What’s next for Hubble?

This is the third and final in a series of posts marking the 25th anniversary of the Hubble Space Telescope. Read the first here, and the second here.

Hubble won’t last forever – electrical faults could render any of its instruments inoperable at any time. Though this has happened before, there is no longer a Space Shuttle that can be launched to send astronauts on a repair mission, so any future instrument failures are likely to be permanent.

Moreover, the telescope needs to reliably and steadily lock onto the position of the astronomical objects it is observing. It does this thanks to gyroscopes dotted around the spacecraft – but these will eventually wear out and fail too. Engineers are quietly confident that Hubble can last till at least 2015, but beyond that, the observatory’s future is unclear.

By the end of 2018, the James Webb Space Telescope should join Hubble in orbit – with hardware built at UCL on board. The Webb telescope is not a like-for-like replacement. Webb will have far more powerful capabilities in infrared light, allowing it to peer deep into dust clouds, observe planetary systems being formed, and the see distant redshifted light of the first galaxies.

But it will not have Hubble’s abilities in ultraviolet and visible light. A new breed of telescopes on the ground, such as the European Extremely Large Telescope and the Thirty Meter Telescope will partly replace Hubble’s visible light capabilities (although not with Hubble’s sharpness).

But when Hubble fails, no telescope in operation or in development will replace its ability to observe ultraviolet light, which is blocked by the Earth’s atmosphere.