Navigation:

• ISS Complete Tracking
• Image Handling
  • Pulling the Image
  • Running the Image
  • Building a New Image
• Queries to Use
  • Load/Reload Data
  • Delete Data
  • Print Entire Data
  • Print Comments
  • Print Header
  • Print Metadata
  • Print Current ISS Location
  • Print List of Epochs
  • Print Specific Epoch
  • Print Location of Specific Epoch
  • Print Speed of Specific Epoch
• Desribing the ISS Data

ISS Complete Tracking

This git repo contains the script iss_tracker.py. This script is a flask application that is used to return data from the iss trajectory data. The data returned is explained in the sections below. An indepth writeup about the application is located in the ISS Tracking Application WriteUp.pdf file.

iss_tracker.py

• This flask app contains functions that are called when queries are sent to the running app, therefore returning values that were requested. The functions are:
  • delete_data(), post_data(), data(), get_comment(), get_header(), get_metadata(), current_location(), epoch_data(), specific_epoch_data(), location(), calculate_epoch_speed(), and help().

The functions correspond to the queries in the "Queries To Use" section, respectively.

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Image Handling

Pulling the image jaeestee/iss_tracker from Docker Hub:

To pull the existing image, run this command:

$ docker pull jaeestee/iss_tracker

If done properly, jaeestee/iss_tracker should show up with the tag latest when running this command:

$ docker images

The output should look similar to this:

REPOSITORY             TAG       IMAGE ID       CREATED         SIZE
jaeestee/iss_tracker   latest    d8276d24fa21   2 hours ago     897MB

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Running the image:

To start running the containerized Flask app, run this command:

docker-compose up

Remember that the docker-compose.yml file must exist in the same folder for this to work! If done properly, the output should look similar to this:

Starting iss-tracker_flask-app_1 ... done
Attaching to iss-tracker_flask-app_1
flask-app_1  |  * Serving Flask app 'iss_tracker'
flask-app_1  |  * Debug mode: on
flask-app_1  | WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
flask-app_1  |  * Running on all addresses (0.0.0.0)
flask-app_1  |  * Running on http://127.0.0.1:5000
flask-app_1  |  * Running on http://172.19.0.2:5000
flask-app_1  | Press CTRL+C to quit
flask-app_1  |  * Restarting with stat
flask-app_1  |  * Debugger is active!
flask-app_1  |  * Debugger PIN: 125-216-670

Now the app is running!

IMPORTANT: Have this running on a separate window and keep it running while sending queries!!!

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Building a New Image:

To build a new image from the Dockerfile present in this directory, run this command:

$ docker build -t <dockerhubusername>/iss_tracker:<version> .

IMPORTANT: Make sure to be in the same directory as the Dockerfile and DO NOT FORGET THE "." at the very end of this command!!!

If done properly, the output should look similar to this:

Sending build context to Docker daemon  10.24kB
Step 1/6 : FROM python:3.8.10
 ---> a369814a9797
Step 2/6 : RUN pip install Flask==2.2.2
 ---> Using cache
 ---> bbf69ba6f74f
Step 3/6 : RUN pip install requests==2.22.0
 ---> Using cache
 ---> 9cccc52676f6
Step 4/6 : RUN pip install xmltodict==0.13.0
 ---> Using cache
 ---> 3813629386c4
Step 5/6 : COPY iss_tracker.py /iss_tracker.py
 ---> Using cache
 ---> 071d505247d6
Step 6/6 : CMD ["python", "iss_tracker.py"]
 ---> Using cache
 ---> d8276d24fa21
Successfully built d8276d24fa21
Successfully tagged jaeestee/iss_tracker:test

Now you have successfully created your own image!

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Queries To Use While The App is Running:

To load/reload the data, run this command:

$ curl localhost:5000/post-data -X POST

If done properly, the output should look like this:

Successfully reloaded the dictionary with the data from the web!

