NASA's Space Propulsion Research

The Breakthrough Propulsion Physics
"The term breakthrough propulsion refers to concepts like space drives and faster-than-light travel, the kind of breakthroughs that would make interstellar travel practical.

For a general explanation of the challenges and approaches of interstellar flight, please visit the companion website:Warp Drive: When? The Warp-When site is written for the general public and uses icons of science fiction to help convey such notions. This website, on the other hand, is intended for scientists and engineers.

This research falls within the realm of physics instead of technology, with the distinction being that physics is about uncovering the laws of nature while technology is about applying that physics to build useful devices. Since existing technology is inadequate for traversing astronomical distances between neighboring stars (even if advanced to the limit of its underlying physics), the only way to circumvent these limits is to discover new propulsion physics. The discovery of new force-production and energy-exchange principles would lead to a whole new class of technologies. This is the motivation of breakthrough propulsion physics research.

Objectively, the desired breakthroughs might turn out to be impossible, but progress is not made by conceding defeat. Reciprocally, breakthroughs have a habit of taking pessimists by surprise, but can equally remain elusive. By proceeding in small, incremental steps that focus on the immediate questions and by emphasizing the reliability of the findings rather than their long-range implications, relevant and dependable knowledge will result. Regardless of whether the breakthroughs are found, this inquiry provides an additional perspective with which to seek answers to the lingering unknowns of our universe." ... more

Marc Millis
"Marc has been with NASA's Glenn Research Center since 1982 after earning a degree in Physics from Georgia Tech. In addition to his more conventional engineering assignments that have included designing guidance displays for aircraft low-gravity trajectories, ion thrusters, monitoring systems for rocket engines, and cryogenic propellant delivery systems, he has researched possibilities for creating propulsion breakthroughs. As a part of this research, he forged collaborations with other researchers across the nation to create the NASA "Breakthrough Propulsion Physics" (BPP) Project. Mr. Millis managed this Project from 1996 through 2001, and has recently stepped down from Project Management to return to conducting research. Mr. Millis is also a graduate of the 1998 International Space University Summer Program. In his free time, he builds, photographs and writes articles on scale models.

Breakthrough Propulsion Physics: Warp Drive, When? The term breakthrough propulsion refers to concepts like space drives and faster-than-light travel, the kind of breakthroughs that would make interstellar travel practical.

Contents
          -  Why is interstellar travel so tough?
          -  From Inspirations to Inventions
          -  Ideas based on what we know
          -  Ideas based on what we'd like to achieve
          -  Some Emerging Possibilities
          -  Links to Related NASA Activities
          -  So, can we do it?
          -  Frequently Asked Questions" ... more

In-Space Propulsion Technology Objective
"The objective of NASA's In-Space Propulsion Technology Program: to develop in-space propulsion technologies that can enable or benefit science at new destinations; to significantly reduce the time, cost and mass required for spacecraft to reach their destinations - in other words, to "Get More Science Sooner". Accomplishment of this objective will allow mission planners to shift their focus from the difficulty of the journey to the science challenges at the destination.

In-Space Propulsion Technology: What We Do
          -  Aerocapture systems to slow a ship down at its destination without the use of significant on-board propellant...
          -  Electric thrusters that can run not just for minutes but for years, enabling a spacecraft to accelerate continuously through space, rather than merely coast...
          -  Space sails powered by sunlight, capable of quickly pushing spacecraft to the very outskirts of the solar system - or enabling satellite to "hover" at a specific point in space...

