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Sentinel orbit illuustration
The wide field of view of the proposed Sentinel spacecraft and its Venus-like orbit, illustrated above, will enable the spacecraft to discover hundreds of thousands of near Earth asteroids, provided the B612 Foundation can raise the several hundred million dollars needed to build and launch it. (credit: B612 Foundation)

A private effort to watch the skies

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Astronomers have long relied on wealthy benefactors to support their efforts. Philanthropists have donated money to support the development of observatories that allowed astronomers to look deeper into the cosmos, from the Lick Observatory in California and Yerkes Observatory in Wisconsin in the late 19th century to more contemporary examples like the Keck Observatory in Hawaii. Those funders, in turn, got those observatories named after them. The universe for astronomers, and immortality of a sort for their benefactors; a pretty good deal for both.

That philanthropic model hasn’t extended to space astronomy, though. The Space Age has coincided with a much larger role for government agencies in funding scientific research, particularly in space sciences, where early missions often had a geopolitical role that overshadowed their scientific one. It’s become the expectation of most scientists and the general public alike that space science missions are the exclusive domain of the government, especially as their costs grow into the hundreds of millions or even billions of dollars. But does that always have to be the case? One organization is trying to go back to that old philanthropic model for a mission whose ultimate goal is nothing short of saving the planet.

A Sentinel for NEOs

On Thursday, the B612 Foundation—named after the asteroid in Antoine de Saint-Exupéry’s The Little Princeannounced its plans to develop its own spacecraft, called the Sentinel Space Telescope. Its mission: to scan the inner solar system, looking for near Earth objects (NEOs), particularly those that pose an impact hazard to the Earth. Over the course of a five-and-a-half-year mission, the B612 Foundation believes that Sentinel could discover half a million NEOs, including the vast majority of the larger NEOs that could cause significant damage if they struck the Earth.

In many respects, Sentinel looks like a number of other NASA missions.

The foundation’s current plans call for launching Sentinel in 2017 or 2018 on a SpaceX Falcon 9 rocket. The spacecraft would leave Earth orbit and head towards Venus. A gravity assist there would put the spacecraft into a “Venus-like” orbit around the Sun. Once there, Sentinel will look out away from the Sun, using a 50-centimeter telescope equipped with a wide-field thermal infrared imager, scanning the skies to look for NEOs. With its orbit and wide field of view, the foundation believes that Sentinel can scan half the sky every 26 days.

In many respects, Sentinel looks like a number of other NASA missions. Ball Aerospace, the company working with the B612 Foundation on the spacecraft, has built a number of similar NASA missions. In a teleconference with reporters Thursday, Harold Reitsema, Sentinel mission director and the former director of science missions at Ball, said Sentinel incorporates some technologies used on previous NASA missions built by Ball, including a sunshade based on the one flown on the Spitzer Space Telescope and systems from the Kepler mission to enable wide field of view observations.

B612 also has support from NASA to carry out this mission. Ed Lu, the former NASA astronaut now working as chairman and CEO of the foundation, said they have a non-reimbursable Space Act Agreement with NASA to provide time on the Deep Space Network for communications with Sentinel, access to an existing “data pipeline” to process the NEO observations made by the spacecraft, and NASA experts to support the mission. Reitsema added that the Sentinel data will immediately go into NASA archives, although the B612 and NASA team will have a six-month proprietary period to use the data for scientific publications, similar to NASA missions.

The idea of an infrared space telescope devoted to NEO searches is also not a new one. A March 2007 NASA report to Congress, requested in the agency’s 2005 authorization act, examined existing and proposed systems to meet the Congressional goal of discovering 90 percent of the potentially hazardous asteroids at least 140 meters in diameter by 2020. That report concluded that existing groundbased systems could not achieve that goal, finding only 83 percent of such objects by the 2020 deadline. However, a 0.5-meter infrared telescope in a Venus-like orbit—the essential characteristics of Sentinel—could, on its own, find 89% of such objects by 2020 if flown by 2013. Coupled with groundbased systems, the report concluded it could meet the 2020 deadline set by Congress.

