Will SpaceX borrow half of the Sea Dragon idea?SpaceX has talked about making their rocket sea-water resistant. When I was picturing the fully-reusable future SpaceX launcher, I was picturing a first stage which after separation, turns around, re-ignites some or all of its engines with residual fuel, and boosts back to the launch pad for a propulsive landing. Might SpaceX instead just propulsively slow it down above the ocean enough to slip in without sustaining damage, to be pulled up, perhaps by an amphibious erector tower or tow-cable to be taken back to the pad? Is one of the reasons for building a new Texas pad a range rule against boosting your stages back in the direction of a Florida pad?
Sea Dragon is not needed. It's $300 per kg to orbit in 1963 is $2160 per kg in 2011 dollars, which means it would be competing with Russian rockets (Zenit) and Falcon Heavy on a cost per kg basis.
Why was Sea Dragon so much more efficient at BEO?
Aerojet did some fantastic engine work and doesn't get the credit like the bigger boys LM, Boeing etc.
Wait till you see the finished performance of the AJ-500.
SD was proposed before the F-1 got on the test stand and revealed the problems with large engines and combustion instability. The guarantee of combustion instability on a single-bell 80 million pound thrust first stage engine, or a 7 million pound thrust upper stage engine is simply ridiculous.
The cost is also prohibitive. How expensive was the 1 million pound thrust RS-84 was going to be? How expensive is the quarter-million pound thrust J-2X? Warp drives would be cheaper to develop than an 80 million pound single-bell engine.
That amount of power in the ocean will kill everything within miles. Environment groups will make it illegal long before the first test flight ever came close.-MP.
If you change Sea Dragon to use an aerospike, it's almost Direct P2.
Quote from: Jason1701 on 08/02/2011 02:03 pmIf you change Sea Dragon to use an aerospike, it's almost Direct P2.sHaha, it looks like I needed to pay more attention to what Ross, Chuck, et al are up to these days. So is this what C-Star is doing?
Several people have mentioned their concern over developing a large rocket engine due to combustion instabilities. With modern software/analytical tools, is combustion instability still considered a practically insurmountable challenge for developing really big engines?
SD was proposed before the F-1 got on the test stand and revealed the problems with large engines and combustion instability. The guarantee of combustion instability on a single-bell 80 million pound thrust first stage engine, or a 7 million pound thrust upper stage engine is simply ridiculous.The cost is also prohibitive. How expensive was the 1 million pound thrust RS-84 was going to be? How expensive is the quarter-million pound thrust J-2X? Warp drives would be cheaper to develop than an 80 million pound single-bell engine.That amount of power in the ocean will kill everything within miles. Environment groups will make it illegal long before the first test flight ever came close.Nice idea. Totally impractical.-MP.
Quote from: Max_Peck on 11/15/2010 01:38 amSD was proposed before the F-1 got on the test stand and revealed the problems with large engines and combustion instability. The guarantee of combustion instability on a single-bell 80 million pound thrust first stage engine, or a 7 million pound thrust upper stage engine is simply ridiculous.I should probably point out that as knowledge was gained in the F1 program the design was changed to several combustion chambers feeding a single nozzle so it wasn't "actually" a single engine design QuoteThe cost is also prohibitive. How expensive was the 1 million pound thrust RS-84 was going to be? How expensive is the quarter-million pound thrust J-2X? Warp drives would be cheaper to develop than an 80 million pound single-bell engine.The last design upgrade I recall had the engines being developed from the F1 it self so the design costs were a lot less than expected overall.QuoteThat amount of power in the ocean will kill everything within miles. Environment groups will make it illegal long before the first test flight ever came close.Engine "burp" or simply fireing up the turbopumps will clear the area in a hurry. A couple of "sounding-charges" (big band, little actual blast) would effectivly clear out all the life within a couple of square miles within seconds. IIRC there is actually a Navy procedure number for such an operation QuoteNice idea. Totally impractical.Ok, Quick fix. Plug Nozzel for the first stage and about 10 to 15 F-1 engines on the second stage. Problem solved.
That amount of power in the ocean will kill everything within miles. Environment groups will make it illegal long before the first test flight ever came close.
Nice idea. Totally impractical.
If fact, such a launcher, pound for pound (or kilogram for kilogram, if you will) would be a couple of orders of magnitude cheaper than any current launcher, including the Falcon 9.