Having the second chair is a pretty glaring violation of the “no margin for error, bare essentials only” premise in itself. (Yes, there would be situations where a trained specialist is the “emergency delivery” – but it still makes no sense for a second seat to be a standard fixture rather than something installed in the cargo compartment along with extra life support on an ad hoc basis).
Arthur C. Clarke set up the situation more plausibly in “Breaking Strain” – a micrometeor takes out part of the ship’s air supply, and now there’s enough for one person to make it to Venus. Regrettably, there are two people in the crew…
Well, not unless you don’t bother to check (stupidity), or unless the ship is so sprawling that someone could realistically hide from a search (contraindicated by the whole “minimal craft with no margin for error” thing). And unless you didn’t put a trivially small and cheap CO2 sensor in the life support system (we’re back at “stupidity”) or failed to look at it (must I repeat the “s” word?)…
It’s an emergency, they were in a hurry. I think they had a short launch window. And why add a search to the checklist or add a CO2 sensor to cover a case which never had happened before? NASA had people turning screws and people watching people turn the screws. The culture in the story didn’t have that. I bet things slip through when a cropduster is taking off which would never slip through when a 767 is taking off.
The thing that bugged me most about the story wasn’t the engineering, it was the total lack of any sort of common sense in preventing the problem. Instead of posting a guard and doing a cursory search of the ship before launch, or even just locking door, all they did was put up a sign that said “UNAUTHORIZED PERSONNEL KEEP OUT!”. Stowaways were unusual, but happened often enough that they actually had a procedure in place for the pilot to eliminate the stowaway and report it to Records, down to which color form to use. You’d think some pilot, somewhere along the line, would have thought “Having to space a stowaway would really suck. Maybe we should come up with a slightly better way to make sure there aren’t any aboard before taking off.”
If he had at least tossed in a line or two where the girl saw a crewmember enter a code to get into a secure area, or talked one into letting her see the EDS and then sneaking off, it would be a lot more believable.
Not neccessarily.
The small craft could be very standardized. The only variable is the payload mass and or number of folks on board.
You know the performance of your standard craft. You know what your payload/number of passengers is SUPPOSED to be. Run the computers. Figure out where the mothership needs to drop you off so you can just make it.
One could even make an arguement that in the long run, keeping things pretty standard even if it makes it suboptimum is the safer way to go.
I think the more regrettable thing is the destination is Venus 
Not so. From Richard Harter’s critique (which raises many of the points mentioned earlier in this thread and adds a few more):
Evidently they weren’t in so great a hurry that the pilot felt any need to be hanging around the craft, ready to jump in and take off as soon as the cargo was loaded.
The need to check for excess mass if excess mass jeopardizes a mission speaks for itself. The reasons for including a CO2 sensor as part of a life support system (e.g. to diagnose failure ASAP) is equally obvious, even if this story were taking place in a universe where they had some sort of ultra-tech science-fictional device that prevented unauthorized people from opening doors leading to places where they aren’t supposed to be.
That is precisely the problem – the story relies upon everybody doing something stupid.
IIRC, the story was written in the days when “jungle planet Venus” was at least a plausible possibility.
Of course they would be standardized. The standard, given the “no margin for error” premise (and the “automation not an option” implicit premise) would be one seat, with a second added in the cargo hold if and only if necessary for the mission.
You can have the “no margin for error” premise, or you can have a “suboptimum” design. You can’t have both without making the story require the characters to be idiots.
Doesn’t bother me. I don’t remember the details of the story, but…
About engineering overkill, here’s Buzz Aldrin on descending to the moon in the lunar module:
[INDENT]“Neil didn’t like what we were heading toward, and we selected a safer spot alongside a crater with boulders in it. We landed with a little less fuel than we would have liked to have had, maybe 20 seconds of fuel left.” [/INDENT]
I have no trouble accepting that a cheap commercial vehicle making a flight of established distance would not take extra fuel.
I don’t remember the details of the two chairs. Could they have been built in, with bases full of electronics, and with a pound of padding up top? The part of a chair that “interfaces” with a body could be trivially light.
That’s not really a good example – if the Apollo capsule had been designed with no margin for error (like the EDS in the story), it would have landed where it was heading toward, whether Neil liked it or not.
In any case, the idiocy of leaving the EDS unattended and unsecured to the point where somebody could just walk on board on a whim, with no warning that it is dangerous to do so (simply declaring an area “unauthorized” is not the same thing) is a more glaring flaw than the engineering lapses in setting up the situation. The problem is compounded by the fact that neither the pilot nor anyone else in the story seems to consider this to be a lapse of judgment. :smack:
I just explained why you could have both at the same time. AND the reason for it. Once you start changing things up, its just something else for somebody/something to screw up.
And again, there is a difference between NO margin for error and not enough margin for error given an unexpected/rare situation.
Hi Steve MB. I think the Apollo 11 comparison is decent. That was a mission where engineers were counting on the unexpected and trying to plan for it. And there was still just 20 seconds of fuel to spare. If someone wrote a story about a fictional first moon landing that ends in disaster because they ran out of fuel, would there be posters here writing that there’s no way engineers would let that happen?
In comparison, The Cold Equations dealt with a situation where variables just weren’t expected. It’s space. It’s an arena of almost pure physics. X number of kilos to X velocity takes X amount of energy. There’s no need for back-up. (Unless the ship is landing, which introduces some variables.)
About stowaways… eh, people have stowed away in the wheel wells of jets. If the mission was routine, familiarity breeds carelessness. If the mission was unusual and rushed then procedures can get compromised.
