James Webb Space Telescope
The James Webb Space Telescope is an infrared observatory in space designed to study distant galaxies, stars and planetary systems.
Also known as: JWST, Webb telescope
How big is it?
21.2 m · deployed sunshield length
Deployed sunshield length · specified
A little perspective
James Webb Space Telescope vs Doubles tennis court: length comparison
The length of a doubles tennis court is about 1.12 times the deployed sunshield length of the James Webb Space Telescope.
The James Webb Space Telescope is an infrared observatory in space designed to study distant galaxies, stars and planetary systems.
A doubles tennis court is the marked playing surface used for tennis with the outer doubles sidelines included.
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions. Horizontal rulers compare the selected spans; vertical brackets also identify height on the artwork.
Measurements, assumptions & sources +
James Webb Space Telescope
Deployed sunshield length: 21.2 m; specified.
JWST’s deployed observatory spans about 21.2 m by 14.2 m across its sunshield and has a mass of approximately 6,200 kg. The long sunshield axis is the default scale span.
The marked deployed sunshield length is calibrated. Unmeasured illustration details are representative.
Doubles tennis court
Length: 23.77 m; standard.
23.77 × 10.97 m playing surface. Excludes surrounding space.
The marked length is calibrated. Unmeasured illustration details are representative.
Use the visual comparison to explore its scale, then check the measurements and sources.
Change your perspective
Put it next to…
Choose a suggestion to redraw the comparison, or open its page to learn what it is.
Why this measurement?
Why we use 21.2 m
We compare the deployed sunshield length of the James Webb Space Telescope. This value follows a stated specification; check its scope in the notes.
JWST’s deployed observatory spans about 21.2 m by 14.2 m across its sunshield and has a mass of approximately 6,200 kg. The long sunshield axis is the default scale span.
The marked horizontal span follows the measured feature, not the edges of the image. How calibrated comparisons work →
Recorded properties
Dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 21.2 m | Not recorded | specified | |
| 14.2 m | Not recorded | specified | |
| 6.2 t | Not recorded | specified |
Around this scale
Explore nearby values.
Compare examples with lower, similar and higher values. Each card names the measurement being compared.
Nearest lower valuePlanets, moons and spaceJuno spacecraft20 mDeployed solar-array spanJuno is a NASA spacecraft sent to study Jupiter’s atmosphere, magnetic field and structure, powered by three large solar arrays.
Around the same scaleSport and equipmentBaseball batting cage21.3 mDefined enclosure lengthA baseball batting cage is a netted enclosure used for practising batting, allowing players to hit balls safely without risk of them travelling far or causing injury.
Nearest higher valuePlanets, moons and spaceSkylab36.1 mOverall orbital lengthSkylab was the first American space station, used for scientific experiments and crewed missions in Earth orbit during the 1970s.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- NASA — Webb fact sheetDeployed sunshield dimensions and observatory mass.
There’s always another scale
Follow your curiosity.
SpaceHubble Space Telescope13.2 mThe Hubble Space Telescope is an orbiting observatory launched by NASA to capture detailed images of astronomical objects.SpaceSkylab36.1 mSkylab was the first American space station, used for scientific experiments and crewed missions in Earth orbit during the 1970s.
SportDoubles tennis court23.77 mA doubles tennis court is the marked playing surface used for tennis with the outer doubles sidelines included.SpaceJuno spacecraft20 mJuno is a NASA spacecraft sent to study Jupiter’s atmosphere, magnetic field and structure, powered by three large solar arrays.
Living thingsBlue whale25 mA blue whale is a baleen whale that feeds by filtering small animals from seawater.
TransportCanal narrowboat17.7 mA canal narrowboat is a long, slender vessel designed for navigating the narrow canals of the United Kingdom.
SportSingles tennis court23.77 mA singles tennis court is a rectangular surface with marked lines used for playing one-on-one tennis matches.
Everyday things10 × 20 m garden20 mA garden is an outdoor space where people cultivate plants, flowers or vegetables for pleasure, relaxation or food.