1.   But getting speech systems into small devices means overcoming size and power constraints.

2.   The challenge in developing the imaging system is not to design or manufacture in individual components but to integrate them without exceeding tight mass and power constraints.

3.   Because power constraints prevented the primary oxygen generator from running nonstop, the men had been forced to use solid-fuel canisters to supplement their air supply.

4.   Even though the oxygen generator was up, power constraints prevented the crew from running it as long as desired.