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To delete the data, run this command:

$ curl localhost:5000/delete-data -X DELETE

If done properly, the output should look like this:

Successfully deleted all the data from the dictionary!

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To print the entire data set (whether it exists or is empty), run this command:

$ curl localhost:5000/

This will send a get request using curl to the app that should be running.

If done properly (WITH THE APP RUNNING ON A SEPARATE TAB), the end of the output should look similar to one of these 3 outputs:

• Output possibility 1:

"metadata": {
            "CENTER_NAME": "EARTH",
            "OBJECT_ID": "1998-067-A",
            "OBJECT_NAME": "ISS",
            "REF_FRAME": "EME2000",
            "START_TIME": "2023-048T12:00:00.000Z",
            "STOP_TIME": "2023-063T12:00:00.000Z",
            "TIME_SYSTEM": "UTC"
          }
        }
      },
      "header": {
        "CREATION_DATE": "2023-049T01:38:49.191Z",
        "ORIGINATOR": "JSC"
      }
    }
  }
}

This will print out the entire data set, but as long as you see the metadata section, it printed everything properly.

• Output possibility 2:

The data set does not exist yet!

This means that the POST method has not been called.

• Output possibility 3:

{}

This means that the DELETE method was called, emptying the data.

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To print the comments in the data, run this command:

$ curl localhost:5000/comment

If done properly, the output should look similar to this:

[
  "Units are in kg and m^2",
  "MASS=473291.00",
  "DRAG_AREA=1421.50",
  "DRAG_COEFF=2.80",
  "SOLAR_RAD_AREA=0.00",
  "SOLAR_RAD_COEFF=0.00",
  "Orbits start at the ascending node epoch",
  "ISS first asc. node: EPOCH = 2023-03-08T12:50:10.295 $ ORBIT = 2617 $ LAN(DEG) = 108.61247",
  "ISS last asc. node : EPOCH = 2023-03-23T11:58:44.947 $ ORBIT = 2849 $ LAN(DEG) = 32.65474",
  "Begin sequence of events",
  "TRAJECTORY EVENT SUMMARY:",
  null,
  "|       EVENT        |       TIG        | ORB |   DV    |   HA    |   HP    |",
  "|                    |       GMT        |     |   M/S   |   KM    |   KM    |",
  "|                    |                  |     |  (F/S)  |  (NM)   |  (NM)   |",
  "=============================================================================",
  "GMT067 Reboost        067:19:47:00.000             0.6     428.1     408.4",
  "(2.0)   (231.1)   (220.5)",
  null,
  "Crew05 Undock         068:22:00:00.000             0.0     428.7     409.6",
  "(0.0)   (231.5)   (221.2)",
  null,
  "SpX27 Launch          074:00:30:00.000             0.0     428.3     408.7",
  "(0.0)   (231.2)   (220.7)",
  null,
  "SpX27 Docking         075:12:00:00.000             0.0     428.2     408.6",
  "(0.0)   (231.2)   (220.6)",
  null,
  "=============================================================================",
  "End sequence of events"
]

A message will appear if the data is empty or doesn't exist yet.

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To print the header in the data, run this command:

$ curl localhost:5000/header

If done properly, the output should look similar to this:

{
  "CREATION_DATE": "2023-067T21:02:49.080Z",
  "ORIGINATOR": "JSC"
}

A message will appear if the data is empty or doesn't exist yet.

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To print the metadata in the data, run this command:

$ curl localhost:5000/metadata

If done properly, the output should look similar to this:

{
  "CENTER_NAME": "EARTH",
  "OBJECT_ID": "1998-067-A",
  "OBJECT_NAME": "ISS",
  "REF_FRAME": "EME2000",
  "START_TIME": "2023-067T12:00:00.000Z",
  "STOP_TIME": "2023-082T12:00:00.000Z",
  "TIME_SYSTEM": "UTC"
}

A message will appear if the data is empty or doesn't exist yet.

