A robotic spacecraft to get a close-up of Pluto. A high-speed landing on a comet. And a mission to test twins - one in space and one on the ground - to understand the effects of space on genetics.
NASA isn't expected to fly its own astronauts into space for a decade, but here are five of the coolest space missions - by the U.S. and other countries - to look forward to in the next few years:
The New Horizons spacecraft was launched in the middle of the last decade. And now well beyond the orbit of Uranus, some 27 times the distance from the Sun than Earth, the NASA-built spacecraft is closing in on Pluto.
On July 14, 2015, the spacecraft will fly to within about 6,000 miles of Pluto, allowing astronomers for the first time to get a close look at the celestial body formerly known as the solar system's ninth planet and its moons, including Charon.
Mike Brown, an astronomer at the California Institute of Technology who is widely credited with "killing" Pluto after he discovered Eris, a dwarf planet farther from the Sun than Pluto, said he's nonetheless eagerly awaiting this mission.
"Pluto will get all the press, but in many ways I really want to see Charon more," Brown said.
"Pluto is sufficiently large that it holds on to an atmosphere and thus also has a frosty surface covering its 'real' surface. So from looking at Pluto we'll see weird stuff about frost and atmosphere interaction, but we won't actually learn much about what is below that tiny frost layer."
Launched nearly a decade ago by the European Space Agency, the Rosetta mission in November 2014 will attempt to deliver a lander named Philae to the surface of a comet.
"I cannot wait for Rosetta to arrive at, and then orbit a comet, and then land its little lander on the surface," said Emily Lakdawalla, a geologist and author who blogs for The Planetary Society. "There are only a few worlds in the solar system whose surfaces we've landed on, and even fewer for which we have good pictures."
The $1.4 billion mission, scheduled to enter into orbit around the Comet 67P/Churyumov-Gerasimenko next year, will follow the comet as it makes its closest approach to the Sun. After the comet flies back out toward the orbit of Jupiter, becoming dormant as it moves away from the Sun's heat, Rosetta is designed to deliver a 50-pound lander packed with nine scientific instruments onto the comet's surface.
"The data provided by this mission and the lander is without doubt the most anticipated in the field of small solar system bodies," said Franck Marchis, an astronomer with the Carl Sagan Center of the SETI Institute.
It's been two years since humans launched into orbit around Earth from the United States, during the last spaceflight of Atlantis.
This launch-less streak should end sometime in 2016 or 2017 when a space capsule built by a private company, most likely SpaceX or Boeing, lifts off from Florida on a privately managed mission.
NASA is spending hundreds of millions of dollars a year to help three private companies develop the capability to transport astronauts into space.
"SpaceX has arguably been the most successful to date, having flown three cargo missions successfully to the International Space Station," said Leroy Chiao, a four-time astronaut who is now CEO of Diomics, a life-sciences business.
"The other companies, Boeing and Sierra Nevada, are also making good progress. I would anticipate that we will see at least a flight test of a commercial crew vehicle to low-Earth orbit in the next five years."
Much sooner and simpler than flights to orbit, commercial providers are expected to begin offering brief suborbital flights for passengers.
In March 2015, astronaut Scott Kelly is scheduled to fly to the International Space Station aboard a Russian spacecraft.
His planned year-long spaceflight is the longest space mission ever assigned to a NASA astronaut. It is designed to test how the human body responds to such a prolonged period in space. This kind of information is important if humans are to undertake long duration journeys to destinations like Mars.
Earlier this month, NASA announced a twist to the mission - Scott Kelly's more well-known brother and twin, retired astronaut Mark Kelly, will take part in a study to compare changes in their bodies during the year-long mission.
"This is a once-in-a-space-program opportunity," said John Charles, a scientist with NASA's Human Research Program.
Scientists plan to collect periodic blood samples from the twins before, during and after the mission.
To send astronauts to more ambitious destinations beyond low-Earth orbit, NASA has been developing its Orion space capsule and an Apollo-like heavy-lift rocket, known as the Space Launch System.
The space agency will conduct its first test flight of the Orion spacecraft next year, launching it into space aboard a privately built Atlas V rocket. The unmanned flight will test how well the spacecraft's heat shield handles the very high rate of speed at which Orion will fall back to Earth through the atmosphere, similar to that of a lunar mission.
Then, in 2017, the space agency is planning to test the performance of the Orion space capsule atop its heavy-lift rocket - with a so-called full-stack flight.
"That will be a huge event as it is the step before sending people on the space launch system to deep space," said Abigail Harrison, aka 16-year-old "Astronaut Abby," who aspires to be the first astronaut to fly to Mars. Harrison has gained notoriety on social media by publicizing her spaceflight hopes and plans to attend the Air Force Academy.