CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith Overview History of the NASA Space Program Rockets 101 Rocket Fuel Today Green Rocket Fuel

CBE 55510/10/2006Katie Smith NASA Space Program: Space Race Rocket technology dates back as far as the 11 th century Late 19 th and early 20 th centuries studied liquid fuels → Research conducted primarily by Russian and American scientists → American Robert Goddard the first to develop a practical liquid rocket fuel in 1926 With WWII came acute international tensions between the USSR and the United States → Tensions bled into scientific communities Space Race effectively began on October 4, 1957 with the Soviet military’s launch of artificial satellite Sputnik 1

CBE 55510/10/2006Katie Smith

CBE 55510/10/2006Katie Smith NASA Space Program: Space Race Prior to the launch of Sputnik 1, space exploration in the United States was primarily a military endeavor US Government deemed its military infrastructure incapable of keeping up in the Space Race → Prompted the National Aeronautics and Space Act ▪ Created the National Aeronautics and Space Administration (NASA) ▪ Oversees both military and civilian space exploration The Act was signed by President Eisenhower on July 29, 1958 Space Race lasted until 1975

CBE 55510/10/2006Katie Smith NASA Space Program: Human Spaceflight NASA’s earliest research was in how to send a human into space → Project Mercury: can a human survive in space? → Project Gemini: conducted experiments relating to a moon mission → Apollo Program: designed to land humans on the moon and bring them safely back to Earth Probe missions conducted concurrently to provide further data for human spaceflight → Pioneer Program → Ranger Program → Lunar Orbiter Program → Surveyor Program

CBE 55510/10/2006Katie Smith

CBE 55510/10/2006Katie Smith NASA Space Program: the Shuttle Era Began in the late 1970s-1980s → First orbital spacecraft designed for partial reusability Composed of three main assemblies → Orbiter Vehicle (OV) + Space Shuttle Main Engines (SSMEs) → External Tank (ET) → Solid Rocket Boosters (SRBs) Each shuttle (4 total) designed for a lifespan of ~100 launches (approximately 10 years) Space shuttle to be retired in 2010 and replaced with new, manned spacecraft Orion

CBE 55510/10/2006Katie Smith

CBE 55510/10/2006Katie Smith Rockets 101 Most broad definition: any vehicle that obtains thrust by the reaction to the ejection of fast-moving fluid from within an engine → water → steam → chemical (solid, liquid, hybrid)*** Chemically powered rockets can have → internal combustion engines (heat supplied from the propellant’s reaction) → external combustion engines (heat supplied from something other than the propellant) Basic design…

CBE 55510/10/2006Katie Smith Rockets 101

CBE 55510/10/2006Katie Smith Rockets 101 Casing can be a wide range of materials → Dependent on rocket’s use → SRBs made of steel → Any rocket with steel casing requires a government permit Nozzle designed to dramatically accelerate mass by converting thermal energy into kinetic energy → Propellant flow goes sonic at the throat (up to M > 10) → Expansion ratio multiplies exhaust flow speed by an additional factor

CBE 55510/10/2006Katie Smith Rockets 101

CBE 55510/10/2006Katie Smith Rockets 101 Design specifications lead to a system of equations: → Fuel burns at a predictable rate, given its physical state and the chamber pressure → Chamber pressure determined by the nozzle orifice diameter and the fuel burn rate → Allowable chamber pressure is a function of casing design → Length of burn time is determined by fuel’s physical state

CBE 55510/10/2006Katie Smith Rockets 101 Specific to the Space Shuttle: → OV composed primarily of aluminum alloy; SSMEs made of titanium alloy → ET composed of 1/8”-thick aluminum-lithium alloy → SRBs composed of 1/2”-thick steel

