[HN Gopher] Realtime telemetry from ISS internal components
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Realtime telemetry from ISS internal components
Author : MontagFTB
Score : 144 points
Date : 2024-03-06 05:28 UTC (17 hours ago)
(HTM) web link (iss-mimic.github.io)
(TXT) w3m dump (iss-mimic.github.io)
| AriedK wrote:
| Can anyone explain what the number before the timestamp is? GMT
| 66 / 43 / 41
| ins0 wrote:
| It's the DayOfTheYear followed by Hours, Minutes and seconds in
| UTC.
| diggan wrote:
| Is this the datetime format they use onboard on the ISS or
| why is it being used in this webui?
|
| This is the first time I come across this particular format,
| but also never near space-stuff so wouldn't surprise me if
| they use some specific format for some specific purpose.
| pyrolux wrote:
| That's very common in ISS operation schedules - next
| spacewalk is on GMT xx next launch on GMT xx, etc
|
| I expect it's easier and more useful to track days until
| event or days since event
| dr_orpheus wrote:
| Yes, using Day of Year for time GUIs and measurements is
| pretty common in spacecraft operations. Generally easier to
| do/plan operations for things like "we need to perform this
| maintenance activity every 5 days"
| dr_kiszonka wrote:
| 66 could be the day of the year.
| mmh0000 wrote:
| As a date command format string:
|
| ``` $ date -u '+GMT %-j/%R:%S' GMT
| 66/17:05:57
|
| ```
| orbital-decay wrote:
| This is being used to sync a 1:100 model of ISS with the actual
| station: https://github.com/ISS-Mimic/Mimic
| auto wrote:
| This is incredibly cool!
| pavinjoseph wrote:
| Incredible! I wonder how much delay there is between the sensor
| data coming in to ISS, being relayed to NASA, fetched by these
| guys and forwarded to their model's actuators.
| close04 wrote:
| What's the reason behind using the "Off"/"Not-Off" notation for
| "on-off status" instead of "On"/"Off" or even "On"/"Non-On"? I
| see some "state" parameters marked as "ON".
| the-kenny wrote:
| Guessing here: If you have a breaker switch after an additional
| switch, labelling the breaker with 'on/off' may be misleading
| as 'on' doesn't necessarily mean the connected device is
| powered. It may be off because the other switch is off.
| wolrah wrote:
| Reading this post led to one of those moments of realization
| about "no shutdown" in Cisco IOS and similar environments.
|
| The config file can't guarantee the interface will be up when
| it's loaded as that depends on external factors but it can
| guarantee the interface will not be shut down.
|
| I've used "no shutdown" as an example of illogical UI for
| decades because it seems backwards as the user, especially
| when new to IOS and trying to learn by exploring, but from
| this perspective it makes sense.
| justsomehnguy wrote:
| > moments of realization about "no shutdown" in Cisco IOS
| and similar environments
|
| > but from this perspective it makes sense
|
| No, it's just a clunky way to _remove_ the config line, it
| has nothing with the engineering safety.
|
| It's still better than Huawei's lingo, though.
| gregmac wrote:
| Certain controls -- like valves or vent dampers -- are not
| binary. Even if normal operation is either fully-closed or
| fully-open, it can technically be anywhere in between.
|
| Having an absolute position sensor would tell you this, but is
| complex and expensive compared to having two binary state
| switches (fully-open vs fully-closed) which is also more
| expensive than a single state switch.
|
| Probably in many cases it just isn't worth it to instrument
| beyond the single state, especially if the affect of the
| control is being monitored (eg: flow, temperature, power).
| However, communicating the state as accurately as possible is
| important to avoid confusion ("This valve says ON, so that's
| not the problem" vs "I can see this valve is NOT OFF, but let's
| double check it's fully-on?").
| idiotsecant wrote:
| I am a controls engineer and saying something is CLOSED when it
| is actually only observed to be NOT OPEN is my personal
| windmill I tilt at regularly. People have deied before because
| what the screen said was that the valve is closed, but what the
| PLC actually observed is that the valve had left the open
| position, which was the only limit switch present. Maybe the
| valve is travelling slowly, jammed halfway open, etc. When
| operators make the complaint you just did I tell them that what
| I've told them is reality and if they want a true closed we
| need a closed limit switch.
| bmitc wrote:
| This was my first guess, although I do not have explicitly
| experience in life-or-death type of control systems. In such
| systems, does it make sense to have more than two states?
| Something like "open", "unknown but not open", "unknown but
| not closed", "unknown", "closed"? (Assuming that you have
| enough limit switches.)
| tagami wrote:
| quantum switch
| idiotsecant wrote:
| That's exactly what you do. In all systems you _should_
| have two switches, and you annunciate on / off /
| travelling / error to the operator. Often you inherit
| something that doesn't have that.
