Dragon Splashes Down with Scientific Research

After the Candadarm2 grappled the Dragon spacecraft and berthed it on the space station’s Harmony module, OCO-3 was extracted and installed on the exterior of the Japanese Experiment Module-Exposed Facility. (Credit: NASA)

HOUSTON (NASA PR) — SpaceX Dragon cargo spacecraft carrying 4,200 pounds of scientific experiments and other cargo back to Earth departed the International Space Station at 12:01 p.m. EDT Monday, and splashed down in the Pacific Ocean at 5:48 p.m. (2:48 p.m. PDT).

Flight controllers at mission control in Houston used the space station’s Canadarm2 robotic arm to detach Dragon from the Earth-facing side of the station’s Harmony module and maneuver the vehicle into its release position. Expedition 59 Flight Engineer David Saint-Jacques of the Canadian Space Agency monitored its departure as the spacecraft was released through ground-controlled commands.

Dragon’s thrusters fired to move the spacecraft a safe distance from the station before SpaceX flight controllers in Hawthorne, California, commanded its deorbit burn. The SpaceX recovery team retrieved Dragon packed with science samples from human and animal research, biology and biotechnology studies, physical science investigations and education activities.

NASA’s Biophysics-6 experiment looks at the growth of two proteins of interest in cancer treatment and radiation protection. Scientists are using ground-based predictions and in-space X-ray crystallography to determine which proteins benefit from crystallization in microgravity, where some proteins can grow larger and with fewer imperfections.

Microalgae Biosynthesis in Microgravity (MicroAlgae) studies the effects of microgravity on Haematococcus pluvialis, an algae capable of producing a powerful antioxidant, astaxanthin. It could provide a readily available dietary supplement to promote astronaut health on long-duration space exploration missions. A community college student and alumnae of the NASA Community College Aerospace Scholars (NCAS) program proposed the research, and NCAS is engaging community colleges across the US to conduct ground studies for comparison to the on-orbit investigation.

On Thursday, May 23, 2019, astronauts successfully edited DNA using CRISPR/Cas9 technology for the first time in space, working on the Genes in Space 6 investigation. This milestone advances understanding of how DNA repair mechanisms function in space and supports better safeguards to protect space explorers from DNA damage. Genetic damage caused by cosmic radiation poses a serious risk to space travelers, especially those on long-duration missions to the Moon and Mars. CRISPR/Cas9 now joins a growing portfolio of molecular biology techniques available on the ISS National Lab.

Scientists are using a new technology called tissue chips, which could help predict the effectiveness of potential medicines in humans. Fluid that mimics blood can be passed through the chip to simulate blood flow, and can include drugs or toxins. In microgravity, changes occur in human health and human cells that resemble accelerated aging and disease processes. This investigation allows scientists to make observations over the course of a few weeks in microgravity rather than the months it would take in a laboratory on Earth.

NASA and the Center for the Advancement of Science in Space (CASIS), the nonprofit organization that manages research aboard the U.S. national laboratory portion of the space station, received time-sensitive samples and worked with researchers to process and distribute them within 48 hours of splashdown.

Dragon, the only space station resupply spacecraft currently able to return to Earth, launched May 4 on a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, and arrived at the station two days later for the company’s 17th NASA-contracted commercial resupply mission to the station.