Nine months have passed since Firefly’s Alpha rocket launched for the first time, lifting off from Vandenberg Space Force Base in California. Unfortunately, one of the rocket’s four main engines failed about 15 seconds into the flight, and the rocket was lost about two minutes later.
The period since then has been a difficult one for the company and its founder, Tom Markusic. In addition to dissecting the cause of the Alpha failure, Firefly also ran afoul of rules set by the Committee on Foreign Investment in the United States, CFIUS.
In December, the Air Force blocked Firefly from working at the Vandenberg launch site due to these CFIUS complications with the company’s primary investor, Ukrainian Max Polyakov. Eventually, the issue was resolved this spring after Polyakov sold his interest in Firefly, and Firefly regained access to the launch site. But it was a messy and distracting situation at a time when Firefly needed to focus on reaching orbit.
Now, brighter times appear to be ahead of the company. Firefly emerged from this crisis with a second rocket ready to go for a summer launch. To put this all into perspective, Markusic spoke to Ars about Alpha’s initial failure, the company’s launch plans for the remainder of this year, and finding a new investor to replace Polyakov.
Alpha Flight One
During Alpha’s debut flight last September, one of the rocket’s four Reaver engines stopped firing after an electrical connector failed, closing one of the engine’s main propellant valves. This sent a signal to the Reaver engine to shut down.
After the flight, Firefly engineers found that pins inside the electrical conductor had been subjected to higher than anticipated vibrations and sheared off. “Because this was a unique vibrational environment, this is probably a phenomenon we could only see in flight,” Markusic said.
He explained that the engines on Alpha were some of the first Reavers the company had built, and they “ran a little rougher” than recent engines the company has built. Because the newer flight engines operate with fewer vibrations, he does not think the problem of the electrical pins shearing off will recur.
Nevertheless, the company has taken the precaution of moving the electrical conductor higher on the vehicle, where there are fewer vibrations, and also given it a dedicated mounting bracket to further isolate it. “That problem is not going to happen again,” Markusic said.
Alpha Flight Two
Firefly noted one other issue on Alpha’s first flight that it hadn’t expected. As the engines moved and rumbled during ascent, the rocket’s body began to oscillate in phase with the motion of the engines. This is known as the “tail wags the dog” phenomenon.
Engineers had not observed the rocket oscillating at the same frequency as the engines on the test stand, because the stand itself absorbed that motion. Markusic said that, because the engineering team now understands this phenomenon with Alpha, it can be addressed with some modest changes to the rocket’s guidance and navigation software.
There are other reasons for confidence heading into the next orbital launch attempt. This is the second build of Alpha, so the hardware is more mature. A lot of the parts and sections of the booster simply fit better, Markusic said, making for a more solid overall build. There is also less wear and tear. Before the first Alpha launched, it had been test-fired 18 times. The second rocket has been tested once.
“We’re feeling really good about this second mission,” he said. “I fully expect the second flight to go to orbit, but we’re going to see minor anomalies.” Probably his biggest concern is igniting and flying Alpha’s second stage, which was not tested during the first launch.
The hardware for flight two is already on site at Vandenberg. Markusic said the company is still waiting for final range availability and launch approval from the Federal Aviation Administration, but there is a tentative launch date set for July 17.