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NASA's Perseverance rover will attempt to land on Mars this week
- bargl 6y agoMark Rober has an awesome video on this which outlines a lot and gives a very high level bit of info on it. I can't imagine the amount of stress these engineers are feeling watching this delayed feed. https://www.youtube.com/watch?v=tH2tKigOPBU https://www.youtube.com/watch?v=tH2tKigOPBU
- jcims 6y agoI wonder how many of those engineers have woken up, wild eyed in the middle of the night, as their brain excavates some random issue or loose end that surfaced and silently trailed off years ago, never to be properly resolved before launch.
- proggy 6y agoIt’s happened. Worst one I’ve heard of is when an engineer got an idea of how things could go south just days before the final decision point, ran to the testbed, tried it out, and their worst fears were proven right. They took it to the team, and after much wailing and gnashing of teeth, everyone collectively decided they were more confident in the level-headed plans they had executed to validate the system over the past 5+ years than this last minute, panic-induced test. So...they decided to let the sequence run as planned, and loaded up on a double helping of peanuts for the big day. Well, the big day comes and guess what? The spacecraft performs perfectly. Everyone was absolutely ecstatic. It turns out the test bed had been misconfigured, and there was nothing wrong whatsoever with the spacecraft or any of its command sequences. Really makes you think about how to make the best possible decisions in a crisis.
- bhupy 6y agoThis is fascinating. Do you have a link with more info?
- Taek 6y agoThis would make an amazing blog post.
- dmos62 6y agoWhat's the lesson in that story? I would have thought that you'd postpone until having fixed the problem exposed by that last test.
- codeduck 6y agoThis is only really a viable option prior to launch, of if the probe is coasting and you have enough time. If the probe is already near its destination, you have a very narrow window during which you can adjust its velocity for intercept. If you delay too long you do not have enough deltaV to intercept, and either miss your target entirely, or end up in the wrong final orbit with no ability to correct your inclination or eccentricity to what your mission parameters call for. Then you've basically spent years to send a paperweight to Mars.
- ArnoVW 6y agoIf the issue requires physically accessing the payload (which has been prepared and packaged, and is sitting on top of a huge rocket) it's not always that easy. The minimum-energy launch window occurs every 2 years, and lasts a couple of weeks.
- jcims 6y agoI've had microscopic renditions of this kind of thing in my career. There's a cognitive 'dolly zoom' effect where there's an illusion of growth in a given risk because the field of view has been narrowed by the preconditions and/or assumptions that led you to consider it to begin with. It's like the risk of losing a winning lottery ticket. Broadly the risk is negligible, but when you zoom into the precondition of having won the lottery, it's a big fucking deal.
- nuccy 6y agoThe Cassini–Huygens mission had exactly such a moment [1,2]. A year or so after it was lunched somebody pointed out that Huygens and Cassini communication may fail due to a flaw in handling of Doppler shifted radio signals on Cassini, which should relay data from Huygens. Luckly the spacecraft used a Venus gravity assist and had a close encounter with Earth again, so the issue was tested and confirmed. Engineers had to adjust the descent profile of Huygens, releasing it earlier than originally planned. This made its batteries last shorter after landing on Titan, but the whole mission was saved and data from the surface was properly relayed to Earth. 1. https://en.m.wikipedia.org/wiki/Huygens_(spacecraft) https://en.m.wikipedia.org/wiki/Huygens_(spacecraft) 2. https://youtube.com/watch?v=3ubr151wrHQ https://youtube.com/watch?v=3ubr151wrHQ
- throwaway0a5e 6y agoThe progress from "we can hit a region and maybe last a year" circa the Spirit/Opportunity era to the current state of "if we don't hit it we're close enough to drive to it" has been amazing. Better computing resources, better simulations, better materials, better and cheaper process control have enabled engineers throughout the entire supply chain to do more with less and when you take snapshots of progress at multi year intervals like NASA does with its Mars missions the progress really shows.
- BugWatch 6y agoOh, in Spirit's/Opportunity's case, that was 90 days (if memory serves me). So, they were successful beyond the wildest dreams. Curiosity, too.
- throwaway0a5e 6y agoThey knew they would last more than 90 days. 90 was just the number they picked for the "days before we can declare success" threshold. They weren't counting on 10yr.
- dmix 6y agoTIL the pacel pirate bomb marker guy worked at JPL for 9yrs. That's a really interesting career trajectory.
- duxup 6y agoThat's how NASA funding pays off!
- andbberger 6y agodude mentions it every chance he gets...
- ddingus 6y agoAs he should. Nasa is cool.
- Judgmentality 6y agoI understand the dude needs to sell himself, but "hey I'm _____ and I worked at NASA!" isn't really that different from "hey I'm _____ and I went to Harvard!"
