The components are immensely expensive. The mirrors alone required new manufacturing techniques to be invented and these components are largely invented by doct

The components are immensely expensive. The mirrors alone required new manufacturing techniques to be invented and these components are largely invented by doctorate level research scientists. Not to mention the spacecraft and all the deployable systems must withstand intense G forces to achieve escape velocity. The design also requires complete verification. Each component must be created and a test bench then has to be engineered to ensure viability after launch. It is an immense undertaking to develop experimental equipment (ultra-high vacuum, pulsed powered laser physics background), to then add the additional expectations of space launch and zero opportunity for corrective intervention means the standards are exacting.