37 ms·

You can also watch an EDL visualization in your browser: https://eyes.nasa.gov/apps/mars2020/#/home https://eyes.nasa.gov/apps/mars2020/#/home And read about h

You can also watch an EDL visualization in your browser: https://eyes.nasa.gov/apps/mars2020/#/home https://eyes.nasa.gov/apps/mars2020/#/home And read about how it will use Terrain Relative Navigation to find a safe landing spot: https://www.jpl.nasa.gov/news/a-neil-armstrong-for-mars-landing-the-mars-2020-rover https://www.jpl.nasa.gov/news/a-neil-armstrong-for-mars-land... Perseverance is phenomenally complex, its Sample Caching System alone contains 3,000+ parts and two robotic arms. So exited for all the sciencing this nuclear-powered, sample-drilling, laser-zapping behemoth can do when it joins its friends on the only planet (known) to be inhabited solely by robots. Edit: Percy is about to release its two 77 kg Cruise Mass Balance Devices (is this what NASA calls 'weights'?) to setup the right lift-to-drag ratio for entry. Mars InSight will be listening for the 14,000 km/hr impacts of these weights, providing useful calibration data. We wrote about this in this week's issue of our space-related newsletter, Orbital Index - https://orbitalindex.com/archive/2021-02-17-Issue-104/ https://orbitalindex.com/archive/2021-02-17-Issue-104/

