George, your Mars Lander quad-copter is freakin' AWESOME !!!
Possibly the best rocket project I have seen in the 45 years in this hobby.

What do you use for power ?
An Aerotech full-impulse 18mm D ?

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, AGITATION, CHAOS, TURMOIL, FIASCOS, AGGRAVATION, INSTIGATION, NUISANCE-ACTION, and HAVOC !