Need help finding how long a moon landing takes.

[Technical Ben]

I guess I could do a Kerbal landing and multiply up the timescales/distances, but I'm not that good at maths or KSP!

So, I am writing a little bit of sci-fi. I'm at the penultimate chapter, and, I'm stuck. I need a very precise measurement. Why? Well, one is because I'm trying to stick to Hard Sci-fi, the other is to be plausible and also add some suspense.

The crew is in a lander, about to approach a moon. I've lampshaded the transit time to just 3 days. This should not need any explanation in the narrative, as I've not covered the power/thrust etc of the vehicle, or the distance to the moon. So I can be flexible and just say "it's 3 days". The other details are not needed for the story, so I've left figures out in case I get them wrong.

However, with the landing, I don't want it to be totally imposable, or to get it completely wrong. So how long roughly, did the NASA moon landing take from the orbital stage to touch down on the moon? When the lander approached the surface, am I right to consider it came in rather horizontal, found the spot, killed the velocity, then landed vertical? What time scale was between those additional course changes? How long should I keep my readers in suspense as to if the craft makes it in one piece* or not!?

*This detail is actually redundant, it's going to have explosions, because it's titled "In the Air: Explosions".

[DisarmingBaton5]

Not very much if they're lithobraking properly

Seriously, I would guess no more than 10 minutes, if you count only a final braking burn and vertical descent.

Also, depending on circumstances, you may want to change your title. There is no atmosphere on the Mun! (I mean moon, right? right?)

[astropapi1]

About 15 minutes.

[Bacterius]

There is no atmosphere on the Mun! (I mean moon, right? right?)

There is one, sort of, but I wouldn't count on it slowing you down enough before impact

[Technical Ben]

Not very much if they're lithobraking properly

Seriously, I would guess no more than 10 minutes, if you count only a final braking burn and vertical descent.

Also, depending on circumstances, you may want to change your title. There is no atmosphere on the Mun! (I mean moon, right? right?)

Lol! I covered that. This is the penultimate chapter. We've already left the home planet, a Gas Giant, 1 chapter ago. :~)

Thanks though. 10 mins is more than enough, and I'd probably go with just 3 or so. I'll see how the dialog pans out, and if it needs to be mentioned, or can just be assumed to cover the time involved in the actions portrayed.

astropapi1, ah thanks. That's a little longer. No idea if I plan on making this moon smaller or larger, but I'll watch the video and get an idea of the pacing.

PS, wow those last 3 mins are amazing in the video. Sadly I'll not get to cover it in that detail in my story, it just glances over such events.

Edited November 11, 2013 by Technical Ben

[goldenpeach]

There is one, sort of, but I wouldn't count on it slowing you down enough before impact

If it don't work it's because of two reasons:

1) there is not enough parachutes

2) There are not large enough.

Funny fact:

Parachutes can be used to deorbit the Cubesat( very tiny satellites) after they finished their work.

Also, my "idea" about larges parachutes to land on the moon could work, in theory(in practice you would end up with a lot more weigh that you would have by using rocket fuel).

[voneiden]

That video is always beautiful to watch and listen.

[KvickFlygarn87]

Well, less than an hour depending on things such as atmospheric stats, gravity, landing technique, TWR, and more.

I'd love to read the book when it's done!

[Mr Shifty]

Stephen Baxter's Moonseed has two or three detailed lunar landing sequences. (Besides being a rip-roaring disaster novel.) If your lander utilizes harenodynamics, it could probably get down fairly quickly.

[PakledHostage]

If your lander utilizes harenodynamics, it could probably get down fairly quickly.

Which is also a good way to save delta-V. Stochasty used the method very effectively in the Minimum Delta-V to the Mun challenge from last winter (although nobody used the term "harenodynamics" to describe the landing). Sadly that thread was lost along with so many good threads when the forum database crashed.

I was able to find his video, though: