First firing of the Falcon 9-R advanced prototype rocket. Via Elon Musk on Twitter.

SpaceX Tests Falcon 9-R Advanced Reusable Prototype Rocket

Article Updated: 23 Dec , 2015


Over the past weekend, SpaceX fired up a new version of the Falcon 9, known as the Falcon 9-R, with “R” being for “reusable.” It was the first-ever firing their new advanced prototype rocket. SpaceX told Universe Today the hold-down firing occurred on Saturday, and it lasted for approximately 10 seconds. Elon Musk had tweeted the image above earlier this week, but the company doesn’t normally discuss testing or results, so have not said much about it.

But SpaceX’s communications director Christina Ra did tell us that the Merlin 1D engines used on the test is the same as what’s used on Grasshopper, which is the 10-story Vertical Takeoff Vertical Landing (VTVL) vehicle that SpaceX has designed to test the technologies needed to return a rocket back to Earth intact.

While the Grasshopper uses just one Merlin 1D engine, the Falcon 9-R uses nine, which Musk said via Twitter provides over 1 million pounds of thrust, “enough to lift skyscraper.”

While most rockets are designed to burn up in the atmosphere during reentry, SpaceX’s is hoping their new rocket can return to the launch pad for a vertical landing.

At the end of April Musk had shared another image of first test of the Falcon 9-R ignition system.

Word on the street is that the next test will be a full 3-minute test firing.

Here’s the Grasshopper test flight in April:

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41 Responses

  1. cschur says:

    Can you just imagine, watching a rocket go up, dissapear into the blue, then a few minutes later – here comes the booster, flying back to the launch pad! this is better than science fiction to me…

    • justatinker says:


      Imagine a Falcon 9-R Heavy launch! Two boosters landing simultaneously a couple of hundred meters apart, then the third one coming in a couple of minutes later. Good thing rocket companies don’t sell stocks or a lot of innocent people would get ruined on that day! (Except SpaceX share holders, of course.)


    • philw1776 says:

      As God and Robert Heinlein intended.

  2. LSAGuy says:

    Anyone out there able to postulate how much extra fuel is going to have to be carried in order to bring the booster back? Either they’re going to have to burn the engine an amount proportional to the sum of its empty weight and the return fuel or they’re going to let it fall to some predetermined point and then burn the engine to arrest the fall. Either way that extra fuel has to be accounted for in payload not delivered to orbit and when you come down to it parachutes are lighter and less polluting. Then after you get it back you have to put a whole lot of inspection time into finding what can safely be reused and what can’t.
    I’ve got a quarter that says when push comes to shove, it’s not economical to fly it back under power. Takers?

    • philw1776 says:

      I’ll take it. Let’s worst case a thought experiment and assume pessimistically that the fuel penalty allows only 1/3 the payload to orbit. Under 3% of a rocket’s cost is fuel. After 3 flights you’ve delivered the same payload to orbit, you still have your rocket and the other guy pissed away a rockets cost to orbit the payload. Gets worse for the other guy with more flights. You don’t need that much fuel because you let the rocket fall. It can’t exceed terminal velocity as it approaches the ground at around 250 mph. Brief rocket firing slows to 0 and you land.

      • Olaf2 says:

        How do you get that number 250 mph for this rocket?

      • philw1776 says:

        Swag at terminal velocity at sea level. Not likely off by more than tens of mph.

      • Olaf2 says:

        It would be interesting to actually calculate the terminal velocity expected by this Falcon at the height that it want’s to start it’s boosters.

        3.66 meter diameter, fin down. = 10.179 square meters.

        I don’t know the empty mass with the fuel left.
        I do not know the drag coefficient, probably some kind of. circle.

        Anyone care to fill in the numbers and actually calculate it?

      • philw1776 says:

        Thanks. Made some tries. Too sensitive to parameters I don’t know. Got numbers too high (speed of sound) with small sq meters surface area. I know that SpaceX calculates a couple hundred mph but can’t find a reference to support that.

      • Olaf2 says:

        Don’t forget that when they fire rockets the mass also goes down because it burns that fuel and reduces terminal velocity much faster.

        I am wondering if the terminal velocity could be reduced when you increase the area and use RCS thrusters to let it fall sideways.

      • Amerman says:

        use RCS thrusters to let it fall sideways.

        === =
        SpaceX boosters are super light… fuel tanks with heavy engines at one end, with some remaining fuel.. consider the aerodynamic structural stress of falling sideways.
        By landing time, the vehicle is very light.. shouldn’t take much fuel to arrest even a large descent rate..
        and there are options for aerodynamic deceleration like drag ‘chutes…

        I look forward to seeing the innovative, efficient SpaceX solution.. but since fuel is cheap, and complexity is bad, I wouldn’t be surprised if they use the engines as the only method of velocity control.

