NCAR Conference Surveys Instrument Stabilization

If a telescope or other astronomical sensor can be lifted by a balloon above much of the earth’s atmos­ phere, more detailed planetary and stellar observations u»_o of various kinds are possible than can ever be achieved HO cd from the ground. In every balloon-borne experiment of this kind, however, the problems are the same: How can an astronomical sensor find and track a pinpoint target? How can the spatial orientation of the balloon platform be controlled sufficiently to allow the delicate E "e3 pointing apparatus to do its work? A considerable number of approaches have been or are being tried to solve these questions. A recent NCAR-sponsored conference brought together scien­ tists actively engaged in balloon-borne astronomical exploration, in order to sketch an over-all picture of the state of the art, and to accelerate progress by increasing communication among them.

CONFERENCE IMPRESSIONS At the conference, held in Cambridge, Massachusetts r------i I " I in late October, some general impressions of the present state of the art emerged from descriptions of various stabilization systems: —Tracking stability to within one minute of arc is well within present capabilities. —The achievement of better-than-one-second-of-arc stability represents engineering of a high order of skill. J Nevertheless, theoretical limits of stability are much higher; even the .02 second of resolution hoped for the Stratoscope II system does not approach them. —A balloon vehicle provides a platform with excellent 0 / e ) P 5 ! stability. At float altitude, pendulum motion is usually five minutes of arc, and seldom exceeds thirty minutes. —In balloon flights involving precise tracking systems, most of which are relatively heavy, the reliability of the balloon vehicle is still the most serious problem. NATIONAL CENTER FOR Fundamental requirements can be stated that apply ATMOSPHERIC RESEARCH to all the projects discussed; for example, all must turn against some opposing force to compensate for the BOULDER, COLORADO balloon’s random rotation, and the sensors must find and hold to their targets as steadily as is appropriate to No. 8, March, 1963 the scientific task. But differences in requirements and Issued each March, May, July, September, and November. Second-class postage paid at Boulder, Colorado 2 SCIENTIFIC BALLOONING

techniques to meet them vary widely. Here ficiently reduced to permit coronal observa­ is a brief rundown on the projects repre­ tions to several solar radii from the sun’s sented at the conference, and on their limb. The old workhorse, the Stratoscope I stabilization systems. gondola that has been flown successfully PROJECT BALAST nine times, will carry the coronagraph aloft. A coarse sun-seeker system is used for With the planet Venus as the observation initial orientation and a set of fine photo target for the Balast (for “balloon astron­ eyes holds the platform within one minute omy”) project, Dr. John Strong, of Johns of arc. In order to minimize vibration, Hopkins University, and his associates wish single-torque motors with gear coupling to redetermine spectral absorptions by have replaced the dual-torque motors and water vapor in the planet’s atmosphere. magnetic clutches used in the Stratoscope I Planned experiments include measurements system first flown by Dr. Martin Schwarzs­ of the planet’s near-infrared spectrum, its child of Princeton University in 1957. total albedo, and its total emission. Three flights of Coronascope II from Though Dr. Strong’s target is Venus, the the NCAR Scientific Balloon Flight Station, method for tracking it begins with the sun. Palestine, Texas are planned for late sum­ “Coarse eye” photoelectric sensors stabilize mer, 1963. the platform’s orientation to the sun while a torque motor driven against a reaction POLARISCOPE wheel turns the platform. A programmed In the Polariscope project of Dr. A. M. J. offset from the sun on two axes (Beta and Gehrels of the University of Arizona, a 28- rho) points the telescope within one degree inch telescope and a polarimeter are the of the Venus sight-line, and a vidicon basic instruments used to determine the tube on the telescope axis is then electron­ polarization and scattering of radiation from ically scanned in a spiral mode until the the planets. image of Venus is detected. Upon acqui­ Target acquisition is achieved by means sition of its target, the vidicon converts to of a television camera that has a relatively an x-y scanning pattern to provide the wide viewing angle, while a second tele­ error signals that are fed back to the track­ vision tube that pictures finer details is ing drive system to stabilize the telescope used for accurate alignment. on the planet’s image. Torquing azimuth and elevation gyro­ The telescope, which has a one-degree scopes connected servomechanically to the field of view, has performed well in labora­ gondola provide the rotation. The tendency tory tests, achieving a tracking accuracy of of the gyros to drift after alignment on two seconds. However, the flight program target is overcome by fine tracking eyes has been delayed both by failure of the that feed back to the gyros. Tracking ac­ system during final ground checks to ac­ curacy of the system is expected to be on quire its Venusian target through the hazy the order of one minute of arc. daytime atmosphere, and by a series of First flight of the telescope and stabili­ balloon failures. The tracking system is zation system is scheduled for October, being “tightened up” and tougher balloons, 1963 from the canyon of the Colorado made from Schjeldahl GT-12 Mylar-and- River just below Glen Canyon Dam, Ari­ Dacron scrim, will be used for future flights. zona, CORONASCOPE II SKYTOP The plan of Dr. Gordon Newkirk, of the A north-seeking gyro provides the basic High Altitude Observatory, NCAR, for azimuthal orientation of Dr. Alvin H. How­ Coronascope II is to photograph the solar ell’s Skytop telescope platform. The 12- corona from above 100,000 feet, where inch telescope, coupled to an interferometer, atmospheric light scattering should be suf­ will be used for observations of Venus. SCIENTIFIC BALLOONING 3