These are just a few examples of the technologies now being investigated and developed by NASA's In-Space Propulsion Program. Together with leading propulsion researchers from academia, industry and other government organizations, we seek to identify, fund and fly those technologies that promise to enable a new era of scientific discovery throughout our solar system." ... more

Links Related Links
Fuelling Interplanetary Travel - Andrews Space Ballute Reentry Technology - Firestar Technologies

Power & In-Space Propulsion
"Plan, conduct and direct research and technology development in the fields of aerospace power and electric propulsion. This includes providing technology, expertise and research facilities for aerospace as well as non-aerospace and commercial programs. Power system technologies include photovoltaics, space environmental effects, fuel cells, batteries, solar thermal propulsion, thermal energy conversion, flywheels, Stirling converters, and power management and distribution components. The electric propulsion technologies include ion engines, pulsed plasma thrusters, Hall thrusters, magneto-plasma dynamic thrusters and plasma contactors.

Research is conducted in-house and through cooperative agreements with universities, other government agencies and not-for-profit organizations. Technology development is accomplished both in-house and through contracts and space act agreements with industrial partners. Flight experiments are conducted cooperatively with other agencies and public and private entities and organizations.
Research Focus Areas
          -  Electrochemistry
          -  Photovoltaics & Power Technologies
          -  Propulsion & Propellants
          -  Thermal Energy Conversion" ... more

Related Links about Power & In-Space Propulsion

Electric Propulsion Systems - Hall Thrusters - History of Hall Thrusters - Busek Co, Inc - Hall Thruster Experiment at PPPL - Hall Thrusters at Particle in Cell Consulting

Electric Propulsion (EP) at JPL
"The Electric Propulsion (EP) laboratory at JPL maintains several vacuum facilities for evaluating the operation, performance, lifetime, and integration of electric thrusters and related technologies on deep-space missions. Chambers range in size from small bell jars to the large 3 m diameter by 10 m long Endurance Test Facility used for high-power EP thruster testing. Most chambers are cryopumped with sufficient pumping speed to handle flow rates typical of electric thrusters. Thermal vacuum testing is accomplished with a large thermal shroud for testing over temperatures of -120 to 215 degrees C. Vibration testing is also available using other facilities at JPL. Diagnostics include several thrust stands and multiple probe-based systems for measuring plasma properties.

Test facilities are equipped with on-site machine tools and fabrication equipment for support of test activities. There is significant electrical power and liquid nitrogen infrastructure for facility operation. A wide range of power supplies with up to kilovolt and kiloamp capabilities, electrical diagnostic equipment, and data acquisition equipment are available. Most facilities are setup to safely operate unattended for long duration tests. A 420 sq. ft., class 10,000 clean room is available for test and flight hardware. Our facilities and personnel are available to support development activities in government, academia, and industry." ... more

Links from the EP Laboratory
Busek Co, Inc - Space Electric Propulsion

The Electric Propulsion Group at NASA's Jet Propulsion Laboratory (JPL)
"The Jet Propulsion Laboratory (JPL) is a NASA Federally Funded Research and Development Center focused on space exploration. Innovative technology created and/or used by JPL has taken humanity far beyond regions of space where we can actually travel ourselves. In order to enable such challenging flight missions, JPL utilizes state-of-the-art propulsion systems. Activities in advanced deep space propulsion are essential at JPL in order to expedite the adoption of new propulsion technologies and have full confidence the flight systems will meet all mission requirements.

The Electric Propulsion (EP) Group at JPL performs two principal functions: First, it provides technological expertise for robotic spacecraft mission planners, implementers, and operators in support of current and near term flight projects. This expertise is geared toward A) increasing the reliability and life of EP systems as well as, B) reducing cost and mission time for spacecraft that would otherwise use conventional chemical propulsion systems. Specific examples of recent project support include the Ion Propulsion System (IPS) on the Dawn spacecraft and the development of the flight Colloid thrusters for ST7.

The second function of the Electric Propulsion Group is to identify and evaluate, through experiment and simulation, the feasibility of advanced propulsion concepts that may lead to significant advances in space transportation capability. Such new propulsion systems will be necessary to enable fast robotic exploration of the solar system (including sample return missions, outer planet orbiters and landers) and of the local interstellar neighborhood.

