Page 2 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.
><i>....but it is a modified version of the Shuttle SRB concept.</i><p>The only thing that SpaceShip One's engine and the Shuttle RSRM have in common is Newton's Second and Third laws of motion.<br /></p>
<blockquote><font class="small">In reply to:</font><hr /><p><br />Hybrid Rocket Motor - A new non-toxic liquid-nitrous-oxide / rubber-fuel hybrid propulsion system was developed specifically for SpaceShipOne. Its unique design simplifies mounting and reduces leak paths. The<br />composite nitrous tank and case/throat/nozzle omponents were developed at Scaled, with Thiokol providing the tank’s filament wound over-wrap, and AAE Aerospace supplying the ablative nozzle. <p><hr /></p></p></blockquote><br /><br />This SpaceShip One rocket motor is indeed very friendly from an environmental aspect, as against the Shuttle version it puts out almost nothing but water into the atmosphere.<br /><br />I have been here all along, my friend. As stated, it still is, by any objective measure, one of the toy kit model rockets with a hole drilled through the "SRB" that is the commencement of the area to "burn" once an ignitor is armed and fired. <br /><br />As said, semantics aside, the SpaceShip One rocket motor principles are the SRB by any other name, which is still a Solid Rocket Booster.<br /><br />Laughing Gas combined with an eraser? Or aluminum powder within a tire? Same result. Bottle rocket.<br />
Halman,<br /><br />Have you heard about Scaled Composites being one of the group of companies winning a 3 million dollar contract to develop the CEV and lunar infrastructure?<br /><br />Here's a link.<br /><br />How much will that affect Scaled's ability to get involved with suborbital tourism vehicles? They might be too busy with their part of the lunar contract. <br /><br />I don't think they are abig enough company to be part of both ventures. What do you think?
http://science.slashdot.org/article.pl?sid=04/09/10/1852237&tid=160&tid=134<br /><br />Volunteers Needed for Space Launch<br /><br />"The Ansari X Prize needs volunteers to help at the Scaled Composites and da Vinci Project's launch attempts in the next few months! I've digitized and created BitTorrent's of an Ansari X Prize video that is pretty cool and can tell you more about what we are doing. Want to be a volunteer? Sign up here. I've also set up a carpool and rideshare list for those who can offer or want a ride down to Mojave, CA to see history made." <br /><br />Head over to slashdot to get the links.
Arobie,<br /><br />I don't think that suborbital flight is the primary emphasis of Scaled Composites, merely a means to an end. (Ah, I mean 'goal.') I believe that Burt Rutan wants to prove to the big investors that airborne launching is a viable way of getting a vehicle into space, and this is a way to do it which offers some return on the investment, plus a more friendly attitude from the U.S. government. Rutan has already stated that Scaled is not going to go into the tourist business. They will probably be very happy to build vehicles for another outfit to operate, but that is not a major challeng to their design team.<br /><br />Also, a Crew Exploration Vehicle can be as simple as a capsule, which requires very little engineering. If a contract had been awarded to build a launch system AND a CEV, then I would be wondering if Scaled were getting ahead of themselves, biting off more than they could chew, so to speak. I strongly suspect that their partners in this venture needed someone to give them respectability, and Scaled is a well known innovator in aerospace.<br /><br />But, only time will tell just how big of a commitment this contract is, and whether Scaled proposes a capsule, or a lifting body capable of gliding. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>
> <i><font color="yellow"> The contract is not to develop any hardware. The contract is to develop a PLAN and a CONCEPT for a possible CEV design.</font>/i><br /><br />I think that is primary goal for all the first round contracts: <i>Go and develop a more detailed proposal.</i></i>
Exactly. I hope t/Space is selected to build a CEV prototype. I think they would make the usual suspects look really bad.<br /><br />Then again, the two companies which will be selected next year for the fly-off in 2008 will very likely be Lockheed Martin and Boeing. *sigh*
<font color="yellow">I hope t/Space is selected to build a CEV prototype</font><br /><br />Unlikely as those companies are pretty small compared to the aerospace giants. I hope they get awarded contracts to work on some of the CEV's components though. <div class="Discussion_UserSignature"> </div>
<br />DaVinci just posted a new PDF on their website in the past few days. No great revelations or photos of actual hardware in it, though. Seems mainly to be a means to show more pretty graphic images of WF6, inspiring quotes from Feeney, and the GP.com logo.
