Posted on 08/19/2002 12:17:30 PM PDT by cogitator
NASA/APL Hoping CONTOUR Will Send a Signal
While efforts to locate the lost in space Comet Nucleus Tour (CONTOUR) spacecraft continued through the weekend, speculation has begun on what may have thrown the mission awry.
Over the last several days, a series of telescope, radar and radio checks were conducted in search of the probe.
Hope now centers on CONTOUR's built-in smarts to cycle through and broadcast over a set of onboard antennas.
That sequence -- lasting several hours -- was pre-programmed to start 96 hours after CONTOUR received its last command. That could mean ground controllers might hear from the probe as early as 4:09 a.m. Eastern Daylight Time (EDT) this morning, or as late as 10:09 p.m. EDT.
Photographic evidence
Those searching for CONTOUR were aided August 16 by the Spacewatch Project in Tucson, Arizona. Telescope imagery showed two objects along a path close to CONTOURs predicted trajectory.
Mission operators "know where to look now," said Robert Farquhar, CONTOUR mission director from the Johns Hopkins University Applied Physics Laboratory (APL).
"We arent sure that the spacecraft is completely gone, and thats what were going to be working on over the next several days," APL's Farquhar said.
APL built CONTOUR and is managing the mission for NASA. Total cost of the project is $159 million.
Using its 34-meter antennas, NASA's Deep Space Network stations are scanning the spacecraft's expected path beyond Earth's orbit, hoping to pick up radio signals from CONTOUR's transmitters.
Educated guesswork
Meanwhile, educated guesswork as to what happened to CONTOUR has begun.
One focus for troubleshooters is the CONTOUR STAR 30BP solid-propellant rocket motor and its mating to a cylinder called the Spacecraft Payload Attach Fitting (SPAF). Both the motor and the SPAF have flanges with an identical bolt hole pattern. Several dozen of these holes are aligned to mate the motor to the SPAF.
CONTOUR's mating with the STAR 30BP motor took place at the Kennedy Space Center, with the motor resting upright in its support stand. CONTOUR was then lowered onto the solid propellant engine - with great care required to align the holes in the two flanges. Once the spacecraft was resting on the motor in the support stand, bolts that join the elements were installed.
The fact that Spacewatch imaged two pieces of CONTOUR may provide an important clue, according to SPACE.com sources.
One possible scenario -- admittedly conjecture at this time -- is that the back end of the solid rocket motor blew out and the second piece is the motor nozzle/igniter assembly. The rest of the spacecraft could be relatively intact, with CONTOUR, perhaps, having been protected by the SPAF cylinder structure.
Using the STAR 30BP solid rocket motor to boost CONTOUR beyond Earth's gravity was a cost-reduction decision. Some $10 million in overall mission costs were saved in contrast to a more costly system that would have shoved the probe directly after launch into deep space.
CONTOUR is one of the econo-class -- cheaper, better, faster -- type of craft in NASA's Discovery-class line of space science missions.
Last contact with CONTOUR
After circling Earth since July 3, CONTOUR fired up its STAR 30BP solid-propellant rocket motor, with ignition programmed to occur at 4:49 a.m. EDT on Aug 15. That rocket blast would nudge the probe out of Earth parking orbit and onto a trajectory to encounter two comets over the next four years.
The craft would have been spinning at 60 revolutions per minute as the 50-second engine burn kicked CONTOUR into a solar orbit, where it would later intercept comets Encke in November 2003 and Schwassmann-Wachmann 3 in June 2006.
Clearly, the rocket motor did fire. Space surveillance radar found no traces of new debris in Earth orbit, the leftovers if, indeed, the comet-bound spacecraft had exploded.
However, mums the word from CONTOUR.
As the hours since last contact with CONTOUR now stretches into days, spacecraft managers, engineers, and scientists are increasingly worried the probe is truly lost to space.
Cost-cutting doesn't always cut costs.
I can identify with that. It's the story of my career.
Some then wonder why there seems to be a shortage of "qualified" engineers in the U.S. and they just HAVE to bring in more furriners. Who wants a sawtooth "career" like that anyway?
I think I'd prefer the three F's: "Faster, Finished, Functioning."
Thanks. I realized after I hit the POST button that is was "PICK TWO," not "PICK ONE." And the management principle holds as true as any law of physics, making it very obvious that the bean counters and squishy liberal arts types are in charge at NASA - not the engineers. Tragically wasteful.
There's nothing wrong with the "Faster, better, cheaper" paradigm per se; part of the cost of FBC is the acceptance of some failures. One should become concerned when the failure rate begins to exceed a reasonable amount -- in planetary exploration, say, greater than 20% or so.
One must remember the historical context for FBC -- in the 1980's, we had billion-dollar missions that failed (seemingly every time you turned around), not because of ill-luck as this one appears to be, but because of institutionalized incompetence (e.g., Hubble mirror flaw; the Galileo high-gain antenna). The thought was that by making missions "smaller" (focused missions with a few, carefully chosen instruments and no "Christmas tree"-ing of spacecraft with every instrument under the sun) and making them "faster" (small, lean organizations that flew missions, drawing board to data return, within ~3 years, as opposed to the decade-scale, mega-missions of the '80s), you made them "better" -- because you actually got data and science, instead of welfare for the engineering infrastructure of JPL.
FBC works. That was shown in the Clementine, Lunar Prospector, NEAR, and Pathfinder missions. Even if CONTOUR is lost, the management philosophy it was designed and built under has not been "discredited."
With NASA throwing that kind of cash at the smallest, least significant projects, it is easy to see why no one has any interest in commercial space ventures. Why would they want to deal with people trying to make money with NASA dumping truckloads of cash at the drop of a hat.
I agree with what you say above and with the rest of your post. The original reason for the title was to point out that spending just a bit more -- i.e., being a little less cheap -- might reduce the failure rate significantly. A possible failure scenario for CONTOUR fingers the solid rocket booster, and the articles indicate that the expenditure of an additional $10 million for a "direct to trajectory" launch (don't know what else to call it) might have avoided this particular failure scenario. Solid rocket boosts have blown up before - I remember a geostationary satellite released from the Space Shuttle that went boom a few years ago. The Mars Lander failure posted by another respondent also appears to be the result of spending just a bit too little to fix what turned out to be a mission-ending problem.
Funny you should mention the Galileo antenna: that failure may have been caused by the Challenger explosion and the subsequent shipping of the satellite prior to launch. The "stuck" rods of the antenna are believed to be the ones the the antenna weight rested on when the satellite was moved while waiting for a launch.
NASAS GALILEO MISSION TRIUMPHS OVER ADVERSITY
So the problem (had it been found) could have been fixed with a couple dollars' worth of lubricant.
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