A two-stage-to-orbit (TSTO or DSTO - Double/Dual-Stage-To-Orbit) launch vehicle is a spacecraft in which two distinct stages provide propulsion consecutively in order to achieve orbital velocity. A rocket launch is the first phase of the flight of a Rocket. It is intermediate between the more common system with more stages, such as the three-stage-to-orbit system, and a single-stage-to-orbit (SSTO) launcher, which does not exist yet. The three-stage-to-orbit launch system is a commonly used rocket system to attain Earth orbit A single-stage-to-orbit (or SSTO) vehicle reaches Orbit from the surface of a body without jettisoning hardware expending only propellants and fluids
At liftoff the first stage is responsible for accelerating the vehicle. At some point the second stage detaches from the first stage and continues to orbit under its own power.
The advantage of such a system is that the entire mass of the spacecraft is not carried into orbit. This reduces the difficulty involved in reaching orbital velocity.
Contents |
Examples of two stage to orbit systems
- Angara rocket (LEO) future
- Athena I
- Cosmos-3M
- Delta IV rocket (medium)
- Saturn 1b
- Tsyklon-2
- Zenit-2
It is not always clear when a vehicle is a DSTO. The Angara rocket is a planned space-launch vehicle, designed to place heavy payloads into orbit The Athena rocket is a Lockheed Martin launch vehicle It has undergone several name changes in its lifetime The Cosmos-3M (11K65M ( Космос-3М) is a Russian space Launch vehicle. The Delta IV is a family of Delta Rockets designed by Boeing 's Integrated Defense Systems division and built in United Launch Alliance's The Saturn IB was an uprated version of the Saturn I, which featured a much more powerful second stage the S-IVB. The Tsyklon (Циклон "Cyclone" also known as Tsiklon) GRAU index 11K67 was a Soviet / Ukrainian -designed Expendable launch Many designs which use a very small boost at the beginning of their flight are referred to as single-stage-to-orbit. Some have also coined the expression 1. 5STO for 'one-and-a-half-stage-to-orbit', e. g. , the Atlas. Atlas is a family of US space Launch vehicles The original Atlas missile was designed in the late 1950s Also, many launch vehicles have side-mounted booster rockets which are jettisoned early which are called "stage-0".
Reusable launch systems
With reference to a reusable launch system this approach is often proposed as an alternative to single-stage-to-orbit (or SSTO). A reusable launch system (or reusable launch vehicle, RLV is a Launch system which is capable of launching a Launch vehicle into space more than once Its supporters argue that, since each stage may have a lower mass ratio than an SSTO launch system, such a system may be built without approaching as close to the limitations of its structural materials. In Aerospace engineering, mass ratio is a measure of the efficiency of a Rocket. It therefore should require less maintenance, less testing, experience fewer failures and have a longer working life.
Critics argue that the increased complexity of designing two separate stages that must interact, the logistics involved in returning the first stage to the launch site, and the difficulties of conducting incremental testing on a second stage will outweigh these benefits. In the case of airplane-like lower stages they also argue how difficult high speed aircraft (like the SR-71) are to develop and operate, and question performance claims. WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout Many 'mini-shuttle' designs that use transport aircraft as first stages also face similar problems with ice/foam as the Space Shuttle due to the requirement they also carry a large external tank for their fuel. NASA 's Space Shuttle, officially called the Space Transportation System ( STS) is the Spacecraft currently used by the United States
On the other hand, the two-stage approach allows the lower stage to be optimized for operation in the Earth's lower atmosphere, where pressure and drag are high, while the upper stage can be optimized for operation in the near-vacuum conditions of the later part of the launch. This allows an increase in the payload mass fraction of a two-stage vehicle over single-stage or stage-and-a-half vehicles, which have to perform in both environments using the same hardware.
Helicopter-like first stage
Taking the view that airplane like operations do not translate to airplane-like appearance, many TSTOs have first stages that operate as VTOL or VTOHL aircraft. VTOL is an abbreviation for Vertical Take-Off and Landing. VTOL describes Fixed-wing aircraft that can lift off vertically VTOHL is an acronym for Vertical Take-Off Horizontal Landing. The DC-X has proven the VTOL option design workable. The DC-X, short for Delta Clipper or Delta Clipper Experimental, was an unmanned prototype of a reusable Single stage to orbit launch vehicle built Other designs like the DH-1 concept take it a step further and use a 'pop-up/pop-down' approach, which delivers the orbiting stage to a point about 60km above the earth's surface, before dropping down to the launch pad again. This page refers to the DH-1 rocket proposal not the Airco DH In the case of the DH-1, the upper stage is effectively an 'almost SSTO' with a more realistic mass fraction and which was optimised for reliability. This page refers to the DH-1 rocket proposal not the Airco DH
Airplane-like first stage
Many TSTO designs comprise an airplane-like first stage and a rocket-like second stage. Overview Fixed-wing aircraft range from small training and recreational aircraft to Wide-body aircraft and military cargo aircraft. A rocket or rocket vehicle is a Missile, Aircraft or other Vehicle which obtains Thrust by the reaction of the The airplane elements can be wings, air-breathing engines, or both. This approach appeals because it transforms Earth's atmosphere from an obstacle into an advantage. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Above a certain speed and altitude, wings and scramjets cease being effective, and the rocket is deployed to complete the trip to orbit. A scramjet ( s upersonic c ombustion ramjet) is a variation of a Ramjet with the distinction being that some or all of the combustion process
SpaceShipOne
While not an orbital vehicle, the successful private SpaceShipOne suborbital spacecraft developed for the Ansari X Prize demonstrated that the problems of integrating a two-stage system, with a winged aircraft as the "lower half", that can reach the edge of space are not insurmountable. SpaceShipOne is a Spaceplane that completed the first privately funded Human spaceflight on June 21, 2004. The Ansari X PRIZE was a Space competition in which the X PRIZE Foundation offered a US$ 10000000 Prize for the first non-government As of 2005, the team behind SpaceShipOne is working on a commercial sub-orbital launch system based on this technology. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar.
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic