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Mars Base

Liftoff! Delta IV Launches Next Generation GPS Satellite - 0 views

www.universetoday.com/...-next-generation-gps-satellite

scibyte66 GPS

shared by Mars Base on 05 Oct 12 - No Cached
  • A Delta IV rocket launched
  • sending a next-generation Global Positioning System satellite into orbit
  • satellite that will be part of the GPS system that is used by both civilians and the military
  • ...3 more annotations...
  • will replace a 19-year-old navigation satellite in the global system that includes 31 operational satellites on-orbit which broadcast position
  • the third of 12 planned launches to provide improved GPS signals
  • featuring improved anti-jam technology, more precise atomic clocks, an upgraded civilian channel for commercial aviation and on-board processors that can be reprogrammed in flight
Mars Base

Potent antibodies neutralize HIV and could offer new therapy, study finds - 0 views

medicalxpress.com/...es-neutralize-hiv-therapy.html

scibyte72 HIV

shared by Mars Base on 14 Nov 12 - No Cached
  • Michel Nussenzweig's Laboratory of Molecular Immunology found that a combination of five different antibodies
  • effectively suppressed HIV-1 replication and kept the virus at bay for a 60 day period after termination of therapy
  • longer half-life
  • ...13 more annotations...
  • current antiretroviral drugs require daily intake.
  • These especially potent antibodies were only recently discovered
  • identified and cloned from HIV-infected patients whose immune systems showed an unusually high ability to neutralize HIV
  • Antibodies had been written off as a treatment for HIV/AIDS because previous studies showed only a limited effect on controlling the virus
  • before these more potent antibodies were discovered
  • HIV-1 is notorious for evading the immune system's attacks by constantly mutating
  • antibodies target HIV-1's surface protein gp160, a large molecule that forms a spike that seeks out host cells and attaches to them
  • One antibody alone wasn't enough to quell the virus; neither was a mix of three
  • five of them in unison proved too complicated for gp160 to mutate its way out of.
  • Although HIV-1 infection in humanized mice differs in many important aspects from infection in humans, the results are encouraging to investigate these antibodies in clinical trials
  • It also may be that a combination of antibodies and the already established antiretroviral therapy is more efficacious than either alone
  • could be used as a treatment one day, it is conceivable that patients would only need to take traditional drugs until the virus is controlled
  • then receive antibodies every two to three months to maintain that control
Mars Base

SpaceX's First Mission to the Space Station: How It Will Work | Dragon COTS 2/3 Flight ... - 0 views

www.space.com/agon-space-station-flight.html

scibyte47 SpaceX iss PrivateSpaceTravel

shared by Mars Base on 16 May 12 - No Cached
  • SpaceX's unmanned Dragon capsule is due to deliver food, supplies and science experiments
  • SpaceX is one of two companies with NASA contracts for robotic cargo delivery flights (Virginia's Orbital Technologies Corp. is the other), but is the first to actually try a launch
  • Here's how the robotic mission is expected to play out:
  • ...50 more annotations...
  • Step 1: Launch
  • from Cape Canaveral Air Force Station in Florida. SpaceX has use of the facility's Space Launch Complex 40
  • The initial ascent is powered by Falcon 9's first stage, consisting of nine SpaceX Merlin 1C rocket engines
  • Step 2: Main Engine Cut Off/Stage Separation
  • At a little before 180 seconds into the flight, the Falcon 9's first stage engines will cut off, and the first stage will drop off, falling back to Earth
  • the booster's second stage engines should start, further propelling the vehicle into orbit.
  • Step 3: Payload Separation
  • Around 9 minutes into the flight, the Dragon capsule should separate from Falcon 9's second stage and orbit on its own
  • capsule will deploy its solar arrays to start soaking up energy from the sun
  • Dragon is on its own and must maneuver using its onboard thrusters
  • Step 4: Orbital Checkouts
  • Dragon will begin a series of checkouts to make sure it's functioning as designed and ready to meet up with the station
  • test out its abort system to prove it can terminate its activities and move away from the space station if something goes wrong.
  • demonstrate its performance in free drift phase, with thrusters inhibited
  • Teams on the ground will lead the vehicle through tests of
  • Absolute GPS (AGPS) system, which uses global positioning system satellites to determine its location in space
  • Step 5: Fly-Under
  • fire its thrusters to perform a fly-under of the International Space Station
  • to 1.5 miles (2.5 kilometers) below the outpost
  • make radio contact with the station using a system called the COTS Ultra?high frequency Communication Unit to communicate.
  • Dragon will also test a secondary locator system called the relative GPS system, which uses the spacecraft's position relative to the space station to establish its coordinates
  • the six-person crew inside the orbiting laboratory will be monitoring their new visitor
  • use a crew command panel onboard the station to communicate with the capsule and send it a command to turn on a strobe light.
  • After completing the fly-under, Dragon will loop out in front, above and then behind the space station to position itself for docking.
  • Step 6: Rendezvous
  • during Dragon's fourth day of flight, the spacecraft will fire its thrusters again to bring it within 1.5 miles (2.5 kilometers) of the space station
  • there, NASA's Mission Control team in Houston will run through a "go-no go" call to confirm all teams are ready for rendezvous
  • If everyone is "go," Dragon will inch closer, to about 820 feet (250 meters) away from the space station.
  • series of final checkouts will be performed to make sure all of Dragon's location and navigation systems are accurate
  • If all looks good, Dragon's SpaceX control team on the ground will command the vehicle to approach the space station
  • When it reaches 720 feet (220 meters), the astronauts onboard the outpost will command the capsule to halt.
  • After another series of "go-no go" checks
  • approach to 656 feet (200 meters), and then 98 feet (30 meters), and finally 32 feet (10 meters), the capture point.
  • Step 7: Docking
  • Mission Control will tell the space station crew they are "go" for capturing Dragon
  • astronaut Don Pettit will use the station's robotic arm to reach out and grab Dragon, pulling it in to the bottom side of the lab's Harmony node, and then attaching it.
  • The next day, after more checkouts, the crew will open the hatch between Dragon and the station.
  • Over the coming weeks, the astronauts will spend about 25 hours unpacking the 1,014 pounds (460 kilograms) of cargo that Dragon delivers
  • none of the cargo is critical (since this is a test flight),
  • capsule will arrive bearing food, water, clothing and supplies for the crew.
  • Step 8: Undocking
  • Dragon is due to spend about 18 days docked at the International Space Station.
  • the station astronauts will use the robotic arm to maneuver the capsule out to about 33 feet (10 meters) away, then release it. Dragon will then use its thrusters to fly a safe distance away from the laboratory.
  • Step 9: Re-entry
  • About four hours after departing the space station, Dragon will fire its engines to make what's called a de-orbit burn
  • will set the capsule on a course for re-entry through Earth's atmosphere
  • spacecraft is equipped with a heat shield to protect it from the fiery temperatures of its 7-minute re-entry flight.
  • Step 10: Landing
  • due to splash down in the Pacific Ocean to end its mission
  • There, recovery crews will be waiting to collect the capsule about 250 miles (450 kilometers) off the West Coast of the United States
  • Mars Base on 21 May 12
     