Two motor-driven wheels spinning at a component that results in a precession constant 12,000 r.p.m. provide the torque. torque. The energy consumption per radian In the neutral configuration, the two spin­ of payload rotation is a modest one-eighth ning wheels have a common axis of rotation watt-second. that lies in a hinged horizontal shaft. An To prevent excessive winding of the 100- amplified signal from the north-seeking foot parachute train as the result of balloon gyro causes the hinge to bend, providing rotation, the parachute and balloon have the vertical with an angular momentum a motor-driven coupling that is kept rough­ SOME BALLOON ASTRONOMY STABILIZATION SYSTEMS Balost Coronascope II Polariscope Skytop Star Gazer Stratoscope II Principal J ohn Strong, Gordon New­ A.M.J. Gehrels, John Salisbury, J. Allen Hynek, Martin scientist Johns Hop­ kirk, High Al­ Univ. of Air Force Northwestern Schwarzschild, kins Univ. titude Obser- Arizona Cambridge Re- Univ. Princeton Univ. atory, NCAR search Labs. Stabilization James L. Robert Lee, Ernest Morri­ Alvin H. M. Winston Harold Hem- system Pritchard, HAO; son, Univ. of Howell, Markey, street, Perlan- principals Idea Lab.; ( Stratoscope Arizona Tufts Univ. M.I.T. Elmer Co. Morris I, Russell Birnbaum, Nidey, et al.) Labrascope Scientific Measurement Study of the Polarization Infrared Variation of High-resolution missions of the near- solar corona of planetary measurements, stellar scintil­ observations of infrared to several radiation 30-micron lation with planets and spectrum and solar radii band height. Feasi­ other astrono­ albedo of bility of man­ mical objects. Venus ned astronom­ ( Infrared meas­ ical flight. urements of Infrared Mars, Feb. ’63) measurements Principal Telescope Corona- 28-inch 12-inch 12-inch 36-inch scientific and infrared graph telescope and telescope and telescope (200- telescope measurements spectrometer polarimeter infrared inch focal interferometer length Casse- grain) Acquisition Sun-seeker Automatic Ground control North-seeking Manual Ground control mode with pro­ sun-seeker through tele­ gyro and pro­ through grammed off­ vision link grammed off­ television link. set to Venus. set to planet Spiral scan on vidicon. Tracking X and Y Photo eyes Gyro-stabilized Photo eyes Gyro-stabilized Photo eyes mode scan on photo eyes photo eyes vidicon. Stabilization 2 sec. 20 sec. 1 min. 6 sec. 1 min. .02 sec. accuracy (Root Mean Squared) Weight of 2,000 1,200 1,500 450 pounds 405 pounds for 6,300 pounds telescope and pounds pounds jiounds telescope and stabilization stabilization; system (4,000 pounds including two- man gondola) Number of 0 0 (6 for orig. 0 3 1 0 completed Stratoscope I flights and 3 for Co­ ronascope I ) SCIENTIFIC BALLOONING ly oriented to magnetic north by a magnetic on the ground in the Polariscope system. sensor. One flight of Star Gazer was made in Target acquisition data is programmed December, 1962. The balloon vehicle func­ onto two recording tapes, the incremental tioned completely successfully. However, signals of which are amplified and received apparently low battery voltages caused by the telescope drive motors. One of the faulty operation of the stabilization gear tapes gives the azimuth coordinate relative and the system tended to drift from its to north as a function of time and the other targets, so that many of the scientific ob­ tape does likewise for the elevation co­ jectives were not met. ordinate, the assumption being made that Two additional flights are now planned the gondola remains in the vertical. Ground for the Star Gazer system. commands can correct the program to com­ STRATOSCOPE II pensate for such conditions as a large error Dr. Martin Schwarzschild’s Stratoscope in the north-seeking gyro because of a II system has been the subject of much north-south component of balloon velocity. discussion. It is the most sophisticated sys­ The telescope beam is split, half going tem, electronically and mechanically, ever to the tracking system and half going to to be carried by a balloon. To lift it, a the interferometer. Photosensors receiving new launch system, a new dual balloon light from the split telescope beam main­ configuration, and a new balloon film tain the tracking. (Schjeldahl’s laminate of Mylar and Dacron Payload weight of the Skytop system, less scrim) were developed. ballast and parachute, is 450 pounds. Three The 36-inch telescope, designed to per­ flights of the Skytop system have been mit greatly improved nocturnal observation made to date. of planetary and stellar objects, has a reso­ STAR GAZER lution of 0.1 second, and the tracking sys­ The feasibility of manned astronomical tem is designed for an accuracy of .02 balloon flight, with the flexibility of selec­ second RMS error over a period of 5 to 10 tion of targets that manned flight provides, minutes of time. is the- central issue for the Star Gazer pro­ A mercury bearing is used for the azimuth ject of Dr. J. Allen Hynek, Northwestern axis. Coarse elevation and roll axis control University. Observations include sight test­ are provided through x-position, y-position, ing of visibility as a function of altitude, and rotation axis detectors resolved into image motion and stellar scintillation, and elevation and roll axes. Torque motors infrared photometry. drive the telescope mount in the two coarse Since the Star Gazer gondola contains axes. The fine elevation and roll axes use an excellent programmer and torque reser­ flexure bearings that are free to rotate ±5 voir in the form of a man, its stabilization degrees, eliminating the gear and other system must furnish only stable tracking, bearing noise associated with conventional with no need for acquisition capability. bearings and drives. Two single-degree-of-freedom gyros indi­ To acquire the target image, a coarse cate the angular deviation of the gondola and a fine television screen in the control relative to a reference star. The gyros are van are used by the astronomers to find a drift-corrected by a device that locks on pre-selected guide star. The fine guidance the star with photo eyes. System accuracy system consists of lenses within the tele­ is one minute of arc, and the telescope and scope which move the image for precision stabilization gear weigh 405 pounds. tracking. The image is split between the In concept the Star Gazer system is very recording camera and the four tracking similar to Polariscope with the single dif­ eyes. The eyes provide lock-on to two guide ference that the astronomer is in situ on stars to provide stabilization in two axes. Star Gazer and is at a television console In the first telescope flight, scheduled for SCIENTIFIC BALLOONING