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To print the current location of the ISS, run this command:

$ curl localhost:5000/now

If done properly, the output should look similar to this:

{
  "Epoch": "2023-069T06:48:00.000Z",
  "Location": {
    "altitude": {
      "units": "km",
      "value": 419.7851549137822
    },
    "latitude": 28.659367107265545,
    "longitude": -126.3121600929075
  },
  "geo": "The ISS must be over an ocean...",
  "speed": {
    "units": "km/s",
    "value": 7.666292075028554
  }
}

A message will appear if the data is empty or doesn't exist yet.

You can use this website, ISS Real Time Tracker, to check that the latitude and longitude given in the output is similar to the latitude and longitude of the website's tracker.

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To print out a list of all Epochs in the data set, run this command:

$ curl localhost:5000/epochs

If done properly, the end of the output should look similar to this:

  "2023-082T11:20:00.000Z",
  "2023-082T11:24:00.000Z",
  "2023-082T11:28:00.000Z",
  "2023-082T11:32:00.000Z",
  "2023-082T11:36:00.000Z",
  "2023-082T11:40:00.000Z",
  "2023-082T11:44:00.000Z",
  "2023-082T11:48:00.000Z",
  "2023-082T11:52:00.000Z",
  "2023-082T11:56:00.000Z",
  "2023-082T12:00:00.000Z"
]

A message will appear if the data is empty or doesn't exist yet. Additionally, there should be a lot more data points, this is a shortened version.

It is also possible to use the query parameters limit and offset:

$ curl localhost:5000/epochs?limit=<int>'&'offset=<int>

where limit prints out a specific number of Epochs and offset changes the starting point.

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To print a specific Epoch, run this command:

$ curl localhost:5000/epochs/<epochKey>

Make sure to replace the epochKey with a specific Epoch as shown below:

$ curl localhost:5000/epochs/2023-063T12:00:00.000Z

If done properly, the output should look similar to this:

{
  "EPOCH": "2023-063T12:00:00.000Z",
  "X": {
    "#text": "2820.04422055639",
    "@units": "km"
  },
  "X_DOT": {
    "#text": "5.0375825820999403",
    "@units": "km/s"
  },
  "Y": {
    "#text": "-5957.89709645725",
    "@units": "km"
  },
  "Y_DOT": {
    "#text": "0.78494316057540003",
    "@units": "km/s"
  },
  "Z": {
    "#text": "1652.0698653803699",
    "@units": "km"
  },
  "Z_DOT": {
    "#text": "-5.7191913150960803",
    "@units": "km/s"
  }
}

A message will appear if the data is empty or doesn't exist yet.

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To print the location of a specific Epoch, run this command:

$ curl localhost:5000/epochs/2023-063T12:00:00.000Z/location

If done properly, the output should look similar to this:

{
  "Epoch": "2023-082T12:00:00.000Z",
  "Location": {
    "altitude": {
      "units": "km",
      "value": 426.493361256541
    },
    "latitude": 3.693612400678767,
    "longitude": 67.77071661260686
  },
  "geo": "The ISS must be over an ocean...",
  "speed": {
    "units": "km/s",
    "value": 7.6603442162552815
  }
}

A message will appear if the data is empty or doesn't exist yet.

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To print the speed of a specific Epoch, run this command:

$ curl localhost:5000/epochs/2023-063T12:00:00.000Z/speed

If done properly, the output should look similar to this:

{
  "speed": {
    "units": "km/s",
    "value": 7.6603442162552815
  }
}

A message will appear if the data is empty or doesn't exist yet.

Describing the ISS Data:

An Epoch is simply a point in time that the ISS is at. It is represented in 3D cartesian coordinates (X, Y, and Z components), as well the corresponding vector components (X_DOT, Y_DOT, and Z_DOT). The units of the coordinates are kilometers, while the vector components are in kilometers per second. Lastly, the Epoch Key (example: 2023-063T12:00:00.000Z) represents the year, date, and time, in that exact order.

From the NASA ISS Trajectory Data Website

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