A related report by the National Research Council in 2010, requested by Congress in NASA’s 2008 authorization legislation, also mentions a 0.5-meter infrared space telescope in a Venus-trailing orbit, proposed by Ball Aerospace. This “NEO Survey” telescope could, in conjunction with groundbased systems, detect 90 percent of NEOs at least 140 meters in diameter in less than five years. The NRC report did not pass specific judgment on this mission concept, but concluded that a spacebased telescope was the better approach if the goal was to complete the survey as close to possible to the 2020 deadline. (If saving money was the preference, the report recommended a less expensive groundbased telescope, although that would push completion of the survey out to as late as 2030.)


While Sentinel may not involve new technologies or even be a new concept, it does break ground in one essential way: how it will be funded. The B612 Foundation plans to seek donors to pay for the cost of the mission. “What we are planning to do as a nonprofit organization is to raise the money philanthropically,” said Lu. “What we want to do is something very similar to what museums, performing art centers, art museums, and academic buildings do worldwide. They raise their money philanthropically.”

“I feel like we’re breaking no new ground in the philanthropy region,” said Lu. “I feel like what we’re doing that’s new and innovative is the space mission aspect of this.”

Lu, though, was reticent to share specifics about how they planned to raise the money, or even how much money they were looking for. The spacecraft itself would cost a few hundred million, he said, with the launch and operations also cost a few hundred million. (The NRC report stated the Ball “NEO Survey” mission had a price tag of $600 million, based on a presentation Reitsema gave the committee in 2009.) “I believe that all of this is going to come in significantly less than the building we’re sitting in right now,” he said, referring to the California Academy of Sciences museum in San Francisco, whose current facility opened in 2008 at a cost of $500 million.

“We can’t say too much about the funding, because things are in negotiations right now,” Lu said about ongoing fundraising efforts. He said the foundation didn’t expect to raise all the money in one lump sum, but instead as a “phased project” with milestones and fundraising goals tied to them. “It’s the same with every other philanthropic project,” he said. “I feel like we’re breaking no new ground in the philanthropy region. I feel like what we’re doing that’s new and innovative is the space mission aspect of this.”

He did suggest that they would try to seek a broad base of donors from around the world. All major funding raising projects, he said, “have a mix of donors, from small to large. We want to be as inclusive as possible. We want as many people as possible feeling like they have some ownership of this mission.”

Unlike Planetary Resources, which announced its plans in April to develop its own small spacecraft to study and eventually extract resources from NEOs (see “Planetary Resources believes asteroid mining has come of age”, The Space Review, April 30, 2012), there’s no profit motive for the B612 Foundation. (In a FAQ on the B612 website, the foundation says they have no connection with Planetary Resources but that they “know them and support the work they are trying to do.”) Instead, their goal to map out the population of NEOs is driven by a desire to identify those objects that, years or decades or even centuries into the future, could pose a risk to the Earth. “I think it would be, as Neil deGrasse Tyson says, embarrassing were we to be struck by a major asteroid in the next few decades simply because we didn’t do anything about it,” Lu said.

“Today, I think we see that we’re at a tipping point, a real convergence of a number of activities that make possible private, commercial, adventurous missions with lower cost and at a faster pace than through government efforts,” said Hubbard.

But if the goal of this is effectively to support planetary defense, isn’t that a role for the government, not a private foundation? “Federal budgets are constrained very severely right now, not just in the United States but almost worldwide,” said former astronaut Rusty Schweickart, the chairman emeritus of the B612 Foundation. Those constrained budgets make it difficult for agencies like NASA to take on new initiatives like this. “We felt this was a far more expeditious as well as a more economical way to realize this goal. If we can do it, why not?”

Taking on the Sentinel mission does reflect a change in direction for the B612 Foundation, which Schweickart co-founded a decade ago. The foundation had originally shown an interest in studying asteroid deflection techniques, including a concept called the “gravity tractor,” and had focused its concerns on the asteroid Apophis, which has a small but non-zero chance of colliding with the Earth in 2036 (see “The three D’s of planetary defense”, The Space Review, March 19, 2007).

