NASA has tweaked the path of its Mars Science Laboratory (MSL) in preparation for the planned Aug. 6 landing of the car-sized rover in a crater near the Martian equator.

Controllers at the Jet Propulsion Laboratory fired thrusters on MSL twice for a total of 6 sec. at 1 a.m. EDT July 29. The thruster burn was designed to nudge it west of its projected entry point into the planet’s atmosphere by 21 km (13 mi.), after tracking with Deep Space Network antennas indicated it was that far off its target entry point.

Although subsequent tracking indicated the maneuver worked, the mission navigation team has two more flight-path adjustment opportunities in the final 48 hr. before entry if needed. Landing using the untried “sky crane” method was set for 1:31 a.m. EDT Aug. 6.

To get the best chance to confirm the tricky approach and landing have worked, controllers also adjusted the Mars Odyssey spacecraft’s orbit with a thruster burn July 24 that also lasted 6 sec. The maneuver advanced the spacecraft in its orbit by 6 min. That will bring it over the landing zone in time to provide a direct communications relay with Earth, which will have set below the horizon by then (Aerospace DAILY, July 26).