Astra AAD

[dpreguy 14]

Is the Astra AAD still an item? I googled it and the last info was......uh 2008? I haven't seen one on a skydiver parachute, so I wondered if the product was still being used/sold to the sport market. I haven't called FXC or looked in the Para Gear catalog to see if it is available. Info on Astra use?

[Remster 24]

I still see the odd one at SDAZ once in a blue moon. I even think I saw one last weekend.

Remster

[PhreeZone 14]

I know there is one at SDAZ since it was the only one around here in Ohio and the jumper moved out to SDAZ last year. I have seen a total of 2-3 in the last 10 years and have not had to rig on one yet. They are a rarity anymore. One of the ones I saw had a fire at 8k since the jumper had accidentally turned it off and then turned it back on while climbing since they did not know better and then in freefall it fired.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[riggerrob 558]

"

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... One of the ones I saw had a fire at 8k since the jumper had accidentally turned it off and then turned it back on while climbing since they did not know better and then in freefall it fired.

"

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That same silliness will scare the next dozen other models of AADs.
Some of the smarter AADs will get so confused that they refuse to turn back on.

Bottom line" meddling with any AAD - in an airplane - creates far more problems than it solves!

[nt8us 0]

back in the old days of the sentinel mk 2000, someone calibrated his sentinel in the airplane,then made his jump. resulting in a fatality when another jumper punched thru his opening reserve canopy

[Unstable 8]

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One of the ones I saw had a fire at 8k since the jumper had accidentally turned it off and then turned it back on while climbing since they did not know better and then in freefall it fired.

Sounds like a testimant to the ASTRA to me....The unit worked (and cut through the loop!)

=========Shaun ==========

[riggerrob 558]

When Francis Xavier Chevrier brought the ASTRA prototype to Rigging Innovations, we said: "smoother cutter, stronger cables, stronger battery box, that control head will not fit into all the Cypres windows, but the biggest limitation is having to remember to turn it off after every jump."
ASTRA batteries only last for about ten days ... if you forget to turn them off.

The end result is that too many ASTRAs needed batteries replaced too often.

Hint: none of the other AAD manufacturers trust skydivers to turn off their AADs at the end of the day.

In the end, few ASTRAs were sold, because they required skydivers to learn too much.

[JerryBaumchen 1,046]

Hi rob,

I cannot remember when but I visited FXC back when I heard that were developing a new AAD.

They showed me their prototype & some ripcord cable that they had cut with one of them.

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In the end, few ASTRAs were sold, because they required skydivers to learn too much . . . if you forget to turn them off.

IMO this was their shortcoming with the design. I liked everything else about it; even bought & used one for quite some time, never had a bit of any problem with it. Something about RTFM, I think.



JerryBaumchen

[Unstable 8]

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When Francis Xavier Chevrier brought the ASTRA prototype to Rigging Innovations, we said: "smoother cutter, stronger cables, stronger battery box

What were the concerns with the cutter, cable and Battery box. (IIRC, doesn't it use a machined billet for a battery box?). Do you think these improvements have been made?

=========Shaun ==========

[riggerrob 558]

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When Francis Xavier Chevrier brought the ASTRA prototype to Rigging Innovations, we said: "smoother cutter, stronger cables, stronger battery box

What were the concerns with the cutter, cable and Battery box. (IIRC, doesn't it use a machined billet for a battery box?). Do you think these improvements have been made?

......................................................................

Perhaps you mis-read my statement.

I was trying to say that ASTRA was BETTER than Cypres 1 on all but two counts: thick control head and the need to remember to shut it off.

[sundevil777 93]

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When Francis Xavier Chevrier brought the ASTRA prototype to Rigging Innovations, we said: "smoother cutter, stronger cables, stronger battery box

What were the concerns with the cutter, cable and Battery box. (IIRC, doesn't it use a machined billet for a battery box?). Do you think these improvements have been made?

......................................................................

Perhaps you mis-read my statement.

I was trying to say that ASTRA was BETTER than Cypres 1 on all but two counts: thick control head and the need to remember to shut it off.

I think there are other important considerations. I believe the Astra was quite dumb - not capable of being smart about the conditions under which it operates. It could not realize what data was due to transient effects vs what a jumper could physically do. That it was possible to get it to turn on/arm itself despite the fact that it was climbing in a plane is just one example of how software that has some reality checks in it is so valuable.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[pchapman 261]

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I believe the Astra was quite dumb - not capable of being smart about the conditions under which it operates. It could not realize what data was due to transient effects vs what a jumper could physically do.

Yes I believe that was a factor at the time. There was talk (on rec.skydiving) about how simple the processing seemed to be, from the little that had been heard about the internal logic. It just didn't sound like there had been much attempt even to design smart logic.

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That it was possible to get it to turn on/arm itself despite the fact that it was climbing in a plane is just one example of how software that has some reality checks in it is so valuable.

But all of the electronic AADs will get fooled by that, so that can't be held against the Astra.

[sundevil777 93]

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But all of the electronic AADs will get fooled by that, so that can't be held against the Astra.

I think not. I remember reading from the Cypres manual that it will not complete the start-up check if it detects such pressure changes. I'm not going to bother looking it up, I'm quite sure it is there.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[sundevil777 93]

From page 18 of the Cypres 1 user's guide:

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During its self-test, CYPRES will measure the air pressure several times. Should the unit
detect large differences between pressure values, it will conclude that there is a problem
and will not proceed to operating mode. In such a case, it will abort its self-test and display
the number 100.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[pchapman 261]

You could well be right but I'm not sure. Is the pressure change during climb a "large difference"? Haven't people had Cypres' boot up OK in the aircraft during climb, and fire early in freefall due to that?

