Community > Forum > Bigelow's America's Space Prize > Possible Craft

Possible Craft

Posted by: Sev - Sun Oct 10, 2004 4:10 pm
Post new topic Reply to topic
 [ 201 posts ] 
Go to page Previous  1 ... 10, 11, 12, 13, 14  Next
Possible Craft 
Author Message
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post    Posted on: Thu Aug 25, 2005 9:12 am
While researching for some concrete informations regarding another thread I found the following issues about the advantages of air launches. May be that they have been mentioned already but it not that decisively, concretely and detailed as far as I remember.

AirLaunch LLC under www.airlaunchllc.com/News.htm say

Quote:
...

... there are fewer delays waiting for specific launch windows (to match desired orbits) because the vehicle can be flown to an alternate launch point that is better aligned with the desired orbit. In addition, ground launches must be postponed whenever ships enter the ocean zones near the coastal launch sites or where rocket stages are expected to drop; the QuickReach carrier aircraft can avoid such delays by flying to a different release point.


Air launching also simplifies the design of the vehicle, which simultaneously ... improves reliability. The modest performance gain of launching at 25,000 to 35,000 feet, and with some forward speed, makes it easier for a two-stage rocket to put payloads into orbit. In addition, the first stage engine and nozzle can be designed solely for operation at a significant altitude – this avoids the design challenges of also needing to operate efficiently at sea level air pressure during lift-off.


Listed:

- fewer delays
- vehicle can be flown to alternate launch point
- simplification of design
- better reliability
- performance gain
- it's easier to put payloads into orbit
- design solely for operation at significant altitude possible ==> design challenges avoided



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Moon Mission Member
Moon Mission Member
avatar
Joined: Tue Feb 10, 2004 2:56 am
Posts: 1104
Location: Georgia Tech, Atlanta, GA
Post    Posted on: Thu Aug 25, 2005 6:45 pm
Hitch being, it's also a lot heavier. A traditional rocket only has to withstand stress in the vertical direction -- the direction along which a cylinder is strongest. An air-launched rocket, on the other hand, has to be able to make the initial climbing turn, under a reasonably high g-load (something like 3 or 4 is probably a good guess), that would make the mighty Saturn V undergo a RUD event.

_________________
American Institute of Aeronautics and Astronautics
Daniel Guggenheim School of Aerospace Engineering

In Memoriam...
Apollo I - Soyuz I - Soyuz XI - STS-51L - STS-107


Back to top
Profile
Space Walker
Space Walker
avatar
Joined: Fri Jul 30, 2004 3:17 pm
Posts: 243
Location: So Cal, baby!
Post    Posted on: Thu Aug 25, 2005 7:00 pm
...enter the T/LAD method, which does it at a fraction of the energy with a nylon cord.

You could also do it a bit more slowly, without wings and with minimal lateral loading using your gimbal-steering or something like that; you'd have to get a good pitch from your dropship to make it happen, but as I have said before, it was done with a minuteman missile and a C-5 using a cargo sled and a drougue chute. That is essentially the same method AirLaunch wants to use (only with a C-17 'cuz QuickReach is smaller than a Minuteman).


Back to top
Profile
Space Station Commander
Space Station Commander
avatar
Joined: Wed Mar 09, 2005 1:25 am
Posts: 891
Post    Posted on: Fri Aug 26, 2005 7:04 pm
I like Truax's sea launch better myself. He had a rocket of more modest size called Excalibur that could put 50 tons in LEO. This would also use pressure-fed tech--would need no launch pad--no airplane...and is self-erecting.

http://www.astronautix.com/astros/truax.htm
http://www.astronautix.com/lvfam/truax.htm

John London at Marshall (author of LEO ON THE CHEAP), and Bill Sprague of AERA are among the few big pressure-fed advocates aside from Beal and the old AMROC crowd with their hybrids which the orbital version of Dream chaser might use.