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- ugh123 6y agoThis video goes into much better detail on the science experiments loaded up on the river. https://youtu.be/95hMM2u6Fgw https://youtu.be/95hMM2u6Fgw
- ragebol 6y agoFor some more technical details: https://www.youtube.com/watch?v=W0NakShgbHY https://www.youtube.com/watch?v=W0NakShgbHY. This makes me even more anxious, there are just so much things that have to go right.
- 4gotunameagain 6y agoI work in aerospace, one of my colleagues is part of the team for one of the instruments on the rover. Tomorrow we will attend a NASA telecon with our new mission t-shirts :) I asked him if he was stressed, his exact reply: "nah not really, not a whole lot we can do now"
- whalesalad 6y agoMy brother-in-law and two friends of mine played a big part in the assembly of the rover - I am so stoked for them to finally see it in action.
- iamcreasy 6y agoWow, please tell us more. What did they work on? Are those technologies ITAR restricted?
- whalesalad 6y agoskycrane :D
- mrfusion 6y agoIs it your siblings spouse or your spouses sibling?
- cdolan 6y agoCompany training tells me you are phishing
- doitLP 6y agoI’ll bet they worked with my friend who is the Deputy Surface Mission Manager for the rover. He gave us a little presentation of what he worked on, including the little helicopter that is attached to the underside of the rover. Veritasium did a cool video about it a couple years ago. [1] Kudos to everyone who worked on the project and got it launched during the pandemic! [1] https://youtu.be/GhsZUZmJvaM https://youtu.be/GhsZUZmJvaM
- IntemerateApe 6y agoThe helicopter is the thing I am MOST excited about!
- sathackr 6y agoSo everyone says the helicopter would be the first powered flight on another planet. Wouldn't the Skycrane be considered powered flight?
- holoduke 6y agoSending a probe in the direction of Mars is one thing, but the landing procedure is just mind boggling. Wonder how they simulate the stress and mars environment. I also noted that there will be a drone and HD video from many cameras.
- mhh__ 6y agoCombining modelling for even simple experiments is a pain so I can't even imagine - even if the end result is "simple" - the amount of book-to-forehead contact required for a rover.
- blisterpeanuts 6y agoAlmost more significant than the new Perseverance mission is the old Curiosity mission (https://mars.nasa.gov/msl/mission-updates/ https://mars.nasa.gov/msl/mission-updates/) which has been operating for 3,034 (Earth) days since its landing on August 6, 2012. (Technically it's been 3,116 days since the landing, but Nasa reports the smaller number, perhaps because of some downtime.) One can only imagine the internal debates and budgetary fights around a new rover mission to Mars while a team is still actively operating a very successful and healthy existing rover. Luckily, this new mission did get the green light. One also might speculate, amidst these multi-trillion dollar "stimulus" bills, what lost opportunities (no pun intended) there have been, had Nasa been budgeted more than its puny $22.6 billion allotment (as of 2020, 5% up from the previous fiscal year). I can hardly imagine a better investment in the future of the country, the future of science, and the future of humankind, than to explore the Solar System and develop the necessary technologies to enable humans to move off-planet in large numbers.
- mhh__ 6y agoI imagine it's similar to the LHC where an expensive project over decades breeds a lot of new technology and techniques (if you imagine the statistical equipment required to condense hundreds of petabytes of data over multiple years down to about 100 points on a graph, let alone building CMS and ATLAS).
- uomo 6y agoThe 3,034 days refers to how many sols (Martian days) it has lasted. The discrepancy is due to the fact that a Martian day is roughly 24 hours 40 minutes long. That extra 40 minutes over roughly 3000 days leads to the 82 day difference.
- blisterpeanuts 6y agoAh you're right, they did say Solar days.
- throwaway0a5e 6y agoOpportunity had been driving around Mars since 2004 when Curiosity landed. When NASA does their typical "get kids interested in science" outreach programs the kids they talk to have lived their whole lives with something driving around Mard.
- mrfusion 6y agoWill there be something to watch live as it lands? What should I expect?
- wlesieutre 6y agoThey'll have a stream on NASA TV. Not so many camera feeds as a SpaceX rocket, but I'm guessing similar to this: https://www.youtube.com/watch?v=LAL4F6IWC-Y https://www.youtube.com/watch?v=LAL4F6IWC-Y Space.com says NASA's landing broadcast will start at 2:15 PM EST on Thursday: https://www.space.com/mars-rover-perseverance-landing-webcasts https://www.space.com/mars-rover-perseverance-landing-webcas... There's already some Perseverance stuff being broadcast today, I tuned in for a while earlier and they were answering questions from social media about stuff like the team working on Mars time after landing.
