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The Military NASA Space United States

Robotic Space Plane Launches In Mystery Mission This Week 110

Posted by samzenpus from the flying-into-a-mystery dept.
mpicpp writes: The United States Air Force's robotic X-37B space plane will carry a NASA experiment into orbit when it launches on its next mystery mission Wednesday. The liftoff will begin the reusable space plane's fourth mission, which is known as OTV-4 (short for Orbital Test Vehicle-4). Since it's classified it's not entirely clear what the space plane will be doing once it leaves Earth Wednesday. This has led to some speculation that the vehicle might be a weapon, but officials have repeatedly refuted that notion, saying X-37B flights simply test a variety of new technologies. The X-37B looks like a miniature version of NASA's now-retired space shuttle. The robotic, solar-powered space plane is about 29 feet long by 9.5 feet tall (8.8 by 2.9 meters), with a wingspan of 15 feet (4.6 meters) and a payload bay the size of a pickup-truck bed. Like the space shuttle, the X-37B launches vertically and lands horizontally, on a runway.
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Robotic Space Plane Launches In Mystery Mission This Week More

Robotic Space Plane Launches In Mystery Mission This Week

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  • No Mystery (Score:4, Funny)

    by Anonymous Coward on Monday May 18, 2015 @10:15PM (#49723423)

    The Air Force has weaponized systemd and is launching satellites that can download it onto enemy computers at a moments' notice.

    • Re: (Score:3)

      by amiga3D ( 567632 )

      No wonder they all hate us. If someone infected my computer with that shit I'd launch a jihad.

      • Re: (Score:2)

        by wbr1 ( 2538558 )
        Is that pronounced Jiha-D? What services does that daemon provide the system, particularly the Islam Kernel ? Does it respond correctly to shutdown and restart requests?
  • Here's hoping it's an EM drive + battery. I know that's not likely with an organization as ironically conservative as NASA but wouldn't it just be cool?

    • Well, close...

      FTFA:

      For example, the space plane is carrying a type of ion engine called a Hall thruster on OTV-4, Air Force officials said. [...] “A more efficient on-orbit thruster capability is huge,” Maj. Gen. Tom Masiello, commander of the Air Force Research Laboratory in Ohio, said in a statement. “Less fuel burn lowers the cost to get up there, plus it enhances spacecraft operational flexibility, survivability and longevity.”

      I gotta admit, I'm curious why the NASA mission flying on there couldn't have been done on ISS...

      • Re: EM drive? (Score:5, Insightful)

        by Anonymous Coward on Tuesday May 19, 2015 @12:31AM (#49723819)

        Maybe because NASA is a political football that isn't allowed to do really cutting edge stuff without subcontracting the work to 48 out of 50 states to secure funding from Congress, while secret military programs can do science with less bother. Some of the Area 51 programs involved in developing OXCART ended up ahead of schedule and under budget because keeping stuff confidential sheltered it from the usual MIC/appropriations morasd. Likewise SpaceX is now on the cutting edge of rocket recoverability because it's more capable of taking risks and less hamstrung by accounting oversight. Maybe covert projects like the X37b are simply easier organizationally and thus easier avenues to doing unconventional science like testing ion engines than is the civilian space program. Remember, Hubble became possible because of Keyhole, which worked out the materials science and engineering aspects in secret.

      • Re: (Score:2)

        by tsotha ( 720379 )
        The plan is to put VASIMR on the ISS for station keeping. The station may simply be too large to get decent data from a hall effect thruster.

      • One possibility is that DoD was planning to fly anyway and offered NASA some payload capacity because they were interested in the results of that program. There are almost always more experiments queued up than there is funding to run them, so people are always looking to scrounge unused capacity--especially for small experiments that aren't funded for their own vehicle. Capacity for long-duration missions on ISS is especially tight because of the recent launch failures.

    • You realize that NASA has absolutely nothing to do with this mission, right?

  • The military aren't going to sit around and wait. They are looking for a delivery vehicle that can act as a drone.
    http://news.discovery.com/spac... [discovery.com]
    where it states in 2012 it completed a 224 day mission, terming it 'drone'.
    With China's attempt in weaponizing space, the US military are being foresighted.
    Ramming speed?

    • Re: (Score:1)

      by Anonymous Coward

      I believe I read somewhere that the space shuttle had a specific design requirement of 1000 NM cross-track steering on reentry, and this was because the Air Force wanted to use the space shuttle to launch from Vandenberg into polar orbit, grab a Chinese or Russian satellite, then deorbit, reenter, and land back at Vandenberg without completing a full orbit. I suspect the Air Force is still interested in this mission profile, and this is one of the things this vehicle is built for. That said, they seem to

    • Re: (Score:2)

      by swb ( 14022 )

      I've always been curious why there haven't been battlefield "disposable" drones that could be launched from a high altitude bomber, controlled by units in the field, fire a couple of guided missiles and then be delivered as a weapon itself on a target.

