| I want to introduct something about Hand Oil | | | | to refurbish the Shuttle after it has landed. The |
| Pumps. Providing hand oil pumps,hand drills,breast | | | | fuel used is orders of magnitude cheaper, and, if a |
| drills,ratchet drills,hand grinding wheel | | | | single stage to orbit design SSTO avoided some |
| machines,charcoal irons,meat mincers,corn grinders | | | | of this refurbishment, costs would drop, although |
| and past amachines. Hand operated oil pumps are | | | | this could require more repairs. But in this case |
| suitable for delivering petrol,lube | | | | the staging solution is not available, by definition, |
| oil,kerosene,diesel,edible oils,etc. For more | | | | so it becomes harder to use both fuels. |
| details,please feel free to contact us. Hand Oil Pum | | | | SSTO rockets could simply carry two sets of |
| A tripropellant rocket is a rocket that uses three | | | | engines, but this would mean the spacecraft |
| propellants, as opposed to the more common | | | | would be carrying one or the other set "turned |
| bipropellant rocket or monopropellant rocket | | | | off" for most of the flight. With light enough |
| designs, which use two or one fuels, respectively. | | | | engines this might be reasonable, but an SSTO |
| Tripropellant rockets appear to offer fairly | | | | design requires a very high mass fraction and so |
| impressive gains for single stage to orbit designs, | | | | has razor-thin margins for extra weight. |
| although to date no tripropellant rocket design has | | | | And thus the tripropellant engine. The engine is |
| been developed to the point of testing that would | | | | basically two engines in one, with a common |
| prove the concept. | | | | engine core with the engine bell, combustion |
| There are two principally different kinds of | | | | chamber and oxidizer pump, but two fuel pumps |
| tripropellant rockets. One is a rocket engine which | | | | and feed lines. The engine is somewhat heavier |
| mixes three separate streams of propellants. For | | | | and more complex than a single-fuel engine, but |
| example, a mixture of lithium, hydrogen, and | | | | the complexity is generally a little less than 50% |
| fluorine produced a specific impulse of 546 | | | | more than a single engine, hence less than two |
| seconds; the highest ever of any chemical rocket | | | | engines would be. Of course there are numerous |
| motor. The other kind of tripropellant rocket is | | | | practical reasons why this would be more |
| one that uses one oxidizer but two fuels, | | | | complex. |
| switching between the two in mid-flight. In this | | | | At liftoff the engine typically burns both fuels, |
| way the motor can combine the high | | | | gradually changing the mixture over altitude in |
| thrust-to-mass of a dense fuel like kerosene early | | | | order to keep the exhaust plume "tuned" (a |
| in flight with the high specific impulse of a lighter | | | | strategy similar in concept to the plug nozzle but |
| fuel like liquid hydrogen (LH2) later in flight. The | | | | using a normal bell), eventually switching entirely to |
| result is a single engine providing some of the | | | | LH2 once the kerosene is burned off. At that |
| benefits of staging. | | | | point the engine is largely a straight LH2/LOX |
| Although liquid hydrogen delivers the largest | | | | engine, with an extra fuel pump hanging onto it. |
| specific impulse of the plausible rocket fuels, it also | | | | The concept was first explored in the US by |
| requires huge structures to hold it due to its low | | | | Robert Salkeld, who published the first study on |
| density. These structures can weigh a lot, | | | | the concept in Mixed-Mode Propulsion for the |
| offsetting the light weight of the fuel itself to | | | | Space Shuttle, Astronautics & Aeronautics |
| some degree, and also result in higher drag while | | | | August 1971. He studied a number of designs |
| in the atmosphere. While kerosene has lower | | | | using such engines, both ground based and a |
| specific impulse, its higher density results in smaller | | | | number that were air-launched from large jet |
| structures, which implies less loss to atmospheric | | | | aircraft. He concluded that tripropellant engines |
| drag. In addition, kerosene based engines generally | | | | would produce gains of over 100% in payload |
| provide higher thrust, which is important for | | | | fraction, reductions of over 65% in propellant |
| takeoff, reducing gravity drag. So in general | | | | volume and better than 20% in dry weight. A |
| terms there is a "sweet spot" in altitude where | | | | second design series studied the replacement of |
| one type of fuel becomes more practical than the | | | | the Shuttles SRBs with tripropellant based |
| other. | | | | boosters, in which case the engine almost halved |
| Traditional rocket designs use this sweet spot to | | | | the overall weight of the designs. His last full study |
| their advantage via staging. For instance the | | | | was on the Orbital Rocket Airplane which used |
| Saturn Vs used a lower stage powered by RP-1 | | | | both tripropellant and (in some versions) a plug |
| (kerosene) and upper stages powered by LH2. | | | | nozzle, resulting in a spaceship only slightly larger |
| Some of the early Space Shuttle design efforts | | | | than a Lockheed SR-71, able to operate from |
| used similar designs, with one stage using | | | | traditional runways. |
| kerosene into the upper atmosphere, where an | | | | Although first invented in the US[citation needed], |
| LH2 powered upper stage would light and go on | | | | the only tripropellant engines built were in Russia. |
| from there. The existing Shuttle design is | | | | Kosberg and Glushko developed...(and so on) To |
| somewhat similar, although it uses solid rockets | | | | get More information , you can visit some |
| for its lower stages. | | | | products about lubricating oil pumps, water jet |
| Almost all of the cost of operating the Shuttle is | | | | pumps, . The Hand Oil Pumps products should be |
| for the payroll for the army of workers needed | | | | show more here! |