Parts taken from Solar Max point to 'benign' space environment
Hardware that astronauts recovered from the Solar Max satellite last month has surprised experts by its apparently excellent condition. Unveiled here at the Goddard Space Flight Center, the gleaming metal and golden thermal blankets from the satellite indicate that it has been much less harshly treated by the space environment than had been expected.Skip to next paragraph
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''I think that we have destroyed a lot of old myths about obsolescence and wear-out, micrometeorite damage, (and) atomic oxygen degradation,'' says Frank J. Cepollina, project manager for satellite servicing at Goddard.
Such ''myths'' about the supposed hostility of space have been a significant uncertainty in planning orbiting factories or a permanent space station. Now, as a bonus of the Solar Maximum Mission Satellite repair operation, experts have an opportunity to see just how hostile the space environment has been to equipment that was exposed to it for 41/2 years.
Dr. Cepollina and others here point out they have yet to take the equipment apart and inspect its interior. But a superficial examination of the exterior leads Cepollina to say ''all indications are that it (space at the Solar Max 310 - to 360-mile orbital heights) is a benign environment.''
Shuttle astronauts brought back two major pieces of Solar Max hardware, which they had swapped for new units. One of these - the Attitude Control System (ACS) - failed when three small fuses blew. The other unit is the Main Electronics Box for the Coronagraph/Polarimeter - an instrument that measures ejection of material from the Sun and the effect this has on the Sun's corona, or outer atmosphere. This suffered internal degradation of some microcircuits due to contamination whose source now will be traced. These failures do not seem to be caused by the space environment itself.
National Aeronautics and Space Administration (NASA) technicians have been careful to protect the returned hardware from Earth's atmosphere and other possible sources of contamination. Both units were literally handled with white gloves when they were unpacked Wednesday and put on display in the sealed ''clean room.'' Indeed, the technicians were clothed entirely in white, with hoods over their heads and wearing face masks. NASA, again literally, doesn't even want anyone to breath on this hardware until it has been studied.
As Cepollina notes, it appears at least superficially to be in excellent condition. The golden hue of the protective Kapton blankets has dimmed in some places. But the plastic itself has generally remained intact and serviceable. It has survived better than expected.
Also, the silvery sheen of the exposed metal parts on the ACS - such as aluminum louvers on the front of the unit - look, to the eye, to be as good as new. Cepollina notes several significant features:
* ''The pristine nature of those polished aluminum louvers.
* ''The fact the none of the epoxy glue (used to attach some parts) has come apart.
* ''The fact that white paint in back has stayed integral (not flaking, powdering, or pulling away).
* ''The (stabilizing) gyros - each of which has had 7 billion revolutions - were working well when we brought them home.''
This is good news for space planners. Cepollina explains, ''If you think about commercialization of space, which is where I think we're ultimately headed as a nation, you've got to understand the environment - will it degrade your equipment? . . . And it looks to me - although we haven't done all the work (studying the returned hardware) - that what we really have is a situation where factories . . . are much healthier operating in a benign environment like space than they are operating from the ground. . . .''
Now the hardware will be opened up and inspected in detail. Some elements of it may even be used in space again.
Meanwhile, Solar Max itself is having a busy time on orbit. Chief project scientist Bruce Woodgate says that, with the new ACS, mission scientists no sooner regained the ability for precision pointing of their instruments than they had intense solar activity to study. The present sunspot cycle is in its declining phase. Nevertheless, the strongest flare activity of that cycle has erupted in recent weeks.