From time to time, we hear people asking why companies like Armadillo, Masten, Virgin Galactic, and XCOR are developing suborbital vehicles for scientific research. “Don’t we already have sounding rockets for that sort of thing?”

We can understand the source of the confusion. The NASA Sounding Rocket Program claims to offer “unique opportunities for low-cost, fast-turn-around… access to space.”

That description sounds very much like what the reusable rocket companies are developing. The verbiage may have originated with attempts by former NASA Associate Administrator for Space Sciences Ed Weiler to kill the Commercial Reusable Surborbital Research (CRuSR) program authorized by Congress and divert the money to sounding rockets. The proposed funding for CRuSR was a drop in the bucket compared to NASA’s Sounding Rocket Program gets, but Weiler was opposed to NASA spending any money to fly payloads on reusable vehicles.

So, sounding rockets are now “low-cost access to space” – no matter how much they cost. But there’s a difference between “low-cost access to space” and low-cost access to space.

Do sounding rockets offer “fast turn-around” for scientific payloads? Yes, if your idea of fast turn-around is months or years. Getting a sounding-rocket flight may be faster than getting a payload approved to fly on a satellite or the International Space Station, but that isn’t saying much. If something goes wrong on a sounding-rocket flight, the payload is lost, and the experimenter must start all over again. Rapid reflights are possible only if there’s backup hardware available for both the experiment and the rocket – which is seldom the case.

Suborbital spacecraft are designed to operate more like aircraft. If something goes wrong in flight, they can return to the runway or launch pad for intact abort. If a scientist wants to repeat an experiment, because of a hardware failure or simply to gather additional data, the vehicle can be turned for another flight in a matter of days or even hours.

When it comes to cost, the numbers tell the story. In Fiscal Year 2011, the NASA Sounding Rocket program spent $45.9 million and conducted 13 launches, with one vehicle failure and two payload failures. That’s about $3.5 million per launch, or $4.5 million per mission success.

By comparison, $45.9 million would buy 473 flights of XCOR’s Lynx. If half the money goes to building payloads, it would still buy 236 Lynx flights. That’s about 4.5 flights per week – and those numbers assume the buyer doesn’t negotiate any discount for purchasing flights in bulk. We’ve used numbers like these in the past, and some people still don’t get it. So this time, we’ve decided to draw a picture:

Sounding Rocket / XCOR Lynx flight-rate comparison

Written by Astro1 on November 3rd, 2012 , Commercial Space (General)

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    Edward Wilson commented

    And that assumes a manned or semi-maned flier (semi-manned – a drone)

    Those of us looking at non-rocket technology are talking geo-sync for that price (weight and launch conditions TBD – advise expect Kgees)


    Ed Wilson

    November 4, 2012 at 10:28 am
      admin commented

      Non-rocket technologies will be interesting once they demonstrate the ability to put a payload into space at any cost. Typically, they get very low cost numbers by ignoring initial capital costs.

      November 4, 2012 at 11:09 am
        Edward Wilson commented

        An engineer will see to it that they do. But Captial Costs are amortized over many launches (at least a couple of hundred).

        Sales price is of course set by the compitition in terms of $$$, however non-rocket systems may also be ‘faster’ in terms of order to launch (I’m thinking for a ‘standard’ comsat [Last years tech but…] something on the order of 36 hr to launch, and 60 or so to service).

        November 4, 2012 at 3:26 pm
          admin commented

          Unfortunately, that is not always true. Too many aerospace engineers are weak on engineering economics or ignore it entirely. This comes from decades of working on viewgraph proposals rather than building actual hardware.

          So far, the launch rate for non-rocket systems is zero. That needs to improve considerably for the systems to be useful.

          November 4, 2012 at 3:38 pm
            john hare commented

            There are dozens of non-rocket technologies advocated, any idea of which denomination this one is?

            November 4, 2012 at 5:17 pm
            admin commented

            Thousands of g’s implies some sort of gun system, but the reference to communication satellites does not fit well with gun launch. Of course, viewgraph systems have much more flexibility when it comes to customer requirements.

            November 4, 2012 at 7:03 pm