- Me1000 6y agoThe coverage for Perseverance will actually have seven cameras for landing! https://mars.nasa.gov/mars2020/spacecraft/rover/cameras/ https://mars.nasa.gov/mars2020/spacecraft/rover/cameras/
- chrononaut 6y agoTo ensure it's clear for other readers, footage from the new cameras will not be streamed live during descent, but made available several days later. To get a very "rough" sense of what that footage may be like afterwards (with a lot more cameras), Doug Ellison has a good composition from the Curiosity landing here: https://www.youtube.com/watch?v=RZioPhfxnSY https://www.youtube.com/watch?v=RZioPhfxnSY
- chrononaut 6y agoThe video wlesieutre linked of the Curiosity landing is a great reference of what you will experience for Perseverance's landing while watching it live. The video cuts short but about 10 to 30 minutes after landing they will likely have a half dozen low resolution images from the rover itself, much like they had with Curiosity.
- pengaru 6y agoI'm super eager to hear if the small helicopter manages stable, repeatable flight.
- jojobas 6y agoThey know exactly what the air density and gravity is and tested for the exact conditions. It it makes to the surface in one piece it will fly.
- macksd 6y agoI realize they're very smart and very thorough, but this sounds an awful lot like "I ran the test suite - if you can apply the patch in production it'll work".
- mhh__ 6y agoLuckily physics works pretty well. Unfortunately, everything is trivial in theory.
- pengaru 6y agoIsn't Mars known for extreme winds and dust storms, which seem like quite the challenge for an ultralight drone resting on the surface, let alone flying autonomously?
- MrFlynn 6y agoSince the atmosphere of Mars is 1% the pressure of Earth's, even very high velocity wind would have little energy behind it.
- jojobas 6y agoWind forces are defined by dynamic pressure q, which is proportional to speed squared divided by density. At 1% the Earth's air density, a 100m/s wind on Mars (half the speed of sound!) exerts the same force as 10m/s breeze on Earth. So far the fastest winds observed on Mars are about 30m/s. So, the thin air that makes it hard to fly on Mars makes it safe to stay on the ground.
- quercusa 6y agoThe landing animation video (2/3 way down in article) is really amazing.
- overlordalex 6y agoJPL produced a video titled "7 minutes of terror" that detailed the landing procedure they used for Curiosity, and it's worth a watch. It goes into detail on everything you see in the articles landing video: https://www.youtube.com/watch?v=Ki_Af_o9Q9s https://www.youtube.com/watch?v=Ki_Af_o9Q9s
- sand500 6y agoits been updated for perseverance https://www.youtube.com/watch?v=rzmd7RouGrM https://www.youtube.com/watch?v=rzmd7RouGrM https://www.youtube.com/watch?v=M4tdMR5HLtg https://www.youtube.com/watch?v=M4tdMR5HLtg
- obilgic 6y agooff-topic: more than 60% of page is just ads above fold.
- svnpenn 6y agoEvery time I see a thread like this, I think of XKCD Spirit: https://xkcd.com/695 https://xkcd.com/695 Something profoundly bittersweet about that entry.
- z3t4 6y agoMovie recommendation: Moon (2009) sci-fi
- walrus01 6y agoFor anyone who has ever looked at the code for betaflight, arducopter or px4 and built a moderately complex quadcopter from parts... I really wonder what the balancing/descent/sensor package and software looks like on the rocket-crane thing. As I understand it, after it jettisons the aero shell, it reaches a certain height by radar altimeter and then activates active rocket thrust to balance a big square flying platform over the landing area, with a very limited flight time possible (based on weight budget/fuel supplies), and then uses the skycrane system to lower the rover. What sort of 6-axis IMUs and sensors must be on that thing , and how quickly can it adjust thrust per corner to keep itself flying level while descending... https://www.space.com/16889-mars-rover-curiosity-sky-crane-landing.html https://www.space.com/16889-mars-rover-curiosity-sky-crane-l... Does it swivel the small rocket motors? Or is it based on thrust adjustment only? How many different radar and laser altimeter type sensors does it use to determine that it's above a suitable flat spot? All sorts of fun questions.
