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BU Students Working On a Cheaper, Gentler Suborbital Rocket

Posted by timothy on from the ma'am-this-won't-hurt-a-bit dept.

Zothecula writes The International Space Station may get all the glory, but suborbital rocket flights still play a vital part in space research. The problem is that even though such flights only go to the edge of space, they are expensive, few in number, and put massive stresses on experiments. Partly funded by a Kickstarter campaign, students at Boston University are developing an inexpensive suborbital rocket for educational purposes that uses new engine designs to create a cheaper, reusable suborbital rocket that's easier on the payload.

43 comments

  1. Airship one headed in the right direction by Anonymous Coward · · Score: 2, Interesting

    Cheaper way would be a large high altitude jet to carry the rocket to the edge of space. Use the oxygen in the air as long as possible and not carry the oxygen aboard. A maglev launcher like the Navy is experimenting with,(only bigger) have as much horsepower on the ground as possible.
    Get the whole thing up to 500mph and then 500 ft up. The jet engine takes over and goes up to 60000+ ft. 700 mph, not quite mach 1.
    Then the rocket can kick in and go to the station.

    1. Re:Airship one headed in the right direction by Anonymous Coward · · Score: 0

      There's at least one more way (short of a space elevator).

      Carry only propellant. Let the energy be delivered by laser, using multiply redundant telescope-like devices from the surface.

    2. Re:Airship one headed in the right direction by Solandri · · Score: 2

      Cheaper way would be a large high altitude jet to carry the rocket to the edge of space. Use the oxygen in the air as long as possible and not carry the oxygen aboard. [...]
      Get the whole thing up to 500mph and then 500 ft up. The jet engine takes over and goes up to 60000+ ft. 700 mph, not quite mach 1.
      Then the rocket can kick in and go to the station.

      The great irony of the space age is that is precisely what the U.S. was working on in parallel to Sputnik. Before Sputnik ever went up, clearer-thinking people analyzed the problem, and came to the same conclusion you just did - it's cheaper to strap your rocket to a plane, haul it up to 45,000 ft, and launch it into space from there.

      But then the Soviets put a man into orbit, Kennedy said we should land a man on the moon by the end of the decade, and suddenly doing it quickly took precedence over doing it economically. That's led us 5 decades down the "wrong" technology path (simpler, quicker, but more expensive). And only in the last decade have we been seriously reconsidering the cheaper technology path. I often wonder where we would be if there had been no space race. Would we already have hypersonic transports taking you halfway around the world in an hour? Would space travel be more commonplace because it'd be so much cheaper?

    3. Re:Airship one headed in the right direction by DerekLyons · · Score: 1

      Cheaper way would be a large high altitude jet to carry the rocket to the edge of space.

      The problem is - it's not really cheaper. Fuel is cheap, large high altitude jets aren't - and it takes a very, very, large number of flights to amortize the cost of the latter below the cost of the former. Further, the size of the jet places significant size constraints on the booster. On top of that, your booster is now heavier because the structure must now be strengthened to take the loads of being carried horizontally and dropped as well as the usual longitudinal loads.

      Air launch is one of those ideas that seems to make sense (in the same way that many perpetual motion machines do) on the BOTE and among those who haven't bothered to do the research... but when you move on to rigorous analysis, the whole scheme rapidly falls apart. There's a reason why Pegasus is one of the most expensive launchers around per/kg and why, despite being so "obvious", air launchers are largely noticeable by their near complete absence.

    4. Re:Airship one headed in the right direction by Marxist+Hacker+42 · · Score: 1

      What's wrong with using a balloon, to lift your rocket until the balloon explodes, THEN kick in the engines?

      --
      SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
    5. Re:Airship one headed in the right direction by Anonymous Coward · · Score: 0

      Only ignorant morons think that the space elevator can be build and that it could be cheap.

    6. Re:Airship one headed in the right direction by thrich81 · · Score: 2

      Not intending to bust on you here, but this idea comes up occasionally -- that NASA screwed up by "abandoning" air-launched space planes for ICBM based capsules. Often it is from someone who "had an uncle working on it in 1958" or similar. Seems promising but the physics just don't work that well for air launches and it turns out that putting the rest of your vehicle on a big first stage to get it out of the atmosphere and on a good start for speed is very efficient. There is a huge difference in getting an X-15 to Mach 6+ and an orbital vehicle to Mach 25. Air launch just doesn't work for anything other than small payloads.