February 1963, the fine guidance will not M. Winston Markey, Massachusetts Insti­ be used since the observations, directed by tute of Technology, for Project Star Gazer; Dr. Harold Weaver, University of Cali­ Gordon Newkirk, High Altitude Observa­ fornia, Berkeley, will be of the infrared tory, NCAR, for Project Coronascope; spectrum of the Martian atmosphere, where Russell Nidey, Kitt Peak Observatory; fine resolution is not required. Tracking ac­ James L. Pritchard of Idea Laboratory, curacy is expected to be 1 second of arc. Norfolk, Massachusetts, for Project Balast; The first flight using the complete guid­ Martin Schwarzschild, Princeton University, ance system with the hoped-for accuracy for Project Stratoscope II; of .02 second, is planned for August, 1963. Bobert M. Slavin and Charles S. Tilton, of the Geophysics Research Directorate, Air OTHER STABILIZATION SYSTEMS Force Cambridge Research Laboratories. There have been many stabilization sys­ Chairman of the conference was Vincent tems of lesser accuracy built for balloon E. Lally of NCAR. use. David Gates of the National Bureau of Standards Boulder Laboratories, and SEPTEMBER IN THE RAiN David Murcray of the University of Denver have been flying spectrophotometers with Program for Vapor sun-seeker guidance and stabilization. Ball Brothers Research Corp. has built, for Air Measurement Stems Force Cambridge Research Laboratories, From Conference several sun-seeker systems which guide in About twenty researchers, interested in azimuth only. The Hi-Altitude Instrument the measurement of ozone and water vapor Co. of Denver has built a number of medi­ with instruments carried by balloons to um accuracy sun-seeker systems for several stratospheric heights, met at NCAR in Boul­ groups. M. W. Friedlander of Washington der on November 28 to discuss their pro­ University, St. Louis, has constructed a grams and to explore the possible need for simple magnetic stabilization system for greater coordination of observations. From orientation of emulsions to discriminate be­ the exchange of views came the conclusion tween polar and equatorial angles of cosmic that ozone measurement is moving well, ray flux. The flights were made in 1962 in but that better and more coordinated water the U.S. and South Africa. vapor measurements are needed. PARTICIPANTS AND PROJECTS COORDINATED OZONE PROGRAMS Those participating in the conference Robert F. Myers and Wayne S. Hering were: of the Air Force Cambridge Research Lab­ Morris Birnbaum, Librascope Co., for Proj­ oratories outlined the 1963 U.S. Air Force ect Balast; program for an eleven-station network in Henry Demboski and Harold Glaser, Office North America to measure ozone with the of Naval Research; six - pound Regener chemiluminescent Alfred A. Goddard, Jr., Hi-Altitude Instru­ ozonesonde. Mary W. Hodge, of the U.S. ment Co. for the project of Dr. David Weather Bureau, outlined the Bureau’s Murcray, Denver University; plans for ozone measurements during the Harold Hemstreet, Perkin-Elmer Co., for IQSY (1964-1965). During the Boulder Project Stratoscope II; meeting and at a subsequent IQSY com­ Alvin H. Howell, Tufts University, for mittee meeting in Washington, tentative Project Skytop; plans were made to extend the Air Force J. Allen Hynek, Northwestern University, program through the IQSY period, and to for Project Star Gazer; integrate measurements in both the North­ Robert Lee of the High Altitude Observ­ ern and Southern Hemisphere. atory, NCAR, for Project Coronascope; The problem of ozone measurement ap­ SCIENTIFIC BALLOONING peared from these and other instrumenta­ Raymond E. McGavin and Bradford Bean, tion and measurement descriptions to be National Bureau of Standards: refrac- well in hand. Ozonesondes now in use, tometer; those developed by Regener, Brewer, Mast, Lester Machta, U.S. Weather Bureau: ni­ and Paetzold, are all light in weight and trogen trap; can be carried on conventional radiosonde Emmet Pybus, Ballistic Research Labora­ balloons. Programs for intercomparison of tories : frostpoint hygrometer; the instruments have been carried out at Norman Sissenwine and others, Meteoro­ Arosa, and at Denver; plans logical Development Laboratory, AFC­ are being laid for more such programs; and RL: nitrogen trap, molecular sieve, and coordinated observation programs are un­ alpha radiation device; der way. No major new efforts thus ap­ P. M. Kuhn, U.S. Weather Bureau: radiom­ peared to be needed. eter measurements in conjunction with VAPOR PICTURE MURKY the water vapor measurements. On the other hand, the measurement of Others who wish to participate or to be water vapor in the stratosphere presents a kept informed of plans or results are in­ much less orderly picture than does the vited to write to NCAR for additional de­ measurement of ozone. “Up-down” flights tails. of the Dinger-Mastenbrook dewpoint hy­ grometer highlight the matter. When, during these flights, the balloon was made Jean Felix Piccard to ascend and descend at high altitudes On January 28, his seventy-ninth birth­ several times per flight, it was found that day, Dr. Jean Felix Piccard, emeritus pro­ water vapor on the balloon surface had fessor of aeronautical engineering at the contaminated the instruments, resulting in , and twin brother false measurements. of the late , died at his home in Minneapolis. He was a man of VAPOR PROGRAM PLANNED broad interests, and his contributions to the From the Boulder conference, therefore, fields of chemistry and ballooning were came plans for a field program of water many and significant. vapor measurements, to be conducted in Perhaps the best known of Dr. Piccard’s September, 1963, from Palestine, Texas. At contributions to ballooning was his pioneer­ the same time, Zdenek Sekera, University ing work with for balloon fabrics. of California, Los Angeles, will conduct a His experimentation, starting in 1935, first program to measure the scattering of light with cellophane, and later with polyethyl­ by dust particles. ene, led to the widespread use of the The NCAR Balloon Development Group today as a balloon material. will arrange the September flights. To Dr. Piccard long advocated and helped minimize contamination on all flights on develop the theory and use of multi-balloon which direct measurements are made, in­ systems, clusters of balloons for which he struments will be deployed so that not less claimed advantages in efficiency over sin­ than one kilometer separates them from gle-balloon systems. With his brother, he the balloon. A tentative program will be designed the first American spherical, pres­ distributed in March to those planning to surized balloon gondola, or “space capsule,” participate, and final plans will be made by in which aeronauts can rise into the high June. statosphere. Those who have so far indicated their Still another of Dr. Piccard’s contribu­ interest in the September program, and the tions to ballooning was his development of measuring devices they will fly, are: explosive squibs for the remote handling of David M. Gates, National Bureau of Stand­ some aspects of a balloon flight. ards : spectrometer; SCIENTIFIC BALLOONING

