Good evening from RF mission control!
This evening we will be watching a late night (early morning) launch. This mission is a commercial resuppply mission to the International Space Station brought to you by SpaceX on board a Dragon spacecraft. There is a catch to this mission, however. The landing attempt will not be taking place on a drone ship. The rocket will be returning to the launch site. This will be the second attempt at such a launch attempt. The first one was successful back in December and was the first SpaceX landing in their history. Tonight, they look to do it again!
Let's get to it!
Primary Mission - Dragon Cargo Resupply
CRS-9 will be the 2nd Dragon launch of 2016 and 11th Dragon launch overall.
As with CRS-8, this CRS mission is carrying an important payload in Dragon's trunk. At least one 526kg International Docking Adapter is needed on the ISS to allow Commercial Crew spacecraft (Crew Dragon & CST-100) to dock with the station, starting in 2017. The first IDA flew on the ill-fated CRS-7 mission in June of 2015. The IDA going up for this mission was intended to be the second of two, but has ended up being the first. The second will be sent up on CRS-16, which has no confirmed launch date yet.
One Dragon will pave the way for the next - let's hope it goes better than the last mission that carried this particular payload!
In addition to the 526kg IDA, Dragon will carry approximately 1700kg of experiments, and supplies, and experimental supplies for a total cargo mass of approximately 2300kg. The mass of the pressurized cargo is the same as with CRS-8, but the unpressurized cargo mass of the IDA is much less than that of the record-breaking BEAM. This means that this mission will carry 800kg less in cargo than the previous Dragon.
After being inserted into the highly inclined orbit of the International Space Station, Dragon will spend several days rendezvousing with the ISS. Following that, Dragon will slowly be guided in by the manually-operated Canadarm for its berthing with the station at the nadir port of the Harmony Module.
Dragon will spend approximately a month attached to the station before it is loaded with ground-bound experiments and unberthed for its splashdown in the Pacific Ocean roughly 5.5 hours later.
Secondary Mission - First Stage Landing Attempt
As usual, this mission will include a post-launch landing attempt of the first stage. Most landing attempts use the Autonomous Spaceport Droneship Of Course I Still Love You, but this mission will follow in Orbcomm-2 Mission 2's footsteps by boosting back all the way to Cape Canaveral, where it will touch down on the LZ-1 landing pad just nine kilometers south of the SLC-40 launchpad.
How To Land A Rocket
Just under 2.5 minutes after liftoff, the first stage's engines will shut down and it will separate from the upper stage. Immediately afterwards, the stage will perform a "flip maneuver," using nitrogen gas thrusters to turn itself around and prepare for the next engine burn. The next burn is the three-engine boostback burn, which reduces, negates, or, as in this case, completely reverses the stage's downrange velocity. At this point, the stage is high in the atmosphere and is beginning its descending arc towards the landing site. The next event is the reentry burn, where three engines in a line are relit to slow down and protect the stage as it impacts the dense lower atmosphere. Then, at supersonic velocities, the stage will perform minor trajectory and attitude adjustments using the grid fins. If all goes as planned, the stage will perform a final landing burn (possibly using just the center engine instead of the three used during the previous two burns) and touchdown on LZ-1 approximately eight minutes after liftoff.
What This Means
If successful, this will be the 5th successful landing of any kind, the 2nd RTLS landing, and the 1st RTLS landing of a CRS mission.
The recovered booster would be a very likely candidate for eventual reuse, being one of only three LEO-bound boosters recovered - one of which is the stage used for the Orbcomm-2 Mission 2 launch, which will not see flight again.
Here is a recap of the previous RTLS landing:
This one is a big one, folks! After the failed landing last month, we are looking to SpaceX to bring another Falcon home! Launch is at 1245am, EST tonight!
https://spacexstats.com/live
Cheers to you and all as we always remember the sky was NEVER the limit!
Go SpaceX! Go Falcon9! Go Dragon!