[sundevil777 93]

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You could well be right but I'm not sure. Is the pressure change during climb a "large difference"? Haven't people had Cypres' boot up OK in the aircraft during climb, and fire early in freefall due to that?

I've never heard of that happening. It would be interesting to try turning on a Cypres while climbing slowly.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[sdctlc 0]

I looked on the ASTRA page and the only inherent logic that seems to be in place:

4.1.3 Once the unit is calibrated, it will 'ARM' itself automatically during climbing but 'ONLY' after reaching 1700 feet above that ground level (AGL).

http://www.pia.com/fxc/astrindx.htm#advantage

Also I remember there was an incident a number of years ago where a ASTRA saved a jumper who was injured and waited for it to fire.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2720494;search_string=ASTRA;#2720494

All AAD's are a back up IMHO and can be subject to a failure or missfire. The ultimate responsibility lies in your own hands.

Scott C.

Edited to add, I have an ASTRA on a spare rig and have a Cypress in my main rig.

"He who Hesitates Shall Inherit the Earth!"

[pchapman 261]

As for the Astra being dumb, here are some quotes from the 1996-1998 in rec.skydiving:

From FXC documents copied to the newsgroup:

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The computer averages 16 pressure readings each second and stores the initial average value (approximately 20 seconds after turn on), the last average value, and the current average value. The difference between the initial value and the current value indicates altitude, and the difference between the current value and the last value indicates rate of change in altitude.

And about the main sensing part of the software, the main software loop:

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Check if the unit is above 400’. (If it is below 400’ the unit disarms).
Loops until the unit is less than 1200’ above calibration altitude.
Checks velocity, if faster than 135 fps an immediate fire, if less than 135 fps but greater than 100 fps recheck once, if still at that speed or faster immediate fire.

So the Astra did simple averaging to determine the speed. It also did inhibit firing until below 1400'. It was supposed to fire at 1000' +/- 200'. If you think about the averaging method, the vagueness of the altitude makes sense. At say 200 fps it wouldn't detect 1200' until 1100' because it would be averaging the last second's worth of input, ranging from 1300' down to 1100' -- at which point the average finally reaches 1200'. It isn't that it would fire low, just that it had to be in effect set a bit high so that due to the lag from the averaging, it would still first roughly at the desired altitude.

A very very simple system.

Before the Astra came out, Bill von Novak had this to say:

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as far as i can tell, the astra is based on a PIC16x50 board from parallax called the BASIC Stamp. the processor is not the problem - the PIC16CX series is a good choice for a small, battery-powered device like an AAD. the BASIC stamp uses one of these processors to implement a BASIC interpreter, which gets its instructions from a serial EEPROM. it's an added layer of complexity and unreliability. in addition, most EEPROMS are vulnerable to accidental erasure, and only guarantee data for about ten years.
it can certainly be made to work, but it's clumsy.

FXC confirmed in some document that the Astra does indeed use an interpreted language:

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A EEPROM is programmed with FXC's custom software and is read and executed by an interpreter

Whether it was actually BASIC was debated, but it sounds plausible.

I'm no microcontroller programmer, but using INTERPRETED BASIC seems a very crude way to do things. Not the sign of sophisticated design even then. Code in assembler or compile some language.

In 1998 FXC claimed "improved and more sophisticated signal processing and software driven
filtering" in its latest software upgrades, but there was no sign of any major changes.

While most people didn't ponder the software design, they could see that the battery life and on/off switch design made it a lot clunkier than the Cypres. (And a pain for schools where it was easier for an AAD to be left on.) So it never got popular.

The last Astra I rigged was about 2-3 years back but I've seen one other one around somewhere. Very rare.

[BrianM 1]

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I believe the Astra was quite dumb - not capable of being smart about the conditions under which it operates. It could not realize what data was due to transient effects vs what a jumper could physically do.

Yes I believe that was a factor at the time. There was talk (on rec.skydiving) about how simple the processing seemed to be, from the little that had been heard about the internal logic. It just didn't sound like there had been much attempt even to design smart logic.

Sounds a lot like the Vigil, to be honest. Those seem to be selling well. I'm not convinced that is the reason (or at least not the only reason) that the Astra didn't do well.

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I'm no microcontroller programmer

I am. I wouldn't use a BASIC stamp in any production environment, even for non safety critical applications. It's like the Sears microscope I had as a kid: an suitable toy for the hobbyist who wants to learn a bit, but it's not a real tool. No scientist has a Sears microscope in their lab.

Using a BASIC Stamp for an AAD blows my mind.

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Code in assembler or compile some language.

It's impossible to code in assembler because there is no such language. You can code in assembly though, then use an assembler to convert it into machine code.

"It's amazing what you can learn while you're not talking." - Skydivesg

[pchapman 261]

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You can code in assembly though, then use an assembler to convert it into machine code.

Point taken as to preferred usage. But even the printed notes from my prof Dr. Vranesic calls it both assembler language and assembly language... back when learning to program the Motorola 6809!

[BrianM 1]

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You can code in assembly though, then use an assembler to convert it into machine code.

Point taken as to preferred usage. But even the printed notes from my prof Dr. Vranesic calls it both assembler language and assembly language... back when learning to program the Motorola 6809!

Lots of people call it assembler - it's just always been a bit of a pet peeve of mine for some reason. Pay me no heed!

I haven't done much with the 6809 family, but have done a lot of assembly on the 68000 (plus a handful of non-Motorola microprocessors, mostly the 8052 family).

"It's amazing what you can learn while you're not talking." - Skydivesg

[Unstable 8]

Back on the original subject ~ does anybody know if the Astra is still in production? I noticed that Paragear took it out of the latest catalog while leaving the FXC 1200-series units in........

=========Shaun ==========