The late Dr. Jean Piccard, with Miss Emily Frisby, photographed in June, 1962, watch­ ing a balloon launching during a meeting of the Aerostat Society of America. THE FLIGHT RECORD Balloon specifications Flight (polyethylene Float Flight Payload operation unless specified; altitude duration weight Date Location Sponsor Investigator conducted by vol. in cu. ft.) (feet) (hours) (pounds) Experiment Flight Notes 20 Oct. Holloman AFB, AFCRL A. Howell, AFCRL 104,000 36 450 Project Venus & moon New Mexico (Tufts U.) Skytop infrared meas­ urement in the 2/2-30-micron r a n g e . 5 Nov. Sioux Falls, ONR K. Anderson ( U. Raven 0.75 mil 110,000 8% 174 Cosmic ray South Dakota of Calif., Berkeley) 1 million measurements 8 Nov. Sioux Falls, N.Y.U. D. Mendell, Raven 0.75 mil 90,000 4)4 99 Cosmic ray South Dakota (N.Y.U.) 135,000 measurements 10 Nov. Sioux Falls, ONR T. Cline ( God­ Raven 0.75 mil 110,000 6« 393K Cosmic ray South Dakota dard Space Center) 3 million measurements 8 Dec. Page, Arizona NSF M. Appa-Roa, Winzen 1.25 mil 97,000 22 565 Cosmic ray Because of elec­ (U. of Rochester); 1.25 million measurement, tronics failure, O. Young (South­ transponder & contact with ern Illinois U .); telemetry test balloon was lost. E. Morrison( U. of Payload not Ariz.); E. Lich­ recovered. field (NCAR) 12 Dec. Palestine, NSF- M. Schwarzschild Vitro 80,000 14 9,100 Test flight of Due to mal­ Texas NASA- (Princeton U.) Stratoscope II function of ONR system command sys­ tem, balloon shot down by Navy fighter aircraft off Florida coast. 14 Dec. Holloman AFB, AFCRL J. A. Hynek AFCRL 0.75 mil 82,000 18 4,800 Infrared Manned flight. New Mexico (Northwestern U.) 3.2 million experiments Balloon pilot: (Schjeldahl GT-12 Capt. J. Kitting- Dacron scrim & er, Wright- Mylar laminate) Patterson AFB; observer: W. White, U.S.N. Ordnance Test Station, China Lake. Observa­ tions made through 12/z" Cassegrain telescope. THE FLIGHT RECORD (Continued)