      To get the Apollo lander to the moon the Saturn V had to put 260,000 lbs into low earth orbit. The biggest Boeing 747 now (in 2014) has a takeoff weight of 975,000 lbs. Look at the difference in size between the X-15 and the B-52 which carried it. There is no aircraft which is going to launch an Apollo sized payload into earth orbit. Or looking at it another way -- at burnout and jettison of the first stage of the Saturn V, the rest of the vehicle was already moving faster than the X-15 ever got to (a lot faster) and almost as high.

      If air launch was really feasible, then customers would be knocking down the door at Orbital Sciences which has had their air-launch to orbit Pegasus booster in operation since 1990 and there would be an effort to build bigger versions -- there isn't. That whole X-30 program (National Aero-Space Plane) in the 90's was similar to air launched spacecraft and it didn't get anywhere.
         

    7. Re:Airship one headed in the right direction by Anonymous Coward · · Score: 0

      Here is a single clue: Controlled direction.

      The direction, speed and rate of turn can't be (fully) controlled, making them a completely useless launch platform.

    8. Re:Airship one headed in the right direction by Marxist+Hacker+42 · · Score: 1

      Seems to me a raspberi pi, four stepper motors, and a couple of good accelerometers could easily compensate for that.

      Either that, or just make your rocket bottom heavy.

      --
      SJW: a person who perceives an injustice, and while correcting it, commits a greater injustice.
    9. Re:Airship one headed in the right direction by ceoyoyo · · Score: 1

      A first stage rocket to toss something up to 60,000 feet and well over 700 mph is a lot cheaper than an aircraft to do the same thing, and the engineering to make it carry a rocket as payload. Particularly if it's a solid rocket. The advantage of the aircraft is that it's reusable, but as NASA discovered, you have to do a LOT of flights before that makes much difference, and failure from the extra complexity often bites you in the ass before you get to that point anyway.

      Airplane launched might make sense for frequent, short duration flights like Virgin is planning. Designing and building an aircraft that can launch rockets doesn't sound like an effective replacement for simple sounding rockets, which is what these guys are building.

    10. Re:Airship one headed in the right direction by GNious · · Score: 1

      Sounds like you're almost describing my KSP launch-platform.

      Jet-based initial stage, that gently carries the thing up to the edge of where the jets can breathe.
      Separate, 'chutes to carry the jets back down for salvage, and separatrons for getting some speed-diff.
      Rocket engines kick in when the two are a bit away from each-other, goes to space!

      KSP is fun :)

    11. Re:Airship one headed in the right direction by dougmc · · Score: 1

      Cheaper way would be a large high altitude jet to carry the rocket to the edge of space.

      The problem is - it's not really cheaper. Fuel is cheap, large high altitude jets aren't

      More to the point, the high altitude jet doesn't help much.

      Let's suppose we need to send something to the ISS. The ISS averages around 260 miles above sea level and orbits at about 17,000 mph.

      So, our plane takes off at the equator and flies at 700 mph up to 11 miles (60,000 feet) above the ground. We launch rockets near the equator and to the East if possible to take advantage of the 1000 mph rotational velocity and our plane should do so as well -- so that means we need 16,000 mph more speed.

      So, our high altitude high speed jet has provided 1/23rd of the speed and 1/23rd of the altitude needed to reach the ISS, and our rocket needs to provide the rest. (The fact that both worked out to 1/23 is just a coincidence.)

      However, kinetic energy is porportional to speed *squared*, so really, the plane has only provided 1/500th of the kinetic energy needed to reach the ISS and 1/23rd of the potential energy. At the ISS. a kilogram of matter has about 30 MJ/kg worth of kinetic energy and about 3.4 MJ/kg of energy from the increased altitude (vs. sea level.) Note that the energy from the 17,000 mph is almost 10x as high as the energy from being 260 miles higher than sea level.

