Whenever I give a public talk on space exploration, or speak with someone casually, such as on an airplane or on a bus, I am often asked why NASA isn't doing more: “Why don't we have bases on the Moon? Why aren't there astronauts on Mars, and why didn't New Horizons go into orbit around Pluto or send back a sample?” My answer is invariably, “we would like to do all those things, if only NASA had the funds. We can think of all sorts of marvelous missions, but our budget is so constrained. We are limited to just a few high-priority projects.”

In the past we were able to do so much more, but as NASA's funding dwindled from 4.5% of the national budget during the peak years of the Apollo lunar program, to less than 0.5% today, we are confined to a bare-bones portfolio of exploration. The dreams of my childhood, and of so many others, have been diminished as the budget for scientific work in general has declined. It is not only NASA. IBM also used to have an outstanding group of researchers, and of course there was Bell Laboratories, which spawned so many Nobel Prizes, including the work of Arno Penzias and Robert Wilson with their discovery in 1964 of the remnant thermal radiation from the Big Bang, the Universe's moment of creation almost 14 billion years ago. Less commonly someone will say “Why spend all that money out in space?” I will respond: “None of the money is spent in space. It is all spent here on Earth providing good jobs that cannot be outsourced or eliminated.”

New Horizons will continue on to the smallish Kuiper Belt Object 2014 MU69, Juno started exploring the interior of Jupiter in mid-2016, the Mars Atmosphere and Volatile EvolutioN Mission (MAVEN) is orbiting Mars to understand how it lost its atmosphere, and the InSight Lander will explore the interior of Mars with seismometers and heat-flow detectors. Mars 2020 will follow on the heels of the Mars Curiosity Lander to explore possible habitable environments on Mars and to search for life. But it will only cache a collection of samples for later return because we don't have the funds – or the technological resources – to return this valuable cargo in the near future.