Redmond, WA. – Adrift in space like forgotten elders on frigid polar ice floes, most of the “Pioneers” of NASA’s glory days have performed their missions and exist only as forgotten relics of man’s obsession with “outer” space. Pioneer 6, Pioneer 7, Pioneer 8 and Pioneer 9, in patient silence, endlessly orbit the sun. Pioneer 10 and Pioneer 11 carry evidence of intelligent life beyond the solar system to whatever sentience they may someday encounter. We have lost contact with them. All of them – except one.
It was not supposed to be in touch with Earth this long. Formally dropped from NASA’s budget in 1997, 25 years after launch, its electronics having surpassed a designed life-time of 21 months, Pioneer 10, more than 7 billion miles from home, still beams a tiny signal to a handful of passionate volunteers and an 86-year-old Nobel physicist searching for the “edge” of the solar system.
In autumn of 2000 it truly looked as though last minute attempts to keep the telemetry stream alive had failed. The year before, Dr. James van Allen and NASA physicist Glen Mucklow had talked NASA brass into supporting minimal telemetry contact with Pioneer 10. This allowed Dr. van Allen to continue to receive tiny bursts of data from Pioneer 10’s Geiger tube telescope, the one instrument in outer space searching for the elusive heliopause, the point where the solar wind dies out. Temporary reprieve secured, disaster struck from another direction. NASA lost contact with the spacecraft altogether. After making contact early in August, the team tried several times between August and January with no success.
Shortly after losing those tenuous signals in late August, Pioneer 10 engineers became convinced that Earth-based commands would be required to re-establish contact with spacecraft. However, there had been problems with part of the command generating equipment at Ames Research Labs. It looked as though Dr. van Allen’s nearly 30-year quest for the edge of the solar system was doomed to end in unresolved mystery.
But the karma that had kept this remarkable product of man’s ingenuity alive for so long had not lost its mystical power. The telecommunications command and support system for the spacecraft relies on a number of obsolete computer systems. The key component, the only computer still able to issue commands to Pioneer 10, was a Digital Equipment Corp PDP-11 /44. Like an old couple holding hands on the front porch watching the sun set, the Pioneer 10 spacecraft and this PDP-11 had worked in tandem for decades, getting older and feebler, but still maintaining the vital communications link keeping Dr. van Allen’s project alive.
On December 10th, 2000, the Baltimore Sun published a short article on the Pioneer 10 project. It read like a requiem for the “doughty little spacecraft” and referred to “a cranky 30-year-old DEC PDP-11 that’s constantly on the verge of breakdown”. The article was brought to the attention of Willard West, president of Strobe Data Inc in Redmond, WA.
Confident that Strobe Data Inc, could replace any “cranky” PDP-11 with modern, reliable electronics and exactly replicate the signals Pioneer 10 was expecting from its old partner, West immediately contacted Dr. Lasher, who put him in touch with Larry Kellogg, the engineer in charge of the PDP-11. “How would you like a new PC running Windows to faithfully perform all the functions of your “cranky” PDP-11,” asked West. He told Kellogg that with Strobe’s Osprey Co-Processor card they could replace the PDP-11 and generate the Pioneer 10’s command signals immediately with no other change in the system. He added that Strobe Data would happily lend the equipment to the Pioneer 10 team for as long as they needed it.
Kellogg was grateful, but skeptical. The communications link depended upon special electronics designed only for the PDP-11. When West offered to have Strobe Data Marketing and Sales manager, Alvin Q. Morgan, fly down to Ames Research and install it the next day, Kellogg put him off. “Enjoy your Christmas vacation,” he said. “We’re going to try to establish contact in January. We’ll know better where we stand, then.”
The January 2001 attempts fizzled. Even worse, troubleshooting the spacecraft seemed an exercise in frustration. Without a functioning PDP-11, it would not be possible to make changes in Pioneer 10’s configuration to help the team pinpoint the problem. Strobe’s offer suddenly took on greater significance.
