Slashdot Mirror


Private Rocketplane Test A Success

HobbySpacer writes: "XCOR announced the success of the first phase of flight tests for the EZ-Rocket. In the most recent flight, Dick Rutan fired both of its rocket engines to take off and reach a speed of 160knots and an altitude of 6200 feet. The vehicle is a Long-EZ kit plane modified to hold twin 400 lb thrust rocket engines fueled by isopropyl alcohol and liquid oxygen. The project is not aimed at a homebuilt EZ-Rocket but will demonstrate safe and reliable rocket propulsion. The primary goal is development of reusable launch technology that leads next to a high altitude sub-orbital rocket vehicle for space tourism, rocket racing (e.g. vertical drag racing at air shows) and the X-Prize competition."

2 of 283 comments (clear)

  1. Re:umm, what about balloons? by Gorobei · · Score: 5, Informative

    The main reason is the FAA. If you want to be a high alt attempt, you need to file a lot of paperwork concerning your flight plan and risks to populated areas/foreign airspace. In theory, you could get approval for an orbital shot from two places in the USA (Black Rock and Alaska,) if you have a self-destruct device on board. Note that a self-destruct doesn't make the rocket vanish, it just puts the debris in a safe zone. Now, if you want to float to 120,000 feet before launch, your debris zone is about the size of the Pacific Ocean. You don't get approval, end of story.

  2. Re:Pointless by Rogerborg · · Score: 5, Informative
    • Rockets are the most inefficient method of propulsion that's still in use, a better goal would be figuring out an entirely new propulsion system that could apply to everything

    Got any ideas? Once you're at the edge of the atmosphere, you're pretty much limited to using a self contained reaction motor.

    Ground laser launching relies on superheating air, plus it's only been used to shove vehicles directly up, so it's basically a really cool but expensive way to replace July 4 bottle rockets. A more viable alternative is turning beamed EM into electricity then powering magnetohydrodynamic motors that superheat air, but you still have that pesky problem that you are relying on an atmosphere to get your speed.

    You could accelerate the vehicle in a rail gun or rocket sled until it reaches orbital velocity while it's still on the ground. Ballpark figure, at a (barely) survivable 20g, you'd need a 150km track to reach the 7.73km/s orbital velocity of a typical shuttle mission, ignoring air resistance. Except you can't ignore air resistance, because at 7.73km/sec at 1 atmosphere, you'd burn the vehicle to a toasty crisp.

    Even if you postulated antigrav, you still need to generate lateral acceleration to achieve orbital velocity, which again requires a self contained rocket, or an atmosphere.

    A beanstalk (space elevator)? Heck, maybe we've already got the technology to do it, but we're not going to, not for a long, long time.

    So, really, if you've got any ideas about what to use as an alternative to rocketry today, let's hear them. I'm fresh out.

    --
    If you were blocking sigs, you wouldn't have to read this.