17 Dec. Sioux Falls, NASA T. Cline (God- Raven South Dakota dard Space Center)

Dec. Holloman AFB, AFCRL A. Howell AFCRL New Mexico ( Tufts Univ.) 0.75 mil Aborted 282 Cosmic ray Leak detected, 3 million at measurements launch

1.5 mil 40,000 450 Project Venus & moon 5.27 million ( Flight Skytop infrared aborted) measurements in the 2*2-30- micron range. SCIENTIFIC BALLOONING 9

opj i2 ' wia> Role of Dust in f 2s §3 Ss =^5 -x) a) ^ Earth's Heat Balance: «g3»o c § ” ■£> o A Question Remaining g.S s To Be Answered

«D £ § Many hundreds of radiation measure­ 'sir ments made by the U.S. Weather Bureau and taken with a radiometersonde devel­ oq o1C oped at the University of Wisconsin have ol00 reinforced the possibility that dust plays an important role in the heat balance of the earth’s atmosphere. But obtaining in­ tercomparisons between radiation and dust measurements remains to be done. With the leadership of Dr. P. M. Kuhn of the ©|£jo 4JTJ

J WEATHER BALLOONS USED cc u sS &H The radiometersondes, relatively simple 3 extensions of the standard Weather Bureau radiosondes, have been flown from over 40 Qj U USWB stations as a part of some of the 0) regularly scheduled Weather Bureau radio­ 6 ° > D ' CD sonde observations. These flights have C a}O a -a g£> shown a downward flux of radiation of '■? s ^ o 8 c ^3_ _ from 40 to 60 watts per square meter, a o U.l u Htj value twice as high as the expected value, J estimating generously, for radiation from a <3 P5 c/d 0 the gases that are usually acknowledged to O' fe O £ C contribute to radiation from the night sky u PQ back to earth: ozone, water vapor, and <35i °o carbon dioxide. §0) VARIOUS TECHNIQUES LISTED X o ^ Participants discussed alternative means o o.. o2 o © c/3 cd of measuring dust or radiation with instru­ ments that are carried on balloons. Dr. Rex IXI X Wood of described a direct dust impactor he has used, and the results 10 SCIENTIFIC BALLOONING

lie has achieved. Dr. J. L. Kroening, Uni­ versity of Minnesota, discussed a technique

used to measure number density of small -G ions, with a possibility of correlation with w 3 bO Q.° dust population. Dr. Zdenek Sekera, Uni­ versity of California at Los Angeles, de­ scribed the measurements he plans of the polarization of the scattered visible radia­ tion. And Dr. Gordon Newkirk, High Alti­ i-G t/i

Those attending the discussion session ~ to ° -E -O © concluded that radiation theory is as yet O Ol c o 0 ^ 0 inadequate to support a satisfactory balloon a. > a. field program to try to answer the basic questions raised by the radiosonde meas­ : z. o urements. ■ 3 -C “O There is some hope, however, that by