- sathackr 6y agoBased on available renderings for both skycranes[1][2], the motors do not appear to have any gimble ability, so must be controlled by thrust alone. It's interesting that the valves consume 168 watts of power each, 1.34kw of power just for the throttle valves. The paper in [4] mentions they were adapted from the same engines used for the Viking landers. A paper specifically on the EDL system [4]. Page 13 is where the fun starts. The IMU appears to be a Honeywell MIMU [5][6] and is combined with a radar altimeter for navigation and attitude control. Datasheet for the motor [3] (Pg. 13) [1] https://planetary.s3.amazonaws.com/web/assets/pictures/curiosity_landing_skycrane_PIA14839.jpg https://planetary.s3.amazonaws.com/web/assets/pictures/curio... [2] https://www.youtube.com/watch?t=569&v=obzGkiyelt8 https://www.youtube.com/watch?t=569&v=obzGkiyelt8 [3] https://www.rocket.com/sites/default/files/documents/Capabilities/PDFs/Monopropellant%20Data%20Sheets.pdf https://www.rocket.com/sites/default/files/documents/Capabil... [4] https://trs.jpl.nasa.gov/bitstream/handle/2014/44894/13-0633_A1b.pdf?sequence=1 https://trs.jpl.nasa.gov/bitstream/handle/2014/44894/13-0633... [5] https://aerospace.honeywell.com/en/learn/about-us/customer-success-stories/2019/03/lockheed-martins-mars-lander-counts-on-honeywell-mimu https://aerospace.honeywell.com/en/learn/about-us/customer-s... [6] https://satcatalog.com/component/mimu/ https://satcatalog.com/component/mimu/
- tim44 6y agomeet George Jettison.
- 1970-01-01 6y ago>And for the first time, Perseverance will be taking along a couple of microphones so that we can hear what Mars sounds like. This isn't the first time NASA sent a mic to Mars, but it may be the first time that it works.
- anticensor 6y agoLinks to NASA's official live streams: https://www.youtube.com/watch?v=gm0b_ijaYMQ https://www.youtube.com/watch?v=gm0b_ijaYMQ https://www.youtube.com/watch?v=GIooAx_GkJs https://www.youtube.com/watch?v=GIooAx_GkJs
- input_sh 6y ago> The target is the bottom of Jezero crater, a 50km-diameter impact crater on the northwestern edge of a much larger impact basin called Isidis. In Slavic languages, “Jezero” means lake. Jezero was chosen because it looks (based on orbital imagery) like it was likely a huge lake in the ancient past, with rivers running into it and forming river deltas like we have here on Earth. I mean, yeah, Jezero means lake, but the crater was named specifically after a municipality in Bosnia with about a thousand inhabitants (https://en.wikipedia.org/wiki/Jezero,_Bosnia_and_Herzegovina https://en.wikipedia.org/wiki/Jezero,_Bosnia_and_Herzegovina). IIRC it's something about promoting space exploration in more rural towns and villages around the world. https://planetarynames.wr.usgs.gov/Feature/14300 https://planetarynames.wr.usgs.gov/Feature/14300
- inglor_cz 6y agoFor a Slav, it is very unusual to see any Slavic word in a worldwide context. The roots of pretty much everything seem to be Greek, Latin, English, French, sometimes German and Spanish. Seeing anything in an English text that I can actually understand natively in my head (such as Jezero) is a weird system interrupt. The only possible exception is robot, which does not sound very Slavic on its own. "Robot" does not provoke this interrupt.
- Asooka 6y agoIt can be both. Jezero was named Jezero because it's next to the jezero. Edit: Same as e.g. Volgograd (wet town), which is next to the Volga river, named Volga because it's wet.
- tectonic 6y agoMartian craters are typically named after towns around the world that have fewer than 100,000 residents to avoid political pressures.
- deleted 6y ago[deleted]
- KDJohnBrown 6y agoA $2.7bn RC car.
- echelon 6y ago> A $2.7bn RC car. One that could find life and immediately invalidate every religion's current perception of the world. (Or at least require rethinking from religious leaders on how to adapt to this new information.) A lot of people - even atheists - will have to change their model of the universe. It would probably be the most critical and important moment in human history. From there we have to start thinking about how to protect our own species. Because if we're not the only life, and it's as common as the next planet away, imagine what else lurks out there... It would kick off the next, even bigger, space race. Even if we don't find life, this thing comes so loaded with experiments and new engineering that it propels us forward for the next generation of planetary exploration tech.
- KDJohnBrown 6y agoIf the past 3,000 years has taught us anything it is thwt religions won’t change any of their superstitions when presented with evidence. > It would kick off the next, even bigger, space race. So basically I should be excited about the potential a self-perpetuating beaurocracy Your entire argument is that the goal of spending money on space exploration is to spend more money on space exploration? For people suffering on earth that’s a great argument for defunding taxpayer funded space exploration.
- echelon 6y ago> For people suffering on earth It's just a temporary state, I assure you. It'll all be over soon.
- KDJohnBrown 6y agoHopefully. Human lifespans are way too long.
- novaRom 6y agoThat name is not easy to remember. A shorter more frequent word would be better.
- gorgoiler 6y agoPercy?