1990: Hubble's Blurred Beginning and a Second Chance
A space telescope's difficult start became a story about finding and fixing a problem.
Estimated CEFR reading level: A2. Concrete past-tense sentences explain a problem, its cause and a later response, with a clear three-year sequence. This is an editorial estimate, not an official certification.
Five useful words
British English pronunciation (IPA). Audio uses an available English voice on your device.
mirror /ˈmɪrə/
nounA surface that reflects light.
The telescope used a large mirror.
blurred /blɜːd/
adjectiveNot clear or sharp.
The first pictures were blurred.
install /ɪnˈstɔːl/
verbTo put equipment in place so it can be used.
The astronauts installed new equipment.
correct /kəˈrekt/
verbTo put something right.
The equipment helped correct the problem.
repair /rɪˈpeə/
nounWork that fixes something.
The repair improved the pictures.
The story
A problem above Earth
On 24 April 1990, the space shuttle Discovery carried the Hubble Space Telescope into space. Scientists wanted clear pictures of distant objects. But Hubble had a problem: its main mirror had the wrong shape. Some light did not meet in the right place, so the pictures were blurred.
The telescope could still do some science. However, its pictures did not meet the team's hopes. Engineers studied the problem and planned a way to help.
A repair in space
In December 1993, astronauts visited Hubble. They installed equipment that corrected the path of the light. They did not bring the telescope home or replace its main mirror.
After the repair, Hubble sent back much clearer pictures. Its story shows that an important project can have a difficult beginning. Finding the problem was only the first step; solving it needed more work.
Three questions
Try answering before you open the answer. You can use your own words.
- When did Hubble launch?
Show answer
24 April 1990.
- What was wrong with the telescope?
Show answer
Its main mirror had the wrong shape, making pictures blurred.
- Did astronauts replace the main mirror?
Show answer
No. They installed equipment that corrected the path of the light.
Let's talk about it
Here are some ideas for a chat. Choose any you like.
- Have you seen a space picture that you liked?
- What do you enjoy fixing or learning to fix?
- Would you like to watch astronauts work on a telescope?
- How do you feel when something new does not work the first time?
- Which would you like to see more closely: the Moon, a planet or a group of stars?
Practise a useful pattern
Use but and after to show a problem and a later change. Join these ideas in two sentences: Hubble launched. Its pictures were blurred. Astronauts repaired it. The pictures became clearer.
Frequently asked questions
Which shuttle launched Hubble?
Discovery launched Hubble on 24 April 1990.
When was the first repair mission?
December 1993.
Sources and editorial notes
Original learning article by Poly-Puff, written from the factual sources below. Sources checked on 16 October 2026. The artwork and learning activities were created for this article.
The launch and first servicing mission are separate events. The optical explanation is simplified for A2; corrective equipment compensated for the mirror flaw rather than replacing the main mirror. No current operational status is claimed.
