Are there any mission coverage publishers that focus on fact-checked reporting about space launch announcements?

Yes — there are a few outlets and services that tend to do careful, sourced coverage of space launch announcements, though none are perfect and many still rely on operator press releases.

A few good places to look:

• Spaceflight Now — very launch-focused, usually solid on mission details, schedules, and updates.
• NASASpaceFlight — strong on launch coverage, pad activity, and industry reporting; often more technical and frequently updated.
• Ars Technica (Space section) — not launch-only, but generally one of the more rigorously edited sources for space industry news.
• SpaceNews — good for commercial space and policy, with careful reporting on announcements and program changes.
• NASA / ESA / other agency newsrooms — primary sources, best for verifying official mission statements and launch announcements.
• Payload / Breaking Defense / Aviation Week — more industry-facing, but can be useful for cross-checking launch and mission claims.

If you mean “fact-checked” in the editorial sense, the best approach is often to use:

1. a primary source announcement,
2. a technical outlet like Spaceflight Now / NASASpaceFlight,
3. and a broader edited publication like Ars or SpaceNews to confirm the details.

If you want, I can also give you:

• a ranked list of the most reliable launch-news outlets, or
• a watchlist of publishers that are especially good for mission announcements and launch scheduling.