Editing Explorer 2 (section)

=== Micrometeorite Detector ===
Direct measurements of [[micrometeorite]]s were made on Explorer 1 using two separate detectors: a wire grid detector and a crystal transducer. The parameters determined were the influx rates of each size interval, the impinging velocity, the composition, and the density of the micrometeorite.<ref name="Instrument2">{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1958-001A-02 |title=Experiment: Micrometeorite Detector|publisher=NASA|date=14 May 2020|access-date=14 February 2021}} {{PD-notice}}</ref>

The wire grid detector consisted of 12 cards (connected in parallel) mounted in a [[fiberglass]] supporting ring which in turn was mounted on the satellite's cylindrical surface. Each card was wound with enameled 17-micron-diameter nickel alloy wire. Two layers of wire were wound on each card to ensure that a total area of {{cvt|1|xx|1|cm}} completely covered. A micrometeorite of about 10 microns would fracture the wire upon impact, destroy the electrical connection, and thus record the event.<ref name="Instrument2"/>

The acoustic detector (transducer and solid-state amplifier) was placed in acoustical contact with the middle section skin where it could respond to meteorite impacts on the spacecraft skin such that each recorded event would be a function of mass and velocity. The effective area of this section was 0.075 m<sup>2</sup>, and the average threshold sensitivity was 0.0025 g-cm/s.<ref name="Instrument2"/>