Martin Suchan is a huge fan of astronomy, and has been working on creating apps to be able to watch NASA TV live broadcasts for years. He first brought an app to Windows Phone 8.1, brought that to Windows 8.1, moved up to the Universal Windows Platform for Windows 10, and only three years later than expected, has brought the app to the Xbox One.
Suchan describes the app in a thread on Reddit:
It's super simple app - one click for launching the NASA TV Live stream, second click for full screen. The current version is free and without Ads, but If you like it, you can purchase optional Pro upgrade which costs like 1.5 USD.
NASA TV Live provides access to both the public and media channels, allows viewing of live broadcasts, shows playback in a "full chrome-less mode for the best experience," and is available for Windows 10 PC and Mobile, and now Xbox One.
You can get NASA TV Live from the Windows Store, or from searching for "NASA TV Live" on your Xbox.