Red Rover by Roger Wiens

Author:Roger Wiens [Wiens, Roger]
Language: eng
Format: epub
ISBN: 9780465055982
Publisher: Basic Books
Published: 2015-01-12T16:00:00+00:00

chapter

fourteen

CANCELED

THE MSL ROVER PROJECT GOT ALONG FINE FINANCIALLY FOR the first two years. Some areas grew in cost, but the program had more than enough in reserve to cover these areas. I thought the rover was doing very well for a major project of its size. Most of the large missions I had known ended up in financial trouble immediately. NASA’s usual response was to remove instruments from the payload. These removals, or descopes, could sometimes cripple the mission’s scientific return while yielding only a very small cost savings. But there are only two other options when cost runovers occur: letting the costs rise, or canceling a mission altogether. The problem is that the really big costs on every mission are the launch vehicle (the rocket), the software, and a lot of the engineering needed to make it all work. In short, the bulk of the costs are for essentials.

In the case of the MSL rover, the payload had started at $75 million out of what was then a $1.4 billion mission. If the total mission costs increased by just 7 percent, or $100 million, NASA could conceivably wipe out the whole payload—the whole reason for the mission—and still not save enough money to contain the mission to the original cost.

The $75 million figure for the payload had been inadequate from the beginning. Although all of the instruments had originally added up to $75 million, many things had to be changed on each one to meet the actual specifications of the rover. In the case of ChemCam, the wiring between the mast and the body was to be supplied by JPL. We were going to use voltage converters in the body to power the mast. However, the wires specified by JPL were so thin that the voltage would drop significantly going from the body to the mast, so we had to change our plans. Then there was the issue of the optical fibers, which was taking a lot of our resources.

On top of that, JPL was getting worried about the mass of the rover. Every subsystem seemed to be gaining weight. To hold the line, JPL announced to the payload leaders that it would pay for us to find ways to lighten our instruments. We had planned to make our spectrometers out of titanium, which was very stable thermally, to accommodate our optics. John Bernardin, our systems engineer, suggested that we build these units out of beryllium.

Beryllium is very expensive to manufacture and requires special controls because beryllium dust is a health hazard. Using beryllium for ChemCam would mean a longer time at the manufacturer, special training for team members, and a lot of restrictions on what we could do to modify the units. All of that costs money, but it would save about 2 pounds, almost cutting the weight of our body-mounted unit in half, and JPL was willing to pay several hundred thousand dollars for that. We agreed to lighten ChemCam in exchange for the increase in funding.

The various changes to our instrument added up to a couple of million dollars.

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