“low altitude”28 pages
- p. 41 …Subsequently, a 1946 HQ AMC memorandum surfaced, describ-
ing the constant altitude balloon project and specified…
- p. 205 …The Columbia group was primarily involved in developing
low frequency microphoocs for long rmge detection of…
- p. 250 …Once a target like this comes down from
high altitude or drag, you don't want…
- p. 251 …But most of the detection was via the aircraft because
of the low power receivers.
A…
- p. 464 …of diffusion, which is expected to be low from this balloon,
h not yet known.
C…
- p. 467 1n high al ti·tudes# since it freezes below -BOOC and will flow
readily at low…
- p. 472 …even though the balloon may be be low the tloa tin_g level. (The
switch is…
- p. 473 …l where it falls on-
to the low-altitude conducting segment. {The shelf has been
set…
- p. 474 …IF LEVELING OFF TOO LOW, H.IGH
BALLAST RATE PUSHES BALLO.ON
INTO CONTROL ALTITUDE.
CASE…
- p. 480 …Floating Altitude and Altitude Sensitivi5Y
To determin& the altitude at which a non-extensible balloon will…
- p. 495 …lf • 50 ~ tof:g}af =7820 GII/HR
Values for leakage at several different altitudes…
- p. 504 …For any given allowable back pressure
greater rates of rise are allowable at higher altitudes (where…
- p. 526 …It is important that an electrolyte
be used wHich will not freeze at low atmospheric temperatures…
- p. 545 …1he expected altitude of 38,000 feet
was not reached, and this is believed to be…
- p. 572 …S.T.)
Figure 34
Since the balloon ttid not descend far enough below its maximum altitude…
- p. 575 …Flight 84 was launched in August, 1948 with a low-altitude barograph and no
altitude controls…
- p. 577 …to detennine the ballast requirements
at that altitude, using an automatic ballast valve. No record of…
- p. 584 …deter.mine the flow required at that
altitude using an automatic ballast valve. No recor• of…
- p. 646 …danger of rupturing the
balloon when pressure altitude is reached. On the other hand, if rates…
- p. 654 …Flight Techniques
The general techniques of preparing and launching controlled altitude
balloons are patterned after those…
- p. 670 …Despite this factor, and the low permeability
of the fabric, balloons of thie type are too…
- p. 736 …The only provision
for having the system regain altitude if it descended
too low was by…
- p. 737 …While
the altitude maintained was not constant, these bal-
loons were highly successful for the time…
- p. 739 …At this altitude the ballast release began to
operate and thereafter the balloon maintained its
altitude…
- p. 741 …If this is not done, the altitude
reached is far under the theoretical altitude deter-
mined…
- p. 778 …Transparent, low
permeability, high
tensile strength.
Disadvantages
Low tensile strength,
Milky-translucent,
Medium permeability.
Tears easily…
- p. 783 …poration of the liquid hydrogen low at the high altitudes, without ex-
tensive ani heavy guard…
- p. 916 …The motor speed will
decrease during the flight, as a resul~ of the
low temperatures and…
Fli.g!lt 89: Released from Alamogordo, New Mexico, 1005 MST, August 26, 1948
Not recovered
On this flight a .001", 20-foot polyethylene balloon was used to carry
a ballast meter to about 45,000 feet to detennine the ballast requirements
at that altitude, using an automatic ballast valve. No record of ballast
flow was telemetered during this flight, but it is not known whether the
ballast meter was inoperative or the ballast valve itself failed--possibly
due to failure of a squib to detonate at the combined low pressure and cold
temperatures aloft.
From the height-time curve, l<'igure 39, it will be noted that the balloon
was in a near floating condition for about five hours afterxeaching its maxi-
mum altitude. The total weight available on this flight was 2 kg, so a loss
of 400 grams per hour would have been required if the ballast was used
during this period.
From Flights 70 and 71 we know that a balloon has re~Ained for about four
hours at slightly higher altitudes with no ballast flow to support it; Flight
89, therefore, is not necessarily an example of the action of the automatic
ballast valve control.
M~---r----~---.----~--~~--~----T---~----~
40~ / 1'\
.I V \' I HEIGHT llt.£ CURVE '
I ru~~ ~
20 -+-+---t-----1 Released d Alamogordo;N.M. t---+------!114--'----1
·V ~~"="" \
Fig;ure 39
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