Space Ship Two propulsion?

[gunsandrockets]

Anything definate yet about Space Ship Two's propulsion? I know SpaceDev provided the hybrid liquid/solid rocket engine for Space Ship One but from what I've heard SpaceDev is now out of the picture. Does any other company even sell a hybrid rocket system?<br /><br />So is it known for sure Space Ship Two will use a hybrid rocket engine as Space Ship One did? Or is some other system being considered?<br /><br />Check this out...<br /><br />http://sbir.gsfc.nasa.gov/SBIR/abstracts/00/sbir/phase1/SBIR-00-1-20.02-8728.html<br /><br />I don't know if such an N20 monopropellant rocket has ever been tested but it's similarity to the N20 hybrid is interesting. I can see many advantages of the liquid monopropellant rocket compared to the hybrid bi-propellant rocket, especially for the much larger Space Ship Two. Gassing up (or unloading) a monopropellant spacecraft has to be less hassle than replacing the solid fuel component of a hybrid.

 

[rocketman5000]

I know two companies competed for the contract for the SS1 hybrid motors. I am not sure who the other company is anymore. It used to be on Scaled Composites website during the SS1 program.

 

[vogon13]

{an aside}<br /><br />Congratulations on your new Galaxy ranking.<br /><br />Enjoy wielding your new powers!<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[soyuztma]

I have read that Scaled Composites is designing the propulsion system in house. <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

"I have read that Scaled Composites is designing the propulsion system in house."<br /><br />Very interesting. What experience does Scaled Composites have making rocket motors?

 

[gunsandrockets]

"...such a dangerious propellant."<br /><br />Evidence?

 

[rocketman5000]

SS1? I hope that Scaled had complete understanding of the engine they were strapping into their rocket before they used it. Also they built and used their own mobile test stand during the development of SS1<br />

 

[barrykirk]

shuttle_guy Congradts on your new rank!!!<br /><br />As for space ship 2 and hybrid engines.<br /><br />Recently SpaceDev applied for a patent on a new<br />and improved hybrid motor. If they can<br />get the efficiency of hybrids high enough can they<br />make them affordable for use on orbital rockets.<br /><br />I wouldn't think you'd want to use a hybrid for anything<br />other than a booster stage. <br /><br />Actually, you could also use it for a stage where storability is an issue.

 

[gunsandrockets]

"Read the link YOU posted......"more dangerious than H2O2" !!!!!!!!!!!!!!!!!"<br /><br />Good grief. That's your evidence? Before you accuse someone of misreading a link you better be certain of your own comprehension.<br /><br />The proposed N20 monoprop I linked to is described as less dangerous than H202, not more dangerous as you miscomprehend. The propellants that were described as more dangerous than H202 were the common high ISP monopropellants such as hydrazine.

 

[gunsandrockets]

"I hope that Scaled had complete understanding of the engine they were strapping into their rocket before they used it. Also they built and used their own mobile test stand during the development of SS1"<br /><br />Just because Scaled Composites understands the powerplant doesn't mean they can design or build powerplants. Of course Scaled integrated the rocket engine into Space Ship One, but Scaled bought that engine from Space Dev. Scaled didn't make the hybrid rocket engine themselves just as Scaled didn't make the J-85 jet engines which powered the White Knight mothership. <br /><br />If the Space Ship Company which is making Space Ship Two is designing and building a new rocket engine then they are breaking new ground for themselves as far as I can see.<br />

 

[gunsandrockets]

"As for space ship 2 and hybrid engines. Recently SpaceDev applied for a patent on a new <br />and improved hybrid motor. If they can <br />get the efficiency of hybrids high enough can they <br />make them affordable for use on orbital rockets. "<br /><br />That's great news for Space Dev. The problem is Space Dev isn't making the engine for Space Ship Two. So the question is what is the powerplant for Space Ship Two? Is it going to be another hybrid? No one seems to be saying for certain yet.<br />

 

[gunsandrockets]

"Didn't Scaled Composites fabricate the cases for the motors, to whomever's design?"<br /><br />I don't know for certain. I don't think so. I think the case and nozzle are a single piece design with the fuel pre-loaded. Now I'm going to have to surf around and check it out!

 

[halman]

gunsandrockets,<br /><br />As I understand it, monopropellants are ignited by exposure to a catalyst. Mixing an oxidizing agent with a hydrocarbon usually results in combustion, unless under extreme low temperatures or very high pressure. Since Zurbin neglects in this abstract to discuss any specifics about the implementation of his idea, we must assume that he does not know himself how to make his proposal operational. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[docm]

SpaceDev did indeed manufacture and refuel the engine for SpaceShipOne.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

