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Plasma Jet Electric Thrusters

21 Comments

An interesting Kickstarter project.

Via (former co-blogger) Andrew Case, who writes:

It will be interesting to see if crowd funding of space projects is viable. I know that there’s a guy who successfully funded a project to study a lunar space elevator, but as far as I know this is the first that is focused on something practical that has a real chance of flying in the short term.

I’d be interested to hear your thoughts on the subject.

I think it’s very viable, and a useful model for the future. It will be even better when we can start crowd funding actual businesses via the JOBS Act, and not just technology development.

[Late evening update]

Yeah, I know, I know. I was gone all day, and Trent provided it in comments, but here’s the link.

[Update a few minutes later]

Ignore my response to Paul Breed in comments. Doug Messier is now reporting that the engine exploded. If so, that puts a different complexion on things, but it still proves out their engine-out capability for the first stage, including shrapnel shield. The question is, as Paul notes, what are the differences between first and second-stage Merlins, if any, that can give us confidence in the second-stage reliability? Also, what would have happened to the Dragon had it happened on second stage? Just a loss of thrust, or an explosion of the entire stage (that is, would the explosion have taken out the tanks above as well, or does it have a similar shrapnel shield)?

In terms of commercial crew, the former wouldn’t necessarily require an abort system, and the latter probably wouldn’t be helped by one, unless there was sufficient warning to activate it. So it will be interesting to know from telemetry how soon they knew the engine was going south.

21 thoughts on “Plasma Jet Electric Thrusters”

  4. I understand donating money to something you are enthusiastic about. But $70k is in the microloan range. If someone believes in a project would they not offer a ROI for it?

    This does mean if you don’t have much income to devote to paying back the loan you have to reduce the size of the loan. Also you may end up paying more than 20% annual in some cases.

    I also realize that this project is not intended to produce an engine for actual use but a prototype for further testing.

    So it’s a grant rather than a loan. It’s certainly better for them. I just think that there would be more money for everyone if we embraced the microloan concept where you get $20 for risking a hundred or two. Greed in small doses is good. Liquidity that comes from profit is good.

    Forgive me for being such a wet blanket. Being a scalable high Isp engine sounds like a good thing to pursue.

      1. Microloans are certainly legal and done all the time through a bank that puts together a person wanting a loan with sometimes hundreds of people that want to provide capital for the loan. They bid down the interest rate.

    2. You don’t have to pay back crowd sourced funding. This is a proof of concept project which is perfect for kickstarter because there are no ROI expectations at this stage. If they manage to prove their concept then they could reach out to the engineering community for investments and other support but they are not at that stage yet.

  5. Time for the launch of the next SpaceX/Dragon mission, called “SpaceX Commercial Resupply Services 1”, the first of 12 contracted resupply flights, on NASA TV. The launch is set for around 8:30 PM ET.

    It’s haulting about 1000 pounds up and about 2000 pounds back, perhaps making it the most inefficient rocket flight in history (minus 1000 pounds to orbit!), but on the other hand, it means the cost per pound went negative! 😀

      1. Appears they had a first stage engine shut down early. Some reports of debris falling off of the first stage. Apparently the vehicle was sucessfully able to compensate and put the Sat and Dragon where they were supposed to.

        1. They didn’t seem to mention that during the launch, and had a normal CECO and MECO. How would people even see debiris on a night-launch through clouds, anyway?

    2. Payload to orbit vs. pressurized payload delivered to the ISS is different. If you look at the cost of delivering cargo to the ISS via Shuttle, ATV, or Progress the Dragon is considerably cheaper. I crunched the numbers on this a while ago but didn’t keep my notes, sadly, suffice it to say that the cost of delivering actual cargo to the ISS is about an order of magnitude higher than pure payload to orbit. For example, the ATV has a cost of about $113,000/kg for payload (and fuel) delivered to the ISS. Also, keep in mind that they are keeping the delivered cargo mass at a low level so that they have enough margin to sort out issues should they come up.

      1. Still, with the returned mass being twice the delivered mass, the net mass to LEO goes negative, as must the cost per net pound delivered. 😀

  6. Go check the discussion over at nasaspaceflight.

    Shotwell acknowledged a 1st stage anomaly at the post-flight interview.

    It appears MECO was late and the Second Stage burned longer too.

    1. Does BECO stand for Booster Engines Shut Off or Bunch of Engines Shutting Off? For the Falcon 9, both would be accurate.

    1. That appears to be one engine that wouldn’t be re-usable … Too bad they won’t get the stage back to do an analysis. Obviously a pretty tough rocket.

  10. Whatever. It got to orbit. Elon built in the two-engine-out redundancy for precisely that reason.

    It’s like the Google servers. They use parts that fail because they’re cheap; and move the fail-proofing to the system-level engineering where it only has to be done once. Efficient and effective.

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