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SpaceX finally reaches orbit

Posted: Mon Sep 29, 2008 2:14 am
by BSPhysics

Re: SpaceX finally reaches orbit

Posted: Mon Sep 29, 2008 3:54 am
by djolds1
Nicely done. 8)

Manned Dragon capsule with an ablative reentry shield by 2012 latest, IMO.

With any luck NASA is on track to being split into the National Aerospace Laboratory and Government Space Mission Client, not provider. Assuming things don't go political against Musk & the private ventures. The gov't did successfully suppress private low budget sounding rocket launch a few years back. The legacy Aerospace Cartel has deep pockets and contacts.

Duane

Posted: Mon Sep 29, 2008 10:53 pm
by Skipjack
Awesome work by Musk and his team. Very exciting indeed, even though not revolutionary, they did an awesome job!
Lets hope the best for them in the future, but I think that now things are only going to "go up" ;)

Posted: Tue Sep 30, 2008 3:09 am
by djolds1
Skipjack wrote:Awesome work by Musk and his team. Very exciting indeed, even though not revolutionary, they did an awesome job!
Lets hope the best for them in the future, but I think that now things are only going to "go up" ;)
They built a BDB*. A low cost high reliability conventional booster which should rival the Soviet/Russian Soyuz booster, the "dumbest" and most reliable ETO booster in human history thusfar. This is something the Western Aerospace Cartel has never bothered to construct because their lavish above-cost government contracts allow them to build finely tuned & unstable gold-plated wonder toys

Nicely done. 8)

Duane

* Big Dumb Booster

Posted: Wed Oct 01, 2008 9:20 am
by IntLibber
djolds1 wrote:
Skipjack wrote:Awesome work by Musk and his team. Very exciting indeed, even though not revolutionary, they did an awesome job!
Lets hope the best for them in the future, but I think that now things are only going to "go up" ;)
They built a BDB*. A low cost high reliability conventional booster which should rival the Soviet/Russian Soyuz booster, the "dumbest" and most reliable ETO booster in human history thusfar. This is something the Western Aerospace Cartel has never bothered to construct because their lavish above-cost government contracts allow them to build finely tuned & unstable gold-plated wonder toys

* Big Dumb Booster
There were plenty of advancements in the Falcon 1 btw. Firstly, the Merlin engine is the highest ISP kerosene engine ever built, secondly it is reusable, and throttlable.

The frame of the launcher is unique. They used a thin bladder type construction like the early Atlas used (the tanks were so thin walled they needed to be inflated with positive pressure to keep from collapsing, which is how it was able to make orbit on a stage and a half), BUT they made it stronger with a honeycomb skin rather than mere sheet metal. They have also pioneered CNC stir welding in launch vehicle construction, which is higher quality and stronger than arc welding. Thirdly, the first stage is built to be recoverable and reusable, hence not entirely an expendable launcher (the second stage tends to stay with the payload if its for LEO anyways). So yes, this is a lot more than a BDB.

Posted: Wed Oct 01, 2008 10:56 am
by djolds1
IntLibber wrote:There were plenty of advancements in the Falcon 1 btw. Firstly, the Merlin engine is the highest ISP kerosene engine ever built, secondly it is reusable, and throttlable.
304 seconds Isp? Far from the highest Isp LOX/RP-1 engine ever built.

Reusable? A fine theory, but most attempts have been more expensive than its worth.
IntLibber wrote:The frame of the launcher is unique. They used a thin bladder type construction like the early Atlas used (the tanks were so thin walled they needed to be inflated with positive pressure to keep from collapsing, which is how it was able to make orbit on a stage and a half), BUT they made it stronger with a honeycomb skin rather than mere sheet metal. They have also pioneered CNC stir welding in launch vehicle construction, which is higher quality and stronger than arc welding. Thirdly, the first stage is built to be recoverable and reusable, hence not entirely an expendable launcher (the second stage tends to stay with the payload if its for LEO anyways).
Most impressive.

