Fact Sheet

Launch date

25 December 2021

Mission duration

Nominal duration is 5 years; goal is 10 years. The observatory should have enough propellant to allow support of science operations in orbit for significantly more than a 10-year science lifetime.

Launch vehicle

Ariane 5

Launch mass

6200 kg, including fuel and launch vehicle adaptor


Sun–Earth L2 halo orbit, approximately 1.5 million km from Earth 

Folded dimensions

10.66 m high x 4.47 m wide 6.5 m diameter,

Primary mirror

18 mirror segments of gold-coated beryllium 


22 x 12 metres, 5 layers

Wavelength range

About 0.6 μm to 28 μm (visible to mid-infrared)

Operating temperature

Telescope at –233°C, MIRI instrument at –266°C

Operations centre

Space Telescope Science Institute in Baltimore, USA