The astrophysics decadal survey recommended a scaled-down version of a space telescope concept called LUVOIR as the first in a line of flagship space observatories to be developed over the next few decades. (credit: NASA/GSFC)
by Jeff Foust Monday, November 29, 2021
For much of this year, the biggest puzzle for astrophysicists had nothing to do with dark matter, dark energy, or discrepancies in the value of the Hubble Constant. Instead, the question at the top of their minds was: when was Astro2020 coming out?
Astro2020 was the shorthand for the latest astrophysics decadal survey, the once-a-decade review of the state of the field and recommendations for both ground- and space-based projects to pursue to answer the top scientific questions. The final report by the decadal survey’s steering committee, once expected in late 2020 as the name suggests, had slipped to some time in 2021 because of the pandemic, which forced a shift from in-person to virtual meetings just as work on the survey was going into high gear.
The decision to pick a concept between LUVOIR and HabEx was driven by science and budgets: big enough to do meet key science objectives like characterizing exoplanets, but also small enough to fit into a reasonable cost and schedule.
The committee itself kept quiet about its work, providing little specific guidance about when to expect the final report. At a meeting of NASA’s Astrophysics Advisory Committee in October, Paul Hertz, director of the agency’s astrophysics division, presented the results of an office pool from earlier in the year predicting when the report would be released. All but two thought the report would have already been released by the mid-October meeting of that committee; those two predicted it would be released the week of Thanksgiving.
Fortunately, they and the rest of the astrophysics community did not have to wait until last week’s holiday to get their hands on the report. The document, released November 4, provided astronomers with a long-awaited roadmap for not just the next decade but arguably through the middle of the century, endorsing a set of observatories that can peer back into the distant early universe and also look for habitable worlds close to home.
While the decadal survey makes a series of recommendations for smaller missions and ground-based telescopes, what gets the most attention is its recommendation for a large strategic, or flagship, space mission. That recommendation is just that—NASA isn’t bound to accept it—yet the agency has adopted the top-ranked flagship missions of previous decadals. That includes the one picked in the previous decadal in 2010, which became the Wide-Field Infrared Survey Telescope (WFIRST), renamed by NASA to the Nancy Grace Roman Space Telescope last year.
NASA, in preparation for Astro2020, commissioned detailed studies of four proposed flagship observatories, operating from far infrared to X-ray wavelengths (see “Selecting the next great space observatory”, The Space Review, January 21, 2019.) These studies offered detailed technical, scientific, and budgetary information for the concepts, which were effectively finalists for the being the next flagship mission—although the decadal survey was not under any obligation to pick one.
And, in the end, they didn’t pick one of the four. Instead, the recommended flagship mission was something of a compromise between two of the concepts. One, the Habitable Exoplanet Observatory, or HabEx, proposed a space telescope between 3.2 and 4 meters across optimized to search for potentially habitable exoplanets. The other, the Large Ultraviolet Optical Infrared Surveyor, or LUVOIR, proposed a large space telescope between 8 and 15 meters across for use in a wide range of astrophysics, from exoplanet studies to cosmology.
What the decadal recommended was a telescope six meters across capable of observations in ultraviolet, visible, and infrared wavelengths: similar to LUVOIR but scaled down to a size between the smaller version of LUVOIR and HabEx.
The decision to pick a concept between LUVOIR and HabEx was driven by science and budgets: big enough to do meet key science objectives like characterizing exoplanets, but also small enough to fit into a reasonable cost and schedule. “We thought that six meters provides assurance of enough target planets, but it’s also a big enough gain in capability over Hubble to really enable general astrophysics,” said Robert Kennicutt, an astronomer at the University of Arizona and Texas A&M University who was one of the two co-chairs of the decadal survey committee.
“We realized that all of these are visionary ideas but they require timelines that are pan-decadal, even multi-generational,” said Harrison. “We really think a different approach needs to be taken.”
That telescope—not given a name by the decadal survey—will still be expensive and take a long time to build. The decadal’s estimates, which included independent cost and schedule analyses, projected the telescope would cost $11 billion to build, in line with the James Webb Space Telescope when accounting for inflation, and be ready for launch in the first half of the 2040s. But the original LUVOIR concept would have cost $17 billion and not be ready until the 2050s, according to those same analyses. HabEx, the decadal survey concluded, would have been cheaper but too small to meet many of those science goals.