1964 or 1965 a program can be organized o for systematic measurement of radiation and o its polarization, and of ozone, water vapor, and dust. The aim is to determine radiative ia 0)-a ~ properties of dust and its role in the heat c c .2! c .2 5 *= a I—I fi balance of the atmosphere. . o •a o ° 0>- m 3 O ° 5x S.u I j "o it w w .E io7^ lO "g S°. CO *u >■ g s i Credit .... © Ol O CO o ^ OlQ.R-S! W c o> And Correction D

Much as we wish the report were true CD (since in a single line of type we managed a & N to raise the payload by five tons) we must C/3 “ CD report an error in the “Upcoming Flights” £ rtU section of the November, 1962 issue of fa< O be PQ “Scientific Ballooning.” The payload of w J. Peeci’s planned air sampling flight from Minneapolis was 1,100 pounds, not 11,000 pounds.

Balloon specifications (polyethylene unless specified; Date Location Sponsor Investigator vol. in cu. ft.)

Jan. Brownwood, ONR C. Fichtel 0.75 mil Texas ( Goddard Space 2 million Flight Center)

Jan. Sioux Falls, ONR T. Cline 0.75 mil South Dakota ( Goddard Space 3 million Fight Center)

Jan. Boulder, ONR E. Ney 0.5 mil Colorado (U. of Minn.) 100,000

Feb. La Junta, NASA F. Bartmann 0.75 mil Colorado (U. of Mich.) 2 million Float Flight Payload altitude duration weight Special (feet) (hours) (pounds) Experiment Features

123.000 8 150 Sunseeker

125.000 8 400 Cosmic ray measurements

108.000 8 8 Zodiacal light 2 flights photographs

115,000 10 300 Tiros satellite ( est.) equipment UPCOMING FLIGHTS (Continued)

Feb. Palestine, NSF- M. Schwarzschild Launch balloon: 80.000 Texas ONR- (Princeton U.) 0.5 mil NASA H. Weaver (U. of 300,000 Calif., Berkeley) Main balloon: 0.35 mil 5.25 million Schjeldahl C.T-12 Dacron scrim and Mylar laminate

Feb. Holloman AFR, AFCRL J. Strong 0.5 mil 80,000 New Mexico (Johns Hopkins U.) 3.2 million

Feb. Holloman AFB, AFCRL A. Howell 1.5 mil 102,000 New Mexico ( Tufts U.) 2.9 million

Feb. Page, Arizona NCAR E. Lichfield 0.75 mil 85,000 (NCAR) 600,000 (approx.) O. Young ( South­ ern Illinois U .)

March Brownwood, NASA R. Haymes 0.75 mil 130,000 Texas 5 million

March Pt. Barrow, ONR D. Brown 0.5 mil 135,000 Alaksa ( U. of Calif.) 135,000

March Holloman AFB, AFCRL J. A. Hynek 0.75 mil 80,000 New Mexico (Northwestern U.) 3.2 million 14 10,250 Infrared obser- Stratoscope II vations of Mars

12 2,000 Near-infrared spectrum meas­ urements and albedo of Venus

8 450 Venus and moon infrared measurements in the 2/2-30- micron range

24 500 Transponder test and cosmic ray measure­ ments CETFC OONI G IN N O LO L A B SCIENTIFIC 24 150 Albedo measurements

15 25 Cosmic ray 10 flights measurements

18 4,800 Variation of Manned flight; ( approx.) stellar Capt. J. Kittinger, scintillation balloon pilot; W. with height White, observer 2 SCIENTIFIC BALLOONING

The coffer dam of the Glen Canyon Dam, Page, Arizona, was the launch area for this 1.25-million-cuhic-foot balloon on December 8. The flight tested telemetry and trans­ ponder equipment. Cosmic ray measurements also were made.

PUBLISHED BY THE NATIONAL CENTER FOR ATMOSPHERIC RESEARCH OPERATED BY THE UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH SPONSORED BY THE NATIONAL SCIENCE FOUNDATION ADDRESS REQUESTS FOR COPIES TO NCAR, BOULDER, COLORADO