Duane

Posted: Wed Oct 01, 2008 7:21 pm
by cuddihy
djolds1 wrote:
IntLibber wrote:There were plenty of advancements in the Falcon 1 btw. Firstly, the Merlin engine is the highest ISP kerosene engine ever built, secondly it is reusable, and throttlable.
304 seconds Isp? Far from the highest Isp LOX/RP-1 engine ever built.
Yeah, the RD-180, the Russian Lox/Kerosene engine on the Atlas-V lower stage has a sea-level Is of 311 sec. Vacuum 330s.
Reusable? A fine theory, but most attempts have been more expensive than its worth.
I think it speaks volumes that SpaceX admitted they didn't even try to make the 1st stage recoverable for this launch. When I watched the video it looked like there was a fair amount of impingement on the first stage from the second stage ignition.

Posted: Thu Oct 02, 2008 6:23 am
by djolds1
cuddihy wrote:Yeah, the RD-180, the Russian Lox/Kerosene engine on the Atlas-V lower stage has a sea-level Is of 311 sec. Vacuum 330s.
Paraffin hybrids are supposed to brush up close the theoretical LOX/kerosene max of 350 seconds.
cuddihy wrote:I think it speaks volumes that SpaceX admitted they didn't even try to make the 1st stage recoverable for this launch. When I watched the video it looked like there was a fair amount of impingement on the first stage from the second stage ignition.
NASA's attempt at "reusabililty" with the Shuttle 1975-2000 has been the biggest boondoggle in space access thusfar. SRB recovery is a bad joke on a cost basis and the reason Challenger exploded, reconditioning the SSMEs costs MORE than new build engines (IIRC), and side-mounting the huge-engine aerodyne instead of top mounting a small engine unit like Dyna-Soar is the reason Columbia disintegrated. One shots are MUCH cheaper.

Posted: Thu Oct 02, 2008 10:02 am
by MSimon
One shots are MUCH cheaper.
One reason for that is that you don't have to build in extra margin for wear and tear.

Posted: Thu Oct 02, 2008 4:41 pm
by 93143
I remain a fan of Sea Dragon. And yes, the first stage was to be reusable. Not because of complicated, expensive attempts to preserve its functionality for an even more expensive refurbishment effort, but because it was built like a ship instead of like a pop can. They didn't even need parachutes - just an inflatable drag skirt. The sole engine was of the simplest and most reliable design possible (Isp for the LOX/Kero first stage engine was expected to be ~200, but then high Isp wasn't the point of the design...).

I also remain optimistic about SpaceX's attempt at reusability. They appear to be focused on bringing the cost down, and appear to be doing things more or less right from that perspective. If in this context they think recovering the first stage is possible, they could very well be right.

Posted: Thu Oct 02, 2008 11:26 pm
by BSPhysics
http://www.parabolicarc.com/2008/10/02/ ... 0-million/

SpaceX's first specific lunar plan. Man, do they put the cart ahead of the horse. Or, a 21st Century saying, "They put the rocket on top of the capsule!"

All luck to you SpaceX,

BS

Posted: Fri Oct 03, 2008 8:09 pm
by Skipjack
Hehe, yes, I found that a little premature as well. I think that proposal was born during the first euphoria of their recent achievement. Sure the euphoria was deserved, the proposal is a tad over the top though ;)

Posted: Sat Oct 04, 2008 4:26 am
by djolds1
BSPhysics wrote:http://www.parabolicarc.com/2008/10/02/ ... 0-million/

SpaceX's first specific lunar plan. Man, do they put the cart ahead of the horse. Or, a 21st Century saying, "They put the rocket on top of the capsule!"

All luck to you SpaceX,

BS
A true space prestige program, national or commercial, would be a megastructure launch method to access space on the cheap. Space Elevators require too many materials breakthroughs, but there are additional options. An Aerovator, Loffstrom's Lunacy, Suborb rocket-tether relay, Megaguns, etc.

Moon access and even SpaceX level "cheap" boosters are still too limiting for true ambition.

Duane