      • I've always been curious why there haven't been battlefield "disposable" drones that could be launched from a high altitude bomber, controlled by units in the field, fire a couple of guided missiles and then be delivered as a weapon itself on a target.

        Because that's basically a missile that launches missiles. You'd just use waste payload capacity for duplicate launch mechanism (one of the bomber, another on the missile). Just launch/drop the missiles/bombs directly from the bomber.

        • Re: (Score:2)

          by swb ( 14022 )

          I would recast it as a plane that launches projectiles but becomes a bomb at the end of its mission.

          I think the advantage it would have would be in local (company or battalion level) control and targeting. Combat situations are loose and fluid and there's more than a little complexity involved in having ground troops ID a target, relay this to forward air controllers, relay it to a pilot and have the right target get hit and still be the right target.

          In some circumstances you can do this with IR designatio

  • What's up with that motor? (Score:4, Interesting)

    by gman003 ( 1693318 ) on Tuesday May 19, 2015 @12:42AM (#49723839)

    Okay, I know it's probably the least important thing about the craft, but still...

    Why are they using such an ancient, decrepit-ass rocket motor? The AR2-3 is incredibly old - it dates back to a Gemini-era trainer, basically a modded F-104 that NASA used for early tests and training for spaceflight. It was made back when rocket chemistry was still in the "even the experts don't know much" stage, so it burned jet fuel and high-test peroxide (90%+ H2O2 in H2O).

    Jet fuel is not good for rockets - basically, the restrictions on what compounds can be present is fine for jet engines, but leads to horrible problems with rockets. There's a specific petroleum-product blend designed for rockets, called RP-1, which clamps down on things like sulfur compounds or alkenes that love to gum up the works. This rocket was originally used on a jet fighter and shared fuel with it, so that was understandable... but the USAF recertified the engine for modern JP-8 instead of the old JP-4. So they already went through the effort of making it work with a new but similar fuel. Unless the X-37 hides a jet engine on itself somewhere, I don't see why they couldn't have used RP-1 instead.

    Further, rocket science moved away from peroxide for a reason - it's dangerous. It will explode for basically any reason - peroxide decomposes exothermically, so once it starts reverting to H2O + O2, it's nearly impossible to stop. And it reacts with tankage surprisingly often. Oh, and it does horrible things to your specific impulse, which really hurts you on a last-stage engine like this one.

    Honestly, using the engine at all is a weird choice. Sure, maybe they had some laying around... from the sixties... but that's like putting an F-104 engine in a prototype aircraft, it just doesn't seem right when other off-the-shelf systems work better. An AJ-10 would have worked beautifully. An RL10 might not have fit the aero package (hydrogen is a bulky fuel), but would have given them some impressive dV if they wanted it. Aestus would be a perfect match as well, if they didn't mind outsourcing to the Euros. Even Kestrel would work (although it first flew around the same time as this, so understandable not to use it). Point is, they had options, and being the Air Force, they could easily have just had an engine custom-made for it if they so wanted.

    So what are the implications? All I can think of is a) they don't care how badly the rocket performs, b) they probably aren't going to keep that engine in whatever "production" version they build, or c) they have some other reason to use peroxide or JP8. Maybe peroxide is also their monoprop for RCS? That isn't really worth it though, particularly when UDMH works better as RCS and in the main motor.

    • Re: What's up with that motor? (Score:1)

      by Anonymous Coward

      They're not using the AR 2-3. That was part of the original specs from before DARPA took over the program. It's confirmed to use hydrazine now, but the actual engine is uncomfirmed. See http://space.skyrocket.de/doc_sdat/x-37.htm [skyrocket.de]

    • I'd tell you why it uses that motor... but then I'd have to kill you.

    • Re:What's up with that motor? (Score:5, Interesting)

      by lourd_baltimore ( 856467 ) on Tuesday May 19, 2015 @04:17AM (#49724227)

      There is some speculation that the AR2-3 may not be the engine used in current flights (see other replies to you post).

      However, the AR2-3 is human rated. The X-37 is nominally unmanned, but hey the missions are classified, and because Halo Orbital Drop Shock Troopers. Of course some of the alternative engines you mentioned have been used on stages of previous manned flights and are thus presumably man-rated as well.

      I did some Binging on the AR2-3 and found a NASA/Rocketdyne/OSC presentation [hydrogen-peroxide.us] that looks to be drafted around 2000.