      I haven't worked all of this out exactly, but it looks like putting your rocket on a plane and taking it up to 60,000 feet at 700 mph before launching saves less than 1% of the total energy needed to get to the ISS -- so it sounds good, but in practice it makes a lot more sense to just make your rocket a little bigger and launch from the ground.

    12. Re:Airship one headed in the right direction by cjameshuff · · Score: 1

      Simple: you have to perform your launch from a balloon. You have to cram any support gear that would normally go on a pad into the balloon, and hopefully work out some way to get it back. You can't do any test fires or pad aborts, you're committed to either a successful launch or loss of vehicle and payload once the balloon leaves the ground. You can only launch when the weather's good enough to inflate and fly the carrier balloon, which is far more sensitive to bad weather than rockets. Even gigantic balloons would be limited to tiny rockets...for example, the Falcon 9 v1.1 masses over 500 metric tons, and SpaceX has bigger and more capable rockets planned.

      And the big one: if you're going to orbit, there's just no reason to launch from a balloon. Gaining altitude is a small part of reaching orbit, balloon launch is really only useful for small suborbital rockets where the starting altitude more or less directly adds to the peak altitude reached. And even then, for rockets like Starscraper, there's the above limitations with weather, mass, etc, and the additional added trouble with recovery due to the drift of the balloon before the rocket launches.

  2. Gentle... Rocket? by Ryyuajnin · · Score: 1

    Usually the term "Rocket", and its derivatives, are reserved for describing objects/situations that are powerful, destructive, reckless, etc.; none of which I consider even relatively gentile. What next, gentile dvda?

    1. Re:Gentle... Rocket? by king+neckbeard · · Score: 1

      I'm pretty sure that DVDA is not typically exclusive to Jews.

      --
      This is my signature. There are many like it, but this one is mine.
    2. Re:Gentle... Rocket? by wonkey_monkey · · Score: 1

      What next, gentile dvda?

      Oy.

      What next, gentle dvda?

      Here you go

      --
      systemd is Roko's Basilisk.
    3. Re:Gentle... Rocket? by Ryyuajnin · · Score: 0

      Isn't that exactly what I wrote? kind-of redundant, don't ya think?

  3. Oblig by Bovius · · Score: 2

    I have some guesses about how they're doing their research.

    http://xkcd.com/1244/

    YesIKnowIt'sSuborbitalGoAway.

    1. Re:Oblig by TheCarp · · Score: 1

      rotfl I was thinking the same thing. I live far too close to BU and have played far too much kerbal myself to be comfortable with this project. Does anybody know these kids steam user IDs? A couple of well timed gifts of full versions just might be enough to derail their project before they put a lower stage through my roof.

      --
      "I opened my eyes, and everything went dark again"
    2. Re:Oblig by Required+Snark · · Score: 1
      RTFA

      This year, BURPG has been carrying on an extensive test program on a series of engines and rockets in Sudbury, Massachusetts

      Additionally, there are no radioactive mind control CIA spiders in your basement. Seek professional help.

      --
      Why is Snark Required?
  4. Gentler Suborbital Rocket by koan · · Score: 2

    Now with lubrication.

    --
    "If any question why we died, Tell them because our fathers lied."
    1. Re:Gentler Suborbital Rocket by OhSoLaMeow · · Score: 1

      Now with lubrication.

      But are they ribbed?

      --
      They can take my LifeAlert pendant when they pry it from my cold dead fingers.
  5. um... by Charliemopps · · Score: 1

    Wouldn't another name for these "Rockets" be "ICBMs"?

    Seriously... if an amateur rocket has sub-orbital capabilities?
    Imagine a payload of drones with open wifi and internet access dropped over Beijing...
    Some university kids might think that was a great idea until China shot back.

    1. Re:um... by itzly · · Score: 1

      Suborbital doesn't mean they have the capability to reach another continent.

    2. Re:um... by Anonymous Coward · · Score: 0

      Besides, Beijing already has internet access.

      I, personally, build model rockets. They can reach a kilometer of altitude at best. I would not prefer my rockets to be classified as ICBMs. :P

    3. Re:um... by bswarm · · Score: 1

      Don't you hate the term "model rocket" when you're spending an easy grand on Aerotech 98mm casings and propellant, not to mention the rocket, licensing and FAA waivers? I gave up after my license qualifying H engine flight because the regulations in California are too strict to go any further.

