Agency: Naval Research Laboratory
    Time: 1123 MST
    Altitude: 101 miles

UPPER AIR INSTRUMENTS

    Cosmic radiation: Two geiger counter telescopes (NRL)
    Pressure-temperature: Ram pressure gage installed at nose tip. Nose cone pressure gages
        at base of nose section. Tail section pressure gages ahead of fins. Skin temperature
        gages on nose cone (NRL)
    Solar radiation: Solar spectrograph (NRL)
    Ionosphere: C. W. propagation transmitter (NRL)
    Biological: Selected seeds (Harvard)

DATA RECOVERY INSTRUMENTS

    Telemeter: AN/DKT-1, 23 channel pulse sequential system
    Airborne recorder: NRL 20 channel neon lamp camera recorder
    Physical recovery: Separation of forward portion of rocket with TNT and separation of tail
        section with Prima-cord.

BALLISTIC INSTRUMENTS

    Firing Range
        Theodolites: Mitchell, C & E Stations; Askania C, F, G, N, O, & P Stations
        Cameras: Ballistic, D & R Stations; Bowen-Knapp, U, V, & W Stations
        Tracking telescopes: C Station
        Doppler: B, F, G, & K Stations
        Radar: Two modified SCR-584 S-band radars

    Airborne
        Doppler: DOVAP transceiver
        Radio Cutoff: AN/ARW-17, 3-channel command fuel cutoff, 2-channel command blowup
        Beacon: APN-55
        Other: Roll photocells: 3 photocells at 120 intervals
        Gyro: Roll gyroscope
        Vibration: Three vibration pickups, one along the longitudinal axis and the remaining two
            along he pitch and yaw axis, respectively

ROCKET PERFORMANCE

    Firing angle: 0°
    Program angle: 7° from vertical
    Time to burnout: 63.0 sec.
    Altitude at burnout: 18.5 miles
    Velocity at burnout: 5120 ft. per sec.
    Time to zenith: 220 sec.
    Altitude at zenith: 101 miles
    Time to blowoff: 327-330 sec. Breakup at 406 sec
    Altitude at blowoff: Breakup of rocket at 28 miles
    Flight duration:
    Impact Coordinates: 36 miles north and 1.8 miles east
    Payload weight: 2365 lb
    Unfueled rocket weight: 9180 lb
    Unfueled rocket C. G.:
    Gross weight at takeoff: 28,030 lb

BALLISTIC DATA

    Theodolites: Mitchell, Trajectory 0 to 54.38 sec; Askania, Trajectory 0 to 79.75 sec (Data from
        30.75 computed from one instrument only)
    Cameras: No data
    Tracking telescope: No data
    Doppler: No data
    Radar: No data
    Roll photocells: Roll 0 to 406 sec
    Gyroscope: Roll 0 to 406 sec
    Vibration: Vibration in the plane normal to the rocket's main axis was too small to be
        measured by this installation. Vibrations along the principal rocket axis were recorded
        between 42 and 57 cycles. The peak vibrational velocities ranged between 1.06 and 1.82
        in. per sec. The vibration was not continuous in character, and it seems that it was in the
        nature of shocks originating with the propulsion unit. The upper limit at which vibration
        could be observed was limited by sampling character of the telemeter.

DATA RECOVERY

    Telemeter: Good record to 225 sec and sporadic signals from this time onward
    Recorder: A complete record of the flight was obtained and this data used in preference to the
        telemeter record.
    Physical recovery: All recovery items were returned in good condition, despite the fact that
        the rocket did not break up until it was well within the atmosphere. The items were widely
        scattered in the White Sands region, some of which were recovered only after several days
        of search. The material did deteriorate somewhat from this exposure.

EXPERIMENTAL DATA

        Considerable showers of nonelectronic origin were noted. Of 887 events recorded in flight,
    275 of them were not associated with showers. Of these (above the atmosphere) 25% were
    absorbed in 6 cm of lead, assumed to be nonprimary electrons; 59% penetrated 12 cm of lead;
    the remaining 16% were absorbed in 16 cm of lead. The ratio of total radiation to that of free
    space at sea level was 11.5. The ratio of the hard component to that of free space at sea level
    was 9.0.
        Pressure-temperature: Pressures were measured and temperatures calculated to an altitude
    of 70 km. The temperatures began to lag behind the NACA estimated mean temperatures at 40 km.
    At 55 km the temperatures were different by 30°; at 70 km the calculated temperatures were 50°
    lower than estimated. The estimated accuracies are within plus or minus 10°. Skin-temperature
    rise on the 1/16-in. aluminum nose section was 100°C. Ambient pressures measured on the tail
    section from ground level to 180 km were rather close to the predicted value, the figures com-
    paring with experimental error.
        Solar radiation: The spectra showed 12 lines of Si I of great intensity. A strong line of C I
    was found at 2478A. Other lines were identified as definite V I, V II, Cr II, Mn II, Co I, and
    A1 II; probable Na I, Ni I, Ni II, Cr I, Co II, Be I, and A1 I; possible, Pi I and Cu I. There appears
    to be regions of general absorption between 2886 and 2893 A and between 2442 and 2473 A.
        Ionosphere-Propagation Experiment: The measurements give evidence as to the presence of a
    D-layer as a sharp drop in signal level at the critical frequency was noticed above 60 kilometers.
    This altitude is in general agreement with the previous estimates of the location of the D-layer.
        Biological: Ten plants were grown from the recovered see. Eight were normal and two
    showed pollen sterility approaching 50%. There is some suggestion that a lethal mutation had
    been induced; however, both the slightly reduced germination and increased sterility of these two
    plants could have been caused by exposure to high temperature.

COMMENTS

        Rocket performance: The flight appeared to be quite normal. The impact was three degrees
    east of predicted azimuth. The performance of the power plant was quite satisfactory, although
    it was slightly below predicted performance. The rocket attained a roll period of approximately
    40 sec and did not exhibit an unusual amount of yaw after burnout
        Experiments: All of the experiments performed quite well. Perhaps, the vibration experiment
    should have been provided for better data recovery. The information from this experiment should
    only be used as a guide as it is possible that considerable vibration exists at higher frequencies.

REPORTS AND PAPERS

    Project Directive, NRL Serial S78-1(119)(1320), 1320-492/46, dated Oct. 29, 1946
    WSPG Preliminary Report, EBDetchmendy/1s/164, dated March 11, 1947
    Trajectory of A-4, Round Number 21, based on Mitchell phototheodolite observations prepared
        by Missile Ballistics Branch, BRL, APG
    Trajectory of A-4, Round Number 21, Graphical and Numerical Data, based on Askania photo-
        theodolite observations, prepared by Missile Ballistics Branch, BRL, APG
    Meteorological Measurements for march 7, 1947 WSPG Air-Weather Section
    "Pressures and Temperatures of the Atmosphere to 120 Kilometers" by N. Best, R. Havens, and
        H. Lagow, Phys. Rev., 71; 915-6, June 5, 1947
    "Further Cosmic Ray Experiments above the Atmosphere" by E. H. Krause and S. Golian,
        The Phys. Rev., 71: 918, June 15, 1947
    "Upper Atmospheric Research Report No. IV," by H. E. Newell, Jr. and J. W. Siry, Eds., NRL
        Report R 3171, Naval Research Laboratory, October 1947
    "Photography from the V-2 at Altitudes Ranging up to 160 Kilometers," by T. A. Bergstralh,
        NRL Report No. R-3083, Naval Research Laboratory, April 1947