Frequently asked questions

A website of interactive space and science lessons, printable worksheets, and short missions for grades 6–12.

50 lessons in total. 14 are free: Magnetism, Moon Phases, Gravity Basics, Build an Atom, Periodic Table Challenge, Physical vs. Chemical Changes, Lab Safety, Light & Color, Black Holes and Waves and Sound. The other 29 need Pro. See the lessons page.

Space science, physics, chemistry, earth science, and lab skills — built as simulations you interact with, not just read.

You can browse for free without one. A free account lets you save progress, and Pro gets you every lesson and worksheet.

Sign up with your email on the sign-up page. You'll get a confirmation email to verify it.

Check your spam folder first. If it's still missing, go to the sign-in page to request a new one.

Yes. It works in any modern browser on desktop, tablet, or phone — nothing to install.

Starter is free forever. Pro is $6/month for every lesson and worksheet. Classroom is $99 a year for up to 99 people; School is $1 per person a year for 100 people and up. See the pricing page.

Credit and debit cards, through Stripe. We never see or store your full card number.

Yes, any time. Go to Account settings and click Cancel Renewal. You keep Pro until the end of the month you already paid for.

Purchases are final, except for duplicate charges or billing errors. See the Billing Policy or contact us.

Yes — Classroom is $99 a year for up to 99 people, teachers included, with every lesson and printable worksheet included. Buy it straight from the pricing page; a bigger school can use School instead, at $1 per person a year with a 100-person minimum.

Yes. Students can work through lessons and the mission independently, in class or at home.

They're built to support common middle and high school science standards, including NGSS.

Yes — 94 worksheet packs, covering every lesson on the site and a good deal besides: gravity, moon phases, friction, the periodic table, half-life, and much more. Worksheets are Pro-only. See the worksheets page.

Lessons are built for middle and high school (grades 6–12). Younger learners can still use them with some guidance.

Short challenges that test what you've learned. There are two so far: the Solar System Speed Run, where you put the eight planets in order against the clock, and Planet Hunter, where you read a star's light curve to size up its planet. Each takes 5–10 minutes. See the missions page.

Space-themed merchandise, like our Space Explorer T-shirt. See the shop.

We collect only what's needed to run your account and track your progress — your email and your lesson and quiz activity. We don't sell your data. See the Privacy Policy.

Yes. We don't knowingly collect personal information from children under 13 without parental consent. Details are in the Privacy Policy.

Double-check your email and password, then use the reset-password link on the sign-in page.

Any current version of Chrome, Safari, Edge, or Firefox.

Use the contact page — call, text, or send a message.

Terms of Service, Privacy Policy, Cookie Policy, and Billing Policy are all linked in the footer.

Lessons, worksheets, and other materials are for personal, classroom, or school use only. You can't redistribute or resell them without our permission.