1.   Over the years, spacecraft have landed on Mars and given us the first pictures from its surface.

2.   The extra lift they generate should allow the spacecraft to land without being damaged.

3.   The National Aeronautics and Space Administration hopes the spacecraft can land Wednesday, however, because of dwindling energy reserves.

4.   The spacecraft landed in such a favorable position that the maneuver was unnecessary.

5.   Three IMUs are not needed for landing, however, and flight controllers were confident Thursday that the spacecraft would land as scheduled.

6.   Other scenarios include the possibility that the spacecraft landed on the steep side of a canyon and toppled over, or that its radios broke down.

7.   The small spacecraft landed on the Martian surface on the Fourth of July and has since released its small rolling probe, called Sojourner.

8.   The spacecraft would land on the icy south polar region of Mars.