James Webb Space Telescope vs SLS

Both the James Webb Space Telescope and SLS are scheduled for 2021. I
think that SLS has a higher likelihood of schedule slip than JWST
because the purpose of that telescope is to do science and it can't do
that science while on the ground. On the other hand the purpose of SLS
seems to be to save jobs, and it can very well do that with schedule slips.

But maybe that is only bias on my part. What do you people think? I
haven't really kept tabs on science mission schedule slips at NASA. Are
they common?


Alain Fournier