ma07_v_bw_o_n (62-MA7-33)
“BALLOON EXPERIMENT -- The MA-7 spacecraft has been outfitted with a system that will deploy a tethered balloon during the mission orbital phase. Of primary interest will be the visual phenomena in a space environment. Aerodynamic drag measurements will be a secondary objective.
The visual portion of this experiment will be concerned with the reflection characteristics of various colored surfaces in space. The relative merit of these colors for optimum visibility will be evaluated and a correlation between observed and actual separation of the object from the spacecraft after release will be established. The aerodynamic portion will measure atmospheric drag and stability while deployed and a relationship between these parameters and object separation following release will be analyzed.
An additional objective is provided by simultaneous dispersion of a cluster of multi-colored particles or “confetti” -- one-fourth inch Mylar discs which will be placed in the folds of the balloon. The visual effects and the behavior of these known objects will be closely studied.
The test apparatus consists of a 30-inch, Mylar-aluminum sphere which is to be inflated by an attached 900 [psi] nitrogen bottle. The balloon is divided equally into five segments. The corresponding colors on these reflective surfaces are orange, white, silver (aluminum), yellow, and phosphorescent, which has a glow characteristic at night. The balloon is tethered with a 100-foot nylon line and coiled eight-foot strip of .005 aluminum, which acts as a shock absorber as it uncoils. A small metal beam, instrumented with a strain gage, will provide the means of measuring drag. Electric squibs will actuate the spring-loaded deployment and line-cutting mechanisms.
The entire experiment package weighs about 7 pounds and will be installed within the antenna section.”
No artist signature visible, who deftly employed a textured(?) and mottled depiction of earth's surface, obviating the need to even semi-accurately depict land masses, oceans, etc. ;-)
What a joy to read. I sorely miss the precise, effective & articulate 'old school' style of intelligent, informative writing.
The following, other than as noted, is from the “MERCURY PROJECT SUMMARY (NASA SP-45)”, at:
history.nasa.gov/SP-45/ch12.htm
“A 30-inch mylar inflatable sphere was packaged in the antenna canister of both the MA-7 (see ref. 1) and MA-9 Mercury spacecraft. These balloons were to be ejected, inflated, and towed at the end of a 100-foot nylon line through one orbital pass to measure the drag experienced by the balloon throughout the orbit. The measured drag could then be readily converted into air density over the Mercury altitude profile. In addition, it was hoped that the astronaut could obtain some sightings yielding visual data on objects in close proximity to the spacecraft.
The design, construction, and qualification of the equipment used on this experiment were carried out by the NASA Langley Research Center. The components of the equipment are shown in figure 12-16. The results of this experiment conducted during the MA-7 flight are contained in reference 1.
[reference 1 being “RESULTS OF THE SECOND U.S. MANNED ORBITAL SPACE FLIGHT, MAY 24, 1962”, specifically:
The objectives of the balloon experiment were to measure the drag and to provide visibility data regarding an object of known size and shape in orbital] space. The balloon was 30 inches in diameter, and was constructed of five equal-sized lunes of selected colors and surface finishes The sphere was constructed of a plastic and aluminum foil sandwich material, and was to be inflated with a small nitrogen bottle immediately after release from the antenna canister at the end of the first orbital pass. In addition, numerous 1/4-inch discs of aluminized plastic were placed in the folds of the balloon and dispersed when the balloon was deployed.. is intended, the pilot observed the rate of dispersion and the associated visual effects of the "confetti."
The balloon was deployed at 01:38:00 ground elapsed time, but it failed to inflate properly. The cause has been attributed to a ruptured seam in the skin. Aerodynamic measurements were taken with the strain-gage pickup, but these are of little use since the actual frontal area of the partial inflated balloon is not known. The visibility portion of the experiment was also only partially successful because only two of the surface colors were visible, the orange and aluminum segments. While the balloon was deployed a series of spacecraft maneuvers evidently fouled the tethering line on the destabilizing flap located on the end of the cylindrical portion of the spacecraft, thus preventing the jettisoning of the balloon. No difficulty was encountered during retrofire and the balloon burned up during reentry.]
The above at:
www.hq.nasa.gov/office/pao/History/SP-6/ch1.htm
Briefly summarized, the balloon was deployed satisfactorily but was only partially inflated; hence, little useful data were obtained on this flight.
By a thorough investigation of the MA-7 failure, it was concluded that the balloon failed to inflate because one of the seams connecting the many gores comprising the balloon skin pulled apart.
The experiment was believed to have been of sufficient value to be repeated on a later Mercury flight; therefore, new equipment was developed and qualified for the MA-9 flight. Careful control of balloon construction was maintained throughout the development program and numerous deployment and inflation tests were conducted by the Langley Research Center to insure the quality of the device. These tests were conducted with the flight equipment under conditions which closely simulated the space environment without a single failure. Numerous squib firings were made, without a single failure, to insure that either one or both of the squibs used to unlatch the cover of the canister would accomplish this task. The assembled unit was carefully checked after installation on the spacecraft and was found to be satisfactory. It was, therefore, believed that this experiment was well qualified for flight, but unfortunately the balloon failed to deploy in flight. Failure was attributed to some malfunction in the squib firing circuit that released the hatch cover of the balloon canister. The exact cause of this malfunction could not be determined because the circuit was contained in the spacecraft antenna canister which is jettisoned prior to landing.”
