3 ms·
... but no delivery mode specified. Mars orbit insertion or any landing is up to your 4020 kg of payload, I'm assuming. Wonder what delta-v you need to handle?
by kabdib 11y ago
... but no delivery mode specified. Mars orbit insertion or any landing is up to your 4020 kg of payload, I'm assuming. Wonder what delta-v you need to handle?
- schwarrrtz 11y agoAssuming they'll deliver you onto a Mars transfer orbit, you need ~2 km/s for the Mars capture maneuver. Assuming you have an engine with ~300s Isp, you need a mass fraction of exp(-2/3) ~ 0.5. So you need your payload to be about 50% fuel by mass. Also, this doesn't account for any aerobraking, which should save you some fuel. http://space.stackexchange.com/questions/12660/delta-v-to-low-mars-orbit http://space.stackexchange.com/questions/12660/delta-v-to-lo...
- the8472 11y ago> Assuming you have an engine with ~300s Isp, you need a mass fraction of exp(-2/3) ~ 0.5. So would taking a longer earth-mars route that allowed the use of some more efficient drive (e.g. ion engine) improve the amount of payload that could be delivered?
- schwarrrtz 11y agoYes, definitely. If you had an engine with 3000s Isp, which according to Wikipedia wouldn't be unreasonable for an ion thruster, then your mass fraction would be about exp(-2/30) ~ 0.94. So you'd only need 6% of your payload for fuel in that case. https://en.wikipedia.org/wiki/Specific_impulse#Examples https://en.wikipedia.org/wiki/Specific_impulse#Examples