Following the launch of SpaceX’s 18th Industrial Resupply Services 1 contracted cargo mission, the CRS-18 Dragon has arrived on the ISS on behalf of NASA.
CRS-18 was scheduled to take off from SLC-40 at the Cape Canaveral Air Force Station, FL, on 24 July 2019 in an instantaneous. Dragon arrived 45 min forward of schedule on Saturday, following capture shortly after 9:10 AM Eastern.
The customary white and black look of the Falcon 9 has obtained an upgrade for the CRS-18 mission, coming within the form of a gray band across the bottom of the rocket’s second stage.
Throughout a launch for cargo resupply runs of Dragons to the ISS, the second stage is reignited after deploying its payload into orbit in order that the stage can carry out a destructive reentry over the open ocean.
For CRS missions, sustaining fuel (RP-1 kerosene) and oxidizer (densified Liquid Oxygen) temperatures within the second stage is just not as difficult as it’s for long coast missions which generally require the propellants to be thermally maintained or reconditioned as much as 6 hours after launch – as is the case for few Geostationary Transfer Orbit missions and Defense missions for the United States government.
The most difficult aspect of thermal control up until now had been maintaining the densified (LOX’s) liquid oxygen’s temperature and chilling that LOX back down to an acceptable temperature before second stage reignition on long coast flights.