One aspect of InSight's condition that may be helpful to formulating an answer to the question Could InSight lift off and move somewhere else? is the current status of InSight's propulsion system.

According to this answer and to Spaceflight 101 InSight has 12 Aerojet Rocketdyne MR-107N Terminal Descent Thrusters (TDN)'s (each variable between 109 and 296 Newtons) as well as four Rocket Engine Modules (REMs), each with one 4.5 Newton Reaction Control System thruster and one 22 Newton Trajectory Correction Thruster).

Is it known if all 20 of these are permanently and irreversibly disabled, perhaps by some combination of remaining propellant venting and/or some kind of fuse?

Also from the Spaceflight 101 article:

The Propulsion Subsystem of the InSight Lander is identical to that flown on Phoenix – featuring a total of 20 thrusters broken down in three different groups: 1) Reaction Control System thrusters with a nominal thrust of 4.5 Newtons, 2) Trajectory Correction Thrusters operating at 22 Newtons and 3) Pulsed Landing Thrusters generating 293 Newtons of thrust for attitude control and velocity reduction during the Mars Landing Maneuver. All thrusters are fed from two central tanks containing ~65 Kilograms of usable propellant.

All thrusters use the decomposition of Hydrazine monopropellant over a metallic catalyst bed to create high-pressure gas that can be expelled through a nozzle to generate thrust. The system operates in blowdown mode without in-flight pressurization, starting out at a pressure of 21 bar provided by Helium ground pressurization.


1 Answer 1


Phoenix (the lander design they largely reused for InSight) vented it's helium pressurisation on landing, before waiting for the dust to settle - it's likely the same was done for InSight -- however "helium vent detected" was a call-out for Phoenix, but wasn't for InSight.

In addition, on Phoenix, the remaining hydrazine was expected to freeze during the first night on Mars (The backshell/heatshield kept everything warm by preventing radiative cooling of the electronics during the cruise stage)


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.