Lots of things can happen one time, before procedures are adjusted to make sure they don’t happen again.
There is no second chair. The girl is sitting on the drive control unit.
Anyways, if it is such a bare bones ship, the author should have made it clear by explicitly stating that there was no way to throw out enough mass to lighten the load. Also, as some people have stated, if it’s not unheard of to have to jettison a stowaway, it’s idiotic to not check the closet before you take off.
The author gives us some statistics:
This is a disastrous situation: one dead stowaway in a pilot’s career, common enough to make a law specific to the situation. And the sort of stowaways described by the author aren’t merely a danger to themselves. Presumably “fugitives”, “crackpots”, and “brutal and dangerous men” can be at least as heavily armed as the pilot, and endanger the entire mission. This can all be avoided by the simple procedure of opening and closing the closet door before one takes off.
Mr. Shmendrik, thanks for the excerpt. If the story mentions an on-going problem with stowaways, then yes, there should definitely be a system in place to stop them.
I am convinced that objection is valid. (Although it did take decades to get security doors in commercial cockpits. And moderately effective weapon screening.)
Yes, this is what bothered me too. They should have been doomed because she’d already been on the ship so long by the time they find her.
Actually, it turns out that the differences between the real Apollo 11 situation and the situation depicted in the story point to a need for more margin for error in the latter – see below.
[QUOTE=Baal Houtham]
There’s no need for back-up. (Unless the ship is landing, which introduces some variables.)
[/QUOTE]
The EDS was on a mission that called for a landing:
The EDS is landing on a planet with an atmosphere (which might reduce the expected fuel requirement if the EDS can aerobrake, but certainly introduces more unpredictable variables):
[QUOTE=Baal Houtham]
Lots of things can happen one time, before procedures are adjusted to make sure they don’t happen again.
[/QUOTE]
The biggest flaw in the story is that this clearly was not done, even though stowaways were a known issue – the craft wasn’t even locked, for Ghu’s sake, as evidenced by the fact that the stowaway entered on a whim (see previous message for cite).
I get the premise - the cold physics doesn’t care, you can’t make a solution appear just because you wish it. From that standpoint, I can accept the story.
Engineeringwise, I have trouble accepting the margins being that thin on the fuel. I mean, how is the fuel wasted if they get to the planet with a few pounds to spare? Can’t they recover the ship when the next standard supply ship visits? Extract the fuel then, if not on the planet and use it in their resources? Is carrying fuel on the regular cargo run so expensive they can’t spare any margins?
I also have trouble accepting he can change the flight profile so easily and not affect the target. Stopping decelerating so he isn’t spending fuel means he is traveling faster when it comes time to decelerate later, and that could take more fuel. Changing the flight profile changes the fuel requirement even without changing the payload. The fuel itself has to be included in the calculations.
Plus, the planet isn’t sitting still. It’s moving, which effects the trajectory. And it is rotating - changing the travel time puts him intersecting with a different location in the atmosphere for a touchdown at a different place on the surface - oops, now I will be landing at Site 1 instead of Site 2. Drat!
I think both of those situations are going to be a bigger hit than one person’s weight.
The real error is the managerial decision that they decide up front how to handle a stowaway - which means stowaways are common enough they have form and a process, and a law. That means they need to reconsider their design decisions about their margins.
They should have a preflight checklist check of compartments for stowaways. They should have access control on the doors, not just a sign - cypherlocks, keypad entry, biometrics. My office has a badge access just to get into the offices from the hallway, and labs have keypad entries. It’s ridiculous that passengers would have the ability to enter a restricted area just by ducking past personnel looking the other way. And it’s pretty stupid that the pre-flight briefing of the passengers doesn’t include safety instructions, like “Don’t go into the restricted areas - they are dangerous and you could be killed.”
That would have been a different story. The point of this story is that the girl made a stupid decision without the right knowledge - she knew she was doing something wrong, but thought the penalty would be a fine or jail time or a stern talking to. She had no idea the consequence of her action was either the failure of the mission and death of several people (herself and pilot for sure, probably the people on the planet who needed the medical supplies as well), or her death by jettison. If the cause of the problem was a micrometeoroid strike taking out a fuel tank, then her decision was irrelevant. She’s not the cause of the disaster, she’s merely one player in a list of people doomed by an accident, and solutions weighed upon the value of each crew member. Sure, as a stowaway her value is less than the pilot, but it’s still a different moral and a different meaning. The point of this story is that the only error was the girl’s error, and her bad decision was deadly - because that’s the way the universe rolls.
I read those units as “inch pounds” and was confused, before realizing they were saying the units are “in pounds”. Standard convention for us data types is to drop the modifier and just label the unit, possibly in parenthesis – especially since “in” is a standard unit abbreviation.
Where is everyone getting the second chair? I only see one chair mentioned in the story. When the girl first comes out of the closet, she sits on the drive control units. I would think if there were a chair she would have sat in it then. The chair she sits in later is the pilot’s chair when she’s talking on the radio.
Depends on the physics of the propulsion system, how and when and what the fuel is used for. And the burn rate. And, is it even sorta normal rocket physics or magical future stuff for that matter? And for the umptempth time, the designed in allowable margin of error vs the reality of the current situation (really, how hard is this concept?)
Of course I am referring to the Sci Fi version, where he finds her in short order IIRC.
Well, I’m talking out my ass because I’m not re-reading the story before posting, and also because I’m not an engineer. But hey, it’s just the internet…
Do we know what kind of speed the ship reaches? Again, IANAE, but if the ship accelerates to half of lightspeed and back, I’m guessing that could dwarf any other factors, such as showing up on the wrong side of the world.