Members Login
Username 
 
Password 
    Remember Me  
NUCLEARSPACE MESSAGE BOARD (ACTIVE) -> OPEN FORUM -> another option: "Direct Shuttle Derivative"
Post Info TOPIC: another option: "Direct Shuttle Derivative"
john fraz


Veteran Member

Status: Offline
Posts: 62
Date:
another option: "Direct Shuttle Derivative"
Permalink  

This just came to my attention. It seems to address many problems with the ESAS architecture, cutting development time and increasing commonality between launchers and with the present STS hardware.
This isn't "official"; many of the people working on it from within NASA are doing so anonymously, to protect their jobs.

tnLaunch_Vehicles_DIRECT.jpg

For Release

Cape Canaveral, Florida
25th October 2006

A grass-roots effort, supported by many engineers and mid-level managers within the National Aeronautics and Space Administration (NASA), is announcing its proposal today, targeted to influence NASA to review again its plans for the new "Ares" family of launch vehicles. If adopted, the new approach promises to save the agency $35 Billion over the next 20 years.

Called the "Direct Shuttle Derivative", or "DIRECT", the proposal calls for NASA to replace the separate "Ares-I" Crew Launch Vehicle (CLV) and the massive "Ares-V" Cargo Launch Vehicle (CaLV) currently being designed to replace the Space Shuttle, with a single "Universal Launcher" system capable of performing both roles.

This would immediately cut in half the expected $40 Billion development cost of the two planned launchers, and would also halve the recurring fixed costs of operating two divergent launcher systems concurrently.

The proposal, available on www.directlauncher.com, approaches the problem of Lunar and Mars missions from an integrated perspective, dealing with the most important issues facing NASA today, such as multi-billion-dollar development costs, extensive infrastructure replacement, low vehicle performance, lower safety performance than planned, and long-term program risks.

Coming hot on the heels of recent Congressional Budget Office and Government Accounting Office criticisms that NASA must reassess its spending plans for the new "Vision for Space Exploration", and in the wake of much argument from inside NASA's own Science Community regarding recent mission and budget cuts made to fund the development of the new launchers and the Orion CEV spacecraft, this proposal seems to offer a particularly viable alternative path for NASA to consider.

The DIRECT approach calls for a single launch vehicle, based on the very reliable and already man-rated 4-segment Solid Rocket Boosters (SRB) used on the Space Shuttle today, a Core Stage based very closely on the existing External Tank, but with two RS-68R engines, based on the engines used by the Delta-IV, mounted underneath. This configuration initially offers more than 70 tons of lift capability to orbit, compared to just 22 tons for the Ares-I. Add an Upper Stage, similar to the one Ares-V requires and this performance climbs to over 98 tons on every flight. Two flights of DIRECT exceed the combined payload performance of the Ares-I and Ares-V together, which are both required under current plans for each Lunar mission.

By reusing existing launcher elements, support infrastructure and current manufacturing facilities to the maximum possible degree, DIRECT requires only a fraction of the expensive changes required by the two Ares vehicles. This not only saves Billions, but would also reduce schedules considerably.

The idea itself is far from new, in fact it was originally proposed by NASA's Marshall Space Flight Center in 1986, in the aftermath of the 1986 Challenger accident. However, DIRECT has evolved the concept into a modern integrated approach, which fits with NASA's mandate, workforce retention requirements , and performance needs, and neatly integrates into the current support structure which exists for Shuttle today.

The concept promises to allow NASA to spend an extra $35 Billion of its budget on making use of its new spacecraft, instead of using that money just building and operating the launch vehicles.

For more information, please visit: www.directlauncher.com



-- Edited by john fraz at 07:09, 2007-04-24

__________________
"A devotee of Truth may not do anything in deference to convention. He must always hold himself open to correction, and whenever he discovers himself to be wrong he must confess it at all costs and atone for it." Monhandas K. Gandhi
GoogleNaut


Guru

Status: Offline
Posts: 606
Date:
RE: another option: "Direct Shuttle Derivative"
Permalink  

This concept has been extensively studied and modelled on the nasaspaceflight.com website, especially in the L2 section.

It is interesting but by increasing the SRBs from one to two, you have doubled the danger to the crew on the CEV. The extra performance that you get is lost and the resultant vehicle is very much more expensive than the "Stick" configuration.

Although I am not a real fan of the "Stick," "Shorty" as this configuration has been nicknamed, does not seem to solve the problems of the "Stick." There have been a couple of proposals to adapt the EELV Delta IV and Atlas 5 vehicles to a manned configuration. I believe Bigelow has a contract with Lockheed Martin to extensively study the feasability of manrating the Atlas 5. This seems like a viable and appropriate avenue to take.

NASA however seems rather set on the "Stick" and plans are proceeding to actually start modifying launch pad structures at Pad 39A I think either this fall or next summer to accomodate the Stick. That would seem to me to indicate that as fasr as NASA is concerned the "Stick" is a done deal.





__________________
john fraz


Veteran Member

Status: Offline
Posts: 62
Date:
Permalink  

GoogleNaut wrote:
It is interesting but by increasing the SRBs from one to two, you have doubled the danger to the crew on the CEV.The usual thing I hear about the SRBs is that after they fixed the trouble that killed the Challenger, the SRBs are very safe now. And it should be noted that the "Stick" was originally invented by astronauts, as a safer altenative.
This Direct Launcher also uses them as they were intended, not re-engineered to fly solo. It does eliminate the "twang" associated with the side-stacked SSMEs on the Shuttle.

The extra performance that you get is lost and the resultant vehicle is very much more expensive than the "Stick" configuration.The site addresses the extra lift performance, and I don't see that as being as much of a problem as re-engieering the Stick.
More expensive than having to completely from-scratch develop both the Ares 1 and Ares V? That's the point. It's bigger than the Stick, but cheaper than doing two new launchers at once.

Although I am not a real fan of the "Stick", "Shorty" as this configuration has been nicknamed, does not seem to solve the problems of the "Stick"By a lot I've read, it does. There's a lot of work to be done to get the "stick" ready for a realistic test flight.

There have been a couple of proposals to adapt the EELV Delta IV and Atlas 5 vehicles to a manned configuration.Long past time that this should have been aggressively pursued. Along with the HL-20 or some other crewed launcher.

NASA however seems rather set on the "Stick" and plans are proceeding to actually start modifying launch pad structures at Pad 39A I think either this fall or next summer to accomodate the Stick. That would seem to me to indicate that as fasr as NASA is concerned the "Stick" is a done deal.Don't say that until the final version has flown several times. As of now, things are changing daily. There's so much that's not known about it, that it's a new vehicle, and we know from the last ~35 years how well NASA has done at that.

__________________
"A devotee of Truth may not do anything in deference to convention. He must always hold himself open to correction, and whenever he discovers himself to be wrong he must confess it at all costs and atone for it." Monhandas K. Gandhi
GoogleNaut


Guru

Status: Offline
Posts: 606
Date:
Permalink  

I would also point out that this "direct" derivative isn't quite as "direct." If you count segments on the motors, you'll find that these are infact a 'three segment" SRB so it has as much heritage as the "5-segment" advanced solid rocket motors.

I am optimistic, but guardedly so. I hope that this whole program doesn't end up as a huge government pork program--I think it has a good chance to succeed.

__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
NUCLEARSPACE MESSAGE BOARD (ACTIVE) -> OPEN FORUM -> another option: "Direct Shuttle Derivative"
Tweet this page Post to Digg Post to Del.icio.us


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard