Depends on how large of motors you want to use.
I have launched an H128 off of the Estes Porta-Pad "E" with a stiff 1/4" diameter 5' stainless rod and anchors holding the legs to the ground, but don't reccomend it.
The original Estes Pro Series pad and Pro Series II pads are both better than the Mantis.
The Mantis is actually rather fragile.

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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, CHAOS, TURMOIL, FIASCOS, and HAVOC !