| Explorer 46 | |
| Names List: | Meteoroid Technology Satellite-A MTS-A |
| Mission Type: | Meteroids research |
| Operator: | NASA |
| Cospar Id: | 1972-061A |
| Satcat: | 06142 |
| Spacecraft: | Explorer XLVI |
| Spacecraft Type: | Meteoroid Technology Satellite |
| Spacecraft Bus: | MTS |
| Manufacturer: | Langley Research Center |
| Launch Date: | 13 August 1972, 15:10 UTC |
| Launch Rocket: | Scout D-1 (S-184C) |
| Launch Site: | Wallops Flight Facility, LA-3A |
| Launch Contractor: | Vought |
| Entered Service: | 13 August 1972 |
| Decay Date: | 2 November 1979 |
| Orbit Reference: | Geocentric orbit[1] |
| Orbit Regime: | Low Earth orbit |
| Orbit Inclination: | 37.70° |
| Orbit Period: | 97.80 minutes |
| Apsis: | gee |
| Instruments: | Meteoroid Penetration Meteoroid Penetration Sensors Meteoroid Velocity Sensors |
| Programme: | Explorer program |
| Previous Mission: | Explorer 45 |
| Next Mission: | Explorer 47 |
Explorer 46, (also Meteoroid Technology Satellite-A or MTS-A), was a NASA satellite launched as part of Explorer program.[2]
Explorer 46 was designed to provide data on the frequency and penetration energy of meteoroids and micrometeoroids in low Earth orbit. Explorer 46 consisted of a hexi-cylindrical bus covered with solar cells. Meteoroid impacts were detected and measured using bumper panels that extended after launch and gave the satellite a windmill-like appearance. The central hub of the satellite carried the velocity and impact experiments. When the bumper targets were extended from the satellite, it had an overall width of . Twenty meteoroid impacts were recorded by the bumper panels through December 1972. A set of capacitor detectors recorded over two thousand micrometeoroid hits over the same period.[3]
Explorer 46 was launched on 13 August 1972, at 15:10 UTC, from Wallops Flight Facility (WFF), with a Scout D-1 Launch vehicle.[4]
The objective of this experiment was to measure the meteoroid penetration rates of a bumper-protected target. Penetrations were measured, using 12 2-mil stainless-steel pressure cells located behind 1-mil stainless-steel bumpers. These 12 cells were mounted on 4 bumper panels which extended out from the cylindrical spacecraft body. Due to a malfunction, only two of the four bumper panels deployed.[5]
This experiment measured meteoroid impacts using a thin film capacitor. Due to a spacecraft malfunction, this experiment had to be turned off two weeks after launch, but it had already recorded 2000 micrometeoroid impacts by that time. It was reactivated in August 1974.[6]
This experiment measured the velocity of impacting micrometeoroids, using two thin-film capacitors and measuring the time-of-flight between them. Due to difficulties with the spacecraft, this experiment had to be turned off two weeks after launch, but it was turned on again for 1 week in August 1974.[7]
Explorer 46 reentered in the atmosphere on 2 November 1979.