DLØART/am
3rd launch (08-Oct-1995)

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This time, Murphy really hit us...

We announced a transponder (70 cm -> 2 m) would be part of the payload. We thought so till some hours before launch, but had to find out what the deepest meaning of the word intermodulation is. We mainly blame the telemetry transmitter for that, but we decided that having that one aboard is a bit more important than a transponder... So we have to appoligize if anyone looked desperately for the signal and didn't find it - folks, your equipment is fine (get it out of the garbage can again!) - the signal simply wasn't there.

We hope having the payload (including the transponder) working flawlessly till the next launch (whenever that will be).


ARTOB launch 08-Oct-95:

Launch:        # 3
Launch date:   08-Oct-95
Launch time:   1211 UTC
Launch site:   Nienberge near Muenster, NW Germany, JO32SA 

Payload DLØART/am:
QRG/mod.:  (1) Telemetry beacon: 145,200 MHz  F2D & F2A
           (2) 2nd beacon:       144.991 MHz  F1A (call & info text)
           (3) Transponder cancelled - sorry!
           (4) RX for remote control on 70 cm and 10 m (not used)
Power:     (1) 2 W
           (2) 100 mW
           (3) ---
Antennas:  (1) groundplane
           (2) turnstile
           (3) big wheel for 2 m used to attach the parachute /
                70 cm cancelled
           (4) 70 cm: groundplane / 10 m: lambda/4 vertical
Power supply: (1) & (4): 5 D cells LiSO2 in series (=14.4 V, 6 Ah)
              (2) 1 D cell LiSO2 (3 V) and step-up to 9 V
Diameter ballon: ca. 8.5 ft
Gas:       hydrogen
Parachute: ca. 6 ft
Weight:    4005 g (over all)
Lift rate: ca. 300 g


The balloon has a gaz valve which can be opened to reduce the lift 
rate or start the touchdown procedure.

Schematic of balloon


Talk back of DF teams via repeater Muenster, DBØPD (R84).

(UTC)
10:30  ARTOB team meets at Armin's QTH
11:20  arrival at launch site
11:30  filling the balloon
11.55  phone call to DFS (= German FAA)
12:00  airport Muenster-Osnabrueck (FMO) called; in case we happen 
       to get into their inner control zone we're allowed to pass at 
       a minimum altitude of 30,000 ft (!)
12:05  final testing of gaz valve
12:11  LAUNCH (see nice picture - 130 kB)
       The balloon lifts steadily and drifts to N/NE (35 deg)
12:22  altitude 4,500 ft, rate of ascend (ROA) 475 ft/min.
12:28  altitude 7,575 ft,
       first opening of gaz valve (1 min.); 
       ROA 215 ft/min thereafter
12:30  second opening of gaz valve (1 min.); ROA 180 ft/min.
12:35  third opening of gaz valve; when trying to close it this does 
       not. The volve remains opened till the end of the flight.
12:38  max. altitude: 10,050 ft
12:54  altitude 6,175 ft, rate of descend (ROD) 300 ft/min.
13:10  Touchdown of balloon. Some DF teams lose signal
13:40  balloon found by Oliver, DL9QJ, and Ludger, DL3YBO.

Tochdown site:  "Kattenvenner Moor" (JO32WC), 10 miles E of Greven
Touchdown distance:  13.5 miles

                    max            min
Altitude:          240 ft        10,050 ft
Temp. (outside)    3.1 C          24.7 C
Temp. (inside)    26.9 C          31.5 C
Voltage           14.29 V          14.35 V
The positive thing was that (after we found the signal again) the DFing was easy: simply go straight ahead as long as signal on the HT (vertical car antenna) increases; when it's strong enough, just hit the brakes and find yourself in a distance o 5 ft from the balloon! Indeed, it was attached to a fence next to a small rural road - never forget the confused cows on the other side of the fence...

We had many responses (reports) via PR (someone put us into the DX cluster) - and obviously, the beacons could even be heard in the UK (grid JO02)!

We were not too delighted that again (just like the first flight) the balloon came down too early because of a malfunction of the valve (and not even being the same flaw). We'll anyway redesign the valve till the next launch.

The DF coordinating has to be improved - we also found that giving bearings every 10 min. is to much for the teams - you simply do not make enough miles in case the balloon would be faster. We scheduled "must" bearings for xx:00, xx:20 and xx:40 h - and many teams dropped the (voluntarily) ones at xx:10, xx:30 and xx:50 h. But only one or two bearings would help the coordinating team - so we'll probably change to a xx:00 / xx:15 / xx:30 / xx:45 h schedule. The driving directions of the control team were poor - yes, this time, they had to do everything manually - no help of the PC program (because not enough notebooks available).


If you heard our sigs, pse send QSL via PR / Internet / buro - all will be answered with our DLØART/am QSL cards! Any suggestion or response is always welcome!

Best 73, Oliver

[Oliver Welp, DL9QJ, N3NSF
 Gustav-Freytag-Str.11 / D-48161 Muenster / GERMANY
 Internet: dl9qj@amsat.org  /  n3nsf@amsat.org
 PR:       DL9QJ@DBØEA.#NRW.DEU.EU
 Tel./Fax: +49-2533-7312]

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last edit 07-July-1996
© maintained by Oliver Welp, DL9QJ, N3NSF - n3nsf@amsat.org