Trailblazing has been the business of JPL since it was established by the California Institute of Technology in the 1930s. Pushing the outer edge of exploration, in fact, is the reason JPL exists as a NASA laboratory. JPL’s Electric Propulsion Group is proud to be a part in this on-going exploration of the frontiers of space." ... more

Ion Engines Interactive
Ion Engines are the most exciting new rocket propulsion system since the Chinese invented the rocket about a thousand years ago.

Most rocket engines use chemical reactions for power. They combine various gases and liquids to form chemical explosions which push the rocket through space. Chemical rocket engines tend to be powerful but have a short lifetime.

Ion Engines use electric fields instead of chemical reactions. Ion Engines tend to be much less powerful, but they are so efficient, they can last for years before running out of fuel.

These activities should help you understand how Ion Engines work.

Before you can understand the entire Ion Engine, you need to understand some basics about electric charges." ... more

The In-Space Propulsion Technologies Program
"The In-Space Propulsion Program work being performed at the Glenn Research Center develops primary propulsion technologies that can benefit near and mid-term science missions by reducing cost, mass and/or travel times. The In-Space Program is working to develop next generation electric propulsion technologies, including Ion and Hall thrusters. Solar Sails, which are a form of propellantless propulsion, are also being developed. Solar Sails rely on the naturally occurring sunlight for the propulsion energy. Other propulsion technologies being developed include advanced chemical propulsion and aerocapture.
Next Evolutionary Xenon Thruster (NEXT)
NEXT is one of the projects in the solar electric propulsion technology area. This project is developing the next generation ion engine technology and is managed by the NASA Glenn Research Center. NEXT is a propulsion system that could revolutionize the way we send science missions deeper into the solar system. The thruster uses xenon gas and electrical power to drive future spacecraft. The goal of NEXT program is to develop an ion thruster capable of supporting several key NASA missions in the next decade. The thruster system will enable NASA to reach destinations in our solar system that cannot be reached by conventional chemical propulsion.

The major feature of NEXT is a thruster that utilized design knowledge gained from the ion thruster that successfully propelled the Deep Space 1 to a flyby of asteroid Braille and the comet Borrelly. NEXT will have a significant increase in power compared to that of Deep Space 1's ion thruster while increasing efficiency and system performance characteristics. Advanced power processing, xenon propellant management and thruster gimbal technologies are also being developed by the team to complete the NEXT ion propulsion system.
Thruster Technologies
          -  Ion Thrusters: An ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology currently available...
          -  Hall Thrusters: Hall thrusters use an electric field to accelerate ions, similar to Ion thrusters. Hall thrusters utilize a radial magnetic field to generate an azimuthal Hall current. This current interacts with the radial magnetic field producing a volumetric (j X B) accelerating force on the plasma." ... more

OVERVIEW OF ION PROPULSION
"The propulsion of choice for science fiction writers has become the propulsion of choice for scientists and engineers at NASA. The ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology currently available. Ion thrusters are currently used for stationkeeping on communication satellites and for main propulsion on deep space probes. Ion thrusters expel ions to create thrust and can provide higher spacecraft top speeds than any other rocket currently available.

What Is an Ion?
An ion is simply an atom or molecule that is electrically charged. Ionization is the process of electrically charging an atom or molecule by adding or removing electrons. Ions can be positive (when they lose one or more electrons) or negative (when they gain one or more electrons). A gas is considered ionized when some or all the atoms or molecules contained in it are converted into ions. Plasma is an electrically neutral gas in which all positive and negative charges-from neutral atoms, negatively charged electrons, and positively charged ions-add up to zero. Plasma exists everywhere in nature; it is designated as the fourth state of matter (the others are solid, liquid, and gas). It has some of the properties of a gas but is affected by electric and magnetic fields and is a good conductor of electricity. Plasma is the building block for all types of electric propulsion, where electric and/or magnetic fields are used to push on the electrically charged ions and electrons to provide thrust. Examples of plasmas seen every day are lightning and fluorescent light bulbs.