I guess I just wasn't thinking in terms of rocket engines.<br /><br />I can give my car a bigger fuel tank but I wouldn't say that I had enhanced my car's engine performance.<br /><br />So I was thinking of enhancements other than just more fuel. But in terms of rockets, yeah that's better engine performance.
"Our motor performed flawlessly during that flight," [said] Jim Benson<br /><br />Well then, what was the loud bang that Mike Melville heard? Knowing the wee bit I do about cast propellents, the description pointed to a bit of rubber getting caught and expelled in the throat of the nozzle.<br /><br />Maybe the design is robust enough that such a thing can occur and the engine still "performs flawlessly."
>"The aero controls could easily be too weak to control the vehicle."<br /><br />When do the cold gas thrusters become active? I don't know if they are under pilot control or computer control. I do know that they can control the vehicle's attitude without the use of the aero controls, however. I think they are 50# thrusters.
I don't know is most people know this, but there was a prize not to long ago for $50,000 for the first group to launch an amature rocket to 100km and $250,000 to 250km. It expired before it was ever claimed. Most groups that made an attemp relyed on a ballon based lauching system (like JP Aerospace) only to have weather kill it.
shuttle_guy,<br /><br />If I understood the interview with the engine manufacturer correctly, they have increased the amount of liquid nitrous oxide, which will prolong the most powerful phase of the engine burn. This phase occurs early in the ascent, so control problems are, hopufully, not going to be an issue.<br /><br />Without gimballing the motor, I don't see how attitude control can be acheived above around 150,000 feet. The Reaction Control System would have to be very robust, with a large supply of propellant, to overcome the tendancy to follow the engine.<br /><br />Gimballing the motor probably would have added a prohibitive amount of mass to the vehicle, requiring a larger motor, more propellant, a powerful hydraulic system, and a bigger carrier wing. If adequate velocity can be acheived while still in effective aero control, the vehicle can coast to the target altitude. I think that the team wanted to improve the thrust early in the burn to assure reaching a high enough velocity without having to burn after effective aero control was lost. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>
wvbraun,<br /><br />You know, I have come to really like the 'shuttlecock' feature of SpaceShip One. Having spent time in the U.S. Air Force, I tend to think "In-Iflight Emergency" a lot. When an outfit is trying to make a profit, they sometimes cut corners.<br /><br />I know that a lot of people see huge potential in space tourisim, but, for me, it won't be worth it until there are flights to the Moon. When I travel, I like to go somePLACE, not just spend my time in the car/train/plane.<br /><br />I also have become terribly cynical, after seeing scam after scam after scam. I wouldn't buy tickets until there is harware which has flown a few times! <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>
<font color="yellow">"...and not a single person snaps a photo..."</font><br /><br />Well -- someone snapped a photo... maybe. Unfortunately there's nothing actually identifiable in the photo -- like anything that says Davinci, or GP.com, etc. I'd be less inclined to nitpick if I hadn't located several of their other 'tests' to be pictures taken from other websites.<br /><br />At any rate -- using the person in the picture for scale, and assuming he's approximately 6' tall. The balloon is ~15 feet in diameter and about 32 feet from top to bottom. Approximating its volume using a cylinder 15 feet in diameter and 24 feet in height -- I get 4240 ft3.<br /><br />That volume of helium will lift approximately 267 pounds. Since their full-scale balloon will have to lift ~8500 pounds, that would put this at about a 1/32nd scale model by volume. Keeping the same approximate ratio of height to diameter -- the full scale balloon will need to be somewhere in the realm of 50ft in diameter and ~86 feet tall.<br /><br />The SDC article says the flight was in Colorado and was FAA-approved. Does anyone here know of an online source for pulling up FAA information? I'd think that as a public record -- there'd probably be some means of locating that approval and getting more information about the test. www.faa.gov didn't seem to have the capability to do this, but I might've missed it.<br />