Vertical takeoff, vertical landing (VTVL) is a form of takeoff and landing for rockets. Multiple VTVL craft have flown. The most widely known and commercially successful VTVL rocket is SpaceX's Falcon 9 first stage.[citation needed]
VTVL technologies were developed substantially with small rockets after 2000, in part due to incentive prize competitions like the Lunar Lander Challenge. Successful small VTVL rockets were developed by Masten Space Systems, Armadillo Aerospace, and others.
Starting in the mid-2010s, VTVL was under intense development as a technology for reusable rockets large enough to transport people. In 2013, SpaceX demonstrated vertical landing on a Falcon 9 prototype after climbing 744 meters in the air.[1] Later, Blue Origin (New Shepard) and SpaceX (Falcon 9), both demonstrated recovery of launch vehicles after return to the launch site (RTLS) operations, with Blue Origin's New Shepard booster rocket making the first successful vertical landing on November 23, 2015, following a flight that reached outer space, and SpaceX's Falcon 9 flight 20 marking the first landing of a commercial orbital booster roughly a month later, on December 22, 2015. All launches of the Falcon Heavy rocket by SpaceX have included VTVL attempts for the two side boosters on each rocket. SpaceX is also developing a fully reusable rocket named Starship.[2]
VTVL rockets are not to be confused with aircraft which take off and land vertically which use the air for support and propulsion, such as helicopters and jump jets which are VTOL aircraft.
The technology required to successfully achieve retropropulsive landings—the vertical landing or "VL" addition to the standard vertical takeoff (VT) technology of the early decades of human spaceflight—has several parts. First, thrust must be less than weight, second the thrust is normally required to be vectored and requires some degree of throttling. Guidance must be capable of calculating the position and altitude of the vehicle, small deviations from the vertical can cause large deviations of the vehicles horizontal position. RCS systems are usually required to keep the vehicle at the correct angle. SpaceX also use grid fins for attitude control during landing of their Falcon 9 boosters.
It can also be necessary to be able to ignite engines in a variety of conditions potentially including vacuum, hypersonic, supersonic, transonic, and subsonic.[40]
The additional weight of fuel, larger tank, landing legs and their deployment mechanisms will usually reduce the performance of a soft landing system compared to expendable vehicles, all other things being equal. The main benefit of the technology is seen in the potential for substantial reductions in space flight costs as a result of being able to reuse rockets after successful VTVL landings.[41]
Vertical landing of spaceships was the predominant mode of rocket landing envisioned in the pre-spaceflight era. Many science fiction authors as well as depictions in popular culture showed rockets landing vertically, typically resting after landing on the space vehicle's fins. This view was sufficiently ingrained in popular culture that in 1993, following a successful low-altitude test flight of a prototype rocket, a writer opined: "The DC-X launched vertically, hovered in mid-air ... The spacecraft stopped mid-air again and, as the engines throttled back, began its successful vertical landing. Just like Buck Rogers."[42] In the 2010s, SpaceX rockets have likewise seen the appellation to this popular culture notion of Buck Rogers in a "Quest to Create a 'Buck Rogers' Reusable Rocket."[43][44]
The Young Sheldon episode, "A Patch, a Modem, and a Zantac®" features Sheldon Cooper developing the equations for VTVL in the 1980s, only to have them rejected by NASA for lack of the technical capability to implement it at that time. Sheldon concludes that he is ahead of his time. A flashforward to 2016 shows the successful SpaceX CRS-8 mission, followed by SpaceX founder Elon Musk looking over Sheldon's old notebook then hiding it in a desk drawer.[45][46][47][48]
RKK Energia, ... in the 1980s ... worked on a highly classified project to develop a large crewed capsule, called Zarya ("Dawn"), for a wide range of civilian and military missions.
New Shepard which was made by the "Blue Origin"(founded by Jeff Bezos): Type: VTVL/Unpiloted ... Super Mod: Type: VTVL/Unpiloted ... Xaero: Type: VTVL/Unpiloted
Both of the rocket's stages would return to the launch site and touch down vertically, under rocket power, on landing gear after delivering a spacecraft to orbit.
SpaceX has constructed a half-acre concrete launch facility in McGregor, and the Grasshopper rocket is already standing on the pad, outfitted with four insect-like silver landing legs.
WATCH: Grasshopper flies to its highest height to date – 744 m (2441 ft) into the Texas sky. http://youtu.be/9ZDkItO-0a4 This was the last scheduled test for the Grasshopper rig; next up will be low altitude tests of the Falcon 9 Reusable (F9R) development vehicle in Texas followed by high altitude testing in New Mexico.
The April 17 F9R Dev 1 flight, which lasted under 1 min., was the first vertical landing test of a production-representative recoverable Falcon 9 v1.1 first stage, while the April 18 cargo flight to the ISS was the first opportunity for SpaceX to evaluate the design of foldable landing legs and upgraded thrusters that control the stage during its initial descent.
The DC-X launched vertically, hovered in mid-air at 150 feet, and began to move sideways at a dogtrot. After traveling 350 feet, the onboard global-positioning satellite unit indicated that the DC-X was directly over its landing point. The spacecraft stopped mid-air again and, as the engines throttled back, began its successful vertical landing. Just like Buck Rogers.
Only four entities have launched a space capsule into orbit and successfully brought it back: the United States, Russia, China, and Elon Musk. This Buck Rogers dream started years ago...