Down 47%, should I buy this SpaceX rival for my Stocks and Shares ISA?

A market-focused article compares SpaceX with Rocket Lab as a potential alternative for holders of a UK Stocks and Shares ISA, emphasizing differences in valuation and readiness. It notes SpaceX has a $1.95 trillion market cap while still reporting losses, framing that as a key concern. The piece highlights Rocket Lab (NASDAQ: RKLB), whose shares are down 47% since May, and outlines its lineup of Electron and the larger Neutron, which remains under development. For 2025, it cites 21 successful Electron missions and HASTE, alongside $602 million in revenue, up 38%, followed by Q1 revenue jumping 63.5% to $200 million. It also says Neutron is designed to compete with Falcon 9 in the medium-lift segment, while Rocket Lab continues building satellite and communications capabilities after acquiring Iridium Communications for $8 billion.