Three Transit-5B series satellites were launched by Thor-DSV2A Able-Star rockets with
piggyback Transit-5E series research satellites. The 5E series were launched to obtain
environmental data in the vicinity of the operational orbit of Transit satellites and used
solar power. The Transit-5Es, which reached orbit, yielded excelent data.
This series was built on Transit busses based on the Transit
5A series.
Transit-5E 3 featured following systems:
- Two oven-controlled oscillators (9 parts in 1011 and 7 parts in 1011)
- Transmitters: 54, 162, 324, and 648 MHz
- Transistor beta experiment
- Transistor leakage experiment
- Magnetic stabilization system
- Power system: Solar cells Ni-Cd batteries and DC/DC converter
- Solar charge limiter
- Automatic temperature control
- Command system: 48 possible operating modes
- Telemetry system: 35 channel reed relay commutator and 35 channel solid state commutator
- Whip and dipole antenna system
The objectives of Transit-5E 3 were:
- Evaluate the effect on the operational system of
refraction on radio signal propagation.
- Test an experimental solid-state telemetry commutator.
- Obtain flight test experience of battery-charge control
by current limiting, since charge control circuitry was
intended for use in future satellites.
Objective No. 4 was partially achieved in that charge
control design information gained aboard 5E-3 was used to
improve charge control circuitry in future navigation
satellites. However, improper charge control circuit
operation aboard 5E-3 permitted only partial realization
of Objective No. 1 and ultimately precluded attainment
of Objective No. 2. Objective No. 3 was met.
The charge control circuit malfunction demanded
continuous adjustment of satellite loads to avoid the
development of serious thermal troubles as well as to
determine the inter-relationship of the parameters which
assisted in the analysis of the problem. Because of this
continual adjustment, good four-frequency data which are
mandatory for proper ionospheric research were not obtained
over extended periods of time.
The experimental solid state commutator performed
perfectly, and was the prototype for those used in
subsequent APL satellites.
5E-3 transmissions were last received 19 July 1964.
.png)
