Since Mars' atmosphere is around 2% the density of Earth's then could a much wider rocket achieve orbit?

Could the rocket be in the shape of a capsule or an optimal shape for reentry on Earth?

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    $\begingroup$ With current activity on mars, this rocket has to somehow (one piece launch or built in orbit) reach low earth orbit first. Atmospheric density/drag/viscosity is one shape design consideration, gravity and ascent acceleration is an other one. Best shape for a rocket ignoring gravity and atmospheric drag could be something like a prolate spheroid with long axis aligned with thrust, or closer to one eggly shaped body of revolution. $\endgroup$
    – user19132
    Mar 19, 2019 at 2:13
  • $\begingroup$ @qqjkztd nice start to an answer. $\endgroup$
    – Muze
    Mar 19, 2019 at 2:17
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    $\begingroup$ Still waiting for the first textbook on Martian aerodynamics. $\endgroup$ Mar 19, 2019 at 11:52
  • $\begingroup$ All Mars landers required a heat shield for entry to the marsian atmosphere. Parachutes were used for further slow down. So the influence of the atmosphere to a starting rocket can't be neglected. $\endgroup$
    – Uwe
    Mar 21, 2019 at 11:40

2 Answers 2


Sure. Here is a model of a two-stage, liquid-fueled Mars Ascent Vehicle that was designed to fit efficiently inside a squat aeroshell. Hence the squat shape.

squat MAV

It did have somewhat of a fairing on the front to mitigate drag. That was enough to get it to work in the trajectory simulations with only a small drag loss.


Yes, that would be possible. Check out this video of the launch of a prototype for Zero2Infinity's balloon launched Bloostar rocket. It has 3 concentric stages resulting in a very squat look.

Bloostar is released at around 20-40 km altitude. Surface atmospheric atmosphere on Mars is equivalent to around 35km altitude on earth. So aerodynamically there is no gross reason why you couldn't do it, and it could potentially open up the avenue to different shaped payloads if they don't have to fit into a skinny fairing.



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