    4. Re:um... by bswarm · · Score: 1

      Oh, and the model rocket record altitude stands at 72 miles so far. http://www.hobbyspace.com/Rock...

    5. Re:um... by Anonymous Coward · · Score: 0

      I live in the former USSR and fly them illegally, as is custom here. :)

    6. Re:um... by Charliemopps · · Score: 1

      Suborbital doesn't mean they have the capability to reach another continent.

      I guess you're right. These are more comparable to a Scud Missile with an operational range of 500 to 1000km. But you could hit Russia from Alaska! :-p

  6. suggest checking out Copenhagen Suborbitals by Anonymous Coward · · Score: 0

    I suggest they look for advise and useful materials over here (a bunch of mostly Danish amaterus is doing the same, basically running a crowdfunded space program):

    http://copsub.com

  7. now, about those drones... by turkeydance · · Score: 1

    this could be seen as an escalation.

  8. Reusable != cheap. by 140Mandak262Jamuna · · Score: 2
    A solid rocket is basically a tube of propellants (oxidizer and fuel). The only precision component in there is the rocket nozzle, even that is not very expensive for solid boosters. They need vectored thrust only for a the first few seconds before the rocket attains enough air speed to make the fins produce aerodynamic forces. That thrust vectoring is easily achieved by asymmetrical blocking of the jet flow or by bleeding the jet off the compressor to feed the vernier nozzles. The economics are such that it is never economical to make them reusable. As long as we use chemicals to produce the thrust, nothing is going to be cheaper than solid rocket boosters.

    Using rocket boosted ramjets and scramjets might save you the need to carry oxidizer in the lower atmosphere. That is where drag is highest. Air resistance goes as the square of the air speed. So "lazy" launch speed works only in that region of the atmosphere. These ram and scramjets are also very very simple. Reusability requirements would raise the cost of materials and engineering. If you want to save money, they should concentrate on cost and probably sacrifice reusability.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
    1. Re:Reusable != cheap. by Anonymous Coward · · Score: 0

      Are you confusing solid and liquid rocket engines or are you talking about the hybrid solid/liquid rocket engines? Last I heard solid rocket engines don't have compressors, or any other moving parts. And, fins were replaced with gyroscopes long ago. Yes, I am a rocket scientist.

    2. Re:Reusable != cheap. by fuzzywig · · Score: 1
      Actually, their thrust vectoring is a new system I've never seen before, which creates shock waves in the exhaust inside the nozzle which deflects the exhaust. They claim it's lighter than other control methods. You can see it working in the video in TFA.

      I'm not sure how well their method will work, but it's always interesting to see a new idea.

    3. Re:Reusable != cheap. by Anonymous Coward · · Score: 0

      That particular *idea* is at least as old as Minuteman II, and probably older, because such big gimbal systems really suck the donkey's *****.

      The implementation may be new, though.

  9. How about a Kinder, Gentler Suborbital Rocket? by Anonymous Coward · · Score: 0

    It could launch a thousand points of light. Or would that not be prudent?

  10. Suborbital? by Anonymous Coward · · Score: 0

    I'd wager its doomed to failure. Not that it isn't technically possible, I'm sure a cheap suborbital rocket design is quite attainable and fully within the realms of some students with a background in aerospace. The problem is the insane regulations that surround most air/space flights/launches. I think Elon Musk is quoted as saying that designing and building an orbital rocket was easy compared to the paperwork, regulations, insurance, qualifications, etc required to get permission to launch it. Most of the "cost" associated with the NASA launches probably has little to do with hardware costs, but with a myriad of greased palms in the defense, regulatory & politically connected areas to get the green light to hit the launch button.

  11. Binghamton University? by Theovon · · Score: 1

    When someone says "BU", I'm sometimes not sure if they're referring to Boston or Binghamton.

    1. Re:Binghamton University? by Anonymous Coward · · Score: 0

      I thought it meant Bedazzled Uranium.

    2. Re:Binghamton University? by Anonymous Coward · · Score: 0

      Or indeed Brown, Brunel or Bournemouth (the latter of which specifically brands itself as BU), to name the few that came to my mind.
      I'm sure there are others.