What reading level is the Countdown to Space series?

Countdown to Space books are at a grades 5–8 reading level (average grade level 7), and HootRated recommends the series for ages 9–12. There are 28 books in the series.

What order should I read the Countdown to Space books?

Series numbers aren't available for most Countdown to Space books, so HootRated lists them by publication date: Apollo 11 (1995); Apollo 13 (1995); Challenger (1995); Columbia (1995); Friendship 7 (1995); and 23 more.

What age is the Countdown to Space series appropriate for?

HootRated recommends Countdown to Space for ages 9–12. Content is gentle to intense (HootRated intensity 1–4 out of 5). Intensity varies from book to book, so check individual ratings in the list above.

Countdown to Space Books in Order

Countdown to Space is a 28-book series by Michael D. Cole for ages 9–12, at a grades 5–8 reading level, with gentle to intense content (HootRated intensity 1–4 out of 5).

Books: 28; By publication date
Reading level: Grades 5–8; Average grade level 7
Recommended ages: Ages 9–12; From HootRated age ratings
Content intensity: Gentle to intense; HootRated 1–4 out of 5 · avg 1.5

Countdown to Space Reading Order

Series numbers aren't available for most Countdown to Space books, so they're listed by publication date (oldest first).

#	Title	Reading Level	Ages	Content
1	Apollo 11 First Moon Landing 1995	Level 5-6	9-12	Gentle
2	Apollo 13 space emergency 1995	Level 5-6	9-12	Intense
3	Challenger America's Space Tragedy 1995	Level 6-7	9-12	Moderate
4	Columbia First Flight of the Space Shuttle 1995	Level 5-6	9-12	Gentle
5	Friendship 7 First American in Orbit 1995	Level 5-6	9-12	Mild
6	Vostok 1 First Human in Space 1995	Level 5-6	9-12	Gentle
7	Astronauts Training for Space 1999	Level 7-8	9-12	Gentle
8	Galileo spacecraft Mission to Jupiter 1999	Level 7-8	9-12	Gentle
9	Hubble Space Telescope Exploring the Universe 1999	Level 7-8	9-12	Gentle
10	International space station a space mission 1999	Level 7-8	9-12	Gentle
11	Living on Mars Mission to the Red Planet 1999	Level 7-8	9-12	Gentle
12	Moon base First Colony in Space 1999	Level 7-8	9-12	Gentle
13	Apollo Moonwalks 2000 · Gregory Vogt	Level 7-8	9-12	Gentle
14	Nasa Space Vehicles Capsules, Shuttles, and Space Stations 2000	Level 7-8	9-12	Gentle
15	Space Emergency Astronauts in Danger 2000	Level 6-7	9-12	Mild
16	Space Launch Disaster When Liftoff Goes Wrong 2000	Level 7-8	9-12	Moderate
17	Spacewalks 2000 · Gregory Vogt	Level 6-7	9-12	Gentle
18	Earth The Third Planet 2001	Level 7-8	9-12	Gentle
19	Jupiter The Fifth Planet 2001	Level 7-8	9-12	Gentle
20	Mercury The First Planet 2001	Level 8-9	9-12	Gentle
21	The Moon-Earth's Companion in Space 2001	Level 7-8	9-12	Gentle
22	The sun The Center of the Solar System 2001	Level 7-8	9-12	Gentle
23	Venus The Second Planet 2001	Level 7-8	9-12	Intense
24	Mars The Fourth Planet (Countdown to Space) 2002	Level 7-8	9-12	Gentle
25	Neptune The Eighth Planet 2002	Level 7-8	9-12	Gentle
26	Saturn The Sixth Planet 2002	Level 7-8	9-12	Gentle
27	Uranus-The Seventh Planet (Countdown to Space) 2002	Level 7-8	9-12	Gentle
28	The Columbia space shuttle disaster From First Liftoff to Tragic Final Flight 2003	Level 6-7	9-12	Moderate

Content Intensity Across the Series

Varies

Content intensity ranges from Gentle to Intense across the series.

First book Latest book

Series books grow with readers — but that's also the trap. Most series start at one reading level and one content intensity and drift upward over the course of the run. Countdown to Space (28 books by Michael D. Cole) lands at a grades 5–8 reading level, with average content intensity 1.5/5. Intensity varies from book to book, so check individual ratings in the list above.

The reading-order table above lists every book with per-volume reading level, age and intensity ratings so you can spot any escalation before it catches your reader off guard. For a deeper dive into how we score text difficulty vs. emotional weight separately — and why series readers especially benefit from that split — see our methodology page.