Virgin Galactic SpaceShipTwo Powered Flight Set for Thursday Morning

SpaceShipTwo flies under power for the third time in January 2014. (Credit: Ken Brown)

by Douglas Messier
Managing Editor

The preliminaries are over. And now the moment of truth has arrived for Richard Branson’s Virgin Galactic.

Almost 3.5 years after SpaceShipTwo Enterprise broke up during a flight test on Halloween 2014, the company is scheduled to conduct the first powered flight of SpaceShipTwo Unity later this morning from the Mojave Air and Space Port in California. The test was preceded by seven glide flights.

I’ll be providing live updates on the flight on Twitter @spacecom.

The stakes are very high for a program that has seen two fatal accidents and four deaths since Richard Branson launched it in September 2014. It’s not clear whether Virgin Galactic would survive a third catastrophic accident.

While Enterprise was built and flight tested by Scaled Composites, Unity is a product of Virgin Galactic and The Spaceship Company, which is also owned by Branson’s Virgin Group.

Word has it that Unity will burn its hybrid nitrous oxide-rubber engine for 30 seconds after being dropped from the WhiteKnightTwo carrier aircraft at around 50,000 feet. This will be 50 percent longer than the 20-seconds engine burns performed by Enterprise on its second and third flight tests in 2013 and 2014.

It’s not clear exactly what altitude the spacecraft will reach, but previous flights provide some clues. Enterprise reached 71,000 feet with a 20-second engine burn on its third flight. The plan was to reach 135,000 to 138,000 feet with a 38-second burn on the fourth flight before the vehicle broke up about 12 seconds after engine ignition.

So, a 30-second burn should probably get Unity somewhere north of 100,000 feet. How much heavier (or lighter) Unity is compared with its predecessor, and the degree to which engineers have been able to improved performance of the hybrid engine, will affect the ship’s performance.

The spacecraft will go supersonic and will use its feather system — which re-configures the vehicle’s twin tail booms to slow the vehicle down — during its descent toward the spaceport.

The premature unlocking and deployment of the feather system during powered ascent caused Enterprise to break up. Unity has been redesigned to prevent a recurrence of that fatal error.

The main uncertainty for today’s flight is the weather, specifically the spring winds that have been battering Mojave over the past week. On the final flight of Enterprise, the spacecraft was limited to ground-level crosswinds of only 10 mph (16 kph) for landing. Upper level winds could also be an issue today.

  • ReSpaceAge

    I’m guessing a pilot is testing it.
    Dangerous stuff.
    Shame it can’t fly without a pilot.

  • Hemingway

    The flight seemed successful.

  • Vladislaw

    Congrats to the team .. I hope it has ironed out all the issues and can make it a reality for Americans to enjoy some black sky ..

  • JS Initials

    I read that it achieved Mach 1.6…. Somebody asked if it went above the Armstrong Line (18 km)?
    Why is it called the Armstrong Line, instead of the Yeager Line?

  • JS Initials

    You will still have to mortgage your home, or win a lottery, to buy a seat…wait several years or longer, then maybe you can risk your life for a three minute flight to 80 km.

  • Doug Weathers

    SS2 needs two pilots.

  • ReSpaceAge

    Bet BFS will need Zero pilots and pilots are strictly backup. It is the 21st century you know. Computer age, self driving cars and all that.

  • JS Initials

    The two pilots experienced zero-g for a brief time. The latest is…is that Mach 1.87 was achieved; an altitude of 25 km (80,000+ feet) was reached; they saw the Earth’s curvature; the horizon 600 km (360 miles) away, and the sky nearly charcoal black,.

  • JS Initials

    LOL….When you said Zero pilots, I thought you were a time-traveler from Japan in World War Two seeking kamikaze pilots. 🙂 🙂 🙂

  • Aerospike

    This will be 50 percent longer than the 20-seconds engine burns performed by Enterprise on its second and third flight tests in 2013 and 2004.
    I guess that should be 2014? 🙂

  • Doug Weathers

    I’m sure you’re correct – Falcon 9 needs no pilots, for example.

    There are two primary reasons for SS2 being piloted – history and cost.

    The design heritage of vertical takeoff staged rockets is weapons. Not designed to carry people, but designed to kill them. The first vehicle to leave the atmosphere was the V-2 rocket, built by the Nazis. Rockets that carry people are much less common than unmanned rockets.

    Spaceships with wings come from a different heritage: airplanes. Unmanned airplanes are much less common than manned ones, although this is changing rapidly.

    As for cost, it takes years and millions of dollars to design a new vehicle. Trying to do this without a human in the loop to respond to unforseen events will cost you a lot more in lost vehicles. Again, this is changing – computers and algorithms for autonomous flying vehicles are now available at toy stores. But when SS2 was designed, flight control computers were expensive and limited.

  • ReSpaceAge

    When SpaceX brought their first booster into Port Canaveral, I went to see it since I felt it was a historical event. While there, I talked to a guy that had a rather expensive drone. While we were talking, he launched it with his phone, he continue talking while this thing flew around a cruise ship, videoing it while it was leaving the harbor. Harbor rules make it illegal to fly over the ship. So it was completely preprogrammed to follow and orbit the ship until he pressed one key for it to return to the location from which he launched it.
    Test pilots seem rather quaint indeed.

  • ThomasLMatula

    Yes, the technology has been there for a while. But Burt Rutan and the folks at Scaled Composities liked to do things the old fashion way, real seat of the pants type of flying as in the 1950’s.

    “In those early days of the investigation, the NTSB announced they were
    forming a group that would study human factors issues associated with
    the accident. Hart did not mention that effort in his April speech, but
    did note that one thing that surprised him about SpaceShipTwo was its
    reliance on manual controls.

    “I actually flew the simulator when I was out there to see what it looks
    like. They basically opted against automation. Everything is going to
    be very manual. So when I looked at that cockpit, it was very much sort
    of out of the 1950s, almost,” he said.”

  • Philip Heruterus

    Why? You looking to advance your career as a carny?

  • Kirk

    > SS2 needs two pilots.

    Sounds like the answer to a riddle, just short of the punchline.

    Q: How many pilots does SS2 require?
    A: SS2 needs two pilots, one to fly it and one to pull the self-destruct lever.

    Too soon?

  • Doug Weathers

    I used to work for XCOR Aerospace. They also decided to have a manned vehicle, for cost and schedule reasons as I’ve discussed above. A small, relatively cash-poor company who can attract test pilots is much more likely to go the X-15 route rather than the SpaceX route. (Not counting the mavericks at Masten, who managed to attract the right programmers.)

    The drone is a different class of vehicle, tiny and cheap to develop. You could lose dozens or hundreds of those during testing and not notice the cost. Lose SS2 or the Lynx Mark I while expanding the envelope on a brand new kind of vehicle, and you lose years and many millions of dollars.