Virgil “Gus” Grissom – Commander, Edward White – Command Pilot, Roger Chaffee – Pilot
STS-51 L (January 28, 1986)
Francis R. Scobee – Commander, Michael J. Smith – Pilot, Judith A. Resnik – Mission Specialist 1, Ellison Onizuka – Mission Specialist 2, Ronald E. McNair – Mission Specialist 3, Gregory B. Jarvis – Payload Specialist 1, Sharon Christa McAuliffe – Payload Specialist 2
STS-107 (February 1, 2003)
Rick D. Husband – Commander, William C. McCool – Pilot, Michael P. Anderson – Payload Commander, David M. Brown – Mission Specialist 1, Kalpana Chawla – Mission Specialist 2, Laurel Clark – Mission Specialist 3, Ilan Ramon – Payload Specialist 1
“Communicating from Earth to any spacecraft is a complex challenge, largely due to the extreme distances involved. When data are transmitted and received across thousands and even millions of miles, the delay and potential for disruption or data loss is significant. Delay/Disruption Tolerant Networking (DTN) is NASA’s solution to reliable internetworking for space missions.
The moon is about 250 thousand miles away and Mars is 140 million miles away on average. To communicate across these vast distances, NASA manages three communication networks consisting of distributed ground stations and space relay satellites for data transmission and reception that support both NASA and non-NASA missions. These are the Deep Space Network (DSN), the Near Earth Network (NEN), and the Space Network (SN).
For previous missions from low-Earth orbit to deep space, NASA has used point-to-point (direct) or single relay links to communicate with spacecraft; this operates much like the phone system by directly connecting two communication nodes. While this approach has been successful for previous missions, future exploration concepts will introduce much more complex communication needs, with data transfer between many nodes. These transmissions will need to operate like the Internet here on Earth – involving multiple hops via relay spacecraft and other intermediate nodes, creating the foundation for a Solar System Internet (SSI).
Like the terrestrial Internet, the SSI will offer users a well-defined, standardized platform upon which to build a wide variety of applications by accessing end-to-end network services. The SSI will utilize the Delay/Disruption Tolerant Networking (DTN) protocol suite, which can be used in any scenario, including those with longer light times or frequent link disruptions, where conventional Internet Protocols (IP) fail.”
Music provided by Killer Tracks: “Strange Reality”
Video credit: NASA’s Goddard Space Flight Center/Clare Skelly
“Behind every weather forecast—from your local, five-day prediction to a late-breaking hurricane track update—are the satellites that make them possible. Government agencies depend on observations from weather satellites to inform forecast models that help us prepare for approaching storms and identify areas that need evacuating or emergency first responders.”
Elizabeth Willaman (Willaman Creative): Lead Producer
“The more we see other planets, the more the question comes into focus: Maybe we’re the weird one? Decades of observing Earth from space has informed our search for signs of habitability and life on exoplanets and even planets in our own solar system. We’re taking a closer look at what we’ve learned about Earth – our only example of a planet with life – to our search for life the universe.”
Music credit: Curious Events by Independent Film Score – Andrew Skeet; Teapot Waltz by Benjamin James Parsons; Patisserie Pressure by Benjamin James Parsons
Video credit: NASA’s Goddard Space Flight Center/LK Ward
“By combining the visible and infrared capabilities of the Hubble and Spitzer space telescopes, astronomers and visualization specialists from NASA’s Universe of Learning program have created a spectacular, three-dimensional, fly-through movie of the magnificent Orion nebula, a nearby stellar nursery. Using actual scientific data along with Hollywood techniques, a team at the Space Telescope Science Institute in Baltimore, Maryland, and the Caltech/IPAC in Pasadena, California, has produced the best and most detailed multi-wavelength visualization yet of the Orion nebula.”
Video credit: NASA/Space Telescope Science Institute
“When exoplanet scientists first spotted patterns in disks of dust and gas around young stars, they thought newly formed planets might be the cause. But a recent NASA study cautions that there may be another explanation: one that doesn’t involve planets at all. An alternative explanation suggests the dust and gas in the disk can form the patterns themselves when they interact with starlight.
When high-energy UV starlight hits dust grains, it strips away electrons. Those electrons collide with and heat nearby gas. As the gas warms, its pressure increases and it traps more dust, which in turn heats more gas. The resulting cycle, called the photoelectric instability (PeI), can work in tandem with other forces to create some of the features astronomers have previously associated with planets in debris disks.
A 2013 study suggested PeI could explain the narrow rings seen in some disks. The model also predicted that some disks would have arcs, or incomplete rings, which weren’t directly observed in a disk until 2016. The new simulation includes an additional new factor: radiation pressure, a force caused by starlight striking dust grains. Light exerts a minute physical force on everything it encounters. This radiation pressure propels solar sails and helps direct comet tails so they always point away from the Sun. The same force can push dust into highly eccentric orbits, and even blow some of the smaller grains out of the disk entirely. The new research modeled how radiation pressure and PeI work together to affect the movement of dust and gas, and also found that the two forces manifest different patterns depending on the physical properties of the dust and gas.”
Music credit: “Hyperborea” from Killer Tracks
Video credit: NASA’s Goddard Space Flight Center/Scott Wiessenger
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