MANNED Mars landings of U.S.spacecraft may be possible in the not-too-distantfuture thanks to a uniquely Ticotechnology – and it won’t be freeze-driedgallo pinto.Three University of Costa Rica studentshave worked for the past year with CostaRica’s astronaut, Franklin Chang, helpinghim develop new engine technology for aspace vehicle for the U.S. NationalAeronautics and Space Administration(NASA). Originally scheduled to havearrived in February 2003 (TT, Jan. 3, 2003),the students’ departure from Costa Rica wasdelayed a year due to visa difficulties.Chosen from among 32 applicants, thethree students were recipients of a scholarshipbacked by funds from the NationalCenter for High Technology (CENAT) andthe Costa Rica-USA Foundation.NEARING the end of their stay inNASA’s Johnson Space Center in Houston,Texas, the students have worked in theirseparate, specialized fields on three componentsof a new rocket engine, theVariable Specific Impulse MagnetoplasmaRocket (VASIMR).They saw many of their friends andfamily members for the first time sinceleaving Costa Rica when they gave a presentationwith Chang via videoconferencelast month. Their faces and PowerPointpresentations of their work were televisedbefore friends, family, students and officialsof the Ministry of Science andTechnology at CENAT in San José, and attwo science high schools, one in Palmares,northwest of San José, and the other inCartago, east of San José.Chang, a U.S.-Costa Rican astronautwho has worked on the plasma rocket inthe United States since 1979, said the yearhas been productive, “thanks to the talentedstudents,” and they have achieved“great advances.”HE and the students each took a crackat explaining aspects of the system.Not powered by conventional chemicalreactions, as are the rockets in use today,the plasma rocket uses nuclear power tocreate electricity that heats the propellant.The propellant is a plasma that reachesextreme temperatures – 50,000 degrees Fand above.Some scientists call material at thatheat a fourth state of matter because of itsbehavior, which is different from solids,liquids and gases. It cannot be contained inany known solid substance without meltingor otherwise damaging it, so it is containedwithin a magnetic field, the studentsexplained.Plasma, said engineering studentGonzalo Araya, consists of ionized gasessuch as helium, argon and hydrogen.Rockets using such engines wouldhave to be launched in a vacuum, such asfrom the moon, or they would have to relyon traditional engines to leave Earth beforeswitching to the plasma engine.MUCH faster than conventionalengines, this technology could dramaticallydecrease the time it takes a vehicle bearingastronauts to reach Mars and propelmuch heavier payloads, Chang said.The rocket is contained inside a vacuumchamber, where the gases used to createthe plasma are monitored with twomass spectrometers.Araya, engineering student FrankLavagni and physics student José Castroworked on aspects of the use of miniaturemass spectrometers to analyze the recombinationof gases during the creation ofplasma in the rocket.“This year we have been monitoringthe condition of the plasma and the purityof the gases used for propulsion,” Arayasaid. “And we have monitored possiblecontaminants in VASIMR that could affectthe efficient creation of plasma or the electricalcharge the radio antennas register.”Araya has designed a graphic interfacethat allows scientists to see and analyzeinformation from sensors inside the rocket.His design displays the information inboxes, similar to Microsoft Windows, andshows the rocket’s magnetic field.He considers Chang a personal hero andsaid Chang first inspired his “space fever”five years ago. He told The Tico Times inthe past that he hopes to one day followChang’s lead into space (TT, Jan. 3, 2003).LAVAGNI developed the vacuumchamber in which thermal tests are conductedwith the super-conducting magnetsthat keep the plasma in suspension. Using amore compact version of the rocket withinthe chamber, his work allows scientists toobserve its behavior as if it were a field test.The mass spectrometers serve as diagnostictools for studying the recombinationof the plasma and for detecting heliumleaks.“This is important not only because itallows us to see if one of the substancesthat comes out of the rocket into the air inthe lab is dangerous to our health, but alsobecause it indicates if water or oil hasentered, or if a seal has combusted,”Lavagni said. “The system of control andacquisition of information must be fast tobe able to respond adequately and in timeto any thermal disruption of the magnets.”CASTRO has used a Langmuir probeand a retarding potential analyzer to measurecurrents and voltage in the plasma.With those instruments, scientists calculatethe speed of particles escaping the VASIMRengine and its fuel efficiency and thrust.“Upon arriving at the Advanced SpacePropulsion Laboratory (at the JohnsonSpace Center), it was necessary to design aplatform to mount those two instruments(the probe and the analyzer) within thevacuum chamber,” Castro said. “Usingdesign software, a platform was built thatwas easy to install, easily adjusted, andelectrically isolated from the chamber.Finally, with the instruments in positionand the analysis tools in the computer, Iwas able to take information during theexperiments and calculate the energy andthe speed of the particles in the plasma.These quantities are extremely importantfor the team to plan future experiments.”OF the family members who spokewith the students after they explained theirwork, Lavagni’s father Francisco drew themost laughs when he admitted that he hadn’tunderstood anything his son had said.Francisco Lavagni and his wife SandraBolaños echoed the sentiments most oftenexpressed when they said they were proudof their son and thankful to NASA andCosta Rica for giving him the opportunityto work on the rocket.As for being separated from her son fora year, Bolaños said, “These are the sacrificesparents make for their children – theadvantage is that the children learn to cookand wash their clothes.”
