/sci/ - Science & Math

During Apollo 13, why didnt they use the LEM to fly around the CSM and inspect the damage? Instead they waited until reentry to look back on it.

Delta-V. Not enough. Isn't that obvious?
Next...the CM does not fly with out the service module. The SM provided power, life support, and propulsion. The CM only has batteries and enough Delta-V for the re-entry phase. The SM does all the other work - TLI, Earth return and re-entry burn. There is no way to inspect the heat shield until the SM is jettisoned, and once the SM is gone, you are committed to going down, or croaking if the re-entry had not been set up.
As amazing as Apollo was, the whole operation was, believe it or not, fast, dumb and dirty. They were really hanging it out on the thinnest of margins to pull that off. That there was only one fatal accident (Apollo 1 ) and one mission-critical failure ( 13 ) is as much serendipity as skill. All of the guy's on that program were god-calibre cone heads. They were also supremely lucky. Just imagine if Armstrong and Aldrin did not have that few extra seconds of propellent, god-tier piloting skills and couldn't have found a flat spot to land on.
I also submit that the current crop of cone-heads is not even close the the sublime ability of the Apollo-era rocketeers.
All or those folks were gods.

>>10586824
I'm really pretty shocked that through the entire program there were no horrific bone chilling deaths.

No one was stuck on the moon, being forced to commit suicide there.

No one crashed back into the moon after take off.

No one suffocated to death due to oxygen leak on the way to the moon.

No one burned to a crisp on re-entry

No one got stuck in permanent solar orbit.

Preddy gud

>>10586837
Well a few of them died in a fire and quite a few crashed the planes they were basically gifted

>>10586730
Thou LEM doth not have potential thrust vectors in each direction.

>>10586837
>he forgot about Apollo 1
3 guys burned to death over 30 seconds when locked inside of a test capsule that was pressurized with pure oxygen. Faulty wiring caused a spark that lit all kinds of flammable shit including the aluminum structural parts on fire. Also human flesh is directly flammable in 100% oxygen as well. Even inside that flaming pressure cooker there's no way they died instantly, it would have taken at least a dozen seconds or so. To this day the voice recordings and other tapes/footage are not released and have probably been destroyed, as it would not be good for public image to see and hear three American space heroes burning and charring to death in agony as a direct result of agency shortsightedness and negligence.

>>10586880
Yeah, those were boring deaths though. No one gets to look at the moon and know some of the moon glow is coming off the bodies of 3 dead americans who landed there in the in the 60's and killed themselves.

>>10586892
Yeah that was grisly enough tbf.

>>10586730
Are you crazy? The Capsule was essentially dead, they were running all their life support and electrical needs using the LEM, but they still needed the capsule to perform reentry at Earth. If they detached not only would they be jeopardizing their lifeline, since there's no guarantee that the LEM could redock with the capsule since the latter was unpowered and would start drifting and rotating in a random direction, they also wouldn't be able to do anything about whatever they saw anyway. The solution they chose, which was to shut down the Apollo CSM and use the LEM as a lifeboat while coasting around the Moon and back to Earth, was the best option because it was the simplest and least risky.

>>10586730
Lets just say they did undock and inspect only to find enought RCS thrusters had been taken out that re-docking was impossible.
What if they were able to undock and re-dock fine but found the heatshield was so fucked they were doomed? What can be done?

It would have been a heap of risk for no practical gain.

Sorry, guess I wasn’t quite clear. What I wanted to know was, if you plonked an Apollo CSM, Fully fueled on to a launch pad and hit the ignition button, would it be able to lift itself using its engine?

>>10588054
No. Even with the last drops of fuel, when it was lightest, it would produce less than 1g of acceleration.

>>10588054
i don't think so because the engine is designed to be used in space, not on Earth where it has to fight against Earth's gravity and atmosphere. Even if it could I don't think theres enough fuel to get it into orbit, especially since your talking about one stage.

>>10586837
Apollo one was pretty fuckin gnarly
Read the congressional report and the appendices with all the nice photos and descriptions of the CM after the toast factor went to 11.
There's also interior pics from an auction that you can view online.

>>10586892
Voice recordings have been released and unconsciousness was approx 25 seconds from the failure of the first suit. I don't remember exactly how long it was before the suits failed though. I'm pretty sure the CCTV footage from outside the pad and inside the CM still exist, although none have been released and you couldn't see anything from the inside because the camera was covered in fire.

Oxygen not even once

This is your space suit on pure oxygen.
This is why they're now made out of beta cloth instead of nylon.

>>10586837
The LEM was literally the only piece of hardware that didn’t break or have a failure. Even the flawless Saturn V suffered from pogo oscillations and shut down an engine.

