Rocket Dreams

Musk, Bezos, and the Inside Story of the New, Trillion Dollar Space Race

Part I: Earth, 2016-2018

https://www.gearbrain.com/amazon-robot-jeff-bezos-2322322141

Part II: Earth Orbit, 2018-2020

Part III: Beyond, 2020-2025

Moon versus Mars

Moon

Mars

launch window rate

25 hours

26 months

Hohmann travel time, one way

4 days

260 days

Hohmann round trip time

8 days

1040 days

Landing/Return ΔV

2.7 km/s

7 km/s

Poisonous soil

no

yes

Breathable atmosphere

no

no

Sunlight

1.37 kW/m²

0.59 kW/m²