The conventional method for ionizing the propellant atoms in an ion thruster is called electron bombardment. The majority of NASA's research consists of electron bombardment ion thrusters. When a high-energy electron (negative charge) collides with a propellant atom (neutral charge), a second electron is released, yielding two negative electrons and one positive ion. The ionization process in a xenon ion thruster is shown here:
e- + Xe0 => Xe+ + 2e-
An alternative method of ionization called electron cyclotron resonance (ECR) is also being researched at NASA. This method uses high-frequency radiation (usually microwaves), coupled with a high magnetic field to heat the electrons in the propellant atoms, causing them to break free of the propellant atoms, creating plasma. Ions can then be extracted from this plasma." ... more

The Electric Propulsion Laboratory (EPL)
"The Electric Propulsion Laboratory (EPL) supports research and development of spacecraft power and electric propulsion systems.

EPL features two very large space environment simulation chambers; intermediate and smaller environment simulation chambers suitable for testing small engines or components; bell jars used for development and small-scale component testing; and support areas including an electronics shop, machine shop, clean room, and office space.

The space simulation chambers have been enhanced to support the unique requirements of electric propulsion and power system testing. VF-5 cryopumps 3.5 million liters of air per second with its 33.5 sq meter of 12 K helium cryopanels. VF-6's solar simulator can provide 1.2 solar constants on a 5-meter diameter target or 11 solar constants on a 30-cm target. Several of the chambers have multiple air-locked access ports. These ports allow several tests to be conducted simultaneously in each chamber without cycling the chamber back to atmospheric pressure during introduction or removal of test hardware. Conditioned DC power is supplied to VF-5, VF-6 and VF-12 for powering ion, hall and MPD thrusters.

The staff of EPL have been supporting electric propulsion and power system testing for over 40 years and have developed technology leading techniques with precision thrust balances, thruster erosion diagnostics, plume characterization, and EMI/EMC." ... more

White Sands Test Facility
"White Sands Test Facility (WSTF) conducts simulated mission duty cycle testing to develop numerous full-scale propulsion systems. These systems have been developed for the Apollo Service Propulsion and Lunar modules, Shuttle Orbiter, and the International Space Station (ISS). Additionally, we evaluate upgraded or redesigned shuttle orbiter components to extend service life, enhance performance, and improve mission safety. WSTF is formally certified to perform precision cleaning and depot-level refurbishment of flight-critical propulsion systems components.

The scientific investigation of explosion phenomena at WSTF is aimed at improving safety at launch facilities and other areas where hazardous materials are used. Ultra-high-speed instrumentation helps better define safety and structural requirements for new and existing launch facilities by measuring the effects of exploding liquid and solid propellants.

WSTF is a center of technical excellence in the fields of high-pressure oxygen systems/materials and rocket propellant safety.
WSTF offers:
          -  Functional and performance evaluation tests
          -  Hazards/failure analyses of materials, components, and complete systems
          -  System design evaluation and recommendations
          -  Safety training courses and manuals."... more

Solar Sail
"The concept of a huge, ultra-thin sail unfurling in space, using the pressure of sunlight to provide propellant-free transport, hovering and exploration capabilities, may seem like the stuff of science fiction, but a NASA research team developing the Technology Demonstration Mission known as "In-Space Demonstration of a Mission-Capable Solar Sail" intend to prove the viability and value of the technology just a few short years from now.

Led by industry manufacturer L'Garde Inc. of Tustin, Calif., and including participation by the National Oceanic and Atmospheric Administration, the Solar Sail Demonstration mission builds on two successful ground-deployment experiments led by L'Garde in 2005-2006 in a vacuum chamber at the Plum Brook Facility in Sandusky, Ohio, a research laboratory managed by NASA's Glenn Research Center in Cleveland. It also leverages the successful deployment of the NanoSail-D sail, a 100-square-foot test article NASA launched to Earth orbit in early 2011 to validate sail deployment techniques. "... more

M2P2 Propulsion
"A race to the edge of the solar system and into interstellar space could come out of a grant awarded recently by NASA for the University of Washington to develop an innovative space propulsion concept.

