It's with more than a degree of staring at the heavens in exasperation that we confirm what those of you watching the live coverage of yesterday's Punch and Judy test flights had already deduced - that the Low Orbit Helium Assisted Navigator (LOHAN) team failed to make fire in the sky. Dave and Anthony prepare for launch as …
gotta be careful with fuses in extreme cold if they're the metal strip/wire type.
the strip/wire is very thin and held firmly at both ends, in extreme cold the metal contracts and can snap (not helped by also becoming brittle) especially the cheap ones, the more expensive ones have a twist in them which means they can stretch further and last better in the cold.
when i stayed in canada we often had to replace vehicle fuses for this very reason.
You think YOU have problems?
The hated Yankees beat our Red Sox 4-1 in their first meeting of the year last night in New York.
Repeat after me:
"There's always next time!"
Good luck, guys...
So often it is some trivial component that fails. Best of luck next time
Breast of duck next time
This post contains letters
I may have slightly lost track of the latest plan but I though Helium was very much the SPB lift gas of choice (for lots of good reasons involving proximity of rockets, ignitors, etc.).
But those tanks are bright red, which I thought was the tank colour of Hydrogen?
Re: Hydrogen? Helium?
Dave Akerman always uses hydrogen. You can't get it in Spain, unless you have some form of authorisation from the King or summat, so helium it is for the final launch.
Shame about SPEARS! But what the world really wants to know is "Did Judy's BRASTRAP work?"
Fail, and that is a shame...
I was looking forward to seeing how everything performed, damn that fuse!!
I am sure the next test will be fine.
That's the trouble with us Brits, we're too honest. Would have been better to use NASA-speak and say that it "suffered a non-mitigated power-up anomaly". Ah well, better luck next time - perhaps the Playmonaut can take a spare fuse up with him?
We have in a negative success situation!
Could have been worse - it could have undergone an "Uncontrolled hyper-energetic disassembly" - better known as an 'explosion'.
That's the trouble with us Brits, we're too honest. Would have been better to use NASA-speak and say that it "suffered a non-mitigated power-up anomaly"
Or make like the the NORKs and just say that the glorious eternal president designed and launched it successfully as a toddler in 1915 using only string and the tears of the Japanese emperor. It certainly feels like the project has been going almost that long.
"Would have been better to use NASA-speak and say that it "suffered a non-mitigated power-up anomaly"
But they had a Barogenic Unexplained Metal Meltdown Energetic Rupture instead.
Look to the positives - the Ground Unit Support Staff Event Telemetry Team got a workout...
Best of luck with the rematch.... Still not expecting a pfzzt with the ultimate ride.
John F J
Pitot probe heater?
How are you planning to prevent your pitot static probe from icing up?
Re: Pitot probe heater?
It's an issue that's been raised before. We haven't had time to consider it yet.
Don't overlook the possibility that you were actually saved from a nasty accident during the launch by the fuse. It may have done its job. Fault trees are your friend here.
That said, I concur with that above - temperature rating of the fuse for low temperatures is important. First question - is the fuse blown or failed?
We believe that it actually blew back in the last test in Spain, but the glass wasn't blackened (well not much - just a tad at the underside) so it wasn't obvious. Igniters can short circuit when the blow, plus the battery supply erred on the "let's make sure this goes" side, resulting in an igniter current about 3 times the fuse rating.
So, for next time, "check the damn fuse" gets added to the check list. Also, the SPEARS firmware has been updated to check the fuse and other items so it will report over the radio if there's an issue, and the receiving end will display a "DON'T LAUNCH" message in such a case.
try using a slow-blow fuse next time.
I don't know what the lowest temperature reached by the fuse is, but I would advise against using a glass fuse for various reasons which I'm not going to detail here.
I suggest that you contact Littelfuse, who are the experts in this area, to get some advice.
- iPad? More like iFAD: We reveal why Apple ran off to IBM
- +Analysis Microsoft: We're making ONE TRUE WINDOWS to rule us all
- Climate: 'An excuse for tax hikes', scientists 'don't know what they're talking about'
- Analysis Nadella: Apps must run on ALL WINDOWS – PCs, slabs and mobes
- Apple: We'll unleash OS X Yosemite beta on the MASSES July 24