Screenshot from ULA Webcast of the launch of CST 100. Look Mom. No fairing. Just a funny hat
Mission Rundown: ULA - Atlas V N22 - OFT - CST 100
Written: September 12, 2021
Set your clocks. We fly at dawn
Everything is progressing toward the ULA Atlas V launch carrying the Orbital Flight Test OFT of Boeing’s CST-100 Starliner capsule. The mission is set to lift off at 06:36:43 EST on Friday, December 20, 2019 from Space Launch Complex-41 - SLC-41 at Cape Canaveral Air Force Station in Florida.
The uncrewed mission for NASA’s Commercial Crew Program will rendezvous and dock Boeing’s CST-100 Starliner spacecraft with the International Space Station and return to Earth on December 28.
This test flight will give real live valuable data about Starliner’s performance in the actual environment through each phase of flight and demonstrate its capability to transport crew to the space station and bring them home safely.
Data from the mission will validate spacecraft system performance and will move Starliner farther down the path toward its first flight with astronauts aboard.
Major events during launch - Centaur MECO - Starliner separation - Centaur blowout - In the dessert it says Starliner orbit insertion - Red areas are NOTAM with rocket part debris landing fields
The Boeing CST-100 Starliner
Starliner - Spacecraft 3 - itself is composed of two separate vehicles: the Crew Module and the Service Module. The Crew Module is equipped with 12 Reaction Control System (RCS) thrusters that can produce 100 lbf of thrust each.
The Service Module contains 28 RCS thrusters that produce 85 lbf thrust each and 20 Orbital Maneuvering and Attitude Control (OMAC) engines who produce 1,500 lbf thrust each. The Service Module’s OMAC engines will be used to perform abort maneuver during launch, the first crucial Orbit Insertion Burn after launch, all major in-orbit maneuvers, and the critical deorbit burn at the end of the mission.
The bottom of the Service Module contains the four Launch Abort Engines and all of the solar panels for power. For this OFT mission, the Launch Abort Engines will be disabled.
For OFT, Boeing and ULA did not want a miscalibration of the Emergency Detection System or a “miscommunication” between the system and Starliner to accidentally trigger an abort when nothing is actually wrong with the rocket.
In total, Starliner is capable of launching and landing seven people at the same time. This is largely driven by NASA’s desire for a full seven-person Station crew to pile into Starliner to quickly evacuate the Station if all crew happen to be on the U.S. side of the outpost if an emergency occurs.
Engineers breakdown of CST-100 in mayor parts - Note launch abort engines doubles as CST-100 orbit insertion engines after detachment from Centaur 2nd stage flying similar to a Shuttles ascent
A complement of four will be the normal crew rotation number, with Boeing having the option to sell a fifth seat to a private astronaut.
To accommodate this NASA requirement, Starliner has an internal pressurized volume of 11 cubic meters (390 cubic feet) for crew and cargo. 270 kg of ISS cargo being flown on this OFT mission. Most of it is food.
However, the OFT mission to the ISS – set for docking 25 hours after launch – was placed into doubt after Starliner suffered an orbital insertion issue. It was later confirmed that an issue with the Mission Elapsed Clock timing, which was ahead by 11 hours for the orbital insertion burn, had forced the decision to return Starliner to White Sands, as opposed to docking with the ISS, by Sunday.
The OMAC thrusters weren’t used to insert Starliner into the first orbit insertion only the smaller RCS thrusters were burning propellant like crazy to correct the Starliner into its believed orbit in the Mission Elapsed Clock timeline.
Propellant vital for ISS approach maneuvers were wasted and docking with ISS became impossible so that part of the mission got canceled. The rest of the mission went ahead as scheduled with ISS approach maneuvers in a lower orbit, before deorbiting itself for a landing in White Sands Space Harbour, New Mexico.
Timeline of Starliner’s descent from orbit to solid ground in the yellow line. Blue line is the Forward Heat Shield under its own parachute. Red is the dropped main heat shield’s descent line.
Boeing, in coordination with NASA and the U.S. Army, is working to return its CST-100 Starliner to land in White Sands, New Mexico, on Sunday Dec. 22. The deorbit burn is scheduled for 7:23 a.m. EST, landing for 7:57 a.m. EST - 12:57:00 UTC.
It takes about four months to refurbish a Starliner in the factory. Mostly just run through the acceptance testing procedures again.
The launch Vehicle Atlas V N22
The Starliner is attached to the Atlas V using a launch vehicle adapter (LVA) which includes an aeroskirt to reduce aerodynamic loads on the vehicle. The Atlas V configuration for this mission is powered by dual Aerojet Rocketdyne RL10A-4-2 engines, each producing 22,600 lbs. of thrust. The Centaur also includes an Emergency Detection System (EDS) that monitors the health of the rocket throughout flight.
The Atlas V N22 rocket stands 52.4 meters - 172 feet tall on SLC-41. The Orbital Flight Test will be the 81st launch of the Atlas V and will mark ULA's 136th mission.
There will be loaded 66000 gallon of cryogenic liquid oxygen and hydrogen in the three remaining tanks. Stage one fuel tank is already loaded with RP-1. First step is loading 4150 gallon of cryogenic liquid oxygen into the Centaurs LOX tank. Next, filling the first stage with 48800 gallon of cryogenic liquid oxygen in the core boosters LOX tank.
Atlas V N22 is split in its major parts. Without a standard fairing on or encapsulating the Centaur stage a special Forward Adapter with aero skirts must be used. It’s an Atlas V 422 without fairings
The Atlas V rocket will deliver Boeing’s CST-100 Starliner spacecraft to a 98-nautical mile (nmi) sub-orbital trajectory. Following separation from the Atlas V, the Starliner engines will propel the spacecraft to its final orbit and on to the ISS.
Modified specifically for the Boeing CST-100 Starliner spacecraft, the Atlas V Starliner configuration does not include a payload fairing. Instead, the Starliner’s own protective surfaces take the place of the fairing to protect the uncrewed spacecraft during ascent. This is the inaugural flight of this configuration.
The Starliner attached to the Atlas V uses a launch vehicle adapter (LVA) which includes an aeroskirt to reduce aerodynamic loads on the vehicle. The Atlas V configuration for this mission is powered by dual Aerojet Rocketdyne RL10A-4-2 engines, each producing 22,600 lbs. of thrust. The Centaur 2nd stage also includes an Emergency Detection System (EDS) that monitors the health of the rocket throughout flight.
The second stage is the Centaur, a hallmark of the Atlas family that was first used in 1962. Since then, the Centaur has evolved into the Common Centaur used today. To power the stage, an Aerojet Rocketdyne RL10C-1 engine is used to place its payload(s) into its final orbit. The RL10 engine is historic, having been used over several generations of rocket families and has been produced over 500 times.
It’s also the first flight of Atlas V in the N22 configuration (N = no fairing, 2 = two SRBs, 2 = dual-engine bell Centaur).
The only fault with this failed OTF mission was not to insert Starliner in a stable low earth orbit with the Centaur 2nd stage. Later missions could have fiddled with Space Shuttle flight profiles meaning incomplete suborbital launches, and using abort OMAC engines to circularize Starliners first orbit.
It was too risky in my opinion.
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