'main technical challenges' is correct and can be used in written English.
For example, "The main technical challenges in launching a new website are ensuring the security of customer data and designing a user-friendly website layout."
More specifically, the Mars entry process and main technical challenges are first introduced.
The main technical challenges on the PMT and scintillator are discussed and the corresponding R&D efforts are presented.
Three main technical challenges face nuclear power: making nuclear fuel last longer, keeping weapons-grade material out of the wrong hands, and developing a comprehensive waste management solution.
Designing of a sulfur trioxide decomposer is one of the main technical challenges in the development of a nuclear hydrogen production system.
To highlight the main technical challenges, further research and engineering investigations are needed for interactions between the molecules, phase behaviours, and detailed mechanisms of hydrate formation and dissociation.
This review discusses some of the main technical challenges associated with the development of nanotechnologies for delivery across the blood brain barrier and summarizes ongoing work.
The main technical challenge is load balancing, and we explore three different techniques in combination.
Producing germs that could be spread as a mist had been the main technical challenge facing germ warriors throughout the 20th century.
The balancing of the dc-link capacitor voltages represents the main technical challenge in multilevel diode-clamped converters.
Designing algorithms that can robustly and efficiently handle unstructured urban models at the city scale becomes a main technical challenge.
The loss of correspondence between 3D scene points and their contributions to the detected pulse stream is the main technical challenge.
