One of the saddest what-ifs of the space age concerns a project that was proposed in the early 21st Century called the Jupiter Icy Moons Orbiter also known as Project Prometheus. What it lacked in a budget commitment it had in ambition.
The idea was to marry a nuclear reactor to an electric ion rocket and launch the probe to Jupiter. It would orbited the moons Europa, Ganymede, and Callisto in turn, examining them with an array of remote sensing instruments. It would have advanced a whole host of new technologies while doing this, not the least of which was space based nuclear power, something NASA has not yet managed to master.
JIMO would have been assembled in low Earth orbit in 2015 and then launched directly to Jupiter space in a low thrust direct trajectory. It would have arrived in Jupiter space in 2021 and then begin exploring the icy moons each in turn for the next three years.
The project was first proposed and funded in 2002 and subsequently cancelled in 2005. The reason was that the International Space Station, the return to flight of the space shuttle in the wake of the Columbia accident, and the nascent Vision for Space Exploration, which eventually became Project Constellation, were considered higher priorities. Neither the president nor Congress were willing to expand NASA’s budget to accommodate the JIMO along with what was already on NASA’s plate.
JIMO’s short life and miserable death was yet another symptom of a malady that has afflicted NASA since the end of the Apollo program. It has been called by various names, but the most common phrase now used is “the budget situation” though sometimes “budget realities” is also used. The notion is that a kind of law of nature, much like the one that says that matter cannot travel as fast as light, has settled in that says, “NASA’s budget cannot exceed .5 percent of the overall federal budget.” This begs the question of whether budgets are driven by impersonal forces, like the laws of physics, or by the decisions of politicians, which can be changed at will.
In any case the same “budget reality” that throttled JIMO in the crib us driving further ambitions for the exploration of the Outer Planets. Due to congressional interest, a new start to send a probe to Europa has been included in NASA’s FY 2015 budget request. The trick is that it can cost no more than $1 billion. By contrast, JIMO would have cost $21 billion, including three launches and an on orbit assembly before heading out to Jupiter space, over its 21 year life. Many scientists doubt that any meaningful science can be accomplished for $1 billion.
Could something like JIMO be revived? That would only happen if NASA’s budget were to start getting increases instead of being held static. Otherwise it joins all of the other proposed missions that have fallen prey to lack of money and lack of vision.