The Dr. Robert Winglee's M2P2 - concept
Winglee's M2P2 concept would use the solar wind to push on a small imitation of the Earth's magnetosphere and accelerate the spacecraft(...)

M2P2 would generate a magnetic field and then inject plasma (ionized gas) that would drag the magnetic field lines out and form a plasma bubble 30 to 60 km (18-36 mi) in diameter. This is similar to the Earth's magnetic field trapping a large volume of electrified gas - thus forming the magnetosphere - and forcing the solar wind to flow around it...

For the M2P2 spacecraft, a magnetic field of 0.1 Tesla (about 1000 times stronger than Earth's magnetic field) could be generated by a conventional solenoid. The helicon plasma source "is amazingly simple." With a bottle of just 3 kg (6.6 lb) of helium as the plasma fuel, the magnetic bubble could be operated for three months. The size of the bubble would expand and contract with variations in the solar wind, so the force on the 100 kg spacecraft would stay constant at 1 Newton (about a quarter of a pound). The 3 kilowatts of electricity to run the magnet and plasma generator would come from solar cells.

There is enough power in the solar wind to accelerate a 136 kg (300 lb) spacecraft to speeds of up to 288,000 km/h (180,000 mph) or 6.9 million km (4.3 million mi) a day. By contrast, the space shuttle travels at about 7.7 km/s (17,300 mph) or 688,000 km (430,000 mi) a day."... more

Other Util Links
Advanced Electric Propulsion - WSGC - The Heliosphere - The Magnetospheres

Antimatter Space Propulsion
""Antimatter has tremendous energy density," said Dr. George Schmidt, chief of propulsion research and technology at NASA/Marshall. Matter-antimatter annihilation - the complete conversion of matter into energy - releases the most energy per unit mass of any known reaction in physics.

The popular belief is that an antimatter particle coming in contact with its matter counterpart yields energy. That's true for electrons and positrons (anti-electrons). They'll produce gamma rays at 511,000 electron volts. But heavier particles like protons and anti-protons are somewhat messier, making gamma rays and leaving a spray of secondary particles that eventually decay into neutrinos and low-energy gamma rays. And that is partly what Schmidt and others want in an antimatter engine. The gamma rays from a perfect reaction would escape immediately, unless the ship had thick shielding, and serve no purpose. But the charged debris from a proton/anti-proton annihilation can push a ship. "We want to get as close as possible to the initial annihilation event," Schmidt explained. What's important is intercepting some of the pions and other charged particles that are produced and using the energy to produce thrust."

This is not your father's starship
He's not going to use it the way that the Starship Enterprise did, creating a warp field to move the vessel across space faster than the speed of light. At its most basic level, an antimatter rocket is still a Newtonian rocket moving a space probe through action and reaction. And what a reaction. Where the Space Shuttle Main Engine has a specific impulse, a measure of efficiency, of 455 seconds, and nuclear fission could reach 10,000 seconds, fusion could provide 60,000 to 100,000 seconds, and matter/antimatter annihilation up to 100,000 to 1,000,000 seconds."... more

Other Antimatter Space Propulsion Links
Antimatter Space Propulsion at PSU - HiPAT-LiH (PDF) - Storage of Antimatter (PDF-1) - Storage of Antimatter (PDF-2) - NASA Antimatter Propulsion (PDF) - NIAC
Antimatter Spaceship for Mars

Electrodynamic Tether System
"Researchers at NASA's Marshall Space Flight Center have patented an electrodynamic tether system that can power spacecraft subsystems, charge battery systems, and raise and lower satellites within low Earth orbit. This design is the first bare wire electrodynamic tether developed for use in space and is more lightweight, efficient, and durable than previous designs, which utilize an insulated tether with current collection occurring only at the end mass. In contrast, Marshall's tether collects high electron current from the ionosphere to provide propulsion and power. Novel features of the tether's three separate sections include unique conductive and insulated coatings; Kevlar core-reinforced, stranded aluminum wire; and distinctive splicing of components, all of which contribute to the tether's strength and durability.

