One of the most easily recognized projects in the Search for Extraterrestrial Intelligence (SETI) is SETI@home, the brute-force processing of huge amounts of radio telescope data which hums away, 24 hours per day, on millions of computers around the world, putting up charts and statistics in place of screensavers and converting computer downtime for a project of the utmost importance: finding the strong, pattern-based radio transmissions which would provide the first undeniable evidence of the existence of an alien civilization among the stars.
However, as SETI@home enters its second decade of existence, there are increasing threats to its very existence. In particular, the three largest threats to the SETI@home program include the rise of alternative and equally successful distributed-computing projects, the future of its chosen research platform, the Arecibo Telescope, and, of course, the bugbear of all space research programs, funding.
- About SETI@home -
SETI had its origins in work by academic astronomers such as Frank Drake during the 1960s. Since this time, it has centered around the construction and use of large radio telescopes, operating on the assumption that alien civilizations of advanced intelligence will produce powerful radio transmissions, which we can then use to detect them and even guess their location. Whether this is sound science is as yet uncertain - the assumption that alien civilizations will follow similar technological paths to our own is anthropomorphic at best, and foolishly unimaginative at worst - but it seemed like the best option for new research, and probably still is.
Despite subsequent programs funded by NASA in the United States as well as by the communist government in the Soviet Union, SETI was clearly languishing by the 1990s, regularly cut adrift by funding review committees demanding rigorous, financially accountable research projects with tangible results rather than easily-mocked searches for "little green men." The response, by Berkeley University, was an unprecedently ambitious option: make the search a project of the people rather than of the government. The Berkeley SETI lab, with initial funding provided by the state government and private donors, developed a new program called a distributed computing network, allowing small parcels of analytical work to be handled by any computer around the world.
The result was SETI@home and a networking program called the Berkeley Open Infrastructure for Networking Computing (BOINC) program. A BOINC "client" can be downloaded by any personal or business computer; it then uses free time, usually coming on in place of a screensaver, to process a small packet of data sent by the BOINC server at Berkeley. The results are sent back once completed, and a new packet is sent out for further analysis. In the case of SETI@home, the packets consist of radio telescope data gathered by the Arecibo Telescope, which are analyzed in search of strong, patterned signals indicating extraterrestrial sources. Today, the system has over five million contributors, contributing an output of about 750-800 teraFLOPs of processing power (800 billion floating-point operations per second), effectively qualifying it as a supercomputer.
- Too Much Success? -
Ironically, it is this chief accomplishment - constructing a supercomputer out of a Web server, a networking software program, and a large amount of popular support - which is one of the greatest threats to the SETI@home program. SETI@home proved to a skeptical world that distributed computing was actually a viable project for any project in need of a massive computing budget and supported by an enthusiastic popular audience. The result is that there are now a considerable number of distributed computing projects. The Berkeley network (BOINC) remains by far the largest distributed computing network in the world; however, instead of being merely a vehicle for SETI@home, it is now home to many distributed computing projects, of which SETI@home is just one.
Now that multiple projects are going online, SETI@home in a sense returns to the position it once found itself in, competing for mindshare and material support among people who can easily mock it as a speculative search for little green men. The result is that SETI@home is still powerful, but is increasingly dwarfed by several other projects. Since its creation in 2007, Milkyway@home, an attempt to build new models of the Milky Way Galaxy, has zoomed up the charts and now pulls in twice as much computing time as SETI@home, about 1.5 petaFLOPS (1.5 trillion operations per second). By far the most powerful distributed computing project is now a protein analysis program, Folding@home. Folding@home operates at a minimum of 4.2 petaFLOPs, which makes it not only more powerful than any other distributed computing project by a wide margin, but also more powerful than any actual supercomputer ever constructed.
At the same time, to suggest that SETI@home has been a victim of its own success perhaps exaggerates the case. The original, wildly optimistic dreams of the 1990s envisioned a SETI@home program operating on tens of thousands of PCs. However, personal computers spread more quickly than anticipated, and at the same time improved in power immensely - the result being that a PC today can perform far more work in far less time than its equivalent from 1999. This means that even as SETI@home takes is place as just one of many distributed computing projects, its contributors are still capable of doing more work for the project than they were a decade ago.
- Where Will the Data Come From? -
Increased competition, then, is only one of the greatest threats to SETI@home if SETI@home begins losing that competition. Another more urgent problem is that the program will have to cease simply due to lack of data. This threat to SETI@home actually involves threats to the Arecibo Telescope itself.
The distinctive 300-metre dish of the Arecibo Observatory in Puerto Rico is the largest telescope of its kind ever built. The massive dish is large enough to be the bed of an artificial lake - and was portrayed in precisely that way in Goldeneye, the James Bond movie which portrays the dish as a secret construction of the Cuban government. The telescope has been in operation since 1963, and has made such vital contributions to astronomy as tracing the orbit of Mercury and charting the emissions of pulsars and other neutron stars. However, its most publicized role today is supplying the raw data which SETI@home then analyzes.
However, the Arecibo Observatory has been under threat over the past five years. Its budget, at about $10 million per year, is not massive, but in an age when most of its projects have been taken over by smaller and more advanced, recently built telescopes, it seems increasingly like a dinosaur - except, of course, for those projects which still rely on it, like SETI@home. Its chief patron before Congress, the National Science Foundation, has advocated slashing the budget by millions of dollars, resulting in the facility's closure. Unless private donors are located, the facility will likely be shut down within the next several years.
This would not necessarily mean the end of SETI@home. Searches for alternative data sources are in progress, such as the Parkes Observatory (which would simultaneously allow SETI@home to switch from an exclusively northern-hemisphere data source to a southern-hemisphere one, broadening the search range immensely). However, the reason SETI@home turned to distributed computing in the first place was that it did not have the funds to purchase its own supercomputer. It scarcely has the funds to purchase a massive radio telescope of its own. Without data, the program simply cannot continue.
- Where Will the Money Come From? -
Just as the Arecibo Observatory relies on dwindling public money, the SETI@home program itself relies on the continued financial support of its institutional backing (such as Berkeley) and its public supporters. And if Arecibo's budget is modest at $10 million, SETI@home's is positively puny, at about half a million dollars per year. This small budget is enough for the program to survive, but not to expand - and it could shrink further, if the economic recession or simply increasing disinterest on the part of the public lead existing private sources of money to dry up, as well.
Fortunately, this is also one of the easiest of the threats to the SETI@home program to solve, as well. Increased funding for the central office at Berkeley would allow the server there to continually send out new packets for analysis. If SETI@home runs out of money entirely, then the network would have to shut down, regardless of whether it was still holding its own in the distributed computing standings, and regardless of whether Arecibo or some other data source were maintained for the future.
It would be truly unfortunate if SETI@home were shut down for reasons as seemingly petty and minor as money. However, it would certainly not be the only space program to be shelved due to funding problems. Most of NASA's most ambitious schemes have suffered a similar fate - including, most recently, the manned Orion mission to the Moon.