And so began the mixed history of space tether missions, which seems to be well documented here:
en.wikipedia.org/wiki/Space_tether_missions
Credit: Wikipedia
ma07_v_bw_o_n (62-MA7-33)
“BALLOON EXPERIMENT -- The MA-7 spacecraft has been outfitted with a system that will deploy a tethered balloon during the mission orbital phase. Of primary interest will be the visual phenomena in a space environment. Aerodynamic drag measurements will be a secondary objective.
The visual portion of this experiment will be concerned with the reflection characteristics of various colored surfaces in space. The relative merit of these colors for optimum visibility will be evaluated and a correlation between observed and actual separation of the object from the spacecraft after release will be established. The aerodynamic portion will measure atmospheric drag and stability while deployed and a relationship between these parameters and object separation following release will be analyzed.
An additional objective is provided by simultaneous dispersion of a cluster of multi-colored particles or “confetti” -- one-fourth inch Mylar discs which will be placed in the folds of the balloon. The visual effects and the behavior of these known objects will be closely studied.
The test apparatus consists of a 30-inch, Mylar-aluminum sphere which is to be inflated by an attached 900 [psi] nitrogen bottle. The balloon is divided equally into five segments. The corresponding colors on these reflective surfaces are orange, white, silver (aluminum), yellow, and phosphorescent, which has a glow characteristic at night. The balloon is tethered with a 100-foot nylon line and coiled eight-foot strip of .005 aluminum, which acts as a shock absorber as it uncoils. A small metal beam, instrumented with a strain gage, will provide the means of measuring drag. Electric squibs will actuate the spring-loaded deployment and line-cutting mechanisms.
The entire experiment package weighs about 7 pounds and will be installed within the antenna section.”
No artist signature visible, who deftly employed a textured(?) and mottled depiction of earth's surface, obviating the need to even semi-accurately depict land masses, oceans, etc. ;-)
What a joy to read. I sorely miss the precise, effective & articulate 'old school' style of intelligent, informative writing.
The following, other than as noted, is from the “MERCURY PROJECT SUMMARY (NASA SP-45)”, at:
history.nasa.gov/SP-45/ch12.htm
“A 30-inch mylar inflatable sphere was packaged in the antenna canister of both the MA-7 (see ref. 1) and MA-9 Mercury spacecraft. These balloons were to be ejected, inflated, and towed at the end of a 100-foot nylon line through one orbital pass to measure the drag experienced by the balloon throughout the orbit. The measured drag could then be readily converted into air density over the Mercury altitude profile. In addition, it was hoped that the astronaut could obtain some sightings yielding visual data on objects in close proximity to the spacecraft.
The design, construction, and qualification of the equipment used on this experiment were carried out by the NASA Langley Research Center. The components of the equipment are shown in figure 12-16. The results of this experiment conducted during the MA-7 flight are contained in reference 1.
[reference 1 being “RESULTS OF THE SECOND U.S. MANNED ORBITAL SPACE FLIGHT, MAY 24, 1962”, specifically:
The objectives of the balloon experiment were to measure the drag and to provide visibility data regarding an object of known size and shape in orbital] space. The balloon was 30 inches in diameter, and was constructed of five equal-sized lunes of selected colors and surface finishes The sphere was constructed of a plastic and aluminum foil sandwich material, and was to be inflated with a small nitrogen bottle immediately after release from the antenna canister at the end of the first orbital pass. In addition, numerous 1/4-inch discs of aluminized plastic were placed in the folds of the balloon and dispersed when the balloon was deployed.. is intended, the pilot observed the rate of dispersion and the associated visual effects of the "confetti."
The balloon was deployed at 01:38:00 ground elapsed time, but it failed to inflate properly. The cause has been attributed to a ruptured seam in the skin. Aerodynamic measurements were taken with the strain-gage pickup, but these are of little use since the actual frontal area of the partial inflated balloon is not known. The visibility portion of the experiment was also only partially successful because only two of the surface colors were visible, the orange and aluminum segments. While the balloon was deployed a series of spacecraft maneuvers evidently fouled the tethering line on the destabilizing flap located on the end of the cylindrical portion of the spacecraft, thus preventing the jettisoning of the balloon. No difficulty was encountered during retrofire and the balloon burned up during reentry.]
The above at:
www.hq.nasa.gov/office/pao/History/SP-6/ch1.htm
Briefly summarized, the balloon was deployed satisfactorily but was only partially inflated; hence, little useful data were obtained on this flight.
By a thorough investigation of the MA-7 failure, it was concluded that the balloon failed to inflate because one of the seams connecting the many gores comprising the balloon skin pulled apart.
The experiment was believed to have been of sufficient value to be repeated on a later Mercury flight; therefore, new equipment was developed and qualified for the MA-9 flight. Careful control of balloon construction was maintained throughout the development program and numerous deployment and inflation tests were conducted by the Langley Research Center to insure the quality of the device. These tests were conducted with the flight equipment under conditions which closely simulated the space environment without a single failure. Numerous squib firings were made, without a single failure, to insure that either one or both of the squibs used to unlatch the cover of the canister would accomplish this task. The assembled unit was carefully checked after installation on the spacecraft and was found to be satisfactory. It was, therefore, believed that this experiment was well qualified for flight, but unfortunately the balloon failed to deploy in flight. Failure was attributed to some malfunction in the squib firing circuit that released the hatch cover of the balloon canister. The exact cause of this malfunction could not be determined because the circuit was contained in the spacecraft antenna canister which is jettisoned prior to landing.”
And so began the mixed history of space tether missions, which seems to be well documented here:
en.wikipedia.org/wiki/Space_tether_missions
Credit: Wikipedia