Daily Space Puzzle · archive

#31 Wed, 28 Oct 2026

One space question a day, the same for everyone in the world. Two tries. A new puzzle opens at 00:00 UTC.

From the archive (Wed, 28 Oct 2026). Today's puzzle is #32.

RocketsTwo tries

The two BE-4 engines on ULA's Vulcan booster burn liquid oxygen and which fuel?

Pick an answer. Wrong first time? You get one more try. The answer, its official source and where to read more appear when you finish.

Play any of them; only today's puzzle counts toward your streak. Every past puzzle

One space question a day, the same for everyone in the world. A new puzzle opens at 00:00 UTC. A puzzle you opened before midnight UTC still counts for its own day if you finish it after.
Two tries. Your result is 1/2 (first try), 2/2 (second try) or X/2 (missed), and the share grid shows only that, never the answer.
Every question was checked by hand against an official source (NASA, ESA, JAXA, NOAA, the UN and the like) on the date shown with the answer. Spotted a mistake? Tell us and we will correct it in public.
Your streak counts the days you play (or finish a Learning Zone lesson, or watch 30 seconds of the latest SpaceNexus Daily). Every 7 days in a row earns a freeze that covers one missed day, up to 2. Freezes are earned, never sold.
Your answers stay in this browser. We count starts, finishes and shares as daily totals, with no cookie and nothing that identifies you.
Nothing in the puzzle is sponsored or paid for.