There are no second acts in American lives,” wrote F. Scott Fitzgerald. But the possibility of a second act in the life of a venerable U.S. spacecraft is not only possible, it is quite readily achievable.
The third International Sun-Earth Explorer (ISEE-3) was launched in August 1978 and performed in an exemplary fashion. First it served as a monitor of solar drivers of near-Earth space physics processes from 1978 to 1982. Then, in 1982 and 1983, ISEE-3 was sent on a historic mission to explore the distant tail of Earth’s magnetosphere. In a further fascinating feat of celestial mechanical wizardry, ISEE-3 was sent careening around Earth’s Moon and off to encounter the short-period comet Giacobini-Zinner in 1985. Following this pioneering flight through the cometary tail, ISEE-3 (by then renamed the International Cometary Explorer, ICE) sailed off into a large looping orbit around our sun, where it has been moving relentlessly for the past 27 years.
Much has changed in the two-and-a-half decades since the ISEE/ICE explorations. But one thing that has not changed is the passion that many of us have to utilize fully every possible space asset to study the connected sun-Earth system.
In August 2014, ISEE/ICE will return to Earth’s vicinity, guided by laws of celestial motion back to its point of origin. Present evidence is that the spacecraft and most of its subsystems are in good shape. The spacecraft — last tested very remotely in 2008 — seems to still be generating plenty of power from its solar panels, and the communications transmitter is strong. What is not known fully is how well the dozen or so scientific instruments onboard might be functioning. But from what we know from other experiences, the chances are quite good that instruments that were functioning well in the 1980s are probably still just fine: They have just been in suspended animation for the past nearly three decades.
The scientific, technical and educational communities are being handed a remarkable opportunity by the ISEE/ICE spacecraft return. For a very small investment of time and resources, it will be possible to pull ISEE/ICE from deep-space storage and put it back into the ranks of active monitors of the space environment in Earth’s vicinity.
When ISEE-3 was sent on its mission to stalk a comet, it was a lone sentinel in the far reaches of Earth’s cosmic neighborhood. Now, as it returns from its journeys, ISEE/ICE comes back into the midst of an impressive constellation of Earth-orbiting and solar-observing spacecraft called the Heliophysics System Observatory.
In order to effect the “recapture” of the ISEE/ICE spacecraft and to assess the utility of doing so, several key steps must be taken soon. These include re-establishing commanding capability and evaluating the condition of the spacecraft and its subsystems.
In this time of very constrained federal resources, determining the total costs involved is a key one: How can this mission be done in the most cost-effective way possible? One answer is to involve centrally and very actively the U.S. academic (student) community. At the University of Colorado at Boulder, for example, a space research institute — the Laboratory for Atmospheric and Space Physics (LASP) — has successfully operated numerous NASA space missions. The most recent example is the Kepler mission searching for Earth-like planets around other stars in our galaxy. By emphasizing students in the mission operations roles, LASP is able to carry out mission functions in an extraordinarily effective way. Moreover, the mission operation using students is a highly productive way to educate and train the next generation of young engineers, scientists and managers.
It is proposed that the University of Colorado at Boulder work with a consortium of leading spacefaring universities in the United States to develop a program to command, control and scientifically operate the ISEE/ICE spacecraft. The mission should be returned to the first Lagrangian (L1) orbital configuration that the spacecraft first entered more than 34 years ago shortly after its successful launch. In this orbit, ISEE/ICE can make key measurements to help us understand the three-dimensional space properties in Earth’s upstream region. For a (very likely) modest investment, a “new” multipoint measurement capability would be added to the solar monitoring function of the great Heliophysics System Observatory.
As a further cost-saving measure, one should recall the word “international” in the ISEE/ICE name. There is every reason to believe that spacefaring partners in the international community would love to participate in the restored ISEE mission. For example, colleagues at the Russian Space Research Institute have expressed a strong desire to join the ISEE/ICE program. Through active involvement of academia in the U.S. and separately funded agencies abroad, it should be possible to revivify the ISEE/ICE spacecraft at a very low out-of-pocket cost. In doing so, U.S. taxpayers would be able to further recoup benefits of investments made some 40 years ago.
Daniel N. Baker is director of the Laboratory for Atmospheric and Space Physics at the University of Colorado at Boulder.
