SpaceX is NO GO to launch a Falcon-9 booster with their unmanned Dragon cargo ship on the company’s fifth commercial resupply mission to the International Space Station (ISS) for NASA this Friday, Dec. 19, and will not do so until at least after the new year. The company’s second CRS-5 launch delay, according to SpaceX, is being blamed on an abundance of caution, this time after a recent customary static test fire/wet dress rehearsal (also known as a practice countdown) at Cape Canaveral Air Force Station Launch Complex-40 ended prematurely. Although the exact details of the concern have not been made available, both NASA and SpaceX have decided to push the launch back to give engineers time to review data from the test fire before proceeding with a second test fire and committing to a launch attempt.
“While the recent static fire test accomplished nearly all of our goals, the test did not run the full duration,” said SpaceX in a statement released Dec. 18. “The data suggests we could push forward without a second attempt, but out of an abundance of caution, we are opting to execute a second static fire test prior to launch. Given the extra time needed for data review and testing, coupled with the limited launch date availability due to the holidays and other restrictions, our earliest launch opportunity is now Jan. 6 with Jan. 7 as a backup.”
According to SpaceX, a launch immediately following the Christmas holiday is not an option because the orbit of the ISS will be such that the angle between the ISS orbital plane and the Sun is high (known as a high beta angle), resulting in the ISS being in almost constant sunlight for a 10-day period from Dec. 28-Jan. 7. Thermal and operational constraints prohibit Dragon from being allowed to berth with the ISS during this period, and so the company is now aiming to fly CRS-5 on Jan. 6, with the instantaneous launch window opening at 6:18 a.m. EST (which would result in an arrival at the ISS on Jan. 8).
It’s been nearly three months since the Cape last shook to the roar of the Falcon 9 v1.1’s nine Merlin 1D first-stage engines, and when Dragon does fly again on CRS-5 it will deliver more than 3,700 pounds (1,680 kg) of science experiments, technology demonstrations (such as NASA’s Cloud Aerosol Transport System (CATS)), and supplies for the incumbent Expedition 42 crew, and will remain berthed at the ISS for about four weeks.
The mission is the fifth of 12 dedicated Dragon flights, executed under the language of SpaceX’s $1.6 billion Commercial Resupply Services (CRS) contract with NASA, signed back in December 2008. Under the provisions of the contract, the company is required to deliver a combined total of 44,000 pounds (20,000 kg) of equipment and supplies to the ISS. Dragon accomplished an initial Commercial Orbital Transportation Systems (COTS) test flight to the station in May 2012, before kicking off the first of its 12 dedicated missions (CRS-1) in October of the same year. Further missions followed in March 2013, April 2014, and September 2014, with the launch of CRS-5 slightly delayed from its original target of no earlier than Dec. 16, before today’s delay to Jan. 6, 2015, was announced.
Both the CRS-5 Falcon-9 v1.1 rocket and Dragon space capsule are reportedly in good health.
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