Richard Garriott thinks we are heading into a new golden age of human space flight. One of the first things he mentioned in his SXSW talk was that just over 500 people have left the planet in 50 years of space flight. While he’s happy to be one of those people he agrees that number is dismal. When you factor the costs involved of sending those 500 people to space, the number is especially bleak. Just look at the overview of the International Space Station (ISS) it cost tens of billions to develop and a couple billion to maintain each year. The Shuttle was a couple hundred million per seat and the Souyoz, while cheaper, is about $50 million per seat. These enormous costs are one of the barriers to advancing human space exploration.
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SpaceX is eleven years old, has six successful launches on the books, and forty-one missions scheduled between now and 2017. Their next mission, CRS-2, for NASA is scheduled for launch on March 1. This launch is the second of twelve contracted between NASA and SpaceX to completed by 2015.
The Falcon 9 and Dragon last flew in October 2012. The Dragon docked successfully with the International Space Station (ISS) and came back to earth safely. What seemed to get the most press coverage during the mission was an issue being reported as an engine explosion. About a minute and nineteen seconds into the CRS-1 launch there was what looked like an engine explosion. This was not an explosion but an example of Falcon 9 redundancy in action. The Falcon rocket detected a sudden loss in pressure in Merlin engine 1 and issued a command to shutdown. The burst, debris, and plume of smoke were the pressure relief panels being ejected to protect engine 1 and surrounding engines. The flight computer then recalculated a new ascent profile and the Dragon continued on to the ISS.
After liftoff and separation from stage one of the Falcon 9 rocket, the SpaceX Dragon capsule must successfully perform several functions to get ready to dock with the ISS. A few minutes after the Dragon separates from the second stage of the Falcon, at about T+12:00, the sequence to activate the solar arrays starts. Try to recall the COTS 2/3 mission webcast, there was cheering from SpaceX employees after the solar arrays deployed. While SpaceX employees have a right to cheer about every aspect of the Falcon and Dragon, the solar arrays are unique. Most spacecraft similar to Dragon only use battery power.
The SpaceX Dragon launches March 1, 2013 at 10:10am EST, are you ready? For the past few of weeks we’ve been breaking down key systems of the Falcon 9 and Dragon to get you prepped for the SpaceX CRS-2 Commercial Resupply Services flight.
Here’s what you missed—
Short for Laser Imaging Detection and Ranging, LIDAR is used for a variety of mapping, distance and speed measuring tasks. It is a key feature in unmanned vehicles, like the SpaceX Dragon spacecraft. SpaceX and NASA worked with Advanced Scientific Concepts (ASC) to design DragonEye, the 3D Flash LIDAR Space Camera developed for the Dragon.
While a DragonEye LIDAR sounds like a subplot to a James Bond movie, it is what the Dragon spacecraft uses to approach and position itself to dock with the International Space Station. Laser precision comes in handy when trying to attach the 1.3-meter hatch of the Dragon to the football-field-sized space station which travels at an astounding speed of 4.71 miles per second. Once the Dragon capsule passes the R-Bar, it has to preform a series of staggered maneuvers to gradually approach the ISS Keep out Zone, a 200-meter border around the ISS, and get ready for the Canada Arm to grab it at 10-meters out.
The thruster we will see in action on SpaceX’s next launch on March 1st will be the Draco. The Draco thruster is the smallest engine in the SpaceX fleet but don’t let the size fool you, it packs 90 pounds (400 N) of thrust. The Draco is a liquid propellant thruster that uses Monomethyl Hydranzine. There is an oxidizer needed with a liquid rocket engine and SpaceX uses Nitrogen Tetroxide, the combination of orbital propellant and oxidizer that were used for the Space Shuttle.
SpaceX went with a liquid fuel rocket because, while the thruster design is more complex, the advantage is variable thrust meaning the amount of fuel and the fuel burn rate can change during flight. Liquid fuel rocket engines can not only be throttled but are able to shut down and be restarted. Having so many options for throttle and restart are helpful in a redundancy situation. It also aides in maneuvering the precise approach required for to berth with the International Space Station (ISS). The combination of the propellant and the oxidizer keeps the fuel stable allowing the Dragon capsule to be berthed to the ISS for up to a year, providing a life boat of sorts for our cosmonauts.
On August 5, 2012, the world’s attention was captured by the Mars Science Laboratory (MSL) landing. One of the key components in the multifaceted landing of the Curiosity rover safely on Mars was the Thermal Protection System (TPS), or heat shield, on the spacecraft carrying the rover.
The thing people remember most about the heat shield is when it popped off the spacecraft and flung like a frisbee across the Martian landscape, landing with a plume of dust. Measuring nearly 15 ft (4.5 m) in diameter, the MSL heat shield was the largest to ever travel to another planet. That may sound impressive, when it comes to entering an atmosphere bigger is not necessarily better. While more resistance can act as a natural braking system the trade off is enormous heat build up on the spacecraft. And we’re talking serious heat here, 3360º F (1850º C), almost twice as hot as molten lava. Continue Reading…