It’s mission complete for the Delta II rocket – today at 6:01 A.M. Pacific Time the final Delta II booster launched on the last mission of the program to deliver ICESat-2 into a polar orbit to begin its mission of studying the Earth’s cryosphere.
This launch marks the 155th Delta II launch, the 100th successful Delta II launch in a row, and as mentioned previously, the final Delta II flight ever. This also marks Delta II as being the first booster to achieve 100 successful launches in a row – quite an accompishment to go out on! After 29 years in service, it’s over for this incredible workhorse for the USAF and NASA. This last launch also took a compliment of CubeSats into orbit with it, those being the last payloads delivered, a short while after the deployment of ICESat-2 into orbit.
The exhaust plume of the final Delta II launch.
The launch was a beauty, and even though sight the booster was quickly lost as it ascended into a cloud bank, thermal cameras downrange gave an incredible view of the ascent and the expansion of the exhaust plume from the RS-27 engine which powered the Delta II 1st stage. In a way, this gives us a wonderful last view of the RS-27 doing its job, which is something I can appreciate and love as much as seeing the booster in natural light ascending into the early morning sky.
The Delta II flight ended with the upper stage conducting one final burn over the Pacific Ocean to cause it to descend back into the Earths atmosphere to burn up, with any remaining debris falling harmlessly into the ocean. Just a few hours after launch, it was all over.
Some of my #ICESat2 #DeltaII livestream captures. Really shows the plume expansion during ascent! pic.twitter.com/VpkCjfi2yD
— 민일성 (@Kurisu_Yamato) September 15, 2018
Aside from a few moment of telemetry loss, it looked to be a flawless flight. We even got video of the payload separation, which on its own was beautiful to see. ICESat-2 being deployed from the final Delta II was a wonderful ending piece to an amazing career for the booster.
Naturally, I’ll write more about Delta II and this mission over the next few days, but for now, here’s the launch and early phase of the mission, a clip covering the deployment of ICESat-2, and some additional related videos worth sharing. Enjoy, as always!
https://www.youtube.com/watch?v=xg2IUlyNZRE
#DeltaII’s GEM-40 solid rocket motors and RS-27A engine put on a breathtaking display of ferocity during the launch of #ICESat2 this morning — What an amazing sendoff for the incredible United Launch Alliance vehicle! pic.twitter.com/0zD9w8NB2D
— John Kraus (@johnkrausphotos) September 15, 2018