tectonic 6y ago
Also, InSight's SEIS seismometer is a true marvel: "We have been able to detect, at about 10 hertz, displacement of the ground of the order of less than 5 picometers…which is a fraction of the size of an atom." — https://eos.org/features/a-modern-manual-for-marsquake-monitoring https://eos.org/features/a-modern-manual-for-marsquake-monit...
- peter303 6y ago
  LIGO puts this shame with 10^11 better sensitivity.
  - jvanderbot 6y ago
    At sensitivity/gram insight wins. Per dollar probably not.
WJW 6y ago
> is this what NASA calls 'weights'? Well no, the Cruise Mass Balance Devices are intended to Balance the Mass of the spaceship during Cruise conditions. That these Devices are single-part and constructed out of a single chunk of metal each should not be construed as merely being 'weights'. :)
- deleted 6y ago
  [deleted]
- theelous3 6y ago
  What I'm getting from this, is that you can use weights to balance the mass of the spaceship during cruise conditions.
  - xarope 6y ago
    Ships do this all the time (ballast), and anybody who's ever flown on a light aircraft or helicopter also knows the importance a pilot places on weight distribution. I guess what's surprising is that they needed that much weight (140+kg seems like a lot?) and couldn't redistribute existing componentry; guess the knapsack algorithm wasn't good enough, or that they just couldn't break up enough pieces? And yes, Cruise Mass Balance Devices sounds like the type of name a tired engineer would come up with to convince upper management...lol
    - FredFS456 6y ago
      They can't redistribute existing componentry because of competing requirements: during cruise, the spacecraft needs to be balanced around the rotational axis (perseverance rotates at 2RPM in cruise). During re-entry, an asymmetric weight distribution is needed to generate lift.
  - xarope 6y ago
    Surely you mean: "What I'm getting from this, is that you can use devices to balance the mass of the spaceship during cruise conditions"...j/k
  - 6y ago
koheripbal 6y ago
Any idea when they will start experimentation? I want to find microbial life!
- Nzen 6y ago
  I don't know in general, but JPL published a video [0] yesterday of three interviews. One of the systems engineers for the MOXIE (atmospheric oxygen separation) unit will wait several weeks after landing before their first experiment. Actually, scientific american has published a timeline that seems to corroborate that [1]. [0] https://youtu.be/TUd604rBR6I?t=643 https://youtu.be/TUd604rBR6I?t=643 [1] https://www.scientificamerican.com/article/the-first-100-days-on-mars-how-nasas-perseverance-rover-will-begin-its-mission/ https://www.scientificamerican.com/article/the-first-100-day...
- frabbit 6y ago
  What is it about that that excites you so much? Is it the idea that life could originate elsewhere and that there might really be aliens? Or is it the idea that Mars could support some sort of colony? Or the hope of completely novel microbiology?
  - yellowapple 6y ago
    Yes. Any one of these things would be a massive boon to our understanding of life throughout the solar system and broader universe, right down even to here on Earth. All three of them would arguably mark a new era in Earth's history.
    - cdelsolar 6y ago
      we are very screwed if they find life on Mars. It means life is incredibly common and thus the Great Filter theory is true and we only have a few years left as a species most likely.
      - JohnJamesRambo 6y ago
        I find it extremely hard to believe you could kill every human being on earth at this point. We’ve reached critical mass, we aren’t going anywhere. When we had that few thousand individuals population bottleneck in the past was when it was dicey. What sort of event could kill every human and end our species? I can only think of planet-wide extinction events like massive asteroid impacts that sterilized the whole earth. And we haven’t ever had one of those in billions of years. Call me too optimistic but I think humans are too resourceful. Some of us would survive anything smaller.
twic 6y ago
> Cruise Mass Balance Devices They put those in to make the probe seem higher-quality. They got the idea from Beats headphones.
- jamiek88 6y ago
  Just to set the record a bit straighter and ruin your joke, those pics of beats with weights were knockoff beats from the flea market not real.
  - lathiat 6y ago
    Reporting on that: https://gizmodo.com/are-beats-headphones-really-designed-to-trick-you-1715413621 https://gizmodo.com/are-beats-headphones-really-designed-to-...
- azernik 6y ago
  We were doing that at Meraki back in the early 2010s (it turned out they were also useful as a heat sink and, because the metal was exposed to air, a radiator). Pretty sure Meraki got the idea from some Apple product or other.
  - darkwater 6y ago
    Speaking of Meraki, I had an awful experience with those devices. Basically we were in building with TONS of other wifi networks around and Meraki network just went crazy from time to time until we fine tune it down to the channel for each AP. I mean, for something you pay $$$ to buy the devices and $$$ each month for the subscription is a pretty poor experience.
  - rhodozelia 6y ago
    Nortel and it’s predeccessors bell northern telecom used to put weights in the handsets so they had a nice feel to them.
dmix 6y ago
> And read about how it will use Terrain Relative Navigation to find a safe landing spot: So basically TERCOM from cruise missles but used on space crafts? All you need is a radar countour map of the area and it can automate it's way to the endzone. https://en.wikipedia.org/wiki/TERCOM https://en.wikipedia.org/wiki/TERCOM
- FredFS456 6y ago
  Perseverance's Terrain Relative Navigation uses a camera system and generates a full 3D position fix, but the idea is similar.
- gnzoidberg 6y ago
  Not at all.
spaetzleesser 6y ago
They should make km the default unit and not miles....
- lmilcin 6y ago
  Actually, NASA uses metric system internally. Imperial units are probably used for general public convenience.
  - spaetzleesser 6y ago
    Considering that one of NASA's roles is to inspire young people to enter STEM I think it would be important to promote metric as much as possible.
    - lmilcin 6y ago
      I don't see how the choice here can promote STEM. Do you think kids find it sexy to talk about meters, kilograms and degrees Celcius rather than feet, miles, pounds and Fahrenheit? I can't fault for choosing what is more understandable to the target audience.
- fckthisguy 6y ago
  As another commenter said, NASA uses metric. During the stream, you can hear the various teams giving measurements in metric, whilst the media gave coverage in imperial. It's a pretty interesting video from that perspective, as you can hear the two "realities" being translated for the intended audience.
- mulmen 6y ago
  Ever been on an airplane? Altitude was almost certainly measured in kilofeet. As noted in other comments, NASA (like the rest of the United States [1]) does use the metric system. But it doesn’t matter. Nothing about the metric system makes it uniquely suitable to landing on Mars. Or space travel in general. What matters is a consistent standard. Internally NASA could use Armstrongs. Where 1 is the weight or height of Neil Armstrong at KSC on July 16, 1969 at 13:32:00 UTC. It doesn’t matter. As long as it is consistent. [1]: https://en.m.wikipedia.org/wiki/Metrication_in_the_United_States https://en.m.wikipedia.org/wiki/Metrication_in_the_United_St...
michaelwilson 6y ago
It turns out that they took 640lbs (!) of weight to mars to be tossed off at various points during EDL. The video is worth watching if you'd like some more of the nitty-gritty behind the process: https://www.youtube.com/watch?v=W0NakShgbHY https://www.youtube.com/watch?v=W0NakShgbHY
- thamer 6y ago
  I was hoping someone would link this video, it describes the various phases with a ton of details that. Some of the other videos on this channel are just as in-depth: the ones about the plumes/exhaust of rocket engines as well as star occlusions are incredibly detailed.
- jessriedel 6y ago
  Great video! I am also surprised by the fact that they bring that much mass just to jettison. In theory they could mounted some of the useful mass on a slider/rail system to achieve the necessary adjustment to the mass distribution without dropping mass overall, but apparently it wasn't worth the complexity/volume cost. I'm sort of surprised we don't yet have ML powered "de-accent-ization". His french accent isn't hard to understand at normal speed, but when I set it to 1.5x or 2x speed it becomes hard to decipher in a way native speakers usually are not. If there was just a button (for him or me) to hit to tweak the sounds a bit to reduce the accent, I bet this problem would go away.
  - stargazer-3 6y ago
    I, for one, would be uncomfortable with AI removing my accent. I understand it's for other people to understand me better - and I am fine with AI-generated subtitles - but altering the way I speak would reduce the amount of "me" in ways I'm not fully ok with.
    - jessriedel 6y ago
      You wouldn't need to use it on videos you produce if you don't want.
    - 6y ago
nerfhammer 6y ago
from the author of that software https://twitter.com/mrdoob/status/1362508150507790343 https://twitter.com/mrdoob/status/1362508150507790343

