Stratolaunch also now own "Spirit of Mojave", formerly "Cosmic Girl", the 747 which virgin orbit used to own. I've heard speculation that they'll likely switch

Stratolaunch also now own "Spirit of Mojave", formerly "Cosmic Girl", the 747 which virgin orbit used to own. I've heard speculation that they'll likely switch to using it instead of the Roc for launching the Talon-A rocket-plane which this article mentions. Since the Roc uses so little of its payload capacity for launches like this.