"what if its discovered an "uncivilized alien tribe" there? i'm talking about male and female.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 06, 2012, 03:43:39 pm
content: Quote from: Mechatrommer on August 06, 2012, 02:08:15 pmHow hard can it be to translate "Do not tough high voltage parts!" or "Sorry, is this your rock?"

author: KedasProbe
author_rank: Frequent Contributor
timestamp: August 06, 2012, 04:20:44 pm
content: They have a nice picture of the parachute (taken from 340km), very nice in case something went wrong.

author: MikeK
author_rank: Super Contributor
timestamp: August 06, 2012, 05:00:32 pm
content: That's awesome. I hope they were able to video the full EDL.