One of the most powerful missiles in history, the Delta IV Heavy, is about to retire. But, apparently, he is going to be well remembered before that. After two previous attempts to launch the NROL-44 satellite were canceled a few seconds literally before taking off from the ground, the carrier finally put it into orbit.
The start-off took place on Thursday, December 10, at 20:09 local time. The secret intelligence satellite of the US National Aerospace Intelligence Agency (NRO), number 44, was successfully launched into space. In the coming days, he will continue his journey into geosynchronous orbit, where he will be engaged in the interception of radio signals in a wide range. The device parameters are not known for certain, as well as its capabilities, as well as the exact purpose.
The launch was made from the US Space Force SLC-37 launch pad at Cape Canaveral in Florida. The United Launch Alliance (ULA), the rocket manufacturer and launch operator, had to work hard to keep things running smoothly. The fact is that this was already the third attempt to send the “ill-fated” NROL-44 into orbit. The previous two were interrupted by the carrier’s automation at the very last moment – before taking off from the starting table. And the total number of troubles with this launch exceeds five at all.
It all started with the fact that the launch was postponed from the original date – August 26 – by 24 hours at the customer’s request. The next day, on the 27th, the rocket was refueled, the prelaunch countdown began, but it had to be stopped. Technicians reported problems with the launch pad’s ground equipment pneumatic system. The flight had to be canceled and postponed to 29 August. But this attempt was not destined to be realized. Until the last moment, all processes were proceeding normally, the countdown to the start was practically over, and the engines started up. However, when tongues of flame engulfed the rocket (which is absolutely normal for a Delta IV Heavy), the automation turned off the fuel supply. Perhaps this was the most spectacular cancellation of the start in history.
The launch had to be postponed for almost a month since it was necessary to study the rocket in detail and find the cause of the malfunction. Considering that Delta IV Heavy undergoes mandatory comprehensive tests (including firing tests) before the start, the equipment failure was an unpleasant surprise for everyone at ULA. Once again, Delta entered the launch pad on September 26 but again did not take off. There was a failure when checking the “hand” that diverts the cables and hoses from the rocket during the launch. The attempt failed three days later due to the weather. And on the 30th, the picture repeated itself: the automatics canceled the start, only this time even the engines did not start.
According to the United Launch Alliance head, Tory Bruno, engineers and technicians had to work hard both with the rocket itself and with the launch pad equipment. In particular, several dozen valves and valves were replaced during the bulkhead of the SLC-37 hydraulic mechanisms, and more than 7.5 thousand liters of working fluid.
The Delta IV Heavy launch vehicle first took off in 2004. Despite its high cost, it is one of the most effective means of launching large spacecraft into geosynchronous orbit or other solar system bodies. Its feature is the use of liquefied oxygen and hydrogen in all stages. This is not the most common solution, but it provides maximum media efficiency. The rest of the Delta IV modifications are no longer used since 2019, and the Heavy variant will make five more launches.