Benefits
          -  Efficient: Collects ionospheric electrons and flowing current to provide power to a spacecraft or satellite at a rate that is up to 30 times more effective than those produced by previous end-mass collection systems
          -  Strong: Withstands deployment forces and tether dynamics due to the advanced coatings present on its three separate sections
          -  Durable: Survives harsh space conditions, including the presence of atomic oxygen, extreme temperatures, and micrometeoroid/orbital debris
          -  Lightweight: Fits within volume and weight constraints for many spacecraft propulsion applications "... more

The Lightcraft Project
"The lightcraft is a revolutionary new type of transportation for use in earth-bound transportation as well as space bound flights. The lightcraft takes advantage of beamed-energy technology. Energy beaming allows the lightcraft to carry virtually no on-board propellant, greatly reducing its mass. Mass reduction allows the lightcraft to quickly and cheaply reach speeds which are needed for modern space travel. In the 1960's NASA and the Russian Space Agency first brought man to space. In the near future, the lightcraft will allow mankind as a whole to go there as well.

The Spacecraft Structure
The Lightcraft is an inflated vehicle capable of attaining supersonic speeds while in an atmosphere as well as high-velocity space flight. The primary framework of the lightcraft is constructed around a toroidal pressure vessel at the lightcraft's rim. The main hull section, shaped like a shallow dome, is supported from this structure. The toroidal pressure vessel and main framework of the vehicle are fabricated from an interlocking series of silicon carbide films and frames of varying shapes and sizes.

The toroid itself is pressurized to 25 atmospheres in order to maintain the lenticular lightcraft geometry against the propulsion system loads. The material used in the construction of the toroidal pressure vessel and hull is silicon carbide. Another key component in the framework of the lightcraft are the two high-power, parabolic rectennas that dominate nearly half the vehicle. The central parabolic rectenna is supported by ultra-light "I-beam" truses that are the only spacecraft members to take compressive loads. This basic mechanical framework provides physical integrity to the vehicle during all phases of operation. Active anti-vibrational attenuators are connected at key points in the structure. These attenuators can detect vibrational occurrences and react appropriately, causing counter vibrations, negating detrimental effects in structural members because of oscillatory fluctuations. Numerous system components are built into the hull structure, including the microwave rectennas and photovoltaic power array."... more

The NASA Propulsion Academy
"The NASA Propulsion Academy, at the Marshall Space Flight Center, is a 10-week, residential summer research and educational experience for high achieving sophomores, juniors, seniors and graduate students interested in propulsion.

The emphasis is on preparing young professionals for employment in aerospace positions.

Propulsion is a critical element in NASA's exploration program. Many current and future propulsion technologies are being designed and developed by engineers at the Marshall Space Flight Center (MSFC) and by its contractors.

The Propulsion Academy program is utilizing this development as a training ground for university students who are interested in careers in this exciting field. Research Associates (interns) will work in teams of four, guided by propulsion engineers at Marshall, local commercial entities, and local universities. Each team is composed of a "team lead" and three research associates. The team lead is an advanced undergraduate or graduate student with a demonstrated background in leadership.

The research associates are undergraduate or graduate students with some background or demonstrated interest in propulsion. Site visits, tours, and lectures will demonstrate the various opportunities for employment in the space propulsion field. These visits will expose the research associates to state-of-the-art propulsion development. Tours of local facilities and lectures by experts in propulsion will provide one-on-one interaction with practicing propulsion engineer" ... more

From, The NASA Propulsion Academy
Robotics and International Space links
NASA Robotics Academy Alumni Association - We Want our Future - Botball Robot Competition - FIRST - International Space University