If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
In article ,
Robert Briggs writes: Alan Minyard wrote: At apogee there would be almost no control authority (lack of sufficient air molecules). Do they have a thruster system for control at that altitude?? If there is *any* remotely usable control authority then the thing ain't in space for any reasonable value of "space". A couple or three points: Control Authority doesn't have to mean aerodunamic controls - SS1 has a cold-gas RCS system for attitude control a very low EAS. There is no such thing a "a reasonable value of 'space'". It's not like there's a definite dividing line between Atmosphere adn Vacuum - the density of the atmosphere thrails off as height increases, but it doesn't entirely go away. Aerodynamic drag, and the variations in that that occur was the Earth's atmosphere expands and contracts due to Solar Radiation, are a significant factor in the lifetime of an orbiting satellite. (Remember Skylab). That Orbital Decay that you hear so much of is mostly caused by atmospheric drag. (By the same token, I'd like to punch Eugene Sanger, or his translators, in the nose for starting that whole like of crap about "skipping" off the Earth's atmosphere with a lifting spacecraft. It doesn't and can't happen that way. The only way to change your vector with such a craft while re-entering is to fly up, rather than bounce up - you've got to be flying fast enough, in thick enough air, to allow a normal pull-up. (As a reference, note that Columbia had almost reached an EAS that would have allowed a pull-up, but hadn't yet)) The definition of where "space" starts is completely arbitrary. The USAF specifies it as 50 miles MSL. The FAI specifies it as 100 km. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
#12
|
|||
|
|||
|
#13
|
|||
|
|||
|
#14
|
|||
|
|||
|
#16
|
|||
|
|||
On Wed, 23 Jun 2004 06:50:21 GMT, Buzzer wrote:
On Tue, 22 Jun 2004 22:58:19 -0400, Peter Kemp wrote: Looks like the flight did not go to plan. According to BBC reports quoting Rutan there were severe control problems that forced the pilot (ok, ok, astronaut) to resort to backup controls just after boost (uncommanded roll) and again near Apogee (nothing specific mentioned). He says they're not flying again until they know what the hell happened, and the next flight will not now be the first for the X-Prize, but another test flight. Can't say I blame him, and Starchaser (the next closest IIRC) are 18 months away, so time isn't that critical. Peter Kemp And besides they have to try and find all those stupid M&Ms he let loose in the cockpit. I had to laugh at that. If it were NASA they'd ground the Shuttle for two years and spend a billion dollars on a new "M&Ms-don't-become-airborne" system. |
#17
|
|||
|
|||
In article ,
Peter Kemp writes: On 23 Jun 2004 21:54:57 GMT, (B2431) wrote: From: "Steven P. McNicoll" Date: 6/23/2004 5:49 AM Central Daylight Time Message-id: .net "miso" wrote in message e.com... Note that they will have to make 2 more trips for the prize if they miss the 2 week window. Still better to delay then risk life, limb, and the hardware. They have to make at least two more trips for the prize regardless of anything else, as they have yet to make a single qualifying flight. How did this one not qualify? Not high enough and did not carry 3 humans (although I think 2 of the "passengers" can be weighted dummies. The flight was high enough - IIRC, the apogee was 100.125 km, so they had 1/8 of a km in the bag. (Not enough really, you wnat to have more in the case of an instrumentation hiccup) In order to qualigy as an X-Prize flight, it has to be carrying ballast equivalent to two passengers (And no, you don't get to pick the passengers, it's a specified weight), and the flight has to have been pre-announced by 30 days, with another flight following within 14 days. This flight wasn't intended to be an X-Prize flight, but a test flight. Burt Rutan's been running an orderly and reaosonable test program, taking each stage in bite-sized increments, and resolving problems as he goes. (His normal approach) There hasn't yet been the 30 day pre-boarding call. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
#18
|
|||
|
|||
"B2431" wrote in message ... How did this one not qualify? The X Prize flights require three people aboard or a pilot and ballast equivalent to two people. Melvill flew solo and carried no ballast. |
#19
|
|||
|
|||
"Peter Kemp" wrote in message ... Not high enough and did not carry 3 humans (although I think 2 of the "passengers" can be weighted dummies. It was high enough but did not carry the two passengers/ballast. |
#20
|
|||
|
|||
On Thu, 24 Jun 2004 02:14:44 GMT, "Steven P. McNicoll"
wrote: "Peter Kemp" wrote in message .. . Not high enough and did not carry 3 humans (although I think 2 of the "passengers" can be weighted dummies. It was high enough but did not carry the two passengers/ballast. Sorry for some reason I had 120km in mind - checking I am wrong (again!) Peter Kemp |
Thread Tools | |
Display Modes | |
|
|