SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/astro-hubble-mirror-fix

Hubble launched in 1990 with a flawed mirror. When did astronauts fix it?

December 1993, on the first servicing mission.

Start playing free

  1. It was never fixed
  2. December 1993 ✔
  3. 2009

Why: The 2.4-meter primary mirror had an aberration that blurred early images. Astronauts installed corrective optics on the first of five servicing missions, and Hubble has delivered sharp images since.

Huh, didn't know that: Hubble was the first space observatory designed to be serviced by astronauts in orbit.

The dad joke
Hubble got glasses in 1993 and has been seeing clearly ever since.
Like this card?
Play the game

References

Answer: December 1993. The 2.4-meter primary mirror had an aberration that blurred early images. Astronauts installed corrective optics on the first of five servicing missions, and Hubble has delivered sharp images since.

  1. NASA, Astronaut Missions to Hubble science.nasa.gov/mission/hubble/observatory/missions-to-hubble
    Astronauts corrected that aberration on their first servicing mission in December 1993.
    Checked 2026-10-10.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Astronomy & SpaceWhy must X-ray telescopes like Chandra orbit above Earth's atmosphere?Astronomy & SpaceWhich kind of light has the shortest wavelength, under 0.01 nanometer?Astronomy & SpaceRoughly what wavelength range is visible light?

That's stuff everyone should know.