It was designed for the study of the interplanetary plasma, magnetic field, energetic particles, and solar X-rays, from lunar orbit.

Four arrays containing 6144 n/p solar cells, providing an average of 70 watts power, extended from the main bus, along with two 183 cm (72 in) magnetometer booms.

[3] Part of the Interplanetary Monitoring Platform program, it was of a design similar to Explorer 33 (IMP-D / AIMP-1), which launched in 1966.

[3] Explorer 35 was launched on 19 July 1967 from the Eastern Test Range of Cape Kennedy on a Thor-Delta E1 (Thrust Augmented Delta - TAD).

It entered an initial 800 × 7,692 km (497 × 4,780 mi) altitude elliptical lunar orbit at 147° inclination after a 23-seconds retrorocket burn.

[4] Explorer 35 provided important reference data for magnetic field measurements taken on the Moon during the Apollo program.

The dielectric constant of the lunar subsurface in the scattering region below a depth of about 25 cm (9.8 in) was then determined from a profile of reflectivity values versus the angle of incidence on the Moon.

[6] Three EON type 6213 Geiger–Müller tubes (GM1, GM2, and GM3) and a silicon solid-state detector (SSD) provided measurements of solar X-rays (GM1 only, between 2 and 12 A) and charged particles in the vicinity of the Moon.

[7] This experiment consisted of a 12 cm (4.7 in) Neher-type ionization chamber and two Lionel type 205 HT Geiger–Müller tubes (GM).

GM tube 2 responded to electrons and protons above 22 and 300 keV, respectively, in an acceptance cone of 70° full-angle centered at the spacecraft spin axis.

Past this point, data analysis was more difficult as the zero level drift of the sensor parallel to the spacecraft spin axis was not readily determined.

[9] A planar multi-grid sensor programmed as a retarding potential analyzer was used to observe the intensity of the electron and ion components of the low energy plasma near the Moon.

[10] This experiment was designed to measure the ionization, momentum, speed, and direction of micrometeorites, using thin film charged detectors, induction devices, and microphones.

These measurements (integral and differential) took about 25 s. Both the sum and difference of collector currents were obtained for positive ions.

The orbit would have naturally decayed after this point, resulting in an impact on the Moon at an unknown time and location.