UMSF space history photo of the month Options

[Guest_PhilCo126_*]

Maybe we could make this a monthly item, in which we could look back at the history of Unmanned Space missions.
For January 2008 I've chosen an image showing the coverage of the Sun by early Pioneer 5-8 spacecraft.
Pioneer 5 to 8, or Pioneer V to VIII using the system of Roman numerals in vogue during the early 1960s for spacecraft designations, were directed towards the Sun along the earth's orbit to monitor solar activity. Pioneer V was launched on 11th March 1960 and provided the very first space weather report 4 to 8 hours before a solar storm hit the Earth.
Some of this Pioneer quartet, Pioneer 6-7-8 even provided updates on our Sun's activity during the early Apollo Moon landings in order to check the damaging potential of solar flares to affect the astronauts.

[edstrick]

"...the last contact with these great travelers and why they were not heard from again."

Mariners 6 and 7 did not have any significant cruise science capability. Their entire science package were remote sensing experiments located on the spacecrat's scan platform. After Mars encounter, the primary mission concluded with sufficient tape recorder readouts via different telemetry modes etc until they were sure there was nothing more to recover from the data onboard.

So there was very little science to be done during extended missions. There was one engineering experiment done where the midcourse motor was fired and immediately afterwards, the infrared spectrometer was used to examine the spectrum of the dissapating exhaust plume. They did see spectral features, I presume related to hydrazine and ammonia (from hydrazine breakdown). They may have taken some images of black space possibly with a bright star in the camera's view in attempts to diagnoise noise problems with the analog tape recorders (there was oxide crud on the tape heads -- one reason the images are relatively cruddy). Other engineering exercises were performed on the spacecraft.

The missions ended maybe a year after Mars encounter when attitude control nitrogen gas was depleted and I presume transmitters were turned off, as was Mariner 4's. Some documentation on this was in the JPL TR series mission reports, others, on the later extended mission, in JPL reports on Deep Space Network avtivities. You may be able to find them in government document repositories in Engineering Libraries on large university campuses.



I think thwere was some s