Today sees the launch of the first commercial cargo mission for NASA to resupply the International Space Station when a SpaceX Falcon 9 will launch from the Cape Canaveral Space Launch Complex 40 at 8:35pm EDT. The mission code named CRS-1 will see the SpaceX Falcon 9 booster launch the Dragon cargo capsule up to chase down, rendezvous and dock with the ISS.
Due to the orbital requirements the Falcon 9 must launch exactly as the ISS is passing overhead to allow it to be inserted into orbit at precisely the right point to make the rendezvous. This means that there is no launch window for this mission and the rocket must launch at exactly 8:35pm EDT (0:35 GMT). If the launch goes to plan then the Dragon capsule is scheduled to dock with the ISS on October 10th and to re-enter Earth’s atmosphere and splash down in the Pacific Ocean on October 28th.
Continue reading about the NASA and SpaceX CRS-1 mission, and view the launch pad image gallery:
The total weight of the cargo being transported up to the ISS is 882 pounds. This consist: 260lbs of crew supplies; 390lbs of experiments; 225lbs of hardware for the ISS and visiting spacecraft; and albs of computer spares. During the Dragon’s stay at the ISS the capsule cargo will be unloaded and stowed aboard the ISS and repacked with 1238lbs of experiments and redundant space station hardware.
Unlike the HTV resupply spacecraft the Dragon returns to Earth. This enables a large quantity of experiments to be returned to the scientists on ground for analysis. The HTV burns up on re-entry into Earth’s atmosphere and is only suitable for removing rubbish and waste products from the ISS.
The sequence of events starts today with the roll out of the Falcon 9 from the SpaceX hanger to the launch pad. Unlike other rockets the Falcon 9 can be transported to the launch pad and launched within hours. All the preparation work is done protected from the elements in the hanger a few hundred feet from the launch pad. The rocket is rolled out on a rail system propelled by a plane towing vehicle on the horizontal mobile launch transporter/erector system. Once at the launch pad the rocket is moved into the vertical by built in hydraulics that slowly raise the Falcon 9 and dragon into the launch position.
At T-7.5 hours the Falcon 9 and Dragon capsule are powered up with the computer systems being activated. At T-4 hours the fuelling process starts. The Falcon 9 is powered by 9 merlin engines that consume liquid oxygen and kerosene. All throughout the countdown process the engineering teams are continually monitoring the status of the rocket, the capsule and all the launch systems.
At T-10:30 minutes the terminal countdown starts. All stations from NASA, SpaceX and the USAF (who control the range) are polled for GO. If everything is ‘GREEN’ launch will continue. One minute before the launch the Falcon 9′s flight computer is brought online, this computer can (and indeed has) monitor the rocket and shutdown the launch, even after the engines are lit, right up until the hold-downs are released.
At T-55 seconds the acoustic dampening water system is activated. This covers the entire launch pad area with about 20,000 gallons of water to reduce the effect of acoustic waves that may cause the rocket to vibrate. Unlike other water sound suppression systems the deluge is stopped at T-20 seconds. As the clock ticks down the 9 Merlin engines are started at T-3 seconds. Even with the engines ignited there is still time to abort, the computer checks the pressures and power from each of the engines before it allows the hold-down to be released at T-0 when the Rocket will soar into the skies.
The CRS-1 mission for NASA is the first time since the Space Shuttle was retired back in June 2011 when the USA had the capability to provide supplies to the ISS. In the intervening period the maintenance of the ISS has be provided by the Russian and Japanese spacecraft. Currently the only country with the capability to transport astronauts to and from the ISS is Russia.