Assembling near atomic resolution movies of biological molecules in action is a key goal of biological imaging using X-ray free electron lasers. Much progress has been made at existing facilities, however the MHz repetition rate of the European XFEL promises to hasten progress in this direction by vastly increasing the rate at which structures can be measured. Additionally, the bright X-ray pulses open up new modes of molecular imaging.
First experiments at the European XFEL using MHz pulse trains at the SPB instrument took place in the second half of 2017. Preliminary results indicate that high quality structural data can be obtained using the MHz pulse trains, representing a significant step towards high throughput structural determination using the conventional serial crystallographic approach. Going beyond crystallography, a more challenging goal is obtaining structures from non-crystalline molecules or poorly diffracting crystals. We will describe the current status of non-crystalline X-ray molecular imaging using X-ray free electron lasers, and discuss the prospects of for single particle biomolecular imaging at higher pulse repetition rates.