      • Torbjörn Larsson says:

        The last Grasshopper flight was a demonstration of a slam landing. They nailed it, even with side wind.

        I hear they will change fields for the next series of flights, which will test the rest. I.e. next up will be coming down closer to terminal speed before initiating the slam.

      • Amerman says:

        The bigger problem is to fire the engines to slow the booster down after separation, so the aerodynamic heating and reentry stress don’t destroy it.

        Slowing down by several thousand MPH seems like it would take more fuel than the final slowing/landing.

      • philw1776 says:

        SpaceX is not doing this with the F9 1st stage. First stage velocity is similar to Shuttle SRBs. The DO plan to make the re-useable 1st stage more robust with thicker, heavier airframe. Your issue is on point were they to progress to 2nd stage recovery.

      • Amerman says:

        “The initial recovery attempts will be from a water landing, so the first-stage booster will, after separation, continue in a ballistic arc and execute a velocity reduction burn in the atmosphere to lessen the impact. Then, right before splashdown of the stage, it’s going to light the engine again. So there will be two burns after stage separation, if things go well,” Musk said.

    • dannyR says:

      Air breathing boosters are the future.

      Why waste the air you have to push through anyway?

      Burn it.

      • mattcoop2 says:

        Air breathing boosters cause drag. Careying your own oxygen is more aerodynamic. Air breathing boosters still need a lot of more development work and most company’s want the government to pay for the development.
        The cost of the fuel is $200,000 per Elon Musk. We need the the present day technology, not an air breathing rocket that is a pipe dream for large boosters such as falcon heavy.

      • Olaf2 says:

        There is not enough air. It is out of the atmosphere before it gets a chance to fire up the scram jets.

      • Torbjörn Larsson says:

        That math has been done to death too. While a reusable will lower the payload to LEO from 4 % to 2 % of total, an air breather will lower it to < 0 %. The engines are just too heavy (and expensive, undeveloped, non-reusable et cetera; take your pick).

        The one game changer may be the Sabre system, that uses an extensive cooler to drop the heat of the air to what an ordinary jet can handle. But it has yet to prove itself, and is not the type of air breather (such as scram jets) that people have had flying for a few minutes in small scale prototypes.

        SpaceX wanted to do this with a reasonable payload, a reasonable development time and a reasonable risk.

    • Din Sel says:

      Agree with you. Surely dropping down with a Parachute is much more efficient.

      • vectorjohn says:

        Surely internet rocket scientist Din Sel knows what’s best.

        Elon, Y U So Dumb?

      • Din Sel says:

        Elon is not dumb, you are.
        It would not have been Elons decision anyway, he pays other people to think about those decisions.

      • vectorjohn says:

        What? You’re the internet nobody that thinks he knows better than the actual rocket scientists. You think a parachute never crossed their minds before they started sinking millions into powered descent?

      • Din Sel says:

        I don’t think I know better then the actual rocket scientists, even though I am an Aerospace Engineer.

        The question is Why do you think that I think the parachute never crossed their mind????

        If I state a simple fact, that a parachute return of the rocket is far more efficient. How does that mean that I think they are stupid or they don’t know what they are doing?

        They have obviously opted out for powered descent for reasons other than efficient use of fuel.

      • vectorjohn says:

        Of couse you’re an aerospace engineer. That is one of the laws of the internet, everybody is an expert in whatever they give opinions on.

        The reason I am saying this is you are claiming to know rocket science better than SpaceX. You, random joe on the internet. You know what else is simple fact more efficient? They could just put a little DC electric fan on the side! That would use less fuel than a rocket and less mass than a parachute! But since that doesn’t work, they’re trying something that does.

        If your original comment isn’t claiming you know more than SpaceX, then what on earth were you trying to say? Now you’re just backing up so you don’t sound dumb.

      • Din Sel says:

        You are an Idiot. Do you feel intimidated by my aerospace engineering degree? I suggest you get one yourself, it really isn’t that hard.

        I will express any opinion I like online. I don’t need an uneducated idiot telling me what my comment “really means”.

      • Amerman says:

        I also expected some type of deployed drag devices or ‘chutes.. to reduce the post separation velocity, stabilize the vehicle, reduce the terminal velocity… I also expected some particular configuration and materials to work.
        However, SpaceX/Musk tried various options in previous Falcon 1 and Falcon 9 launches without success…. and seem to have given up, and resorted to the engine powered velocity reduction.

      • Din Sel says:

        I am certain there is a good reason for it. I would like to know what it is.

