How would you really like to celebrate your birthday? We all have our own dreams of the perfect celebration – and for Sir Richard Branson, it meant becoming an astronaut just 7 days short of his 71st birthday.
Branson was one of six people who took to the skies over New Mexico in the first “full” passenger carrying flight of Virgin Galactic’s VSS Unity, in what amounts to one of the last test flights before the company starts flying fair-paying passengers on sub-orbital trips to the very edge of space.
The flight – called Unity 22 to mark the 22 flight of the spacecraft christened by the late Stephen Hawking – took Branson, together with Lead Operations Engineer Colin Bennett and the company’s Vice President of Government Affairs and Research Operations Sirisha Bandla, both of whom were also making their first flights on the vehicle, together with Chief Astronaut Instructor Beth Moses making her return to space on the vehicle, to a peak altitude in excess of 86 kilometres. At the controls were veteran Virgin Galactic pilots Dave Mackay and Michael Masucci.
The entire flight was live streamed by Virgin Galactic in a special show hosted (rather cheesily, it must be said) by Stephen Colbert, although the stream was also carried by a number of You Tube channels such as NASASpaceflight.com, from whom some of the images used here were captured.
Weather had initially interfered with things, forcing the take-off of the mated MSS Eve and VSS Unity to be delayed, but at 14:35 UTC, MSS Eve – named after Branson’s late mother, and to whom he credits his outlook on life and his drive to follow his dreams – took off from Spaceport America in New Mexico, Unity mounted on her main wing spar, to climb into a perfect sky above the Virgin Galactic base of operations.
The climb to the planned release altitude of 15 km took some 50 minutes, the two craft closely observed by chase planes. At ten minutes prior to release, both craft entered a final check-out phase of the flight, with Eve maintaining altitude as both her flight crew and Mackay and Masucci worked with ground-side Mission control to confirm all was in readiness for Unity’s flight. At this point, Unity also switched its internal power, allowing her flight control and avionics to be confirmed as ready for release.
With everything checked and ready, and Eve still holding steady, the pyrotechnics that would blow the retaining bolts holding Unity to Eve were armed. Thirty seconds later they fired, separate the two vehicle, and Unity entered a very shallow dive while Eve started a climbing turn to move away from the wake of Unity’s motor.
That motor fired 2 seconds after release, and within 3 seconds had doubled Unity’s forward airspeed to carry it through Mach 1. With the motor firing smoothly, the pilots placed the vehicle into its “Gamma Turn”, essentially pointing the nose straight up as it continued to accelerate.
At 31 seconds after release, Unity passed through Mach 2, climbing rapidly to reach Mach 3 at 55 seconds from release. Just over 10 seconds later, the motor shut down, but Unity continued to climb, and the flight crew initiated the “feather”, raising the vehicle’s tail booms relative to the hull by 60º.
“Feathering” allowed the craft to effectively “back flip” whilst still climbing, so the windows along the top of the cabin to face towards the Earth whilst the cabin itself entered a period of micro-gravity as Unity headed towards an apogee of approximately 86.77 km, where the flight crew used the reaction control system (RCS), small gas-powered jets, to re-orient the vehicle ready to start a belly-first drop back into the denser atmosphere.
This apogee point – 86-ish kilometres – has become a bone of contention between Virgin Galactic and Jeff Bezos / Blue Origin in the week or so since the Unity 22 flight was announced, as it is around 20 km below the Kármán line. The latter is recognised by many as being the divide between atmospheric flight from space flight, thus marking those who cross it as astronauts. As it is a line Virgin Galactic does not cross (but Blue Origin’s New Shepherd does), Bezos has denigrated Branson’s flight in comparison to his own, which is due to take place on July 20th.
However, whilst not reaching the 100 km mark, the Virgin Galactic flights do exceed 80 km altitude – which is regarded as the boundary between air and space by the US Air Force, NASA and the US Federal Aviation Authority – and so those flying with Virgin Galactic do qualify as astronauts. More to the point, an extra 20km of altitude doesn’t give passengers a more expanse view of Earth compared to 86 km, and the overall amount of time spent in micro gravity conditions aboard either vehicle is roughly the same.