>>10588143
Was even overbuilt enough that they managed to add a car for later missions

So /sci/, you've just touched down on the moon with Neil. After landing, it becomes clear a failure has occurred that totally precludes any possibility of launching back into lunar orbit and docking with the CSM. You're stranded. How do you spend your final hours on the moon?

>>10588179
Draw dicks
Write "USSR IS GEY" and "TEAMSTERS DID KENNEDY" in the dust

>>10588179
Go on space walk to deploy scientific packages. Listen for any other requests from NASA. After goodbyes probably wonder off into the landscape until oxygen runs out.

>>10588143
>Even the flawless Saturn V suffered from pogo oscillations and shut down an engine.
It actually shut down two, one because the engine shut itself down and another at the same time when the computer decided to shut down that same engine but the signal actually went to a completely different perfectly functional engine because it was wired up wrong. Still made orbit on just three of five second stage J-2 engines though.

>>10588179
Didn't they have cyanide pills incase that happened? If so I tape it to the mic inside my helmet, go outside and eat it off the mic while staring at the earth.

>>10588480
I know the Russians often did. I don't know what the plan was with Apollo.

>>10588054
Aside from the thrust to weight ratio being too low, the nozzle was designed to work efficiently in space, which means the exit pressure of the gas was way too low for operating at surface level
I recommend Scott Manley's video on rocket nozzles for a general grasp of what the issue is

>>10586824
If Apollo 11 had run out of fuel, they would have just aborted and gone home. They were not at risk of death from that.

>>10588318
How do you manage to fuck up the wiring so bad that the signal goes to a different engine?

>>10588190
the only real answer. i'd draw the biggest dick so that you could see it from earth with an mediocre teliscope

>>10588900
AFAIK the wires were all out of step by one, so the wire for engine 1 actually went to engine 2, the engine 2 wire went to 3, etc. They fixed the issue later by shortening all the wires on every subsequent stage they built so that it'd be impossible to reach any engine except for the correct engine, kek

>>10586893
Two dead astronauts, the third one would still be in cislunar space

>>10589017
Not possible, the EVA suits didn't have enough time in them for you to walk that far

>>10588179
Carve a giant dick into the regolith, then find a nice vantage point to patiently wait for my O2 to deplete.

>>10586730
In addition to previous objections, they would also have to use some of their critically limited consumables for a fly-around, which they might wind up needing to get home alive.

One of the core concepts at Mission Control was, when working a problem, donlt make it worse. That rules out doing stupid shit out of curiosity, such as sight-seeing, in the middle of an ongoing emergency.

>>10588139
The problem was not oxygen, per se. Even after the fire, they continued to use pure oxygen in flight, to avoid the issues of carrying two (or more) gases.

The problem with Apollo 1 was that while on the pad, they pressurized the capsule enough to acheive positive pressure vs. the outside. This meant there was a SHITLOAD of oxygen in there, seeping into every porous foam rubber cushion and other source of fuel for a fire.

In flight, the pressure needed was much less, and so there was no threat of a super-charged blow-torch of a fire like the one that happened to Apollo 1. And, of course, they switched over to non-flamable materials where possible in the capsule, and paid more attention to sources of sparks.

>>10589644
This, carve the biggest dick I can for future generations to admire

>>10589717
>The problem was not oxygen
-t. Oxygen

>>10588158
Though they added the car by reducing weight elsewhere. One neat trick was to have the CSM fly the LM down much closer to the surface before separating -- this cut down on the fuel the LM needed, saving weight that could be used for consumables for a longer stay on the surface, and carrying a rover.

>>10588892
Depends. The abort procedure following running out of fuel would have had a brief interval between the moment the descent stage stopped firing and the ascent stage engine could fire -- partly caused by the fact that you have to take the time for the stages to separate. During that interval, you will continue descending, accelerating slightly since the descent engine is no longer slowing your fall.

There was a minimum distance above the surface, below which an abort would result in a crash. It was pretty low, but Neil cut it pretty damned close. If fuel had run out below that threshold but before landing, they would have "landed hard" -- how hard depends on how high thee were. How hard a landing resuts in a situation where you can't take off again (because you are ded, because one leg collapsed and you are sitting at an impossible angle, because something in the innards got jarred loose, etc.) is a question that they were fortunate enough not to find answers for.

>>10589729
Shut up, Faulty Wiring I know that's you.

>>10589769
Bad wiring in a vacuum:
>Fucking nothing

Bad wiring in Nitrogen:
>Fucking nothing

Bad wiring in (((oxygen)))
>Raging inferno
Ok shill
Daily reminder that oxygen causes cancer and has a vastly increased risk of fire compared to most other gases. Daily reminder that Big Oxygen has been running a relentless shilling campaign on 4chan and social media.

>>10589790
at least it's not flourine lmao so glad that fuck's in jail

>>10589830
Didn't you hear, he got really buff and teamed up with Chlorine a long time ago.

>>10589872
In carbon jail tho right