      • Hug Doug says:

        the reasons are many. primarily, parachutes are not easily reused. they must be inspected, repaired if necessary, and repacked. the eventual goal for the Falcon 9-R is reuse of a rocket stage within single digit hours. the simplest way to do this is to land the rocket stage without anything that requires labor-intensive inspection, repair, or replacement.

      • Din Sel says:

        Thank you

    • Hug Doug says:

      LSAGuy, the math has been done to death. yes, it is possible to do it, and yes, they will take a payload hit. that’s why the tanks for the v1.1 were stretched, to accommodate extra fuel; and more powerful engines were put on it, to provide more power to get more mass to orbit. but in the end, THIS DOES NOT MATTER because they recover 99% of their costs for the mission – the rocket itself – which they can then reuse. it’s a massive savings in cost per mission. it’s hugely economical.

      parachutes are antithetical to the idea of rapid reuse of a rocket. parachutes are complex, relatively delicate, need to be inspected, repacked, etc. etc. Musk wants to be able to reuse a rocket within single digit hours.

      • Olaf2 says:

        Reuse in a Single digit hours is impossible.

        I would never thrust my satellite to go up on a rocket that landed 9 hours ago and might have a hard bump or a fault during the launch. The launch phase is very traumatic for a rocket. Vibrations, stress, losing air pressure, coldness of space…. Every single component especially electronics are very vulnerable to vibrations.

      • Torbjörn Larsson says:

        Be aware that we are comparing apples and pears. Musk’s ultimate goal is massive scale colonization, and a cheap reusable may then demand a few hours turnaround.

        Since Musk is comparing with an airplane, the turnaround learning curve is reasonable. For example, the 1st stage reuse that is developed now is not subject to very low temperatures or pressures. Everything else is no different from what an airplane sees – in principle of course.

        Meaning the two stages (or 3, in a booster version) may have a different stock for reassembly, with a lot more upper stages. (Here the necessary heat shield will demand more service time if it is ablative and needs redepositing now and then.)

        But it is the lower stages that binds up most capital in the form of tank mass and engines.

      • Olaf2 says:

        But there is a difference between claiming that is must be below 10 hours to launch again and a revision that takes 10 hours to check and if no necessary reparation is required it can go on the next launch next week.

        Also as a satellite developer, I would not choose to put a very expensive satellite that took years to complete on a cheap rocket. If I choose a low cost rocket then it will be for something inexpensive. Something that can be easily replaced if it blows up.

        I am thinking about food supplies, fuel, metal or building materials and spare parts.

        It is interesting that they tried to reuse the first stage of the Saturn V Rocket using some para glider.

      • Amerman says:

        I would not choose to put a very expensive satellite that took years to complete on a cheap rocket.
        ======== =

        Would you have launched on the Nasa Space Shuttle?

        Nasa’s Space Shuttle cost over $1.6 billion per flight, killed 2 crews, and chronic and multi-year service outages..

        Nasa’s shuttle was the most bankrupting unaffordable, dangerous, unreliable space vehicle in history…

      • Olaf2 says:

        A proven rocket like Ariane or the Titan rockets would suffice.

      • Amerman says:

        Space operations of ALL TYPES are limited by cost per LB to Low Earth Orbit.. once in orbit, modules can be connected, fueled for very large missions..

        Nasa uses legacy ELVs like Titan/Atlas with a cost about $5,000 or more per LB to LEO..
        The SpaceX Falcon Heavy vehicle will lift TWICE the Shuttle payload to LEO, at less than $1,000 per LB.

        And the ongoing SpaceX Reusable designs will reduce the cost by another order of magnitude…

        Yet the bloated, pork driven, Cold war legacy Federal Agency Nasa still flushes $100s of billions on unneeded, unwanted, unaffordable, unsustainable $billions/launch shameless earmarked pork SLS/Orion…. and massive useless Center/HQ dead-wood overhead.

      • kllrbny says:

        Then again, there is the fact that SpaceX only exists because of the commoditization of space hardware and software due to decades of NASA “pork”!

        Private is definitely the future though.

      • Amerman says:

        I would never thrust my satellite to go up on a rocket that landed 9 hours ago and might have a hard bump or a fault during the launch.

        Yet you risk your life and your family in an aircraft that landed minutes ago, flown in hard landings, turbulence, rainstorms?
        You think it safer to fly a booster which has NEVER FLOWN.. might have a hundred fatal manufacturing/assembly defects… or one which has flown 50 times successfully.

        What matters is whether the article was designed for reuse.

      • Hug Doug says:

        never say “impossible” 😉

        anyway, that is SpaceX’s eventual goal. they won’t start reusing rockets so quickly until the reusability is well proven.

  3. Aqua4U says:

    Yeah YO! You go Grasshopper – go! But don’t forget to come back!

Comments are closed.