3.2M views · Jun 22, 2012 · 5:08 · 5 HN recommenders · 9 mentions · discussed 2016–2021
NASA JPL engineers explain the final minutes of the Curiosity rover's entry, descent and landing on Mars, which combined aerobraking, a parachute and a skycrane. It lays out the tight sequence of events that all had to work automatically.
Why Hacker News points people here: HN repeatedly recommends it as an awe-inspiring example of engineering problem solving and the go-to explainer on how Mars landings work.
“If you have not watched the seven minutes of terror video produced by NASA, you absolutely must.”HN comment, 2021
“I get goosebumps every time I watch this, absolutely amazing problem solving.”
NASA explains how Curiosity was to land safely on Mars
Reminds of the "Seven Minutes of Terror" video that NASA put out ahead of the Curiosity landing explaining how they intended to make it safely to the surface. this video (Note: I get goosebumps every time I watch this, absolutely amazing problem solving.)
“If you have not watched the seven minutes of terror video produced by NASA, you absolutely must.”
Details exactly how machines are put on the surface of Mars
If you have not watched the seven minutes of terror video produced by NASA, you absolutely must. It details exactly how they put these amazing machines on the surface of Mars. this video
“I highly recommend watching this video from JPL to give you an understanding of where such tools excel.”
Shows JPL simulating, iterating and autogenerating code for complex systems
> I still haven't seen any case for visual programming. Aerodef, automotive, etc all use some form of visual programming. Controls engineers rarely write code, the systems are way too complex. E.g. I highly recommend watching this video from JPL to give you an understanding of where such tools excel. It's about simulating, iterating and then having scientists and engineers autogenerate the code they couldn't possibly write or test this video
“Curiosity used aerobraking, parachutes AND a skycrane to land.”
Explains Curiosity's combined aerobraking, parachute and skycrane landing
Curiosity used aerobraking, parachutes AND a skycrane to land. There's a great video here: this video Previous solutions weren't used because they were less crazy, but because they were more mass efficient for "small" payload sizes.
“It goes into detail on everything you see in the articles landing video”
Detailed walkthrough of the Curiosity landing procedure
JPL 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: this video
“shock loads as the securing pyrobolts blew during landing”
Shows the landing sequence including pyrobolt shock loads
Surprisingly the wheels only weigh a few pounds each! (I still can't think in metric and I don't have a real number.) They were primarily constrained by packing volume during cruise ( link ) and then by shock loads as the securing pyrobolts blew during landing ( this video ).
“Far more things have to go right in order for JWST to become operational.”
Curiosity entry, descent and landing sequence used as a comparison
There's a video showing the JWST deployment sequence. It's set to calm orchestral music, and the visuals are just 3D renters of the spacecraft. link This video makes me far more nervous than "7 Minutes of Terror", depicting Curiosity's entry/descent/landing sequence. Far more things have to go right in order for JWST to become operational. this video
“The robotic program has a very good track record of successes”
Example of a crazy Mars landing that worked
Yup. The robotic program has a very good track record of successes, even for crazy stuff like the Mars Science Laboratory’s sky crane descent stage: this video It’s the human spaceflight program that has had the, um, difficulties. There are signs of hope, though.
“at distances of planets it truly becomes a way of looking into the past”
Illustrates the landing events and Earth-Mars time delay
For perceiving the events happening, sure, that was my point. These time differences are nearly always imperceptible but at distances of planets it truly becomes a way of looking into the past. But to be clear, events happen concurrently, eg NASA knew _when_ relative to earth time and _perceived_ events, each stage was "happening" local to Mars vs Earth (assuming it all went well). They made videos about this "7 minutes of terror", I forgot the name of them but linking here [0] [0] this video
