IEEE.org Sign In Join IEEE

Costa Rica's Radical Rocket

Getting to Mars' or anywhere else in the solar system-may be easier with Ad Astra Rocket Co.'s plasma thruster

01 Jun 2009

WARMING UP: On a sunny afternoon in Costa Rica, engineers at Ad Astra Rocket Co. prepare to test a heat shield for an electric rocket. It is the brainchild of Franklin R. Chang Díaz, a former NASA astronaut. Instead of combusting hydrogen and oxygen, as in a chemical rocket, this engine uses radio-frequency generators to heat a gas, turning it into a plasma. By blasting the plasma out a nozzle, the rocket generates thrust.
▲

Photo: Randi Silberman

BEAT THE HEAT: At Ad Astra’s Costa Rican facility, the thruster is attached to the end of a vacuum chamber. Magnets surrounding the thruster produce magnetic fields to wrap around the hot plasma and protect the thruster’s walls from melting. When the thruster is running, a plasma beam is vented into the vacuum chamber.
▲

Photo: Randi Silberman

MAKING PLASMA: The plasma beam of argon propellant can reach temperatures of a million kelvin. Called VASIMR, for variable specific impulse magnetoplasma rocket, the engine is capable of varying how much propellant it uses to generate thrust. In other words, it can run more or less efficiently to give a spaceship an extra boost or conserve propellant during different phases of a mission. A chemical rocket’s efficiency, by contrast, is fixed at a low level.
▲

Photo: Randi Silberman

FOOD FOR THOUGHT: Ronald Chang Díaz [third from left], is Franklin’s younger brother and in charge of the heat management lab. He handpicked his team of electrical engineers and set up the facility in Costa Rica from scratch. “We’re like a family here,” he says.
▲

Photo: Randi Silberman

AGAINST THE ODDS: Carlos Martinez Castillo, a native of Nicaragua, was working at a Costa Rican gas station when Ronald Chang Díaz showed up asking if anyone wanted a career in rockets. “I worked at a gas station when I was young, and I wanted to help one of those guys get a good job,” Chang Díaz recalls. Castillo manages the machine shop at Ad Astra and studies information technologies at a nearby university.
▲

Photo: Randi Silberman

MACHINE MASTERS: University professors visit the rocket facility for months at a time, advising the team and contributing their research. Here, Ivan Cruz, a local mechanical engineering professor, offers tips to the engineers on operating a lathe.
▲

Photo: Randi Silberman

TAKING CHARGE: Diana Valverde, an electrical engineer, oversees the control systems for the thruster. During a test run, she checks the temperatures of the materials, the RF power levels, and keeps an eye on the pressure in the chamber. "I turn on the magnets and the gas injection system, and then finally hit the pulse," Valverde says. A pulse can last for a few seconds or run for several hours, depending on the experiment.
▲

Photo: Randi Silberman

TAKING THE HEAT: The main challenge for this lab is to design a thermal jacket for the thruster, which will line its walls and remove excess heat that can damage the materials with long-term use. Some of the heat will be radiated out into space, and some of it will be returned to the plasma stream to accelerate the propellant even more.
▲

Photo: Randi Silberman

MOTHER SHIP: In Houston, at Ad Astra’s headquarters, a larger version of the thruster is installed inside a vacuum chamber. Cryogenically cooled superconducting magnets wrap the plasma in magnetic fields and two stages of radio-frequency heating accelerate the plasma out a magnetic nozzle. This thruster can operate at 200 kilowatts, and higher power levels will enable it to produce even more thrust. The next step will be to build and test a 500-kw thruster.
▲

Photo: Randi Silberman

ASTRONAUT’S DREAM: Franklin Chang Díaz, the founder of Ad Astra, says that a VASIMR rocket, could deliver a crew of people to Mars in 39 days. That configuration would require about 200 megawatts to power the thruster, which is about the size of the nuclear reactors on board some submarines today.
▲

Photo: Randi Silberman

HOMEMADE: Loyalty to his roots inspired Franklin Chang Díaz to bring rocketry to Costa Rica. “When I started this company, I was hoping to bring some little piece of it to the developing world, to my country of birth,” says Chang Díaz. “I saw it as a way of saying, Look, the monopolies of knowledge are no longer geographically set in the U.S. or in Europe or Japan.” The response was overwhelming: Now, more than 80 percent of his company is owned by Costa Rican investors.
▲

plasma type:slideshow costa rica rocket engine space flight

IEEE SpectrumFOR THE TECHNOLOGY INSIDER
TopicsAerospaceArtificial IntelligenceBiomedicalClimate TechComputingConsumer ElectronicsEnergyHistory of TechnologyRoboticsSemiconductorsTelecommunicationsTransportation
SectionsFeaturesNewsOpinionCareersDIYEngineering Resources
MoreNewslettersPodcastsSpecial ReportsCollectionsExplainersTop Programming LanguagesRobots Guide ↗IEEE Job Site ↗
For IEEE MembersCurrent IssueMagazine ArchiveThe InstituteThe Institute Archive
For IEEE MembersCurrent IssueMagazine ArchiveThe InstituteThe Institute Archive
IEEE SpectrumAbout UsContact UsReprints & Permissions ↗Advertising ↗
Follow IEEE Spectrum
Support IEEE SpectrumIEEE Spectrum is the flagship publication of the IEEE — the world’s largest professional organization devoted to engineering and applied sciences. Our articles, podcasts, and infographics inform our readers about developments in technology, engineering, and science.
Join IEEE
Subscribe
Follow IEEE Spectrum
Support IEEE SpectrumIEEE Spectrum is the flagship publication of the IEEE — the world’s largest professional organization devoted to engineering and applied sciences. Our articles, podcasts, and infographics inform our readers about developments in technology, engineering, and science.
Subscribe
About IEEEContact & SupportAccessibilityNondiscrimination PolicyTermsIEEE Privacy PolicyCookie PreferencesAd Privacy Options