When you ask Dr. Yajaira Sierra-Sastre what she does for a living, the answer is quite complicated. The UPRM graduate and materials scientist relocated to the D.C. area several years ago and works as a researcher at the Department of Treasuryâs Bureau of Engraving and Printing. In addition, she also functions as an educator and mentor for middle school and high school students interested in nanotechnology, engineering design and programming. Despite her busy schedule, Sierra Sastre is constantly on the lookout for the next job or project, and has a very specific goal in mind: to become the first Puerto Rican woman in space.
Sierra-Sastre first rose to local fame in 2012 when she was selected to participate in NASAâs HI-SEAS (Hawaii Space Exploration Analog and Simulation) program in Hawaii where she, along with five other scientists from various fields, âlived like an astronautâ for four months and conducted research focused on Mars exploration. This experience put her further on the map in the scientific community and improved her chances of achieving her dream of becoming an astronaut, just thirteen years after she graduated from college.
The teacher becomes the student
Sierra Sastre graduated from UPRM with a B.S. in Chemistry, however she started off as a Civil Engineering major. As a freshman, she didnât have any set goals. âI was in a process of self-discovery, and just wanted to be exposed to as many opportunities as possible.â As an engineering major, she was perpetually frustrated in some of her courses because, to her understanding, some professors didnât do a well enough job training students in academia or effectively âcommunicating scientific knowledge.â She recalls dissatisfaction towards professors who simply wrote on the whiteboard without engaging students. Eventually, she found her calling during a General Chemistry class under the training of the professor who would become her inspiration: Dr. Ivelisse Padilla. As she mentions her mentor, her face lights up with clear admiration and appreciation: âher enthusiasm and savvy for explaining complex concepts were what pushed me to pursue Chemistry.â After a meeting as a freshman with Padilla, Sierra Sastre decided to transfer to the Chemical Engineering (INQU) program. However, she eventually made the jump to study full chemistry. âThere werenât many Ivelisse Padillaâs in the INQU program,â she says with a laugh.
Sierra Sastre poses with her mother at graduation from UPRM in 2000. Â Image courtesy of Yajaira Sierra Sastre.
When she graduated in 2000, Sierra Sastre was determined to be a teacher âfor the rest of my life.â She taught math and science courses to middle and high school students at two public schools in Guayama and Arroyo; as fate would have it, she only taught for a year and a half. The summer after her last year as a teacher ended, she was accepted to participate at a full-research internship at Stanford University for three months at a post-bac program aimed specifically for teachers; it was there where Sierra-Sastre had her first experience with nanotechnology. Needless to say, the experience was powerful for Sierra Sastre in many ways.
Not only was it her first experience with nanotechnology, it was her âfirst experience doing research–period,â she explains, and adds that it was also the first time she was fully-immersed in English. During her internship, Sierra Sastre was trained by a team of scientists to research the area of self-assembly of monomolecular films, which are commonly used as coatings to avoid permeation. The experience helped her see chemistry in a new light and as a result âfall in loveâ with learning all over again. âAfter doing this research, I thought to myself âI can do this, I can be a scientist.ââ Â And so upon returning to Puerto Rico, Sierra Sastre enrolled in graduate Environmental Health courses at the School of Public Health at the UPR Medical Science Campus, as well as Chemistry courses at the graduate level at the University of Puerto Rico at RĂo Piedras. Quickly thereafter, she was accepted to pursue a dual MS/PhD program at Cornell University, and relocated to Ithaca, NY.
A blooming scientist
At Cornell, where she studied for five years before graduating in 2009, Sierra Sastre specialized in the field of Materials Chemistry, which consists of studying the structure and properties of new materials. As part of her studies she also dabbled in nanotechnology and nanomaterials, in order to research the fabrication of semiconductor nanowires, which may have applications in field-effect transistors and lithium-ion batteries. While this area of study may seem complicated enough for most, what was most demanding to Sierra Sastre was her TA-ship during her first year. While she had sufficient knowledge and experience teaching, she points out the obvious language barrier between her and her students. âDuring my first week at Cornellâ, she recalls, âa professor came up to me and asked if I had previous experience teaching, and I said yes. He must have praised me after that, but I couldnât understand a word he said,â she remembers with a laugh. That first semester she had to write down and rehearse her lectures prior to meeting her students, which was âvery frustrating,â she explains. This, on top of the pressure to do well in her highly advanced graduate courses, was incredibly challenging. However, her hard work paid off: her students were âvery patientâ with her, and she flourished throughout the year.
Her studies in Cornell led to her first job: a nanotechnology start-up in Ithaca that was a âspin-off,â as she puts it, of one of the research labs in Cornell. She quickly realized that being a scientist was more than just research and fieldwork: Sierra Sastre learned the importance of working with and protecting intellectual property, establishing strong relationships with her clients and customers, and conducting market research. The miniscule start-up, which initially consisted of just her and the founder, grew steadily over the course of two years and eventually had five full-time employees and two student interns. Without provocation, Sierra Sastre smiles cheekily and leans over the table, her hands cupping her tea, and reveals that sheâs considered proposing the same concept of that start-up at UPRM: âIâm constantly trying to bring everything back there [to Puerto Rico].â
The HI-SEAS Program
It was during her post at the start-up company where she first heard the call for scientists for NASAâs HI-SEAS program. Despite the obvious challenges of space travel, Sierra Sastre is still determined in her goal of becoming an astronaut, which is a dream sheâs held close since she was a young girl. In fact, Sierra Sastre first learned about the HI-SEAS Program back in 2011 when she was researching NASAâs call for astronauts, which were open for the first time since she graduated from her PhD just two years prior. According to its website, the HI-SEAS program was developed in order to study and determine what is necessary to keep a spaceflight crew happy and healthy during an extended mission to Mars and while living on Mars. The goal of each mission is to determine what factors, both collective and individual, are necessary to ensure an astronaut can stay physically, mentally, and emotionally motivated during an extended mission to Mars.
