Nature is strict taskmaster
Deadlines on most Hughes programs are dictated by strict military schedules or equally demanding self-imposed time limits.
But the HAC Pioneer Venus Program is facing an unbending adversary – nature.
Engineers and technicians have been working up to 24 hours a day, seven days a week, to have both the Orbiter and Multiprobe spacecraft ready for those precise moments in May and August of 1978 when the Earth and Venus are in the proper relative positions for launches to Venus.
Should they miss the brief launch windows, the next opportunity for the assault on Venus would not come until about 1980.
The latest in a series of milestones on the program came this month as the assembly of the two spacecraft was completed and several months of careful testing began, explained Steve Dorfman, program manager.
Space and Communications Group is prime contractor for the Pioneer Venus Program for the National Aeronautics and Space Administration’s Ames Research Center in Mountain View, CA.
The two spacecraft will be launched three months apart, but because of the difference in the two trajectories, both will reach Venus in December 1978, with the Orbiter scheduled to arrive five days before the Multiprobe spacecraft.
The Orbiter, to be launched in May 1978, will study the Venusian atmosphere over a 243-day period.
Its elliptical orbit will bring it to within 125 miles of the surface. Mr. Dorfman said most of the data gathering will occur when the spacecraft is closest to the planet, about an hour a day.
The Multiprobe, to be launched in August 1978, will consist of a bus, a large probe, and three small probes. The four probes will separate from the bus and enter the Venusian atmosphere, descending to the surface.
The large probe will carry out a detailed sounding of the lower Venusian atmosphere and clouds.
The small probes will make measurements at widely separated points on the planet’s surface as they descend.
The bus will make upper atmospheric measurements prior to its entry burnup.
Round-the-clock efforts to beat nature to the finish line began about three months ago.
“When we saw that our job was tougher than expected, we decided to protect our scheduled launch time by adopting a seven-day-a-week program” Mr. Dorfman said.
“The assembly of the probes proved to be an especially difficult task,” explained Mal Meredith, associate program manager.
“An entire spacecraft’s worth of electronics and scientific instruments had to be squeezed into a pressure vessel sphere 1 ½ feet in diameter, in the case of the small probe, and 2 ½ feet in diameter for the large probe,” he said.
Two manufacturing teams were formed under the direction of Manufacturing Manager Jim Mercier, with the assistance of Tom Willadsen.
The first team was supervised by Ernie Morell and worked 12 hours a day, four days a week. The second team, under the supervision of Jack Dempsey, would work the next four days, 12 hours a day, when the first team would return.
Doug Dahl and Art Zapf provided the engineering support for these two teams.
“With this intense effort, assembly schedule were maintained, enabling the spacecraft to go to the next important phase of the program – integrated system testing. The success of this operation reflected an exceptional degree of coordination among manufacturing, engineering, and quality,” Mr. Meredith said.
“The personal sacrifice of this dedicated team to help Hughes meet this unchangeable deadline has been greatly appreciated,” Mr. Dorfman said.