tectonic 6y ago

Also, InSight's SEIS seismometer is a true marvel: "We have been able to detect, at about 10 hertz, displacement of the ground of the order of less than 5 picometers…which is a fraction of the size of an atom." — https://eos.org/features/a-modern-manual-for-marsquake-monitoring https://eos.org/features/a-modern-manual-for-marsquake-monit...

peter303 6y ago
LIGO puts this shame with 10^11 better sensitivity.
- jvanderbot 6y ago
  At sensitivity/gram insight wins. Per dollar probably not.

WJW 6y ago

> is this what NASA calls 'weights'? Well no, the Cruise Mass Balance Devices are intended to Balance the Mass of the spaceship during Cruise conditions. That these Devices are single-part and constructed out of a single chunk of metal each should not be construed as merely being 'weights'. :)

deleted 6y ago
[deleted]
theelous3 6y ago
What I'm getting from this, is that you can use weights to balance the mass of the spaceship during cruise conditions.
- xarope 6y ago
  Ships do this all the time (ballast), and anybody who's ever flown on a light aircraft or helicopter also knows the importance a pilot places on weight distribution. I guess what's surprising is that they needed that much weight (140+kg seems like a lot?) and couldn't redistribute existing componentry; guess the knapsack algorithm wasn't good enough, or that they just couldn't break up enough pieces? And yes, Cruise Mass Balance Devices sounds like the type of name a tired engineer would come up with to convince upper management...lol
  - FredFS456 6y ago
    They can't redistribute existing componentry because of competing requirements: during cruise, the spacecraft needs to be balanced around the rotational axis (perseverance rotates at 2RPM in cruise). During re-entry, an asymmetric weight distribution is needed to generate lift.
- xarope 6y ago
  Surely you mean: "What I'm getting from this, is that you can use devices to balance the mass of the spaceship during cruise conditions"...j/k
- 6y ago

koheripbal 6y ago

Any idea when they will start experimentation? I want to find microbial life!

Nzen 6y ago
I don't know in general, but JPL published a video [0] yesterday of three interviews. One of the systems engineers for the MOXIE (atmospheric oxygen separation) unit will wait several weeks after landing before their first experiment. Actually, scientific american has published a timeline that seems to corroborate that [1]. [0] https://youtu.be/TUd604rBR6I?t=643 https://youtu.be/TUd604rBR6I?t=643 [1] https://www.scientificamerican.com/article/the-first-100-days-on-mars-how-nasas-perseverance-rover-will-begin-its-mission/ https://www.scientificamerican.com/article/the-first-100-day...
frabbit 6y ago
What is it about that that excites you so much? Is it the idea that life could originate elsewhere and that there might really be aliens? Or is it the idea that Mars could support some sort of colony? Or the hope of completely novel microbiology?
- yellowapple 6y ago
  Yes. Any one of these things would be a massive boon to our understanding of life throughout the solar system and broader universe, right down even to here on Earth. All three of them would arguably mark a new era in Earth's history.
  - cdelsolar 6y ago
    we are very screwed if they find life on Mars. It means life is incredibly common and thus the Great Filter theory is true and we only have a few years left as a species most likely.
    - JohnJamesRambo 6y ago
      I find it extremely hard to believe you could kill every human being on earth at this point. We’ve reached critical mass, we aren’t going anywhere. When we had that few thousand individuals population bottleneck in the past was when it was dicey. What sort of event could kill every human and end our species? I can only think of planet-wide extinction events like massive asteroid impacts that sterilized the whole earth. And we haven’t ever had one of those in billions of years. Call me too optimistic but I think humans are too resourceful. Some of us would survive anything smaller.

twic 6y ago

> Cruise Mass Balance Devices They put those in to make the probe seem higher-quality. They got the idea from Beats headphones.