      Here that seem to make the case high test peroxide (HTP) technologies are the way of the future for upper stage propulsion:

      Hydrogen peroxide was selected over liquid oxygen because it is dense, storable, capable of tolerating months in orbit, and meets safety restrictions for being part of the payload in the Space Shuttle.

      Of course the Shuttle aspect is no longer a factor, but the other factors still seem to be in play.

      Further into the paper, the USFE 10k peroxide motor is mentioned as a project to develop new HTP technologies. These technologies would be used for future HTP-based upper stages. They even have a goal of over 100 uses of an engine before it has to be removed for overhaul. Is that a lot in the world of rockets? As this paper was drafted around 2000 I would guess that the X-37 is using something a bit different that the bog-standard AR2-3 or has moved away from HTP technologies altogether.

      Now to say that rocket science has moved away from HTP is not quite true. I don't think there are any big HTP engines used in lower stages. However, the Bloodhound SSC is using a HTP hybrid motor [bloodhoundssc.com] they are designing.

      There is also research in to using HTP [slashdot.org] as a monopropellant [esa.int] for thrusters using a catalytic bed. I suppose the advantage here is that you have HTP as your oxidizer for an upper stage and then it can be used for maneuvering once on orbit. Similar, as you mentioned, to UDMH.

      Take a look at the Introduction from the ESA paper referenced above. They cite several reasons why HTP is desirable and advantageous. Cost and safety being paramount. They also mention that Soyuz has been using HTP in its maneuvering systems for over 40 years. I think that HTP safety concerns have been effectively mitigated from the "explode because you looked at it funny" era.

      As for performance it seems that HTP is as good as some other technologies, but it's no dog either and it seems to be a good fit for the X-37 or other small stages. Quote from the ESA paper:

      The propulsive performance of hydrogen peroxide monopropellant rockets is about 20% lower than hydrazine, but the volume specific impulse achievable with 90% H2O2 is higher than most other propellants due to its high density. This is particularly useful for systems with significant aerodynamic drag losses and/or stringent volume constraints. With respect to bi-propellant and hybrid rocket engines, hydrogen peroxide yields a specific impulse comparable to other liquid oxidizers like dinitrogen tetroxide, nitric acid and even liquid oxygen..

      It seems that HTP has many uses and rocket science has not moved away from HTP, indeed, it is being actively researched. It may or may not be used on the X-37 right now. It may or may be used on the X-37 in the future. With further attention to cost, safety, and, increasingly, environmental impact, HTP seems to be coming for you...

    • Or, given its the government we're talking about, and a classified project to boot, they're lying about the rocket motor and/or fuel. If it seems anachronistic and unlikely that they'd use it, Occam's Razor suggests that perhaps they aren't.
  • Everyone gets excited about monkeys and dogs and geckos going into space and a robot goes into space and nobody cares. That's racist....speciesist....life-form-ist!
  • Why is the thruster off-center on that thing ? How can it work ?!?

    • You can tell where the centre of *mass* is just by looking at it? Cool, wish I could do that.

      • Re: (Score:1)

        by dargaud ( 518470 )
        Does the thruster operate only in a vacuum ?

        • Does the thruster operate only in a vacuum ?

          What does that have to do with anything? Besides absolutely nothing?

      • Re:Simple question (Score:4, Informative)

        by canajin56 ( 660655 ) on Tuesday May 19, 2015 @12:51PM (#49727229)
        In case you haven't looked at the pictures: Take a look [wikipedia.org]. So, is it true that the internals are lopsided so that that one engine actually is thrusting colinear with the center of mass, like you seem to assume? Nope! If the internals were lopsided then the wings would need to be asymmetric or it would suffer some pretty serious torque when gliding. The reason the engine is offset is that the origional design called for two engines. This was overkill for the amount of thrust required, so they cut one out. It would have taken some redesign to have the single engine back in the center, and since it gimbles far enough that it can still produce a thrust vector colinear with the center of mass, there was no reason to do so.

        So to answer the actual question "It works by turning the engine a little bit to compensate".

  • It would be a wonderful opportunity to send one up, to see if it actually generates thrust without fuel (in a relatively gravity free environment where it would be most useful).

    http://www.gizmag.com/cannae-r... [gizmag.com]

    Although that's a lot of trouble to test the Cannae Drive: just suspend it from a rope, throw the current to it, and see if it deflects from the vertical. (A simple antigravity drive test suggested half a century ago by some well-known science fiction writer.)

  • Lightsail prototype and several other non-military payloads are hitching a ride on this launch. https://www.kickstarter.com/pr... [kickstarter.com]

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