CASA History


The Center for Astrophysics and Space Astronomy (CASA) was formed in 1985, as a breakaway from the Laboratory for Atmospheric and Space Physics (LASP). LASP itself was (and is) affiliated with the Astrophysics and Planetary Science (APS) department.

APS (in another name; see below) was formed it in 1960 by people in the High Altitude Observatory (HAO), founded in 1945. Walter Orr Roberts, founder of HAO, came here from Harvard to study the solar corona from a high mountain, which are common here (this is near Leadville). Walt was a science expert in atmospheric, geological, and astronomical sciences. He started a department here at CU in 1960, which combined all the three sciences (plus plasma physics, to study the solar corona and Earth’s high atmosphere): the Astro-Geophysics Department (A-G). Also in 1960, the National Center for Atmospheric research (NCAR) was placed in Boulder, and HAO became part of NCAR. Roberts was the first director of NCAR.

HAO built its own instruments, and needed some place other that its mountain observatory to make them, and settled on the CU campus in 1946, where a new building was placed near the law school. The HAO astronomy library was said to be the best between Chicago and the west coast. Now the former HOA building is occupied by the Speech and Hearing department and clinic, and the library, which is almost irrelevant nowadays, went to the new (at the time) HAO building by the Diagonal highway.

Other science institutes and companies came to Boulder, largely because CU was already here. They include the Joint Institute for Laboratory Astrophysics (JILA) in 1962; the National Oceanic and Atmospheric Administration (NOAA) in 1970; the National Bureau of Standards (1942) re-named (in 1988) to the National Institute of Standards and Technology (NIST); Ball Aerospace company (which was formed by engineers from LASP), Southwest Research Institute (SwRI), and the Space Science Institute (SSI).

The CU astronomers were historically split into two departments: A-G and Physics and Astrophysics. In the late 1970s the astronomers switched to A-G and later the plasma faculty went to the Physics department, which had dropped Astrophysics from its name. After that the astronomers were in the same department, the name of the department became Astrophysics and Planetary Sciences (APS).

In the 1950’s LASP became a world leader in rocket instrumentation to support the sciences and the commercial abilities were spun off into Ball Brothers. The space research efforts concentrated on the Sun, the upper atmosphere, and the planets. In 1965 Charles Barth became director of LASP and further developed CU’s space capabilities.

The D-Wing of Duane was built for LASP, funded by NASA (those were days!). In the late 1970’s CU decided to develop a space astronomy program housed in LASP to supplement the theoretical and observational strengths housed in JILA. Ted Snow was the first hire of this initiative. Prof Barth served as director until 1992; upon his retirement he was replaced by Dan Baker who still serves today.

Ted Snow January, 2016

CASA history

Ted Snow was hired in the physics department and LASP 1977, partly to help write a proposal to house the Hubble Space Telescope Institute at CU. The proposal failed but LASP rocket research entered the fields of stars and galaxies. Over the years from 1977 to 1985 Snow and others, including Mike Shull, Webster Cash, Tom Ayres, Jeff Linsky, Dick McCray, and John Stocke, found that their research interests were incompatible with the other LASP sciences and governance.

The formation of CASA was not easy. This involved several people, not always in favor. Barth had doubts, as well as the dean of the Graduate School, Bruce Ekstrand, who was succeeded midway by Bob Sievers, who thought another astronomy center was not needed, despite their disparate interests. By 1984 things were coming to a head when the CU Space Initiative, organized by CU President Arnold Weber, in an effort to get CU more recognized in the space-research world, was created. The director of the Initiative was Don Hearth, retired director of two NASA centers: Goddard and then Langley. Don was clearly The Man to advise CU on the Space Initiative. Without Don, no CASA.

The question of CASA as an Institute or a Center came up. An Institute, by CU definition, had to have two or more departments involved, but a Center could have one research field. An Institute director reports to the Dean of the Graduate School, while a Center exists within a department in Arts & Science. Our center in APAS, CASA, is headed by a director who is elected voted by its Fellows every three years, as opposed a director who is appointed by the Dean of the Graduate School for life. LASP is an institute, having members from astronomy, planetary geology, space engineering, and even biology. Clearly CASA should be a center, and it is.

The first director of CASA was Dick McCray (who could be thought of as the Secretary of State), while Snow (the Interior Secretary?) handled the more domestic chores.. After one year McCray stepped down and Snow was elected to be the director of CASA. McCray had headed up negotiations with the CU with the administration while Snow, with others, oversaw the set-up of CASA: The design of the third floor of the C- wing on Duane/JILA building; established a CASA office; assigning people to offices, etc. After about a year when the dust had settled, more or less, things ran of sort smoothly, with hiccups now and then.

One of McCray’s chores was diplomatically deciding where the indirect costs that come with every proposal would be distributed among CASA, LASP, JILA, and the APS department. Of course no one plan would do: CASA decided on a percentage of a proposal budget; JILA wanted to decide on case-by-case basis; and LASP would give a set amount, not any kind of a percentage.

Science of the first CASA Fellows

At the time CASA was founded in 1985, McCray’s research was primarily in the areas of interstellar gas dynamics (e.g., the influence of stars and supernovae on the interstellar gas) and binary X-ray sources. Then, when Supernova 1987A was discovered on February 23, 1987, McCray was one of the first to predict its evolution, and he has continued to study SN1987A to this day, both through observatories such as Hubble, Chandra, and ALMA and through theoretical modeling.

Linsky and Ayres analyze data from space-based telescopes, including IUE in the 1970’s to the 1990’s, and HST after that; mainly cool stars’ atmospheres, and

primarily UV spectra, although with some imaging. Both have used a variety of X-ray telescopes in orbit, starting with HEAO-I and the Einstein Observatory in the 1980’s, then ROSAT in the 1990’s, and more recently Chandra and XMM-Newton since 2000. The spacecraft work also extended to FUSE, Galex, and Kepler during the 2000 timeframe. In addition, Ayres has carried out a long-term program of observational and theoretical modeling of the CO molecule in the solar atmosphere, and the atmospheres of other late-type stars as well.

Snow’s interests when he came to CU were in hot star atmospheric winds and interstellar gas and dust, and the interaction between the two. Much of information about these two subjects lies in UV spectra, so Snow has been involved in rocket and satellite research, from Copernicus, the IUE, FUSE, and the HST. When hot star winds went from observations to theory research, he emphasized ISM studies. He has special interest in the interstellar diffuse bands (DIBs), which contain most of the organic material in the interstellar medium

Starting the 1990s, Snow, with Veronica Bierbaum in Chemistry, has been involved in a lab program, aimed to finding reaction rates on candidate molecules for the DIBs and other ISM molecules.

Shull’s research interests extend to quasars, supernova remnants, galaxy formation, intergalactic medium, high-redshift galaxies

Extragalactic X-ray sources, including QSOs, BL Lac objects, and clusters with and without cooling flows, were Stocke's specialties, then. Now he has changed his focus to use HST, FUSE, and specifically HST + COS (described below) to study the local Ly alpha forest absorbers that are due to clouds either ejected from galaxies or accreting onto galaxies.

Also Stocke has been teaching and given public talks on ancient and indigenous knowledge of the skies including Native American, Polynesian, Incan, ancient Greek, and aboriginal Australian.

Where the money came from

The start-up funding was based on two fairly big NASA grants, and as well as few smaller grants from NASA and NSF grants. At the time, the CASA bank had about $600k per annum in the budget.

Regional Data Astronomical Facility (RDAF)

The International Ultraviolet Explorer (IUE), the second satellite devoted to high- resolution UV spectroscopy, was launched in 1978 (the first was Copernicus, 1972 to 1981). IUE was supported by a combination of NASA and the European Space Agency (ESA) funds, with NASA paying most of the cost and two-thirds of the observing time.

At that time, people had actually go some place get their data and reduce them to into a useful form. Initially the Goddard Space Center (GFSC) was the only some place do to this. We in CASA made the case for another data center, far from Goddard, to reduce travel time and cost. We won, and Regional Data Astronomical Facility (RDAF) was the result. The RDAF was placed on the third floor, the C-wing of Duane, acquired when CASA was formed. We had a stand-alone computer (a DEC-8), later replaced by two MicroVAXs, one funded by NASA/IUE, other provided by the Dean of Graduate

School, Eskstrand. We designed space for these computers, which took up a whole room (now that room houses our printers and network servers). Visitors who came to analyze data had desks in the room next the computers, now occupied by our kitchen and conference room. The CASA library, where our journals (in print!), was in that room with the visitors.

By the time we got the funding for the RDAF, CASA had expanded and Ed Brugel, a new member of CASA, was appointed to direct the RDAF.

The RDAF never really got going because by that time astronomers had learned to analyze their spectra by themselves, and the RDAF was obsolete at birth. And moreover IUE researchers could get their data directly from Goddard, on magnetic tapes (this was before the internet was readily available).

But we in CASA benefited from having the RDAF here. We could gather our resources to reduce data and write scientific programs to help everybody; people outside of Boulder had to do everything at their institutes, by themselves. CASA grad students were involved from the start, and a few of them wrote their theses based on IUE data.

Apart from the IUE, CASA was involved in creating an internet astronomy library for astronomical research papers, accessible to anybody. NASA let out two grants to develop this; one was here, headed by Brugel, and the other at the Harvard Smithsonian Observatory (SAO) in Cambridge, Massachusetts. The SAO proposal was deemed to be superior, and the CASA grant was not funded after three years. Now the Astrophysics Data System (ADS), housed at the SAO, is an essential part of astronomical research.

The CASA rocket programs

The other major grants we had when CASA was formed were two sounding rocket programs. These programs, one UV and one x-ray rocket, were started when we were in LASP, before CASA formed. Snow was the PI in the UV program from 1978 until Cash took it over in 1985, when CASA was created. That grant stayed alive until 2004 with a succession of PIs: Snow, Bill McClintock (who stayed in LASP), Cash, Green, Erik Wilkinson, then Green again, until 2004. In 2006 Green started a new rocket program, and in 2009 Matt Beasley took it over. Beasley was PI until he left CU in 2012, when Kevin France, now in LASP, is the PI.

Most of the launches were made to study interstellar medium, because almost of the important absorption lines in are at UV wavelengths. For instance, both atomic and molecules of hydrogen, along with CO, have spectra below 1500Å, and some highly ionized species (e.g., O VI, N V, and Si IV) live there as well.

When supernova SN1987A occurred, CASA astronomers and others convinced NASA to work with the Australian counterpart to fund a rocket and balloon expedition to the Outback, at place called Woomera (spear chucker, in the Aboriginal language). CASA had three expeditions, the first two headed by Cash as PI, and the third by Jim d, to study RCM 136, a dense cluster in the Large Magellanic Cloud.

While still in LASP, Cash had started a suborbital program in X-ray Astronomy. Initially, in 1979 he started with a collaboration to provide grazing incidence reflection gratings to the Lockheed Palo Alto Research Lab for their large collecting area sounding rocket program. The goal was the first high-resolution spectroscopy of celestial x-ray sources. The gratings didn’t fly until about 1990 when the Aries only made it to 25,000 feet before exploding and destroying the payload. In 1984, while still in LASP, Cash won

one of six Spartans – astronomy payloads to be launched inexpensively on the shuttle (of course that never happened). Cash carried his grant over to CASA.

Subsequently, the Spartan program was cancelled after Challenger, and Cash’s Spartan was redesigned for Black Brant launches. The program has continued until this day. In 2012 the PI-ship was transferred to Randy McEntaffer (former student of Cash) who was, by then, an Assistant Professor at the University of Iowa.


Two big, expensive projects allowed CASA to go from small center within a CU department, to a prominent, nationally recognized center in space astronomy. They were the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Cosmic Origins Spectrograph (COS). At this writing, both missions are described elsewhere on the CASA web site.

The science goal of FUSE was to make observations below Lyman-alpha where highly ionized elements (e.g., O IV, N V and Si IV) and molecules, especially H2, which all has of its absorptions bands below Ly-α.

FUSE was selected in response to a NASA MOU seeking proposal for new Explorer astronomy missions. At first Al Boggess at the GFSC was the PI, but the expense went over the Explorer limit, FUSE was canceled. A few post-docs and grad students in CASA lost their jobs.

The FUSE mission was revived when NASA allowed the PI to be outside NASA. Warren Moos at the Johns Hopkins was now the PI, and the Co-Is came from CASA, Berkeley, Canadian Space Agency, and the Centre National d'Etudes Spatiales (CNES; the French Space Agency). Green here was CASA’s Co-I. CNES provided the gratings, Berkeley built the detectors, and CASA, with Ball, built and tested the spectrograph (that’s when the “big tank” was built and put the large room at our the Campus East building). Now the mission was under the Explorer limit. FUSE was launched 1999 and observed successfully until 2007 when the reaction wheel failed, the last way to stabilize the pointing.

The Cosmic Origins Spectrograph (COS) was installed on the HST in 2009, on the Shuttle mission 4 (SM4). It had been schedule to be launched in 2004, but it was delayed after the Shuttle Columbia tragedy.

The COS is much more sensitive; about 20 times more the STIS at some wavelengths. It can observe many more faint objects, such as QSOs, faint stars, galaxies, comets, and more. More than 100 journal papers have been published with COS data.

The science team has a few CU/CASA members: Green (PI), Cindy Froning, Steve Osterman, Shull, Stocke, Linsky, and Snow. Other Boulder members are at SwRI were Alan Stern and John Spencer, and Dennis Ebbets at Ball. Boulder dominated COS.

CASA facilities and locations

At first CASA was given space on the third floor C-wing of Duane, former JILA/Physics laboratories, now converted to offices – very weird offices. There were four large lab rooms, with sinks and water spigots on the walls, and a business office by the freight elevator. Now the former the labs have been separated by thin walls and the faucets and sinks are gone. Grad students had desks in front of the faculty offices, in

kind of entryways to the offices behind. (There was a joke saying two or three of the students could have offices in the freight elevator, which is larger than their cubbyholes.)

To give CASA the space that was promised, there were a couple of offices in the D-Wing, right next to the C-Wing. Also, we had a few offices in the Duane tower and eventually, in the Stadium as well.

When CASA was formed we had to have start a lab capable of supporting suborbital hardware. Cash took over the UV rocket in 1985 and temporarily unified it with the Spartan program, to make the most effective use of the financial resources. By early 1987 we had a functional lab operating in the Nuclear Physics Lab’s (NPL) in an old accelerator control room.

That lab supported the needs for some time, but when we got more hardware grants we needed more lab space; we outgrew NPL. FUSE paved the way. CASA was heavily involved, taking of parts of the design, fabrication, calibration, and testing. The CU administration had promised space to do this, if we got the FUSE contract, which we did. Cash and Snow found the CU Facilities Department storehouse and shop on the East Campus, which was perfect for our needs. It had several wood and metal shops, and a very large room storage room, with a very high ceiling and only a few columns to interfere with CASA experiments and fabrication of rockets, and later, orbiting space instruments.

By chance, the Facilities department had already decided to move a new building elsewhere on the East Campus, and CASA got the former Facilities building and called it the Astrophysical Research Laboratory (ARL). Later, in 1997, when CASA (with Ball) had the contract to built and test the Cosmic Origins Spectrograph (COS), the building was expanded to house the new people who came here to work on COS.

In the meantime, CASA, along with Physics and the new Atmospheric and Oceanic Sciences (PAOS) (later, in 2005, the CU department called Department of Atmospheric and Oceanic Sciences, or ATOC) the needed more space in Duane.
The first option was to add a fourth floor on the west end of the building. Preliminary drawings were made before it was realized that added weight couldn’t be supported, and that idea was dead.

Another option was to add a new wing on Duane, to be placed on the east side of the building. It would be called the “H" wing. This was intended to house all of the astronomers in CU (even those in JILA) and Applied Math. Physics and ATOC could expand into the offices astronomers left behind by the astronomers. Our proposal was approved by campus planning committees, and it went high of the list on new campus buildings to be constructed. But when the Physics Department joined our proposal, to build new laboratory space under the field on the south of Duane, the project got too big and expensive, and the H-wing also was dead.

Some LASP people moved from the D-wing to a new building on the East Campus, freeing up a few offices in Duane, and CASA was able to expand.


Snow had decided to step down when ARL was in place, and he resigned as CASA director, in 1996. Snow was succeeded by Bally (1996 to 2000), Green (2000 to 2004), Cash (2004 to 2008), Green again (for three terms; 2008 to 2014), and now Jason Glenn.

From the first, another directorial position was allied with the Director: an Associate Director, or AD. The AD fills in for the director as needed, and serves a supervisory role over staff members, who actually do most of the day-to-day work.

Snow was the AD for one year (assistant to McCray), and when Snow became the Director, Cash took the AD position (1986 to 1995), then Ayres (1996 to 2000), Jon Morse (2001 to 2002), Ayres again (2003 to 2011!), Cyndi Froning (2012 to 2013), Alex Brown (2014 to 2015), and now Nils Halverson (2015).

Another position, Operating Officer (00), was created to oversee practical things, such as the assignment of offices, travel expense reports, etc. Bon Stencil was the first OO, and when he left (in 1990), Bob Geoff Clayton took his place, until 1993 when he left for a faculty position at LSU. After that the OO position was dropped, having so much overlap with the ADs responsibilities and most of his duties.

When Clayton left, his chores were divided up, with Darcy Collins having responsibility for budgets (now Jo Ann Vandel). From the start, we had a computer system administrator (now Scott Maize).

CASA has an executive committee (EC) of four members, elected by the Fellows, which reports to the director (fifth member of EC). Normally the EC has members from the main and East Campuses. The EC is elected every year.

At first the CASA office stayed in Duane, third floor, but it was transferred to the East Campus when CASA got ARL and the big projects got going.

Relationship with APS

CASA is a unit within APS, not a department itself; therefore in principle the CASA director reports the APS chair, but in practice CASA research is under the Graduate School Dean, while CASA faculty reports to the APS Chair for teaching (and committees). The same is true for LASP and JILA. The undergrad labs, Sommers Bausch Observatory (SBO), and Fiske Planetarium are wholly in APS, but there is some crossover. For example, in almost every semester some non-faculty CASA people, mainly post-doc or graduate students, teach courses in APS and given many public shows in Fiske.

Having no world-class telescope, APS joined a consortium with the University of North Carolina (UNC) and the National Optical Astronomy Observatory (NOAO) to build 4-meter telescope in a new southern observatory, meant to serve all three institutions. We were to raise about $4M, the cost for our part of the project. We got far in the planning, the assigning committees to raise money, plan operations, design of the building and instruments (which were to be visible and IR cameras and low- and high low- and high-resolution spectrographs). Observing stations were to be at UNC, CU, and NOAO, for remote observations.

The observatory would named Southern the Southern Astrophysical Research Telescope (SOAR). We even had a logo! The SOAR telescope would be placed on Cerro Pachon (next to Cerro Tololo and a little higher in elevation).

Peter Conti of APS, with many others, led the effort of APS/CASA’s participation in the project. We lagged in raising funds we needed and, in 1989, the Dean of the Graduate School, Ekstrand, pulled us of the project.

In 2001, APS bought into the Apache Point Observatory (APO) consortium, founded by a group of universities headed by the University of Washington (UW). Its

3.5 m telescope, on the Sacramento Mountain ridge in southern New Mexico, was dedicated 1994. At first we had one-sixteenth of the observing shifts, later (in 2006) this was upped to one-eighth. Contributing an instrument would replace some of the money, and Stocke, with graduate student Fred Harty, built the Near-Infrared Camera - Fabrey- Perot Spectrograph (NIC-FPS).

In 2013 APS/CASA entered the Sloan Digital Sky Survey (SDSS) consortium, which had started operations in 2000 with SDSS-I; now it’s SDSS-IV. The SDSS has a 2.5-m telescope, next to the APO dome, with a wide field, and a huge detector, comprised of 30 2048 by 2048 CCDs.

Shull led drive for money for CU’s part of the SDSS-IV. CU funding ($750M) came from a combination of money from the APS/CASA budget, private fundraising, the Provost (Russell Moore), and Vice Chancellor for Research (Stein Sture). CU’s representative on the Sloan Broad is Jeremy Darling, and several others are involved: Shull, Bally, and Stocke.

CASA today and in the future

CASA has expanded, having 16 Fellows, three Fellows Emeritus (Snow, McCray, and Linsky), four Senior Research Associates, ten Research Associates, 14 post-docs, and 18 grad students (as of this writing), and too many undergrads to count.

CASA’s funding comes from NASA and the NSF, so post-docs, grad students, and undergrads depend on these grants. The funding has grown from about $1 million 1985 to the $5 million level (with a peak of $12 million in 2010), with many changes, both up and down, through the years. Recent three-year running averages are $6.7M/yr from NASA, and $820K/yr from NASA. (These numbers are not corrected for inflation.)

CASA research is healthy, with several major programs ongoing or proposed. Going or proposed programs include Glenn (UV KIDS detectors, CCAT, Bolocam, MUSIC); Jack Burns (DARE; proposed), galaxy cluster studies, lunar telerobitics); Green (SubLyme (proposed); Halverson (South Pole Telescope, Polarbear, detector development in collaboration with NIST): Cash (Starshades, UV rocket; proposed); and Al Betz (THz spectroscopy).

Director of CASA, Glenn (on May 28, 2015) circulated the announcement that CASA, LASP, APS, ATOC, and the Provost (Russell Moore) have agreed to re-arrange offices and labs to give space for the LASP collaboration with United Arab Emirates (UAE,) on a new Mars mission (Emirates Mars Mission). Most of new space for that project will be placed in ARL, which will leave about one-third of the building for CASA. That means several people and labs will move back to Duane. Among other things, the third floor of the C-wing of Duane will be restored to labs, which was the original intent before CASA was formed, and most of the people who have offices on the third of the C-wing will move. Part of agreement has ATOC going a new building on the East Campus: Sustainability, Energy, and Environment Complex (SEEC), leaving space for the displaced people from ARL in the C and D-wings.