jamiek88 6y ago
Just to set the record a bit straighter and ruin your joke, those pics of beats with weights were knockoff beats from the flea market not real.
- lathiat 6y ago
  Reporting on that: https://gizmodo.com/are-beats-headphones-really-designed-to-trick-you-1715413621 https://gizmodo.com/are-beats-headphones-really-designed-to-...
azernik 6y ago
We were doing that at Meraki back in the early 2010s (it turned out they were also useful as a heat sink and, because the metal was exposed to air, a radiator). Pretty sure Meraki got the idea from some Apple product or other.
- darkwater 6y ago
  Speaking of Meraki, I had an awful experience with those devices. Basically we were in building with TONS of other wifi networks around and Meraki network just went crazy from time to time until we fine tune it down to the channel for each AP. I mean, for something you pay $$$ to buy the devices and $$$ each month for the subscription is a pretty poor experience.
- rhodozelia 6y ago
  Nortel and it’s predeccessors bell northern telecom used to put weights in the handsets so they had a nice feel to them.

dmix 6y ago

> And read about how it will use Terrain Relative Navigation to find a safe landing spot: So basically TERCOM from cruise missles but used on space crafts? All you need is a radar countour map of the area and it can automate it's way to the endzone. https://en.wikipedia.org/wiki/TERCOM https://en.wikipedia.org/wiki/TERCOM

FredFS456 6y ago
Perseverance's Terrain Relative Navigation uses a camera system and generates a full 3D position fix, but the idea is similar.
gnzoidberg 6y ago
Not at all.

spaetzleesser 6y ago

They should make km the default unit and not miles....

lmilcin 6y ago
Actually, NASA uses metric system internally. Imperial units are probably used for general public convenience.
- spaetzleesser 6y ago
  Considering that one of NASA's roles is to inspire young people to enter STEM I think it would be important to promote metric as much as possible.
  - lmilcin 6y ago
    I don't see how the choice here can promote STEM. Do you think kids find it sexy to talk about meters, kilograms and degrees Celcius rather than feet, miles, pounds and Fahrenheit? I can't fault for choosing what is more understandable to the target audience.
fckthisguy 6y ago
As another commenter said, NASA uses metric. During the stream, you can hear the various teams giving measurements in metric, whilst the media gave coverage in imperial. It's a pretty interesting video from that perspective, as you can hear the two "realities" being translated for the intended audience.
mulmen 6y ago
Ever been on an airplane? Altitude was almost certainly measured in kilofeet. As noted in other comments, NASA (like the rest of the United States [1]) does use the metric system. But it doesn’t matter. Nothing about the metric system makes it uniquely suitable to landing on Mars. Or space travel in general. What matters is a consistent standard. Internally NASA could use Armstrongs. Where 1 is the weight or height of Neil Armstrong at KSC on July 16, 1969 at 13:32:00 UTC. It doesn’t matter. As long as it is consistent. [1]: https://en.m.wikipedia.org/wiki/Metrication_in_the_United_States https://en.m.wikipedia.org/wiki/Metrication_in_the_United_St...

michaelwilson 6y ago

It turns out that they took 640lbs (!) of weight to mars to be tossed off at various points during EDL. The video is worth watching if you'd like some more of the nitty-gritty behind the process: https://www.youtube.com/watch?v=W0NakShgbHY https://www.youtube.com/watch?v=W0NakShgbHY

thamer 6y ago
I was hoping someone would link this video, it describes the various phases with a ton of details that. Some of the other videos on this channel are just as in-depth: the ones about the plumes/exhaust of rocket engines as well as star occlusions are incredibly detailed.
jessriedel 6y ago
Great video! I am also surprised by the fact that they bring that much mass just to jettison. In theory they could mounted some of the useful mass on a slider/rail system to achieve the necessary adjustment to the mass distribution without dropping mass overall, but apparently it wasn't worth the complexity/volume cost. I'm sort of surprised we don't yet have ML powered "de-accent-ization". His french accent isn't hard to understand at normal speed, but when I set it to 1.5x or 2x speed it becomes hard to decipher in a way native speakers usually are not. If there was just a button (for him or me) to hit to tweak the sounds a bit to reduce the accent, I bet this problem would go away.
- stargazer-3 6y ago
  I, for one, would be uncomfortable with AI removing my accent. I understand it's for other people to understand me better - and I am fine with AI-generated subtitles - but altering the way I speak would reduce the amount of "me" in ways I'm not fully ok with.
  - jessriedel 6y ago
    You wouldn't need to use it on videos you produce if you don't want.
  - 6y ago

nerfhammer 6y ago

from the author of that software https://twitter.com/mrdoob/status/1362508150507790343 https://twitter.com/mrdoob/status/1362508150507790343