The end of the Shuttle program does not mean the end of space exploration for the United States. NASA is continuing to go places where humans can’t yet travel by sending robotic missions.
I’m very pro-robotic missions as they’re much cheaper, practical, and easier than human-crewed spaceflight and allow us to go places where it’s extraordinarily hazardous to send humans. While it’s pretty to think of human explorers walking on Mars or seeing Jupiter rise from the landscape of Ganymede I think our notions of exploration are still too fantastical for our technology. Space exploration by humans is a daunting task. From a practical standpoint is ridiculous to even consider leaving the planet—everything we need we must take with us: food, air, water, shelter—so it’s best to let our machines (that have far fewer needs than our fragile bodies) make the trip. On the other hand, of course, all human voyages since the birth of our species have been impractical, from our first travels out of Africa, pre-columbian migration to the Americas, the exploration of Antarctica and the moon shot all required extraordinary courage, skill, and perseverance.
There are several challenges when it comes to getting to Mars and while I don’t think they’re insurmountable they do make a touchdown on the surface out of our reach for right now. A voyage to the outer planets would be even more challenging in terms of time and complexity. I do believe we’ll make it one day, if not in my lifetime. We also have a great many problems here on Earth that need addressing, as well, and robotic missions spare us the resources (would that we used them) to work out the problems humans having living and working on Earth, let alone in outer space.
But I digress. Until we’ve overcome the difficulties of exploring space in person we can send machines to do the work. Which is exactly what NASA will be focused on in the next few years.
Mercury — MESSENGER
Venus — Venus Express
Moon — Lunar Reconnaissance Orbiter, Chang’e 2
Mars — Opportunity rover, Mars Reconnaissance Orbiter, Mars Express, Mars Odyssey
Asteroids — Dawn (Vesta and Ceres)
Saturn — Cassini
Pluto/Kuiper Belt — New Horizons
Comets — Rosetta
Beyond — Voyagers 1 and 2
As a side note, Voyager 1 is the most distant man-made object in history, and the fastest space probe with a velocity of 38,400mph relative to the sun.
Juno is the next mission to Jupiter. The spacecraft will carry 7 instruments to examine the formation and evolution of Jupiter. Not only will this mission give insight into the formation of our own solar system, it will also shed light on the numerous extrasolar planets that are thought to be analogous to Jupiter and the other gas giants of our own solar system.
Juno will launch between August 5 and August 26, 2011 and arrive at Jupiter in 2016.
Due to advances in solar panel technology Juno will also be the first mission to the outer planets to use solar power, rather than a radioisotope thermoelectric generator. Each of Juno’s three solar panels are more than 30 feet long.
Curiosity (also know as the Mars Science Laboratory), on the other hand, will use an RTG, like the Viking landers before it. This will allow the Mini Cooper-sized rover to operate during any season and in a variety of weather.
As I mentioned above, MSL is the size of a Mini Cooper automobile. It’s by far the largest rover ever to be sent to Mars. Curiosity’s enormous size will allow it to carry the most robust suite of instruments and experiments ever brought to Mars. NASA has assigned Curiosity the tasks of determining whether life ever arose on Mars, characterizing the climate and geology (areology) of Mars, and preparing for human exploration.
Curiosity launches between November 25 and December 18, with a Martian landing in August of 2012.
Curiosity will weigh nearly a full short ton and, illustrative of the problems of a Mars landing, the Jet Propulsion Laboratory has come up with an ambitious landing scheme in which the rover will be dropped out of the sky by a crane. If all goes well, Curiosity is expected to explore the area around Gale crater for over two (Earth) years.
These two missions highlight the future of space exploration, both human and robotic, and point towards a promising future of exploration in our solar system and beyond.