NASA develops new satellites and rockets on a somewhat regular basis, however if you're referring to MANNED spacecraft then the answer would be the Ares I Rocket. NASA is going back to rockets after the shuttle program because they are cheaper and easier to produce than shuttles. While the Ares project is currently suspended indefinitely, the Orion Space Exploration Vehicle is one of only two prospective manned spacecraft candidates which could qualify as a potential next-in-line to the shuttle at this time. The Space Launch System (SLS) which replaced the planned Ares rocketsis a more likely possibility, however details are very vague in this early stage of development.
The New Horizons spacecraft. It will reach Pluto July 14th 2015.
NASA
NASA's Pioneer 10 spacecraft.
The spacecraft that took the new pictures of Mars is the Perseverance rover, a NASA mission launched in July 2020. It is equipped with advanced cameras and instruments to capture high-resolution images of the Martian surface.
NASA's Viking 1 and Viking 2 landed on Mars in 1976.
None, but in 2015 NASA's New Horizon will travel to Pluto and will be the first spacecraft to land on Pluto.
Redstone.
Nope, it returned to NASA
Orion capsule
NASA
The space shuttle.
As of 2021, spacecraft have studied five comets up close: Halley's Comet (by the European Space Agency's Giotto spacecraft), Comet Borrelly (by NASA's Deep Space 1), Comet Wild 2 (by NASA's Stardust spacecraft), Comet Tempel 1 (by NASA's Deep Impact spacecraft), and Comet 67P/Churyumov-Gerasimenko (by the European Space Agency's Rosetta spacecraft).