Those priorities changed in the last year, Schweickart said. “We concluded that the current priority needs to go towards finding the 99 percent of these asteroids that we know statistically are out there but have not yet been discovered, and frankly, we’re reaching the limit of the existing telescopic systems can find,” he said. That conclusion led them to decide to take on the Sentinel mission.

Lessons from history and the ATA

Also driving the B612 Foundation’s decision to do the Sentinel mission is the growing capabilities of the private sector, such as lower-cost launch options offered by SpaceX. “Today, I think we see that we’re at a tipping point, a real convergence of a number of activities that make possible private, commercial, adventurous missions with lower cost and at a faster pace than through government efforts,” said Scott Hubbard, a Stanford University professor and former director of NASA’s Ames Research Center who is serving as the program architect for Sentinel.

While Sentinel may be a first-of-its-kind mission (they claim it will be the first privately-funded deep-space mission, although that may depend on whether they can beat the first Planetary Resources missions to NEOs), it does have some terrestrial analogues. One of the closest may be the Allen Telescope Array (ATA), a radio telescope in northern California operated by the SETI Institute. As with Sentinel, the ATA relied on philanthropic funding for its development (it’s named after Microsoft co-founder Paul Allen, who provided an early large donation for the project) with a decidedly non-profit, big-picture goal: to search for any signals of intelligent extraterrestrial origin.

The ATA’s travails suggest that the B612 Foundation may have a steep path ahead of them with Sentinel. The ATA was designed for 350 small dishes, but currently has only 42. “Paul [Allen] was brave enough to fund the technology development of this new type of instrument and the first phase of construction,” Jill Tarter, who directs the institute’s SETI programs, said during a panel session about the ATA at the SETIcon II conference in Santa Clara, California, on June 24. Other donors, though, have been harder to come by, which is why the ATA remains at a fraction of its intended size.

MacDonald cited a quote attributed to Lick in the 1870s: “At some point, it’s going to be as common for interorbital travel as it is to walk down Market Street.”

Tarter said they have had success with smaller fundraising drives, including one that raised over $200,000 last year to revive the ATA when a loss of support from the University of California Berkeley put the telescope into “hibernation” earlier that year. However, she said the institute was still struggling to find the right approach to raise money to both operate the telescope and to upgrade and expand it. “We haven’t yet found the right business model, the right vehicle, maybe even the right game to turn that into sustained funding,” she said.

Private and philanthropic efforts like the B612’s Sentinel and the SETI Institute’s ATA may represent a shift back to the old ways of doing space science. In a panel session about space commercialization on Capitol Hill in Washington last month, organized by the American Historical Association, Alex MacDonald of NASA Ames (speaking only for himself) said that the dominant narrative of space exploration is one that starts in the late 1950s, with government agencies leading such efforts. However, he suggested that the perception of governments leading space exploration is altered when you go further back into history, taking into account activities like the private funding of observatories and the Guggenheim Foundation’s financial support of early rocketry by Robert Goddard.

“If you think of American space history within that broader historical context—what we can think of as a long Space Age—then a very different narrative emerges,” he said, one where the private sector, not the government, has been the driving force. “It is a long-running and enduring trend that is now reasserting itself in the post-Cold War environment.”

So it may be that it will be a 21st century equivalent of a James Lick or a Charles Tyson Yerkes who will step forward to fund Sentinel, although finding such a benefactor may be more challenging than any technical aspect of the proposed mission. If Lick were alive today, though, he might be just the person to support such a mission. Lick, MacDonald said, was motivated to donate a significant fraction of his wealth to the construction of Lick Observatory because of his desire for a legacy. There was, though, something more to it as well, MacDonald said, citing a quote attributed to Lick in the 1870s: “At some point, it’s going to be as common for interorbital travel as it is to walk down Market Street.”