Commands were sent in the blind this afternoon to the Mars Polar
Lander, in an attempt to establish communications with the
spacecraft. The commands were intended to be received through the
low-gain antenna on the lander, and instructed the spacecraft to
perform “big sweep” of the sky with its medium-gain antenna and
send a signal to Earth. The Deep Space Network was waiting to hear
a signal from the spacecraft if the lander was executing the “big
sweep” commands. After about one hour of listening, no signal was
detected from the lander. Early tomorrow morning, the same “big
sweep” test will be performed again.

Mars Polar Lander website: