Monday, February 22, 2021

Thursday's Mars Landing Video

Today, NASA/JPL-Caltech released a short video of the last few minutes of the flight of Perseverance to Mars, culminating in the landing.  If you haven't seen it, you should.

The world’s most intimate view of a Mars landing begins about 230 seconds after the spacecraft entered the Red Planet’s upper atmosphere at 12,500 mph (20,100 kph). The video opens in black, with the camera lens still covered within the parachute compartment. Within less than a second, the spacecraft’s parachute deploys and transforms from a compressed 18-by-26 inch (46-by-66 centimeter) cylinder of nylon, Technora, and Kevlar into a fully inflated 70.5-foot-wide (21.5-meter-wide) canopy – the largest ever sent to Mars. The tens of thousands of pounds of force that the parachute generates in such a short period stresses both the parachute and the vehicle.

“Now we finally have a front-row view to what we call ‘the seven minutes of terror’ while landing on Mars,” said Michael Watkins, director of NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission for the agency. “From the explosive opening of the parachute to the landing rockets’ plume sending dust and debris flying at touchdown, it’s absolutely awe-inspiring.”
I have a tremendous amount of respect for the people involved in designing and pulling off this mission so far; not just the JPL but I'm approaching "five nines" (99.999%) sure that established defense and space contractors who are experienced with designing for space did much of the heavy lifting.  The levels of endurance, resilience, and reliability required in the electronics at every level is almost comical. This hardness is demanded from the components themselves, to the subsystems created, to the entire spacecraft and its auxiliary elements.  The running joke is that all the components used in space, "Class S" components, aren't considered acceptable until the test documents weigh more than the launch vehicle.  The testing should exhaust about half the components expected life (and they routinely work far longer than expected).   

I worked on one of those contracts for the JPL in the early '90s, and the JPL people exude an air of competence.  JPL has a desire to plan for every eventuality and asked rather amazing and dumbfounding questions.  Things like how a system might react when it was turned off if the systems it was connected with did something unexpected.  Most of us think our circuits won't do anything when they're turned off, but it's a worth looking at if the tests can be done.

If you're keeping an eye on SpaceX Boca Chica, you'll know that the expected static firing of SN10 (Sten?  Ted?) didn't happen today.  They have road closures tomorrow and Wednesday and FAA clearances to go for repeat of SN8 and 9's flight potentially as early as this week, although I kind of doubt it.  I don't know what went wrong today, but they didn't get as far as the cryo proof testing done in the last round of tests, judging by looking at the videos from late in the test.  There are never signs of the vehicle venting or getting icy, so it never got fueled. 


  1. Sometimes "Big Space" does it right. Have a friend that was involved with the software for a "special" satellite. While he couldn't talk much about it, he was very adamant about the level of testing and verifying that went on on that side of the project because it had to work right the first time it was actually used (and it did). Same had to go for the hardware.

    I caught on LabPadre that today's issue was some necessary work on the orbital launch mount that had to be done. They may have taken the test process as far as they could with workers that close to the test stand and then shut it down. This weather in Texas has messed up everyone's schedule.

  2. Yeah, what BillB said, and to add something. This is the first time a SpaceX product has been exposed to a prolonged hard freeze. Would not surprise me a bit if ice intrusion on/in test equipment was a factor. I am sure the spectre of the Challenger disaster still looms big in every space operator's mind.

    It wasn't just a prolonged hard freeze, it was really nasty blowing weather, with rain, slush, snow and possibly hail all blowing hard. The type of weather that defeats the best normal seals.

    A serious looky-loo over all the exposed components to see what, if any, effects are found from the deep freeze would be a sensible thing. And SpaceX has always done the sensible thing (some surprising things, but everything they've done has been sensible from 20-20 hindsight.)

    I mean, if I was a project engineer or a technician on the Starship program, I'd love a look at all the stuff to see if any changes or issues show up. Like water intrusion from all those tile mounting holes. Stuff like that. Externally mounted electronics, hydraulic systems, potential moisture in lines, etc. What are the effects? What needs to change, if anything?

    Now is the time to look at all of this. It's not like there's a Starship sized freezer that can be used for testing all of this.

    As to what JPL did? Amazing. Absolutely amazing. NatGeo had a very good 2 hour special on designing and building and testing the Rovers, from the actual space hardware to the test space hardware to the terrestrial test hardware.

    Really interesting thing? After super-duper cleaning of the sampling components, they found that striction between super-duper-cleaned surfaces was going to doom the whole mission. Failure rate in a vacuum approaching near 100%. So the remedy? Only super-duper clean the inside and mouth of the collecting tube, and they only needed to super-clean the rest of the sampling tube in order to not contaminate the sample tube with Earth contaminates.

    Who woulda thunk? That you could get stuff too clean? Can you imagine the brains sitting around, a couple years deep into the project, looking at a game-ending test, and some wisenheimer goes, "Maybe we don't need to clean all of it. Maybe there needs to be some contamination for pieces to slide on?" And then watch everyone's head explode at the sensible concept. A serious 'Duh' moment involving some really brainy people.

    Wouldn't be surprised if it was one of the senior engineering techs that thought that up. Wouldn't be surprised if it was some lowly tech.

    1. About taking a serious inspection of the Starship, I kept an eye on the Nerdle Cam a few times a day over the weekend. There were three or even four bucket lifts in place up and down the ship all weekend. They seemed to be giving it a serious look over.

  3. Bravo NASA and JPL! One of the guys I worked with at Hughes was on-call to get loaned to JPL as soon as they called, and he went there almost weekly, sometimes spending a few days before returning. They wanted things done "Right", and he was one of the guys that knew his stuff.

    It's a fine art to make things almost at the cutting edge, back just far enough that reliability is at an acceptable level. "Works In The Lab" isn't nearly good enough.

    I think some of the difference is that JPL is/was run by Engineers, and NASA is/was run by "administrators".