Last week, Airbus unveiled Adeline, its concept for a reusable rocket, short for ADvanced Expendable Launcher with INnovative engine Economy. Unlike some competitors, Airbus doesn’t try to salvage and re-use the entire rocket: Adeline just contains the rocket’s most expensive components, such as the engine and avionics. During launch, Adeline detaches itself from the rocket, lifts its sleek, heat-shielded body with the help of cute little winglets, and steers autonomously into the earth’s atmosphere for a horizontal landing onto a runway. Its maiden launch is planned for 2025.

This year, SpaceX founder Elon Musk has tried to recover his Falcon 9 rocket from three separate launches: The first time it landed too hard; the second time it landed in the ocean about 30 meters from its target, and the third time it tipped over. Falcon 9 propels the spacecraft about fifty miles into the Earth’s atmosphere before the spacecraft discards that weight, and the rocket attempts to land vertically onto an unmanned moving platform in the ocean. Maybe the fourth time’s a charm: The company has planned at least a dozen launches this year, including another rocket return attempt planned for June 26 on an International Space Station resupply mission.

Named after Alan Shepard, the first American in space, the New Shepard is Amazon.com founder Jeff Bezos’s foray into the reusable rocket market. Bezos’s company Blue Origin ran the reusable rocket’s first test flight on April 29 this year, successfully launching and recovering the crew capsule but failing to recover the rocket. New Shepard shepherded its capsule to about 58 miles in altitude before detaching and attempting a vertical landing. “Unfortunately we didn’t get to recover the propulsion module because we lost pressure in our hydraulic system on descent,” Bezos wrote in an announcement.

Virgin Galactic’s SpaceShipTwo is kind of like an airplane that can fly in space---instead of using rockets, a jet aircraft called WhiteKnightTwo carries the reusable spaceplane to about 10 miles in altitude. After carrying out its space mission, SpaceShipTwo can return by landing horizontally on a runway. The first SpaceShipTwo, the VSS Enterprise, crashed last October, tragically killing one pilot and injuring the other. Virgin Atlantic is building its second SpaceShipTwo.

This April, United Launch Alliance, currently the exclusive launch contractor for the US military, announced their take on the reusable rocket, Vulcan, which uses Blue Origin-made engines. Similar to Airbus’s Adeline concept but with an acrobatic twist, Vulcan ejects its most valuable components---its main engines and thrust section---and a helicopter recovers it in mid-air. United, a joint venture between Lockheed Martin and Boeing, plans to first launch the rocket in 2019.

Like Virgin’s SpaceShipTwo, Sierra Nevada’s Dream Chaser is also a spaceplane, although it is launched by a single-use United Launch Alliance rocket rather than carried into the atmosphere by a jet carrier. According to Sierra, the advantage of the Dream Chaser is that it uses non-toxic propellants and consequently can land on any commercial runway in the world. The Dream Chaser’s first launch is scheduled for 2016.