I am not just saying this due to a falling out with Gump--but sea-based is the way to go. You can take your time with this launch method--and have a bigger rocket than even AN-225 could carry.

Things can happen real fast to an airplane in flight. Boating has a slower pace, and you have time to think about things.


Back to top
Profile
Space Station Commander
Space Station Commander
avatar
Joined: Wed Mar 09, 2005 1:25 am
Posts: 891
Post    Posted on: Thu Nov 17, 2005 8:22 pm
Speaking of which...

Dream Chaser--Orbital version...Part II:

http://www.nasaspaceflight.com/content/?id=4050
http://forum.nasaspaceflight.com/forums ... 5&start=11
http://forum.nasaspaceflight.com/forums ... sp?tid=855
http://www.space.com/missionlaunches/05 ... haser.html
http://www.spacefellowship.com/News/?p=1224

It started out like this:
http://www.popsci.com/popsci/aviationsp ... drcrd.html

The big booster is based on the old AMROC Aquila (not StarBoosters Aquila SDLV HLLV) that was to launch from a converted tanker.

http://www.dogpile.com/info.dogpl/search/web/Edward%2BHujsak%2BTHE%2BFUTURE%2BOF%2BUS%2BROCKETRY/1/-/1/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/-/417/top


Last edited by publiusr on Wed Nov 23, 2005 6:01 pm, edited 3 times in total.



Back to top
Profile
Space Walker
Space Walker
avatar
Joined: Fri Jul 30, 2004 3:17 pm
Posts: 243
Location: So Cal, baby!
Post    Posted on: Thu Nov 17, 2005 9:08 pm
Cool linx, publi (esp. popsci)

Trouble is, SpaceDev just inked with the AF to develop the booster technology, so they will be ineligible for the ASP.

I expect they really want the NASA commercial contract more anyway.


Back to top
Profile
Moon Mission Member
Moon Mission Member
User avatar
Joined: Tue Jul 15, 2003 8:46 pm
Posts: 1215
Location: Kapellen, Antwerp, Belgium, Europe, Planet Earth, the Milky Way Galaxy
Post    Posted on: Thu Nov 17, 2005 9:39 pm
Even newer news, related to SpaceDev on our own news page:

http://www.spacefellowship.com/News/?p=1230

_________________
Heavier-than-air flying machines are impossible. - Lord Kelvin, 1892


Back to top
Profile WWW
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Nov 17, 2005 10:29 pm
I think that SpaceDev has made a good decision by changing from the X-34 to the HL-20 and reducing the number of people it can carry is also a good idea when looking at crew rotations for the ISS.

Not sure whether NASA will fund its development though, I think that Jim Benson will have to look elsewhere for the cash.

One interesting point is that he talks about a suborbital vehicle for $20m and an orbital version for an additional $100m, a quarter of what T-space is asking for, is it really possible to do it that cheaply. Even SSO is reputed to have cost $25m can SpaceDev reasonably expect to build the 6 man suborbital Dream Chaser plus the large hybrid boosters for $5m less?

Another link, the newscientist article shows the seating layout.

http://www.newscientistspace.com/articl ... esign.html

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Moon Mission Member
Moon Mission Member
User avatar
Joined: Tue Jul 15, 2003 8:46 pm
Posts: 1215
Location: Kapellen, Antwerp, Belgium, Europe, Planet Earth, the Milky Way Galaxy
Post    Posted on: Thu Nov 17, 2005 10:49 pm
I think, with the new Air Force deal, + other projects (as SS1) etc, they have experiance, technology available others don't have.

So I think $20m is "possible", but I guess it may cost more than initialy planned (as many projects do). But even $30m isn't gigantic. I do hope.. they will find someone interested with a lot of money... but this can be difficult.

