# To the moon (in one hour!)

sonhouse
Posers and Puzzles 11 Apr '14 13:09
1. sonhouse
Fast and Curious
11 Apr '14 13:09
So its 100 years from now, Fedex has a space division, rockets can go for hours at many g's and there is an emergency on the moon, they have to get this medicine to the moon in one hour or 50 people die from a horrible lunar virus.

So if you can accelerate at some steady g force, then half way turn around and decel the rest of the way to be at the moon with zero velocity, soft landing, how many g's of constant acceleration to get that medicine to the moon in one hour does it take?
2. wolfgang59
Mr. Wolf
12 Apr '14 01:24
Originally posted by sonhouse
So its 100 years from now, Fedex has a space division, rockets can go for hours at many g's and there is an emergency on the moon, they have to get this medicine to the moon in one hour or 50 people die from a horrible lunar virus.

So if you can accelerate at some steady g force, then half way turn around and decel the rest of the way to be at the moon ...[text shortened]... how many g's of constant acceleration to get that medicine to the moon in one hour does it take?
(that's using my left hand and the back of an envelope)

basically you need to know the acceleration needed to get half way (200,000 km) in 30 mins

my estimate is surprisingly low ... ðŸ˜•
3. sonhouse
Fast and Curious
12 Apr '14 06:56
Originally posted by wolfgang59
(that's using my left hand and the back of an envelope)

basically you need to know the acceleration needed to get half way (200,000 km) in 30 mins

my estimate is surprisingly low ... ðŸ˜•
I got about 12.25, you were pretty close. I was wondering if we ever develop propulsion that powerful how much long term acceleration could a person take?

Obviously 12 g's would kill you but could you take it for an hour? I don't think so.

1 g would get you there in a few hours however, so that is possible.

2g's? maybe.

The formula is T= square root of (2S/A) T=time, S=distance, A=acceleration.
4. talzamir
Art, not a Toil
12 Apr '14 18:15
From livescience.com, "What Are the Limits of Human Survival":

"According to a recent article in Popular Science, 14 Gs of lateral acceleration can tear your organs loose from one another."

...

"...suggest we can slow down at a rate of 45 Gs, or the equivalent of the gravity of 45 Earths, and still live to talk about it."

So who knows, maybe there will one day be pizza on the moon within 30 minutes of order so the pizza won't be cold or free.
5. sonhouse
Fast and Curious
12 Apr '14 18:382 edits
Originally posted by talzamir
From livescience.com, "What Are the Limits of Human Survival":

"According to a recent article in Popular Science, 14 Gs of lateral acceleration can tear your organs loose from one another."

...

"...suggest we can slow down at a rate of 45 Gs, or the equivalent of the gravity of 45 Earths, and still live to talk about it."

So who knows, maybe ...[text shortened]... will one day be pizza on the moon within 30 minutes of order so the pizza won't be cold or free.
Nah, they would just use a heated 3D printer already there....

What does that mean, slow down at 45 g's? If 14 g's can tear you apart, why wouldn't 45 g's turn you into jelly?

In our example, are they saying we might be able to survive 12 g's? For an hour?