That selection of a flagship mission was, alone, not that different than past decadal surveys. Even that compromise pick is not unprecedented, as the previous decadal’s recommendation of what would become Roman emerged from combining several concepts. What was different, though, was the realization that, after the delays and cost overruns suffered by past flagships, notably the James Webb Space Telescope, NASA needed a different approach to developing such missions.
“We realized that all of these are visionary ideas but they require timelines that are pan-decadal, even multi-generational,” said Fiona Harrison of Caltech, the other co-chair of the steering committee, referring to the four flagship concepts studied for the decadal. “We really think a different approach needs to be taken.”
What the decadal survey recommended was that the space telescope it recommended be just the first mission to emerge from a new Great Observatories Mission and Technology Maturation Program at NASA. That program would mature technologies for a series of flagship missions in a coherent fashion.
“The survey committee expects that this process will result in decreased cost and risk and enable more frequent launches of flagship missions, even if it does require significantly more upfront investment prior to a decadal recommendation regarding implementation,” the committee concluded in the report.
Specifically, it recommended that, five years after starting work on the large space telescope that was the report’s top priority, NASA begin studies of two other flagship missions, a far infrared space telescope and an X-ray observatory, at estimated costs of $3–5 billion each. Both are similar to the other two flagship mission concepts studied by NASA for this decadal survey, the Origins Space Telescope and Lynx X-ray Observatory.
Setting up studies of those future mission concepts, without committing to them, allows NASA to adapt if both technologies or science goals change, another member of the decadal survey steering committee noted. “If the progress appears to be stalled or delayed, then we can rapidly onramp another one of the compelling, exciting ideas,” said Keivan Stassun of Vanderbilt University. “We can be phasing in multiple great ideas.”
“We were tasked and encouraged by the funding agencies, including NASA, to really think big, bold, ambitious, and long-term,” Stassun said.
The idea that it takes a long time to develop flagship space telescopes is not new: the first studies of JWST, originally called the Next Generation Space Telescope, predate the launch of the Hubble Space Telescope more than three decades ago, and that spacecraft is only now about to launch. But the study’s proposal recognizes that the problems experienced by JWST and, to a lesser extent, Roman, require a different approach to managing such complex, expensive missions.
It also reflects the realization that some of the questions that astrophysics is seeking to answer can’t be easily fit into decade-long timeframes. “We were tasked and encouraged by the funding agencies, including NASA, to really think big, bold, ambitious, and long-term,” Stassun said. “We took that to mean that we should not be thinking only about that which can be accomplished in a ten-year period.”
NASA’s Hertz had, in fact, urged the decadal survey to be bold on many occasions before and during its deliberations. “I asked the decadal survey to be ambitious, and I believe they are certainly ambitious,” he said at a November 8 meeting of the Committee on Astronomy and Astrophysics of the National Academies’ Space Studies Board.
NASA is only starting to review the overall recommendations of the decadal, he said. That includes not just its analysis of flagship missions but endorsement of a new medium-class line of “probe” missions, with a cost of $1.5 billion per mission and flying once a decade. Such missions would be analogous to the New Frontiers line of planetary science missions that fall between planetary science flagships and smaller Discovery class missions.
The delay in completing the decadal means it won’t have an impact on NASA’s next budget proposal for fiscal year 2023, which is already in active development for release in early 2022. Hertz said he’ll provide some initial comment on the decadal at a town hall meeting during the American Astronomical Society meeting in early January, particularly any recommendations that can be accommodated in the fiscal year 2022 budget. A complete, formal response will come later next year after a series of town hall meetings.
Those plans will depend on budgets. The first views Congress has on the decadal, including its flagship mission plans, will come Wednesday when the House Science Committee’s space subcommittee holds a hearing on the report.
Hertz was optimistic in general about the state of NASA’s astrophysics programs, citing the impending launch of JWST and Roman passing its critical design review. “I’m really excited. This is a great time for astrophysics,” he said. Astronomers hope the decadal’s recommendations, if implemented, can make it a great few decades for the field.
Jeff Foust (jeff@thespacereview.com) is the editor and publisher of The Space Review, and a senior staff writer with SpaceNews. He also operates the Spacetoday.net web site. Views and opinions expressed in this article are those of the author alone.
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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
