SpaceX Falcon 9 V1.1 - Jason-3 - Launching January 17, 2016
Screenshot from SpaceX Webcast of the launch of Jason-3 in the fog
Mission Rundown: SpaceX Falcon 9 V1.1 - Jason-3
Written: February 1, 2021
I can’t see. Where’s the lightswitch?
With this mission, SpaceX’s Falcon 9 rocket will deliver the Jason-3 satellite to low-Earth orbit for the U.S. National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA), French space agency Centre National d'Etudes Spatiales (CNES) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).
The Jason-3 launch is targeted for a 18:42 UTC launch from Space Launch Complex 4E at Vandenberg Air Force Base, California. If all goes as planned, the Jason-3 satellite will be deployed approximately an hour after launch.
This mission also marks an experimental landing of the first stage on the SpaceX second drone ship named “Just Read the Instructions”. The landing of the first stage is a secondary test objective. Unfortunately one of the landing legs lockouts didn’t deploy, so the first stage tipped over and was destroyed. The wreck was brought back to port.
The Science Payload
Jason-3 will supply data for scientific, commercial, and practical applications to sea level rise, sea surface temperature, ocean temperature circulation, and climate change.
Jason-3 mission is to make measurements related to global sea surface height. When sea surface height is measured via altimetry, mesoscale ocean features are better simulated since the Jason-3 radar altimeter can measure precise global sea-level variations with very high accuracy. The scientific goal is to produce global sea surface height measurements every 10 days to an accuracy of less than 4 cm.
In order to calibrate the radar altimeter, a microwave radiometer measures signal delay caused by atmospheric vapors, ultimately correcting the altimeter's accuracy to 3.3 cm. This data is important to collect and analyze because it is a critical factor in understanding the changes in Earth's climate brought on by global warming as well as ocean circulation. NOAA's National Weather Service uses Jason-3's data to more accurately forecast tropical cyclones.
Jason-3 flies at the same 9.9-day repeat track orbit, this means Jason-3 will make observations over the same ocean point every 9.9 days. The orbital parameters are: 66.05º inclination, 1380 km apogee, 1328 km perigee, 112 minutes per revolution around Earth. Jason-3 is flying one minute behind Jason-2. The one minute time delay is applied in order to not miss any data collection between missions.
Jason-3 entered orbit about 15 miles (25 kilometers) below Jason-2. The spacecraft will gradually raise itself into the same 830-mile (1,336-kilometer) orbit and position itself to follow Jason-2’s ground track, orbiting a couple of minutes behind Jason-2. The two spacecraft will fly in formation, making nearly simultaneous measurements for about six months to allow scientists to precisely calibrate Jason-3’s instruments.
In the SpaceX launch Webcast it was stated that the LOX was not super chilled for easier loading of propellants. That means they are in the transition phase between different rocket types, and the Vandenberg launch facility was not ready for it. Or it means that the Falcon 9 V1.1 was not built to be loaded with RP-1 and superchilled LOX in a hurry.
Second stage deorbit burn
After hardley one orbit Falcon 9’s second stage was commanded to deorbit over the north pacific ocean near the american west coast. A large ocean area was declared a no go area in a NOTAM Notice To Airmen and Mariners in the north pacific ocean.
Notam area southeast of Hawaii used to deorbit the second stage after deployment of Jason-3
In the bottom right corner are the Notam area used for the launch of Jason-3 with a small black X - SpaceX - indicating Just Read The Instruction position, which is further to the west of the launch trajectory with a 66.05º inclination.
That required a shift of flight direction during the boost back burn, which I believe was one of the causes of booster B1017 demise including the fog at Vandenberg Air Force Base combined with the long LOX loading of Falcon 9. There was enough time to freeze everything over in a thick layer of ice including the leg lock latches.
The failure to lock one of the landing legs is the only reason that booster B10117 didn’t land properly as the only one of its production model V1.1. Alas it was not to be, B1017 tumbled over and destroyed itself on the barge deck of JRTI.
Second stage of this Falcon 9 launch usually delivers 75% of the work done on the payload before releasing the payload into its low earth polar orbit. The unsung heroes of SpaceX Falcon 9 launches are the second stages who with a single Merlin vacuum optimised rocket engine. In this case it's probably designated B2017, where B stands for booster, 2 stands for second stage and 017 is the production number on the second stage.
Nothing is certain about B2017 other than it deorbited after 140 minutes after barely one orbit southeast of Hawaii in the pacific ocean. For all I know the second stage booster could be launching out of number order. It's been known to happen for first stage boosters that they were launched out of numerical production order.
No comments:
Post a Comment