The Mars rover known as Perseverance is set to launch this Thursday  and begin its seven-month journey to the Red Planet.

NASA aims to land Perseverance at Jezero Crater, a geologically rich area formed billions of years ago. If life has ever existed on Mars, the ancient lake will be one of the most likeliest places to hold biological clues — biomarkers that the rover will search for on its mission.

In addition to its seven science instruments, Perseverance also comes equipped with sophisticated landing gear, including a Terrain-Relative Navigation  to avoid hazards and a Mars Science Laboratory Entry, Descent, and Landing Instrumentation 2 (MEDLI2 ) sensor suite to gather atmospheric data. (Learn more about the Mars 2020 Entry, Descent, and Landing  technologies and procedures.)

When it comes to sticking the landing, however, how much control does NASA have? Can the rover be guided, joystick-style, to the Jezero crater?

In a live Tech Briefs presentation titled Mars 2020: The Legacy Continues for NASA Space Robotics, a reader asked Keith Comeaux, Mars 2020 Deputy Chief Engineer at NASA's Jet Propulsion Laboratory:

"Is there any opportunity to makes commands or command corrections during the entry, descent, and landing (EDL) phase? Or is it all automated?"

{youtube}https://www.youtube.com/watch?v=s595S1Vf3PE {/youtube}

Read Comeaux's edited response below.

Keith Comeaux, Mars 2020 Deputy Chief Engineer, NASA JPL: This is a great question. We have a period of about 5 days before entry in which we're paying very close attention to our position in relation to Mars, as our navigators collect ranging and Doppler data.

As we approach Mars, that gives us a better knowledge of how we’re going to enter. There are things we can do to improve our entry geometry. Namely, we can do a small trajectory correction maneuver in the day or two preceding entry. We can also update the guidance algorithm with our most current estimated position. That will give the entry capsule the best chance possible of hitting our [landing site] precisely.

However, because of the light time delay between Mars and Earth, we cannot "joystick" this entry, descent, and landing. It is essentially on its own to find its way to the surface of Mars. In fact, by the time we actually hear that we’ve landed, we’ve probably been on the ground already for about 10 or 12 minutes.

What do you think? Share your questions and comments below.

More of your Mars 2020 questions answered: