From Ted Gull, GSFC/NASA:

I am certain that thousands of stories can be told of IUE development, operations and science, but here are some of my experiences...

Prelaunch:

Even though I was hired six months before IUE and helped with the final thermal vacuum testing data analysis, I never got to see the actual space craft. Yet in a small way, I contributed to a last minute repair at the Cape.

I had designed and built a number of spectrographs for ground-based and airborne telescopes, and specifically two echelle spectrographs. Given the long optical paths, thermal and gravitational flexure were always an issue. In late October, 1977, Al Boggess asked me to examine IUE's spectra taken during thermal vacuum testing as the spectra were moving and possibly due to changes in instrument temperature. Eventually I realized that the optical bench was flexing and was able to isolate it to a specific area at the far end of the bench. Several meetings ensued, including one on a Saturday over Thanksgiving weekend in the project manager's office where I explained the phenomenon. Dennis Evans suggested that the thermal cannister was too tight and contacting the bench at the position I mentioned. But it was too late to do anything at Goddard. The spacecraft was shipped to the Cape and then the instrument was pulled apart. Scratch marks were noted at the position I had suggested. Spacers were inserted to shift the thermal cannister away from the optical bench. IUE was then reassembled, checked for electrical functionality and launched.

Over the next month, I had nightmares of the instrument failing on orbit. Eventually when the first on-orbit tests were done, we confirmed that the flexure had dropped nearly at least an order of magnitude, thus enabling long exposures, especially in the echelle mode. I could relax!

Orbital testing:

By shear coincidence, I was in the Building 21 science operations center monitoring the checkout of IUE at the time that the onboard computer crashed for the first time. It was quite frightening to see the readouts indicate that the spacecraft was maneuvering and out of control. Eventually, the engineers in Building 3/14 gained control and over the following days, software patches were uploaded to skip across the bad memory in the prime computer.

The first blind offset:

Not being on the IUE international team, I assisted in various operations as each mode of the instrument was checked out. My experiences of helping bring on the Kitt Peak Mayall Telescope paid off as I had worked with faint objects and offsets from reference stars. The first extragalactic observation was to be of NGC4151, which was too faint to be seen by the focal plane sensor, so we prepared to do a blind offset from a nearby star. I realized that a PDS microdensitometer and glass copies of the Palomar Sky Survey were in the building, so quickly used programs I had brought from Kitt Peak to measure reference stars, the offset star and NGC4151 on the specific plate. We then used those offsets to set on NGC4151 to take the first UV spectra of an extragalactic source. Unfortunately, we missed! The gyros had not yet been sufficiently nulled for drift error and the long procedures between offset and acquisition led to drifting off target. We planned to repeat in two days. Unfortunately, Art Davidsen and his sounding rocket team were sitting at White Sands to observe the same object and accomplished such the next day. We successfully observed NGC4151 the second time. However, Davidsen saw C IV emission with an absorption in the core. We saw a complete line profile, so the two IAU telegrams describe different results taken a day or two apart. The 'variability' later appeared to be attributed to saturation of the sounding rocket detector in the core of the line.

The faintest objects:

Ted Stecher and Steve Maran, in a collaboration with Lawrence Aller, included me in observations of planetary nebulae in the Magellanic Clouds. Again, I used the PDS microdensitomer and film copies of the southern sky survey to measure the positions of the planetary nebulae and reference stars. These objects had an effective magnitude of 20 to 21, yet obviously were bright in narrow emission lines in the UV. Of the more than dozen PNs we observed, all except one were successful in one and two shift observations with IUE. The one missed, I later realized when newer astrometry was available, was due to the reference star having a very high proper motion, something we could not have known about at the time!

The staff:

IUE was an excellent training ground for many young astronomers learning to study objects in the UV and for many researchers, engineers and technicians supporting remote observations and space observations. In the seventeen years that IUE was operated, well over a hundred people were involved in the spacecraft operations, scheduling and supporting of the hundreds of astronomers both here at Goddard and at VILSPA in Spain. Many international collaborations occurred due to the shift operations moving on a twentyfour hour basis from Goddard (US1 and US2 shifts) to VILSPA (European shift). As we were able to extend exposures up to 16 hours by using the European and US1 low radiation shifts, faint objects dictated these collaborations. I personally fondly remember those activities pushing me to do extragalactic observations when I had been more focused on galactic stars and nebulae. But it was hell coming in for a shift beginning at 3 am, taking the handover from VILSPA and simply continuing the exposure for another seven hours before reading out. Eventually the observers room in the SOC had a cot for the guest observer, and many of us grabbed a few hours sleep during those shifts so that we could still work the next day!

