Hot Rod Job For SpaceShipOne

rwven writes "MSNBC is reporting that the engine on SpaceShipOne has been modified to provide more thrust, for a longer amount of time. Mainly, the Nitrous Oxide tank has increased in size to lengthen the amount of time before the dropoff of thrust when it goes from a liquid to a gas. Also reporting is Space.com."

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In related news...

[nkrumm]

In related news the name of the project has been changed to RiceRocketOne.

Re:In related news...

[Any Web Loco]

All the shuttle needs now is some Type-R stickers & it's good to go.

Oooh

[iamdrscience]

Next up: Spoiler, racing stripes and a window decal that says "Outta Space!".

The racing stripes alone decrease wind resistance by 17% you know.

Re:Oooh

[iamdrscience]

No no, "If you can read this, you're SpaceshipTwo".

Re:Oooh

[errxn]

Don't forget the obligatory "Calvin taking a whiz on the NASA logo" sticker.

Just say N2O

[Doc Ruby]

Using just a nitrous oxide charger and a balloon, I was never higher than low Earth orbit. But with a 60L tank, a garbage bag, and a mattress to jump on, I achieved full astral projection, even interdimensional travel! I recommend a complete crew of 1 extra spotter breathing 21:78:1 O2:N2:Ar2, for a safe return voyage. YMMV.

Re:*** Questionable Content Detected ***

[DarkMantle]

It kinda looks like one with wings too.

Even so, I can't wait till I can go for vacation on the moon. Now THAT would be getting away from it all.

Only one thing to do...

[hookedup]

*Insert Tim Allen grunts*

Wasting precious resources

[WillWare]

They've got a big tank of nitrous oxide and they're using it as rocket fuel? Priorities here, people!

Re:Wasting precious resources

[AndroidCat]

The nitrous oxide is the oxidizer, they use rubber for fuel.

SpaceShipOne uses a hybrid rocket engine that uses both liquid and solid propellant to propel it into space. The complete system consists of a liquid nitrous oxide (or laughing gas) oxidizer and a solid form of rubber fuel, which are burned together for about 76 seconds during an average flight, Benson said.

They really are burning rubber into space.

Re:Wasting precious resources

[interiot]

More here.

• SpaceShipOne burns ... HTPB, a common ingredient in tire rubber.

• In conventional rockets, propellant can be pre-mixed -- as in the solid rocket boosters (SRBs) used NASA space shuttle -- or sit in tanks that are filled just prior to launch, like liquid oxygen and hydrogen rockets. In both engine configurations, the are highly volatile and can be toxic to handle.

  "The fact that the oxidizer and fuel are not molecularly mixed in these [hybrid] engines, makes them non-explosive," explained Greg Zilliac, a hybrid engine researcher at NASA's Ames Research Center in Moffett Field, California. "We've actually shipped fuel grains by UPS in the past."

Re:Wasting precious resources

[Rei]

Yeah. It's an easy fuel/oxidizer combo, but not very scalable. The specific impulse is just too low, and the nitrous tank too heavy. I do find it funny that they described hybrid rocket engines as not being "conventional rockets" ;)

And before some of the posters here start going off on a "Specific impulse isn't everything!" line, I'll add: It's not everything, but it is *incredibly* important. And if you can't have lightweight tanks to compensate for your loss of specific impulse (which you can't with nitrous), you're not going to scale. Plus, using a carrier launch, you're not going to handle the spiralling mass increase very well.

In short, this type of design, while great for getting the X-prize (it's very simple - self pressurizing, no liquid/liquid combustion, etc), would never scale to orbit. I'd like to see a good tow-launch LOX/subcooled propane rocket; that should be scalable and yet still take advantage of air breathing power to get to altitude, and wouldn't have to deal with LH.

What everyone hopes for are some of the things that are on the horizon, that have high ISP without the various tank mass or cryogenic limitations. For example, alane (stabilized aluminum hydride) hybrid boosters, which have an ISP that even with a weaker oxidizer like H2O2, nears LOX/LH's isp, and a very high density. Everyone in rocketry would like such a panacea; however, for now, everyone has different opinions on what is the best way to go.

American Spaceship

[ktakki]

I hope the Discovery Channel picks this up next season...


