Satellites over time

​​
​

Template request | Bug report​
Tags: #celestrak #opendata #satellites #analytics #plotly
Author: Dumorya​
We analyze the number of satellites in the space from the first launch to now, and the part of them which became inactive. These data come from http://www.celestrak.com/. It provides free data as CSV files easily accessible. The CSV file we got contains many data as the name of the satellite, its owner, launch site, id, apogee and many others. What interested us the most were the status code, the launch date and the decay date, in order to create a graph with years in X axis and number of satellites in Y axis.
Input
Import librairies
import pandas as pd
import plotly.express as px
import plotly.graph_objects as go
import numpy as np
Variables
URL = 'http://www.celestrak.com/pub/satcat.csv'
Model
Recovery and processing of CSV data
df = pd.read_csv(URL)
df = df[['OPS_STATUS_CODE', 'LAUNCH_DATE', 'DECAY_DATE']]
df['DECAY_DATE'] = df['DECAY_DATE'].mask(df['DECAY_DATE'].isnull(), '9999')
df['LAUNCH_DATE'] = df['LAUNCH_DATE'].str[:4].astype(int)
df['DECAY_DATE'] = df['DECAY_DATE'].str[:4].astype(int)
years = df['LAUNCH_DATE'].unique()
inactive = list()
active = list()
​
for year in years:
    active.append(len(df[
        ((df['OPS_STATUS_CODE'].isin(['+', 'P', 'B', 'S', 'X'])) & (df['LAUNCH_DATE'] <= year))
        | ((df['DECAY_DATE'] > year) & (df['OPS_STATUS_CODE'] == 'D') & (df['LAUNCH_DATE'] <= year))
    ].index))
    
    inactive.append(len(df[
        ((df['OPS_STATUS_CODE'] == 'D') & (df['DECAY_DATE'] <= year))
        | ((df['OPS_STATUS_CODE'] == '-') & (df['LAUNCH_DATE'] <= year) )
    ].index))
    
Output
Display plot of the number of satellites in space over time
fig = go.Figure(data=[
    go.Bar(name='Inactive satellites', x=years, y=inactive),
    go.Bar(name='Active satellites', x=years, y=active)
])
# Change the bar mode
fig.update_layout(
    title="Number of satellites in space over time",
    xaxis_title="Years",
    yaxis_title="Number of satellites",
    barmode='stack'
)
fig.show()
Source: http://www.celestrak.com/pub/satcat.csv
Display the percentage of inactive VS active satellites from 1957 to now
labels = years
widths = [100/len(years) for year in years]
​
active_percentage = list()
inactive_percentage = list()
​
for index, _ in np.ndenumerate(active):
    total = active[index[0]] + inactive[index[0]]
    active_percentage.append(active[index[0]]/total*100)
    inactive_percentage.append(inactive[index[0]]/total*100)
​
data = {
    "Inactive": inactive_percentage,
    "Active": active_percentage
}
​
fig = go.Figure()
for key in data:
    fig.add_trace(go.Bar(
        name=key,
        y=data[key],
        x=years,
        offset=0
    ))
​
fig.update_xaxes(range=[years[0],years[-1]])
fig.update_yaxes(range=[0,100])
​
fig.update_layout(
    title_text="Percentage of inactive VS active satellites from 1957 to now",
    barmode="stack",
    uniformtext=dict(mode="hide", minsize=10),
)
Celestrak
Cityfalcon
Last modified 1mo ago