Sounds like some seriously amateur hour electrical shit. I've seen photos of their setup. An off grid photovoltaic system with battery storage, and propane generator that feeds a battery charger, is not rocket science.
Telecom people build them all the time for remote mountaintop sites with kWh/day loads much greater than their habitat. They can't ground things properly and have exposed wiring? For the multi million dollar budget, inexcusable.
I could build a better power system than what I've seen pictured for well under $80,000 in one time equipment expenses.
This article focues on how the medevac compromised their experiment. How about their failure to adhere to proper engineering standards compromised their experiment? Nobody wants to take the blame.
Not disagreeing with you at all; just keep in mind that these conditions are ultimately no more dangerous than camping — where exposed, temporary electrical setups are common — which probably gave them a false sense of safety about the setup.
Real NASA systems would need to be orders of magnitude more safe/reliable, but I suspect this experiment was at least partially designed to identify potential failure points that engineering solutions need to be built for (I.e. what things can a human fix safely and what needs failsafes and self-healing).
The Wh stored in their battery and the AC power of their inverter are significantly larger than that you'd see camping. Maybe what you'd see "camping" in a $90,000 50 foot luxury motorhome.
I'm guessing the habitat has a battery bank of at least eight 12v 100Ah batteries (if AGM lead acid, or equivalent capacity), and at minimim one 4000W sine wave inverter feeding several 120v 15a circuits. Also sounds like somebody shocked themselves on the AC power side, maybe the generator transfer switch, maybe just exposed wiring. Either way there are safe ways to do temporary ac power with twist lock receptacle extension cables and distribution boxes that are insulted up to 600 or 1000V and won't shock people.
>Sounds like some seriously amateur hour electrical shit
You'd think that setting up electrical for something like this would be covered under whatever contract the union hammered out and be done by university employees who do all the other electrical which would at least ensure it's not too dangerous.
>I could build a better power system than what I've seen pictured for well under $80,000 in one time equipment expenses.
You're not working with the overhead of a publicly funded university.
- If it's true that the system was not properly grounded, that raises the question of how a real Mars habitat would be grounded and did they even try to have that thought process?
- Without knowing the real voltages / amps involved there's no real way to know if an outside medical intervention was necessary. For example people who work on Navy subs, I mean you presume there are people on that crew who know that stuff in complete detail.
1. In an isolated power plant, you ground things by literally stabbing a long conductor, with an appropriate diameter of perhaps an inch, about ten feet down into the ground. The depth is a key factor, usually to reach natural moisture in the soil, past the frost line in cold climates, and sometimes hit a shallow water table depending on local geography. Although ambient moisture and even static discharge via dry surface area alone usually do the trick. You literally ground a metal rod by sticking it deep into the ground, and then route gounding leads back to a service that provides electrical contact to the rod.
2. It isn't about the amps/voltages at all. It's all about heart strain, which is why they made note of the chest pains the victim was presenting with. With electricity, there are two main injuries to cope with: burns and cardiac arrest. In this case, it sounds like a brief discharge without any burning electrical arc, so no burns. The chest pains would seem to indicate that the current passed through the heart and surrounding pacemaker nerves, long enough to perhaps clench and strain the muscle (pulled miscles/soreness leading weakened low pressure), or stop the heart, denying blood flow, which can damage both heart and brain tissue. With brain tissue damage due to oxygen deprivation, loss of blodd flow, it would resemble a concussion. Based on the provides description of the event, CPR wasn't necessary, so figure it was electrically induced heart strain and not full cardiac arrest.
Honestly, the whole thing sounds like a sort of staged social experiment, to see how a personality mix devolves, amid a stressful, seemingly life-threatening incident.
Isn't electrical grounding relative? So, only the electrical components which are directly or indirectly connected to each other need the same relative ground?
Looks like 36 300w panels. 10,000 volts DC. If you were doing this type of setup on a roof in Massachusetts there is a law requireing safe voltage, and quick system shutdown. The panels would limit the voltage to 48v or there would be microinverters on every two panels to keep the voltage at 110v AC.
The phrase 'As primitive as a farm in Vermont' jumps out at me. These people have no idea what there talking about, any farmer would know how to test pH and NPK values of the soil and take tissue samples for analysis, there's a lot of data involved in farming, not to mention it being one of the few industries to utilize gentic modification.
You aren't going to wire 36 panels in series. The largest off grid pv charge controllers handle strings of up to 1000VDC. You create strings of a certain size and then start paralleling.
I don't think this setup uses microinvertersb because it is highly inefficient to charge a battery bank by first having ac power, convert to DC, them back to AC to run loads.
I highly doubt the person who was shocked was shocked from the DC side, more likely they touched an exposed 120v 15/20a circuit on the AC load side.
Telecom people build them all the time for remote mountaintop sites with kWh/day loads much greater than their habitat. They can't ground things properly and have exposed wiring? For the multi million dollar budget, inexcusable.
I could build a better power system than what I've seen pictured for well under $80,000 in one time equipment expenses.
This article focues on how the medevac compromised their experiment. How about their failure to adhere to proper engineering standards compromised their experiment? Nobody wants to take the blame.
Edit: Here is a photo of their pv setup. All COTS stuff. https://www.cbsnews.com/news/mars-nasa-hi-seas-project-hawai...