MONDAY

VINNY
Senior says that we have to have this spaceship ready for the X-Prize in November, but I just don't see it happening. We're just halfway through the mock-up and the combustion chamber has to be at the chromers by tomorrow.

TUESDAY

MIKEY
(Takes out the trash)

WEDNESDAY

PAUL, JR.
Whenever we do a theme spaceship, we always run into some problem. Like with this one, the attitude control thrusters were too close to the sissy bar. But Cody came through when he reversed the polarity of the positronic matrix and reconfigured the EPS conduits to emit tachyons through the deflector shields.

THURSDAY

PAUL, SR.
I really had my doubts about this spaceship, but Justin came through in the end. He did a killer job on the tins and the flames and pinstripes on the body really make the design work.


k.

Re:OT: how does NOx work in cars?

[Sooner Boomer]

" Can somebody tell me what nitrous oxide does in a car engine? It's not a flammable gas, is it?"

In a word, oxygen - nitrous contains more oxygen than air and is in a highly dense liquid form. In a car engine, nitrous, along with additional fuel is squirted into the intake. In the hybrid rocket engine, a large cylinder of rubber is the fuel; the nitrous is the oxidizer.

Re:OT: how does NOx work in cars?

[CreateWindowEx]

Since combustion of one unit of gasoline requires more than ten units of air (containing oxygen), most car engines are limited by how much air they can get into the cylinders--it's fairly easy to just squirt more fuel, but to get more air in you have to either force it in with a turbocharger or a supercharger or reduce sources of friction on the way in (lower-restriction air intakes, etc) or fool with cam timing. Nitrous oxide is a cheap and easy way of adding more oxygen for a short period of time, plus it has the added benefit of helping to cool the cylinders, preventing "knocking" (premature ignition of the fuel by "hot spots" in the engine == $$$ if left unchecked).

Usually nitrous oxide systems are set up to inject extra fuel along with the nitrous oxide to keep the correct fuel/oxygen ratio.

As an aside, F&F fans should realize that NOS (Nawz) is the logo of Nitrous Oxide Systems, not a chemical abreviation for nitrious oxide, although they spend a lot of money trying to get their name associated with it.

Re:OT: how does NOx work in cars?

[OldJohnno]

The oxygen component actually provides only a small part of the power increase. NO2 has an extremely high latent heat of vapourisation - in other words it absorbs massive amounts of heat when it is injected and vapourises. This tremendous cooling effect allows a much denser cylinder charge and requires (a lot) more fuel be injected along with the NO2 to maintain the correct fuel/air ratio.

OB Simpsons

[laejoh]

Buzz: Homer, you broke the handle.
Race: With that hatch open, we'll burn up on re-entry! That's it: if I
go, I'm taking you to hell with me.
Homer: Wait a minute, Race. Wait a minute...wait!
[breaks off a support rod]
Aha! Now I'll bust that pretty face of yours!
[tries to swing it, but it catches in the door]
Aw, stupid bar.
Buzz: Wait, Homer. If that bar holds, we just might make it back to
earth.
Homer: Oh. [voice rising] I'll bash you good!
-- One-track minds, "Deep Space Homer"

Changes made to improve flight profile

[hpulley]

What has not yet been mentioned in this /. discussion is briefly, though not directly, mentioned in the aforementioned space.com article. The changes to the engine were made at least partly to offset the previous glitch encountered during the previous flight. "...the increased liquid nitrous oxide should delay that drop off and provide more thrust earlier in the flight, when SpaceShipOne's control surfaces can still bite into the Earth's atmosphere for steering." They hope this will allow them to reach their target altitude this time (almost missed the space altitude last time) without having to resort to secondary guidance systems.

What isn't said...

[RayBender]

is why they are hot-rodding the vehicle. I saw mention that the increased burn time would allow SpaceShipOne to achieve higher speed at lower altitude "where the control surfaces can bite into the air"; this tells me they are working to fix the near-disaster they had on the last flight. It sounds like they have no control authority outside the atmosphere - i.e. that whatever reaction-jet system they have isn't working well, and they are having to jury-rig a fix. Increasing the impulse of a rocket by 20% (which is what they are doing) is a significant, and risky, change. They wouldn't be doing it unless they had to.

New Version Number?

[permaculture]

So it's not yet SpaceShipTwo.

SpaceShip1.2, perhaps?