Ariel payload assembled for testing; launch now more likely in 2031 than 2029

European Space Agency/Ariel

Ariel's multinational payload was assembled as a whole for the first time and is being tested to show it can survive launch and the cold vacuum of space. The telescope's 1.1 m mirror is a single block of silver-coated aluminium, so the whole telescope expands and shrinks evenly and stays in focus. Launch, once set for 2029, is now considered more likely in 2031.

• The finished mirror was not yet part of the test setup.
• Next: integrate the parts and mirror, then check performance.
• Rachael Drummond of RAL Space is the UK national project manager.