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The story is compellingly written, but I thought it was also confusing. It sounds as if this team made several mistakes, not just one mistake. It's also not cl
by curiousObject 3y ago
The story is compellingly written, but I thought it was also confusing.
It sounds as if this team made several mistakes, not just one mistake. It's also not clear if the result of these mistakes was that there might be real damage to the spacecraft, or if the result was just wasted time and hours of confusion about why the spacecraft wouldn't start up.
The first mistake is they didn't realize that the multimeter was not only measuring, but it was also completing the circuit.
That sounds like a real bad idea. But if it was totally necessary to arrange it like that, then that multimeter should never have been touched.
That's not just one guy's error. It's at least two guys at fault, along with whoever is managing them, and whoever is in charge of the system that allows it.
The second mistake is with the break-out-box. They think he misdirected power wrongly into the spacecraft. Then they jump to the conclusion that has generated a power surge which has damaged the spacecraft, because it won't start up.
But they're not sure where the power surge went and what might be damaged. Anyhow they're wrong.
The reason the spacecraft won't start up is just because he took the multimeter out of the circuit before the accident.
I'm still sort of confused about what happened or if they ever really figured out what happened.
He said "Weeks of analyses followed on the RAT-Revolve motor H-bridge channel leading to detailed discussions of possible thin-film demetallization".
Does this mean that they decided that the misdirected power surge might have flowed into the RAT-Revolve motor H-bridge channel and damaged that?
- maxerickson 3y agoIt started up fine. The multimeter was connecting up the telemetry, so they weren't getting any information from it until they restored that circuit. The power absolutely did feed into that circuit, they were trying to decide if it would have damaged it (but a motor driver is going to be able to handle power coming from the motor, so they decided that it probably didn't damage it).
- curiousObject 3y ago> It started up fine. Thanks. I understand that better now. The spacecraft did start up, but it seemed as if it could be badly damaged because they were not receiving any telemetry data
- sopooneo 3y agoThat is my reading too. But why was the multimeter connecting up telemetry? That seems very strange to me.
- rchard2scout 3y agoAccording to the article, it was monitoring bus voltage, but I could imagine it was used to measure the current being used by the telemetry system. So if it was used as an ammeter, it would've been placed in series.
- tempestn 3y agoI assume it was wired up in series to measure current.
- prmoustache 3y agoYou forgot: the telemetry guy (Leo) didn't mention they had lost Telemetry before the storyteller told him he did a mistake. I mean shouldn't they have cancelled all testing until they have it back?