When Claudia Mitchell tried to push her way out of the thicket beside Highway 71, her brain repeatedly sent commands along nerves that now went nowhere.
As part of the testing process, the crew sent commands to the capsule to stop or temporarily move away, ensuring that Dragon could be safely sent off if something went badly awry.
Several times in December and January, NASA ground stations sent commands telling the polar lander to switch on its ultrahigh frequency transmitter and send out the equivalent of a Mayday.
Data received during the launching indicated that the spacecraft's computer had sent commands to set off small explosive charges to split the nose cone in two, like opening a clamshell.
Also using a form of command guidance were television-guided missiles, in which a small television camera mounted in the nose of the weapon beamed a picture of the target back to an operator who sent commands to keep the target centred in the tracking screen until impact.
The chances of this happening were increased slightly in the last few hours of battery life when mission controllers sent commands to rotate the lander's main body to expose the solar panel with the greatest area to the available sunlight.