The support staff had a very significant turnover, which was really great. Many staffers today are around Goddard or at STScI or Hopkins having supported numerous astronomical and earth science spacecraft. IUE indeed was an excellent training ground for all.

IUE as a pioneer for remote observing:

IUE was also a teaching tool for remote observations. As it commenced operations, only a few telescopes were controlled by computers, Lick, KPNO and CTIO being three examples. More computer-controlled instruments and telescopes came on line and observers began to realize that they didn't really need to travel to the telescope to accomplish the observations. Perhaps the major shift came about with SN1987A. It took 14 hours to get the information about the discovery at CTIO to IUE control center. George Sonneborn happened to be the resident astronomer that shift and commenced to observe the UV spectrum over the next shift, and others participated over the next week, and even followed up for a year afterward with IUE. Today Hubble monitors the evolving supernova remnant in the UV, visible and NIR and astronomers will continue for decades to come with even more sophisticated instruments. But the realization that it took so long to get the information to IUE and other observatories brought about extension of the internet to southern observatories, the eventual remote monitoring of observations and ultimately remote operations. Much has changed, but even today, we are not able to do the realtime interaction with a space observatory that was possible with IUE in geosynchronous orbit.

From Ted Simon, U. of Hawaii:

Aloha Karen, Wow! Three decades, it's hard to believe. Time flies when you are doing good science with such a top-notch team of space pioneers, and in general just enjoying the company and friendship of so many terrific people at IUE. It's obviously just a coincidence, but this past Monday I came across my old IUE coffee mug and I placed it proudly on my desk, where it now sits. And that got me to thinking--actually, to dreaming--about the old science operations room in Building 21 at Goddard and the many long back-to-back 8-hour shifts I spent there over the years. I recall the suspense of watching the display peel back to reveal either great success or, as I must confess sometimes did happen, disappointing failure. Heck, on my very first pair of IUE shifts, in a GO program to observe the pre-main sequence stars in the distant open cluster NGC 2264, the first 5 or 6 images were completely blank, as I recall. That was pretty discouraging, you can believe. But then: SUCCESS! Emission lines! Mg II--in a 16th magnitude star, no less, which wasn't even visible and had to be acquired by blind offset!

Later yet, on another observing program to observe a heavily spotted late-type star, I was totally shocked to see a bright red swath of overexposed emission in the SWP camera, where only a faint array of isolated emission lines was expected. That was the first hidden white dwarf companion I ever found. Boy was I taken by surprise to see that brilliant continuum show up where none was expected. That led to one of my better papers, I think, at least one that I really enjoyed doing as it took me into an area of research I knew nothing about. It's great to be taken into the mysterious nooks and crannies of astronomy, isn't it? And over the years, while I had many wonderful experiences working on Mauna Kea, helping to establish it as the premier infrared observatory in the US, I have always reserved a special regard for IUE, "The Little Telescope That Could". Isn't that what we dubbed it? IUE opened a new window on the Universe, paving the way for its larger successors, but never yielding second place to any that followed. I owe my best and most enjoyable publications to IUE. I owe many sleepless nights and days to IUE. I was fortunate to be part of a great NASA project, for which I am truly grateful. My ever lasting thanks to the team of scientists, engineers, and support staff at Goddard who deserve enormous credit for their foresight in creating IUE and for their dedication that made it all work so well. As we say in Hawaii, Mahalo nui loa (which means thank you very much). Although I may not be able to make it to the East Coast for the celebrations, I will truly give it some serious thought over the next few weeks. I do sincerely appreciate getting the invitation. And by the way, I still have all of my spiral notebooks with my console log notes for every IUE observation I ever made. They are an interesting collection of historical notes and personal memories. I remember pretty nearly every star and each spectrum I took as if it were a personal friend.

From Don Luttermoser, East Tennessee State U.:

Greetings to the IUE Family! Sorry that I can't make it to the festivities. I owe much of my early research career to the IUE telescope. As a former GO and RA, I have many good memories of the staff that worked at the observatory, especially the TOs that I worked with including Scott Snell, Charlie Loomis, Tom Walker, Andy Groebner, and Mark Schlegel. I do miss writing my (hopefully humorous) RA memos and reading the always hilarious TO memos from the guys!