High altitude balloon payload, from Sable-3 discussion Options

[djellison]

Just so no one thinks I've totally forgotten about this - Helen and I went out to Cambridgeshire today to see James et.al. launch one of their payloads. I was able to track it with good binos for about an hour. The comms died after about 50 mins, probably at 15-18km altitude, somewhere just north of Cambridge.

Some pics and a movie here : http://www.rlproject.com/launch_feb_2008

They found it !!

http://www.pegasushabproject.org.uk/wiki/d...firefly:fhalp-2

[djellison]

And...looking at the imagery ( which is very cool ) - lesson learnt... if you want those big ass panoramas....you've got to take multiple images at the same time. There's so much chaotic motion, it doesn't work on its own.

Doug

[AndyG]

There's so much chaotic motion...

I don't there needs to be. Aren't the answers to this:

A longer bridle.
A fishing swivel.
A vane on the instrument housing to stabilise the unit in any (apparent) wind?

Andy

[jamescanvin]

Hmm.

I think the lesson I'm taking away from the imagery is that the motion of the platform is too great for the camera to deal with. The payload must have twisting on the line connecting it to the balloon quite severely which ruins many of the images.

I'm sure the balloon itself is a much more stable platform. I think it would be a good idea to try and couple the payload to the balloon better to stop this rotation, using multiple lines or a stiff connecting rod rather than cord (I think there are laws restricting the strength of the connection so this may be a no-no)

Cross posted with Andy - That's a good idea as well - anything to reduce the rotation of the camera housing.

[djellison]

To be fair - they really did set up that camera to be a troublesome child - it wasnt decoupled very well - if you look at the pics I took of the stack, it was going to be a nightmare from the get go.

They might be launching again - sat or sun, from Cambridge.

[ilbasso]

Didn't catch sight of this guy by any chance, did you?

[nprev]

Classic example of evolution in action... (Shouldn't make light of a tragedy, but, c'mon...can anyone realistically say that the outcome was unexpected?!)

I just can't summon up much pity for people who take such enormous risks for no apparent reason other then self-indulgence of whatever nature; you pays your money & you takes your chances. I just hope nobody was hurt or killed during the rescue/recovery ops, and frankly that's what really ticks me off about these stunts.

For example, the following scenario plays itself out with depressing regularity: Some fools decide to climb a mountain in bad weather, end up needing to be rescued, and one or more of the rescuers are hurt or even killed in the effort, to say nothing of the money & resources expended. This guy should've been required to post at least a $1 mil bond to cover potential rescue operations before he was allowed to lift off.

[SpaceListener]

I was in amazement when the priest phoned to police station from a small town in Brazil asking on how to use the GPS so that they can ubicate him!

Horror!

[nprev]

Well, we're all gonna die someday. My personal objective is not to do so foolishly, and of course not to endanger the lives of others in the process. (Frankly, 150 years old in bed with satellite TV & broadband Internet access sounds like a worthy goal...)

[djellison]

Best I could manage.

Also - put this into a plain text doc, and save it as FHALP2.kml - and it will show the track in Google Earth

CODE

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.2">
  <Document>
    <name>FHALP-2</name>
    <description>Flight Path</description>
    <Style id="yellowLineGreenPoly">
      <LineStyle>
        <color>7f00ffff</color>
        <width>4</width>
      </LineStyle>
      <PolyStyle>
        <color>7f00ff00</color>
      </PolyStyle>
    </Style>
    <Placemark>
      <name>Absolute Extruded</name>
      <description>Transparent green wall with yellow outlines</description>
      <styleUrl>#yellowLineGreenPoly</styleUrl>
      <LineString>
        <extrude>1</extrude>
        <tessellate>1</tessellate>
        <altitudeMode>absolute</altitudeMode>
        <coordinates>
            -0.092153,52.251855,53.3
            -0.095018,52.25504,490.6
            -0.099425,52.262608,990.0
            -0.106652,52.269028,1487.9
            -0.108017,52.272517,2032.7
            -0.105082,52.275055,2571.0
            -0.10243,52.277088,3089.0
            -0.098177,52.280335,3648.4
            -0.094415,52.280095,4203.3
            -0.087797,52.278503,4754.2
            -0.082655,52.276082,5284.2
            -0.075252,52.274807,5842.9
            -0.066357,52.272615,6373.8
            -0.057512,52.270577,6941.8
            -0.050978,52.269398,7507.0
            -0.045985,52.267428,8102.5
            -0.040037,52.264032,8695.3
            -0.031882,52.258668,9348.6
            -0.026875,52.258317,10020.5
            -0.022673,52.259387,10704.9
            -0.018747,52.259537,11399.7
            -0.013763,52.260188,10078.6
            -0.006772,52.25733,8802.7
            -0.000268,52.254915,7527.9
            0.008457,52.252997,6378.8
            0.015442,52.251082,5253.8
            0.020585,52.24862,4210.0
            0.022993,52.249298,3191.5
            0.025522,52.251703,2215.4
            0.023407,52.255915,1287.1
            0.015588,52.264823,20.6
        </coordinates>
      </LineString>
    </Placemark>
  </Document>
</kml>

Doug

Attached thumbnail(s)

 

[djellison]

Successful launch, and recovery of FHALP3 today. Flight computer seemed to burp it's way from about 500m altitude till recovery - no real data on board, or real time tracking - but - it sent an SMS on landing with it's lat/long, and it was recovered, 67km ENE of the launch site after a flight time of approx 1hr 45mins. No idea on the peak altitude yet - as no proper data on the flight computer. They were trying a dual stage balloon design - an over inflated, and a lower inflation balloon, with the over inflated designed to punch thru the jet stream, cut down, and then the lower pressure to take over...the 'mess' on landing was one burst balloon (high pressure) and one deflated balloon ( low pressure). Personally, I think the high pressure burst, and then damaged the low pressure causing a leak, so that it carried on a little more, before descending. As the flight computer was dead for the entire flight, the cut-down never happened.

Similar camera design to last time ( hence, on the ground at recovery, i said ' You're camera work is CRAP - we have to talk about it!'

Attached thumbnail(s)

 

[djellison]

A few mosaics from yesterday afternoon.

Landing site : http://maps.google.co.uk/maps?q=52.332,0.888

Launch Site : http://maps.google.co.uk/maps?q=52.2513,-0.092

Attached thumbnail(s)

 

[djellison]

A vid of the inflation, the launch, and then tracking out to 20 minutes during the flight.

http://www.rlproject.com/fhalp3/

Doug

[Vladimir R]

hm one interesting question

If i go with balloon on 120.000 ft and then just "left" payload but with only 10 grams How much time will be needed to come back to Earth?
(just small box for example)

(offcourse without parachute) :s

[djellison]

Well - you would need to calculate it's drag, it's cross-sectional area, etc etc.