CBE 55510/10/2006Katie Smith Rocket Fuel Today Aluminum Aerozine 50 Black Powder Decaborane Diborane Guanidine Nitrate Hydrazinium Nitroformate (HNF) Hexanitrohexaazaiso- wurtzitane Hydrazine Hydroxyl-terminated polybutadiene Hydroxylamine Hydroxylammonium nitrate Liquid Hydrogen Liquid Oxygen Monomethylhydrazine (MMH) Polybutadiene Acrylonirile (PBAN) Pentaborane RP-1 Triethylborane Unsymmetrical Dimethyl Hydrazine UH 25

CBE 55510/10/2006Katie Smith Rocket Fuel Today: SRBs Solid rocket fuel is in granular form, composed of: → thermoset elastomers (rigid structure) → fuel (hydrocarbon) → oxidizer → catalyst Grains can be: → solid cylinders (slow-burning) → other geometry with hollowed-out core (variable burn rates) Thrust profile is controlled by grain geometry

CBE 55510/10/2006Katie Smith Rocket Fuel Today: SRBs

CBE 55510/10/2006Katie Smith Rocket Fuel Today: ET Most common liquid propellant combinations: → liquid oxidizer: oxygen, nitrogen tetroxide, hydrogen peroxide → liquid fuel: kerosene, hydrogen, hydrazines ET formula: → LOX + liquid hydrogen

CBE 55510/10/2006Katie Smith Rocket Fuel Today: ET

CBE 55510/10/2006Katie Smith Rocket Fuel Today: comparison Solid fuels → easier to handle and store → lower specific impulse → large mass ratio becomes an issue → difficult to throttle → defects in grain formation can cause runaway reactions leading to explosion Liquid fuels → very difficult to store and handle → better specific impulse → tanks require less material → cheaper than solid propellants, but affect rocket design

CBE 55510/10/2006Katie Smith Rocket Fuel Today: environment Byproducts of burning rocket fuel: → metal (aluminum) oxides → acidic gases (hydrogen chloride) → perchlorate → noxious chemicals Early testing created water pollution → byproducts still found in water today Human ingestion leads to blood and endocrine problems → excess amounts of perchlorate cause hypothyroidism Online advocacy groups: → FreeDrinkingWater.com → Environmental Working Group → Environmentalists Against War

CBE 55510/10/2006Katie Smith Green Rocket Fuel: the Candlestick Rocket New fuel: paraffin candle wax → same material used to make “hurricane” candles Paraffin basics → also called kerosene → product of crude oil refining → saturated, C18 to C36 → melting points from 28 o C to 160+ o C Byproducts: → carbon dioxide → water

CBE 55510/10/2006Katie Smith Green Rocket Fuel: the Candlestick Rocket Theory behind paraffin-based rocket fuels developed by Stanford scientist, Arif Karabeyoglu Key is how the paraffin is burned: → in the presence of pure oxygen gas (hotter temperature) ▪ this had been done in the past → blow the oxygen past the melted paraffin surface ▪ causes the solid to evaporate quickly (think “sea spray”) ▪ tiny paraffin droplets burn much more rapidly » tripled rate of combustion Thus, new fuel is a hybrid (solid + fluid)

CBE 55510/10/2006Katie Smith Green Rocket Fuel Testing currently underway at the NASA Ames Hybrid Combustion Facility → first successful test on September 24, 2001 ▪ test chamber accommodates pressures up to 60 atm → Phase 1: 40 runs to answer the question Will it burn?

CBE 55510/10/2006Katie Smith Green Rocket Fuel Engineers will conduct ~200 tests during the project’s lifetime → one test per day, each lasting 20 seconds or less → Next Phase: new combustion chamber with sapphire windows installed to allow observation of the combustion process using optical instruments Paraffin-based SRBs still many years down the road… → project still considered to be in the ‘demonstration phase’ → likely to be tested on smaller rockets before use on the Space Shuttle or Orion

CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith Green Rocket Fuel

CBE 55510/10/2006Katie Smith References Technical: → 7&rsbci= &rsbci=13267 → → → Green Rocket Fuel: → → → araffin.html araffin.html

CBE 55510/10/2006Katie Smith References, cont’d Background (directed from NASA and ScienceDaily): → → → → → → → → → → → → → → →