4 ms·
Far more important than the parachutes is the atmosphere. Even without parachutes, the atmosphere is responsible for almost all of the deceleration the capsule
by JshWright 11y ago
Far more important than the parachutes is the atmosphere. Even without parachutes, the atmosphere is responsible for almost all of the deceleration the capsule experiences. The atmosphere takes it from orbital velocity (~30,000 m/s EDIT: ~8,000m/s (km/h->m/s conversion fail)) and slows it down to the terminal velocity of the capsule (~100 m/s). The capsule only has to take care of that last bit from terminal velocity down to 0 m/s.
On the moon, there is no atmosphere, so the capsule would have to handle all the deceleration from lunar orbital velocity (~2,000 m/s) to 0. So, in ballpark figures, you're looking at 20 times more 'delta V' (change in velocity) that the capsule would have to accomplish in order to land on the moon. It takes _way_ more fuel to manage that.
- baq 11y agoif you replaced the dragon's trunk with a booster, it should be enough. i'm pretty sure it's not feasible, but in KSP world totally would work.
- sathackr 11y agoobligatory https://xkcd.com/1244/ https://xkcd.com/1244/
- zardo 11y agoI doubt Falcon Heavy could throw enough mass to make it work. Dragon is just a poor vehicle to send to the moon. It should work for landing a few tons on Mars though (one way).
- greglindahl 11y agoFH is 117 MT to LEO vs Saturn V 140 MT, Dragon is bigger/heavier than the Apollo capsule, and the even smaller LEM was the thing that landed on the Moon.
- endymi0n 11y agoNevertheless, quick back-of-the-envelope calculation should make an Apollo-style operation completely viable. Launch Dragon into orbit, Launch a fully loaded second stage without payload into orbit with a second FH and dock with the Dragon, Command Module style, then use the second stage for lunar orbit insertion and back. Should do the trick, even with a much heavier capsule.
- JshWright 11y agoUsing more than one launch is very much not an 'Apollo-style' operation. One of the major features of the Apollo program is that is used a single launch, which distinguished it from all the other competing proposals at the time.
- adwn 11y ago> FH is 117 MT No, FH is advertised [1] as 53 mT to LEO (probably around 200x200 km, 28.5°). [1] http://www.spacex.com/falcon-heavy http://www.spacex.com/falcon-heavy
- greglindahl 11y agoSorry, pounds/kilograms brain fart on my part.
- hughes 11y ago30,000 m/s is several times the escape velocity of Earth... most orbits are close to 8,000m/s!
- JshWright 11y agoYep... km/h -> m/s conversion failure, thanks!
- v0x 11y agoHaving played a number of hours of Kerbal Space Program, I can verify that this information is correct.