As promised, Al Morgan showed up at the Ames NASA Labs in Mountain View, CA, with an ordinary PC fitted with an Osprey card and began connecting the Osprey to racks of obsolete equipment. He turned on the power. Nothing worked.
Trouble-shooting backplanes and cable connections uncovered two dead components in a complex chain of equipment. Creative reconnecting produced signals, but more extensive communications tests would be needed to convince the Pioneer 10 team that the Osprey could carry on the mission of the dying PDP-11. Morgan returned to Strobe and crossed his fingers.
The first hurdle was overcome when the Osprey proved it could reliably communicate with the Deep Space Network, the series of world-wide stations which actually transmit signals to and from modules in outer space. The first test attempt was a disaster, however. Larry Kellogg’s comment to a DSN colleague said it all: “Was up seeing if we got any data from the last tracks and noticed a burnt smell.” You don’t have to be a rocket scientist to suspect a technical problem when the symptom is a “burnt smell”.
That “burnt smell” came from the one part of the PDP-11 still in the communications chain, its power supply. On Al Morgan’s advice, Kellogg tried a different power source and, once again, the system seemed to run. More hopeful than optimistic, Kellogg scheduled a communications test with the Deep Space Network.
Meanwhile Larry Lasher was lobbying to get DSN communications time committed for a conversation with Pioneer 10. At 7.29 billion miles, the “round-trip” communications with the spacecraft would take over 21 hours and that amount of time on network stations is increasingly difficult to come by. However, sympathetic station managers at Station 63, Madrid, promised an up-link/down-link connection in the April/May time frame.
To Kellogg’s delight, the Osprey/PC passed its preliminary communications test with the DSN. Then, finally, on May 11, Madrid targeted 200 kW of signal in Pioneer 10’s direction and the spacecraft’s karma held. Pioneer 10, with its thirty-year-old electronics gamely operating at unbelievably low temperatures, its antenna pointed in the direction of a microscopic speck in the cosmos, called home. Its tiny “beep” signaled, not only that Dr. van Allen’s data was on its way to Earth, but that it could receive and understand any future commands from the Osprey.
The 2001 data stream was interpreted and analyzed. The heliopause Dr. van Allen seeks had still not been crossed. Now the newest telemetry data is being prepared for his graduate students. Even if it appears that the heliopause is still farther out in space than the 7.4+ billion miles from earth Pioneer 10 is today, Dr. van Allen knows that Pioneer 10 is still alive to find it for him, still operating his Geiger tube telescope. And now, to add to its usefulness, scientists are observing an anomaly in its velocity which might point to galactic forces never before discovered.
The little spacecraft just doesn’t give up even though its old companion, the PDP-11, is no longer there to issue its commands. It has a new companion now, a computer like the one you use at home to talk to the Internet. The only difference between yours and NASA’s is Strobe Data’s Osprey card. To Pioneer 10, that Osprey is his old pal the PDP-11 – and no one on Earth is going to tell him it’s not!
March 2 through 4, on the 30-year anniversary of Pioneer 10’s launch, NASA successfully communicated with the spacecraft from 7.4 billion miles away and downloaded data for Nobelist James van Allen who still seeks to define the limits of the solar system.
Although the craft itself still functions marginally, the ground based command and control equipment is crumbling. In particular, the computer which formats the spacecraft commands failed fatally last year. It was feared that without the ability to direct Pioneer 10’s antennas its last precious signals would forever be lost. Strobe Data, a Redmond high tech firm, loaned NASA a modern replacement for the obsolete command computer. The few hours it took to install the PC and Strobe’s Osprey Co-Processor resulted in a system which so completely replicated the functions of the failed legacy computer that NASA engineers were able to at once obtain the vital Pioneer 10 control signals. On March 2, Strobe engineers held their breath. On March 4 they exhaled. The Osprey had performed flawlessly. Pioneer 10 heard NASA’s call – and responded.