"Mixing an oxidizing agent with a hydrocarbon usually results in combustion, unless under extreme low temperatures or very high pressure."<br /><br />It depends on the oxidizer and the fuel.<br /><br />For example a monopropellent of magnesium powder mixed with carbon dioxide is pretty stable. This combo was actually test fired successfully.<br /><br />It wouldn't suprise me if N20 is so stable that it requires a catalyst plus significant heat to ignite as a monopropellant.<br /><br />[update] Aha! I just found this around midnite...<br /><br />"Nitrous oxide can also be used in a monopropellant rocket. In the presence of a heated catalyst, N2O will decompose exothermically into nitrogen and oxygen, at a temperature of approximately 1300° Celsius. In a vacuum thruster, this can provide a monopropellant specific impulse (Isp) of as much as 180s. While noticeably less than the Isp available from hydrazine thrusters (monopropellant or bipropellant with nitrogen tetroxide), the decreased toxicity makes nitrous oxide an option worth investigating. "<br /><br />http://www.nationmaster.com/encyclopedia/Nitrous-oxide<br /><br />[end update]<br /><br />"...we must assume that he [Zubrin] does not know himself how to make his proposal operational."<br /><br />I do not worship at the alter of Zubrin. Even so I think you have it exactly backwards. Zubrin would be pretty stupid to propose something without knowing if it had a fair chance of working.

 

[gunsandrockets]

"SpaceDev did indeed manufacture and refuel the engine for SpaceShipOne." <br /><br /><br /><br />I coulda swore I saw something different just few minutes ago with links and everything. Nah, must be my imagination!

 

[docm]

Might have been <img src="/images/icons/wink.gif" /><br /><br />http://www.space.com/missionlaunches/xprize_sso_engine_040913.html<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Since its historic June 21 flight, in which SpaceShipOne carried the first civilian pilot to the edge of space and back, spacecraft and engine engineers have been working to boost the vehicle's performance.<br /><br /><b>"Our motor performed flawlessly during that flight," said Jim Benson, founding chairman and chief executive of the firm SpaceDev, of SpaceShipOne's inaugural manned spaceflight. "But we beefed up the engine even more."</b><br /><br />SpaceShipOne's engine has been modified to carry more propellant and burn longer than in previous flights, Benson told SPACE.com, adding that the engine has been enhanced to perform 20 percent beyond original requirements. <p><hr /></p></p></blockquote><br /><br /><br />http://www.spacedev.com/newsite/templates/subpage3_article.php?pid=411&subNav=11&subSel=3 <br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Powered by SpaceDev's hybrid rocket technology, SpaceShipOne soared to 328,491 feet. <p><hr /></p></p></blockquote><br /><br />http://www.personalspaceflight.info/2006/06/13/spaceshiptwo-flight-characteristics/<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>The article does note that SS2 will use a “new hybrid rocket motor”, which is not surprising given both that SS2 will be larger than SS1 and the deteriorated relationship between Scaled Composites and <b>SpaceDev, which built the hybrid motors used by SS1.</b><p><hr /></p></p></blockquote><br /><br />http://www.univer</safety_wrapper <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

Huh. So I guess it's a new hybrid motor for SS2 after all. I wonder who will make it and if it will just be a larger clone of the SS1 engine.<br /><br />I still think Zubrin's mixed monoprop liquid rocket engine idea is better.

 

[docm]

Former Scaled propulsion chief Tim Pickens is now President of Orion Propulsion;<br /><br />http://uplink.space.com/newreply.php?Cat=&Board=missions&Number=606142&page=0&view=collapsed&what=showflat&sb=5&o=0&fpart=2&vc=1<br /> <br />and they happen to be working on a new hybrid.<br /><br />Coincidence? <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

I wonder how big a hybrid rocket it would take to propell SpaceShipTwo up to an altitude of 140 km? Seems like a big job for a small start up company to succeed at.

 

[docm]

SpaceDev based some of their work on AMROC's work at Stennis. AMROC tested hybrids with up to 250,000 lbs of thrust and SS1's first X-Prize flight used a rubber based hybrid engine with just 17,000 lbs of thrust, so there's lots of room to grow.<br /><br />If the SS2 engine does use paraffin and its as powerful as reported by Stanford's tests the SS2 engine may not be excessively large. This 2003 article is a great primer on paraffin hybrids;<br /><br />http://www.sciencenews.org/articles/20030322/bob9.asp<br /><br />SpaceDev itself has been working on a hybrid that uses plexiglass as a fuel. Robert Grissing demo'ed an acrylic hybrid for the CSS earlier this year. The demo is interesting because he used acrylic as both fuel and casing so you could see the burn. CSS has a video up showing an early test;<br /><br />http://www.css.ca/meetings/<br /><br />There are experimenters that have used chocolate and salami as hybrid fuels, so who knows what's in store next? <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> </div>

 

[rocketman5000]

you mean the "Myth Busters"?

 

[docm]

I was thinking of Jon London's Salami hybrid @ the 2006 BROP conference and others, but the M/B's episodes will do. <br /><br />I personally know of hybrids made using Gummi Bear-type gels, cast paper and pepperoni to name a few. <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

If SpaceDev was behind the SpaceShipTwo hybrid rocket engine I wouldn't have any doubts. With the inherited wisdom of AMROC and actual manned flight history behind it SpaceDev should be able to cope without much difficulty.<br /><br />But SpaceDev isn't building the SS2 engine. And whoever is building the engine doesn't have the kind of background that SpaceDev does. That's why I'm wondering whether SS2 might go for a something different than a hybrid rocket after all.