_________________
Heavier-than-air flying machines are impossible. - Lord Kelvin, 1892


Back to top
Profile WWW
Moon Mission Member
Moon Mission Member
User avatar
Joined: Mon Nov 01, 2004 6:15 pm
Posts: 1233
Location: London, England
Post    Posted on: Thu Nov 17, 2005 10:59 pm
The air force deal will no doubt help but the boosters for dream chaser are quoted as being 10 times more powerful than the 100,000 lb thrust ones the air force is financing, also I'm not sure whether the airforce booster will be designed to operate in clusters.

_________________
A journey of a thousand miles begins with a single step.


Back to top
Profile WWW
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post    Posted on: Fri Nov 18, 2005 8:26 am
Regarding the $5 million less than the funds for SS1 SpaceDev may get an advantage Scaled Composites/Mojave Aerospace Venture had no chance to get: The production of Virgin Galactic's five vehicles will cause enhancements of the production capacities of the companies who produce materials, elements and components for The Spaceship Company.

From this SpaceDev may have an advantage.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Space Station Commander
Space Station Commander
avatar
Joined: Wed Mar 09, 2005 1:25 am
Posts: 891
Post    Posted on: Fri Nov 18, 2005 11:37 pm
I always liked SpaceDev. They could swap out the X-34 and the lifting body like Buran and Polyus anyway.

Good news at last.

http://www.spacefellowship.com/News/?p=1224

http://www.space.com/missionlaunches/05 ... haser.html


Last edited by publiusr on Wed Nov 23, 2005 5:20 pm, edited 1 time in total.



Back to top
Profile
Space Walker
Space Walker
avatar
Joined: Fri Jul 30, 2004 3:17 pm
Posts: 243
Location: So Cal, baby!
Post    Posted on: Mon Nov 21, 2005 9:28 pm
Do you still like them now?

http://biz.yahoo.com/bw/051121/20051121005496.html?.v=1


Back to top
Profile
Moon Mission Member
Moon Mission Member
avatar
Joined: Tue Feb 10, 2004 2:56 am
Posts: 1104
Location: Georgia Tech, Atlanta, GA
Post    Posted on: Tue Nov 22, 2005 3:17 am
Beautiful. I love it. Just the fact that they told NASA they could do it for a tenth of the projected cost, that's great.

_________________
American Institute of Aeronautics and Astronautics
Daniel Guggenheim School of Aerospace Engineering

In Memoriam...
Apollo I - Soyuz I - Soyuz XI - STS-51L - STS-107


Back to top
Profile
Space Walker
Space Walker
avatar
Joined: Fri Jul 30, 2004 3:17 pm
Posts: 243
Location: So Cal, baby!
Post    Posted on: Tue Nov 22, 2005 5:49 pm
...well, personally I don't think that the fiscal numbers are realistic. I would almost say that they are irresponsible, but I haven't actually seen the study itself, so I can't make a definitive statement. However, basing a program (as described) on the notion of "emerging technologies that will be available by the time they are needed" is a setting your course into a quagmire of project delays and surprise cost overruns.

It's also comparing apples to oranges, considering that Constellation is a project to develop and field a Manned Interplanetary Exploration Architecture, not simply "get to the moon on a vectored-thrust ultralight" and I expect that if the SpaceDev study had included the capacity to send humans to Mars, then the glib notion of "one tenth the cost!" would have been scaled back or absent.

In the end, this begins to read like "NASA-bashing for the purposes of increasing the circulation of our press release," a practice which I find unsavory within this industry and which I would like to see stop. It is something Musk has largely refrained from doing and I think that provides him with a great deal of clout and credibility, and places him on the inside track for actually landing one of Griffin's commercial contracts.

Anyway, I thought it was ironic that the boys from Poway would make this release right after publi said he liked them. Our buddy is gonna have a conniption. Rightly so, in my view.

Speaking of SpaceDev and SpaceX, I read that SpaceDev is buying a Falcon I mission.


Back to top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 201 posts ] 
Go to page Previous  1 ... 10, 11, 12, 13, 14  Next
 

Who is online 

Users browsing this forum: No registered users and 2 guests


cron
© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use