Understanding how fire spreads in a microgravity environment is critical to the safety of astronauts who live and work in space. And while NASA has conducted studies aboard the space shuttle and International Space Station, risks to the crew have forced these experiments to be limited in size and scope. Fire safety will be a critical element as NASA progresses on the journey to Mars and begins to investigate deep space habitats for long duration missions.
The first Spacecraft Fire Experiment (Saffire-I) was the beginning of a three-part experiment to be conducted over the course of three flights of Orbital ATK’s Cygnus vehicle to investigate large-scale flame spread and material flammability limits in long duration microgravity.
The Saffire-I experiment enclosure was approximately half a meter wide by 1 meter deep by 1.3 meter long and consisted of a flow duct and avionics bay. Inside the flow duct, the cotton-fiberglass blend burn sample measured 0.4 m wide by 1 meter long. When commanded by Orbital ATK and Saffire ground controllers operating from Dulles, Virginia, it was ignited by a hot wire. Previous to this experiment, the largest fire experiment that had been conducted in space is about the size of an index card.
After the experiment was ignited, the Cygnus continued to orbit Earth for six days as it transmitted high-resolution imagery and data from the Saffire experiment. Following complete data transmission, the Cygnus spacecraft completed its mission with a destructive entry into the Earth’s atmosphere.
Saffire-I launched inside the Cygnus spacecraft atop the United Launch Alliance (ULA) Atlas V launch vehicle on March 22, 2016. Space Station Crew members successfully grappled Cygnus to the space station on March 26. The Saffire experiments were developed at NASA Glenn Research Center by the Spacecraft Fire Safety Demonstration Project and sponsored by the Advanced Exploration Systems (AES) Division of NASA’s Human Exploration and Operations Mission Directorate. AES pioneers new approaches for rapidly developing prototype systems, demonstrating key capabilities, and validating operational concepts for future human missions beyond low-Earth orbit. AES activities are uniquely related to crew safety and mission operations in deep space, with a strong focus on future vehicle development.
Numerous people love to do stargazing. But what if they see some cannonballs? That’s what Hubble has spotted in space recently.
Researchers believe the blobs of plasma may start the explanation about the planetary nebula formation. According to UPI, the cannonballs were ejected from V Hydrae, which is a bloated red giant 1,200 light-years from the Earth.
Hubble data shows that they are twice the size of Mars. Red giants are considered dying stars in the final stages of life, exhausting their nuclear fuel.
The plasma balls are zooming so fast through space it would take only 30 minutes for them to travel from Earth to the Moon, researchers said. According to the astronomers’ estimation, the stellar cannon has been shooting plasma balls for approximately 400 years.
The fireballs present a puzzle to astronomers because the ejected material could not have been shot out by the host star, called V Hydrae. Astronomers suspect that V Hydrae has likely discarded half of its mass into space during the star’s “death throes.” It has expanded in size and shed its layers into space.
Because scientists do not believe that V Hydrae could eject such balls of fire, the best explanation is that the materials were shot out by an unseen companion star. The theory suggests that the companion star would have to be situated in an elliptical orbit that moves it close to V Hydrae’s atmosphere every 8.5 years.
As the other star enters the red giant’s outer atmosphere, it gobbles up the material, which then settles into a disk around the companion star. The disk serves as the launch pad for plasma balls that travel at approximately half million miles per hour.
Raghvendra Sahai, the study’s lead author and an astronomer at NASA’s Jet Propulsion Laboratory (JPL), says the light of V Hydrae is obscured about every 17 years.
Researchers say that because of the wobble of the jet direction, the plasma balls alternate between passing in front and behind the star system, hiding the dying star from sight.
Sahai says the detection of cosmic cannonballs was the first time they witnessed the process. He said that it was quite pleasing as well because the research helped explain mysterious things observed about V Hydrae by other scientists.
“This discovery was quite surprising,” said Sahai.
Sahai hopes the findings would be helpful in seeing structures in planetary nebulae. He and his colleagues also hope to use Hubble to further observe the V Hydrae star system.
What would it look like to return home from outside our galaxy?
Although designed to answer greater questions, recent data from ESA’s robotic Gaia mission is helping to provide a uniquelymodern perspective on humanity’s place in the universe. Gaia orbits the Sun near the Earth and resolves star’s positions so precisely that it can determine a slight shift from its changing vantage point over the course of a year, a shift that is proportionately smaller for more distant stars — and so determines distance.
In the first sequence of the video, an illustration of the Milky Way is shown that soon resolves into a three-dimensional visualization of Gaia star data. A few notable stars are labelled with their common names, while others stars are labelled with numbers from Gaia’s catalog. Eventually the viewer arrives at our home star Sol (the Sun), then resolving the reflective glow of its third planet: Earth.
The featured video is based on just over 600,000 stars, but Gaia is on track to measure the parallax distances to over one billion stars over its planned five year mission.
While there’s a vast amount of space yet to be explored, it’s easy to forget how much we’ve already learned. And this video shows you how small our little planet actually is.
Note that the true sizes of most stars outside of the Sun and Betelgeuse are not known by direct observation, but rather inferred by measurements of their perceived brightness, temperature, and distance.