|
| In anything that really matters you have a continuous
| position transmitter instead of switches so your state is
| more obvious. In safety systems you might have 2 or 3 of
| those transmitters so you can have a backup or a vote
| xtiansimon wrote:
| So where is the 'leaky' Soyuz module? Haha
| proaralyst wrote:
| All the leaky Soyuz spacecraft have returned to earth at this
| point
|
| The coolant leak: https://en.m.wikipedia.org/wiki/Soyuz_MS-22
|
| The air leak: https://en.m.wikipedia.org/wiki/Soyuz_MS-09
| verytrivial wrote:
| Scott Manley reported three days ago about an apparently
| current, non-threatening leak https://youtu.be/MZgaLzYFCrU at
| about the 18 minute mark if you're interested.
| Bnichs wrote:
| One of those values is "ISS total mass." Is that calculated using
| launch/deorbit weights or is there some kind of sensor on board
| that can measure that? I figure if you did a specific type of
| burn you could calculate the weight from that, but I'm wondering
| if they have something more clever.
| orbital-decay wrote:
| It's just an estimate and isn't that accurate. Yes, the closest
| you can get is orbit determination before and after the
| reboosts, and acceleration data.
| webdoodle wrote:
| The ISS uses Control moment gyroscopes to stabilize it's
| orientation. Couldn't those be used to calculate its mass?
|
| https://en.wikipedia.org/wiki/Control_moment_gyroscope#Inter.
| ..
| dr_orpheus wrote:
| Not its mass directly, but you can use it to calculate the
| moment of inertia. Move the CMGs a fixed angle and looking
| at the responding change in rate of the ISS. Mass can be
| determined from maneuvers when you fire the thrusters.
| Assuming you know the force from the thrusters very well
| (this has its own errors) you can look at the acceleration
| from the orbit determination before and after the thruster
| burns and back out the mass.
| Out_of_Characte wrote:
| Not an expert but I think its possible, the problem is that
| the gyroscope alone wouldn't be sufficient. When the gyro
| rotates once, the massive spacecraft will obviously have
| rotated exactly once relative to the gyroscope. However if
| you could track the space station's rotation relative to an
| independend stationary observer in space (lets say an array
| of pulsar data), then you could count the amount of turns
| of both the gyro and the spacestation relative to the
| background of space. Then the amount of turns of the gyro
| times the mass of the gyro would give you the mass of the
| space station minus the independend floating objects.
| Meaning you'll need to add the mass of the gyro itself as
| well.
|
| Please correct me if i'm missing something obvious. This
| should work right?
| CoastalCoder wrote:
| Hopefully I'm not embarrassing myself with this question, but:
|
| If you know an satellite's orbital path and velocity, and the
| Earth's gravitational strength, is that enough to compute the
| satellite's mass?
| martincmartin wrote:
| In a uniform gravitational field, it isn't. On the earth's
| surface, acceleration due to gravity is 9.8 m/s^2,
| independent of the mass of the falling object. See Galileo's
| Leaning Tower of Pisa experiment.
|
| https://en.wikipedia.org/wiki/Galileo%27s_Leaning_Tower_of_P.
| ..
| CoastalCoder wrote:
| > Hopefully I'm not embarrassing myself with this question,
| but:
|
| Yup, I'm kind of embarrassed :) I forgot that maintaining
| orbit is just a matter of falling at the same pace that the
| earth is falling away from you.
| flainne wrote:
| > maintaining orbit is just a matter of falling at the
| same pace that the earth is falling away from you
|
| Perhaps a better visualization: moving sideways fast
| enough that you miss the earth? :)
| mmh0000 wrote:
| If you've never tried it, I highly recommend playing
| Kerbel Space Program[1] (it works on Linux, Mac, and
| Windows!).
|
| That game taught me so much about orbital mechanics,
| which led to rabbit holes of textbooks and videos[2].
|
| The first big lesson KSP taught me was: why, when
| launching a rocket, you don't just go straight up but,
| instead, have to lean over pretty aggressively.
|
| [1] https://store.steampowered.com/app/220200/Kerbal_Spac
| e_Progr...
|
| [2] https://www.youtube.com/watch?v=dhYqflvJMXc
| staunton wrote:
| The field is not uniform though. So in theory, if you know
| the orbit and firld exactly, you _can_ calculate it.
|
| In the present case, I guess the precision with which one
| knows the orbit and other stuff (like the exact
| gravitational fiel of the earth) doesn't work out.
| pyrolux wrote:
| The mass data is calculated from all the launched mass but I
| have no idea why it's a telemetry value unless the ISS echoes
| it back for some reason
| Horffupolde wrote:
| I assume it's calculated from the propulsion positioning
| system.
| 9dev wrote:
| I'm SO going to build a Grafana dashboard from that!
| malux85 wrote:
| I would love to see that!
| 9dev wrote:
| So, uh, I actually did. Built a small Prometheus exporter to
| read the official data stream, and ingest it in Grafana.
|
| Anyone up helping me create all the charts? It's over 300 of
| them :D
|
| Going to post the result here soon
| franky47 wrote:
| It has a year field, when would that one be updated? Using UTC?
| world2vec wrote:
| Which NASA API/data feed is being used to get this telemetry?
| axus wrote:
| "Several years ago, NASA provided some of the data to the
| public in order to spur interest in the ISS and space
| exploration under the ISSlive project (https://isslive.com/)
| using the lightstreamer service
| (http://demos.lightstreamer.com/ISSLive/)"
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(page generated 2024-03-06 23:02 UTC)