README.md

Getting started with Launch Library 2

Introduction

The Launch Library 2 API (LL2 for short) enables you to request space related data such as launches, astronauts, etc. A full list of features can be found here.

To get you started with the API, this tutorial contains some introduction information together with code examples. For more detailed documentation on all the endpoints, please refer to the documentation.

Since the production API ll has rate limits, the development API lldev will be used in this tutorial, however this should only by used for development.

Quickstart

To query data, endpoint URLs are used. Filters and search terms can be added to these.

Querying the upcoming launch endpoint: https://lldev.thespacedevs.com/2.3.0/launches/upcoming/

Adding filters is done by adding them to the base url.

Examples

Querying & filtering past launches in Python

Filtering

Here two filters are added, a minimum and maximum date and time to get the launches between the two.

The time frame of the minimum and maximum are a month ago and now. The filtered variable is net, which represents the launch datetime.

To filter net we add two underscores __ and the filter terms gte (greater-than-or-equal) and lte (less-than-or-equal). Combining these two filters is done using the ampersand symbol &.

Before adding these filters a question mark ? is added after the base url to indicate the start of parameters. Then the filter parameter name is given with an equals sign = with the value following it.

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 7 to 12 in 1b1a40a

	# Time frame: now - 31 days ago
	now = datetime.now()
	month_ago = now - timedelta(days=31)
	# Adding the time frame to the filters
	net_filters = f'net__gte={month_ago.isoformat()}&net__lte={now.isoformat()}'

Setting response mode

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 23 to 24 in 1b1a40a

	# Set mode to detailed to include all related objects
	mode = 'mode=detailed'

Limiting

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 26 to 27 in 1b1a40a

	# Limit returned results to just 2 per query
	limit = 'limit=2'

Ordering

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 29 to 30 in 1b1a40a

	# Ordering the results by ascending T-0 (NET)
	ordering = 'ordering=net'

Assembling query URL

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 32 to 36 in 1b1a40a

	# Assemble the query URL
	query_url = launch_base_url + '?' + '&'.join(
	(filters, mode, limit, ordering)
	)
	print(f'query URL: {query_url}')

Paginating through all the results

Tutorials/tutorials/getting_started_LL2/launches_past_month.py

Lines 91 to 110 in 1b1a40a

	# Paginating through all the results
	next_url = results['next']
	while next_url:
	# Requesting next data
	next_results = get_results(next_url)
	# Checking if it was succesful
	if not results:
	# Quitting the program as an example
	# use your own error handling here
	quit()
	# Printing next results
	print(next_results)
	# Adding to the original results dictionary
	results['results'] += next_results['results']
	# Updating the next URL
	next_url = next_results['next']