    Mission Overview
Mars Base

Phone app | Venustransit - 0 views

transitofvenus.nl/...phone-app

scibyte48 venus transit

shared by Mars Base on 23 May 12 - No Cached
  • Practising the timing of the contacts
  • Features of the phone app
  • Predicted
  • ...7 more annotations...
  • Predicted times of contact
  • The phone app has a tab which gives you the predicted times of contact for your location, as well as the times of sunset and sunrise.
  • Contacts that cannot be viewed from your location (because the sun is below the horizon) are indicated in grey.
  • Using the timer, just tap the phone’s screen at the moment of internal contact (when Venus appears within the sun, just touching the sun’s edge).
  • As you are looking through the eyepiece and not at the screen, the phone will vibrate when you log your times to let you know the time was successfully recorded
  • app will record the exact GPS time and your location, which then will be sent to the global database.
  • you are also asked to enter your email address. Although this is optional, you will be able to add more info to your entry later if you send your address along with the data.
Mars Base

Santorini Bulges as Magma Balloons Underneath - 0 views

news.nationalgeographic.com/...lava-santorini-volcano-science

scibyte63 Santorini

shared by Mars Base on 13 Sep 12 - No Cached
  • Santorini locals began to suspect last year that something was afoot with the volcano under their Greek island group
  • Wine glasses occasionally vibrated and clinked in cafes, suggesting tiny tremors, and tour guides smelled strange gasses.
  • satellite radar technology has revealed the source of the symptoms. A rush of molten rock swelled the magma chamber under the volcano by some 13 to 26 million cubic yards (10 to 20 million cubic meters)—about 15 times the volume of London's Olympic Stadium—between January 2011 and April 2012
  • ...17 more annotations...
  • even forced parts of the island's surface to rise upward and outward by 3 to 5.5 inches (8 to 14 centimeters).
  • volcano has been quiet for 60 years
  • recent events don't indicate an imminent eruption
  • the earthquake activity and the rate of bulging have both slowed right down in the last few months, it doesn't look as though the volcano is about to start to erupt, and it is quite likely that it could remain quiet for another few years or decades.
  • don't know enough about the lifecycle of large volcanoes in between eruptions to be certain
  • beginning in the January 2011 data, more than a thousand small quakes, most of them imperceptible
  • confirmed a subtle rise in Santorini's surface level with satellite radar images and GPS receivers
  • Catastrophic eruptions on Santorini, which produce mostly pumice rather than lava, appear to occur here about 20,000 years apart
  • The last one, in 1950, oozed enough lava to cover a few tennis courts
  • Despite its relative quiet, Santorini is an ideal location to learn more about processes like the magma chamber's rapid inflation
  • While satellite evidence of swelling magma chambers has rarely been available for an active volcano, the processes the data represent may not be all that unusual
  • some large volcanoes like Santorini and Yellowstone spend hundreds or thousands of years in a state of what you'd call dormancy
  • they'll often have these little restless patches
  • These types of phenomena are likely to be common, but you need the right instruments and technology to detect what are usually rather small changes in behavior."
  • we aren't any closer to knowing if, or when, the next lava eruption might happen
  • likening the recent swelling to someone blowing a big breath into an invisible balloon.
  • don't know how small or big the balloon is, and we don't know whether just one more breath will be enough for it to pop or not
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