Sierra Sastre poses with her Tarzan plushie while on mission at the HI-SEAS program. She held a video conference  with a group of UPRM students from the course INGL3201 before her mission, who then sent her the plushie as a gift. Image via Elenita Irizarry, the instructor of the course and coordinator of the video conference.
She was in Puerto Rico visiting her mother when she found out she had been accepted to participate in the HI-SEAS program. By cosmic coincidence, that same day she was watching Joseph Acaba, the first and only astronaut of Puerto Rican descent, whom Sierra Sastre considers an inspiration, depart on the Soyuz spacecraft to a four-month mission to the International Space Station. âAs I watched Joseph, I felt that my dreams were leaving along with him,â she mused. As fate would have it, during the precise moment that she was watching Soyuzâs liftoff, she received the official e-mail from HI-SEAS. She smiles, pauses, and takes a deep breath-recalling the moment her dreams of space exploration inched closer to reality.
Since 2013, there have been four HI-SEAS missions, each with a different crew of scientists. Sierra Sastre was on the first mission, HI-SEAS-I, where she was also the only Hispanic on an international crew that included scientists from the United States, Russia, Belgium and Canada. Out of 700 applicants from all over the world, only six were selected for HI-SEAS-I: three men and three women. The training sessions, one of which took place in the Utah dessert, lasted almost a year, from June 2012 until March 2013; the actual Mars analog mission lasted four months, from mid-April to August 2013.
The isolated participants, each selected based on their area of expertise, conducted research on food and nutrition, crew dynamics, behaviors, roles and performance, as well as other aspects of space flight. Sierra Sastreâs research involved developing odor-resistant fabrics (âyou canât shower in space!â). Sierra Sastre and the rest of the crew were only allowed to take 4-minute long showers two times per week during the four-month mission, and restricted their showers even more halfway through the mission, when they were forced to ration their water supply. The fabrics she developed also had to be stain resistant and were subject to evaluation during the mission. As a crew, the HI-SEAS-I team also conducted participatory research in health and food studies, the latter of which was one of the main goals of her mission. Sierra Sastre recalls how she and her crewmates âmissed the texture of some foodsâ during the long months of their research. Nevertheless, other HI-SEAS missions have focused on research about psychosocial aspects of extended space travel as well.
Sierra Sastre, far right, at work with other scientists of the HI-SEAS-I crew. Image courtesy of Yajaira Sierra Sastre.
However, there are obvious ethical hurdles to extended space travel. I seized the opportunity to ask Sierra Sastre about these challenges, many of which were presented to me during a Planetary Geology course at UPRM. For starters, how could a crew to Mars be chosen given that it is, essentially, a one-way mission: would there be men and women with reproductive capacities, or would they be segregated? What would happen in the event of someone dying of natural causes during the mission, or if someone got pregnant during the mission, and what would be the age range for the astronauts on board?
Sierra Sastre was eager to discuss this fascinating and complex subject. âIâm not sure what age ranges would be ideal for this type of mission,â she began, measuring her response, and clarifying that the HI-SEAS scientists from her mission were all in their 30s and 40s, âbut I can tell you that the fact it was a co-ed crew definitely led to [the missionâs] success.â In fact, she recalls how one of the male scientists from the mission once mentioned, half-jokingly, that if the crew had been all-male it âwould have been a disaster.â The fact that the crew was diverse in terms of gender, academic and professional backgrounds and goals, as well as culturally diverse was, according to Sierra Sastre, a major component to the success of their mission. While her inferences are based on her experience as a participant, she affirms that the crewâs diversity helped them overcome their isolation and develop a genuine micro-community.
Whatâs Next
After her HI-SEAS program mission, Sierra Sastre began working at the Department of Treasury, which is still her day-job. However, she also has a few projects sheâs passionate about. She is a collaborator of the Puerto Rico Cube Stars program, which congregates engineers, scientists, architects and educators from D.C., Miami and Puerto Rico, who train high school students from the Thomas Armstrong Toro Public School in Ponce in the fields of environmental microbiology, astrobiology, nanotechnology and engineering. All the collaborators of the Puerto Rico Cube Stars program are Puerto Rican except for Sierra Sastreâs husband, who is a native of Tampa, Florida. The school, which specializes in preparing students for the STEM fields, was chosen because Sierra Sastre had previously collaborated with it, and the administration helped pick the four students who would participate in the project. The teamâs mission is to develop an automated nanosatellite called CubeSat, an artifact which will gather allergen samples from the stratosphere atop the glider Perlan II; as part of their goal, the #PRCubeStars team, as they are dubbed on social media, aims to break a world record by exceeding 90,000 feet during flight. âIf anything, working on this project has shown me that geographical distances donât matter when you are united for a greater good,â Sierra Sastre affirms. The team began developing their prototype in January and presented in June, but the project is still ongoing.
Sierra Sastre speaks about her experience with the PRCubeStars team in Washington, D.C. last Spring. Image courtesy of UPRAA.
This effort is just one of Sierra Sastreâs many projects. As for whatâs next, she says she doesnât know. Among her interests: science communications, education and public outreach; essentially, anything that allows her to combine her various interests in research and education. And, of course, sheâs eagerly awaiting NASAâs next call for astronauts and looks forward to reapplying. âIâm always looking,â she admits. By the end of this year, she will know if she makes the cut. âI have a good feeling I could get in this time,â she says wistfully. âAt least, I hope.â