[AR] Re: 500,000 tons per year to GEO (off topic)

  • From: marsbeyond@xxxxxxxxx
  • To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
  • Date: Wed, 2 Apr 2014 22:42:33 -0700

Henry, 

Yes it is a more complicated problem to recover the second stage. But it is an 
evolutionary challenge, not a revolutionary one. SpaceX is simply adding 
Attitude Control Systems to all stages. It really is simple actually! It's been 
there all the time! It is the "holy grail" that rocket scientists have been 
looking for for fifty years! Re-usability thru propulsive recovery! It's such a 
stupidly simple minded idea! It's actually a brilliant implementation of the 
KISS principle. I used to think was an antiquated idea from schlocky 1950's 
sci-fi flicks. 

Everyone THINKS it requires an excessive amount of fuel!

IT DOES NOT!

Serendipity is wonderful! Cassiopeia was almost recovered! It was only going 
~100 mph when it hit the Pacific! Somehow it developed a wicked ACCIDENTAL spin 
that starved the center engine during the final seconds of the flight!

Then It hit me! The AHA MOMENT! What if you INDUCE A SPIN OF THE SECOND STAGE 
FOR GYROSCOPIC STABILITY just PRIOR to RE-ENTRY! You save a tremendous of of 
fuel preventing adverse unintended tumbling and adverse unintended spin! Then 
after the high temp portion of re-entry, you simply DESPIN THE STAGE to settle 
the fuel in the bottom of the tanks! 

(OR YOU COULD RETAIN ACTIVE CONTROL OVER THE STAGE the entire time with your 
second stage ACS rockets, whichever option requires less fuel!)

It's so freakin simple! It's elegant! And it's been in front of our noses the 
whole time! 

When the Falcon 9R and Falcon 9HR recover all stages and the capsule, the price 
of going to LEO DROPS TO 4%! (FUEL COSTS!) That works out to less than $80 a 
pound! I was giving them a generous 20% profit margin and rounding up to $100 a 
pound to LEO!

Sent from my iPhone

On Apr 2, 2014, at 8:58 PM, Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx> wrote:

> Marsbeyond,
> 
> I'd apply several grains of salt there.  SpaceX is close to demonstrating 
> intact first-stage recovery - I wouldn't bet against it this next flight, 
> given how well the last couple tests have gone - but intact second-stage 
> recovery is an even tougher problem that they haven't yet made a visible 
> start on.
> 
> Also, even once they get back intact stages, there's a big question of what 
> kind of shape the stages will be in - how many reliable reflights will be 
> practical, at what cost for handling and inspection and refurbishment.  You 
> need to fly your hardware a LOT of times with minimal between-flights 
> hardware processing costs before you can hope to approach the low three 
> figures payload cost per pound.
> 
> Mind, I've learned to be very careful about betting against SpaceX on their 
> announced goals.  (Have they actually said they'll do this?)  In any case, 
> chances are Cheops' Law will prevail - the project will take longer and cost 
> more than planned.
> 
> Me, I'd be very happy if in two years they're close to reusing first stages 
> on an operational basis.  Given that first stages are probably the majority 
> of an F9's hardware cost, I'd expect that would give them a good start toward 
> breaking the $1000/lb barrier, from their current apparent costs in the 
> neighborhood of $2000+/lb.
> 
> $1K/lb to LEO would be revolutionary enough, is my guess.  With inflation, 
> that's well below the $600/lb the CSTS back in the nineties said should make 
> cost reductions start expanding the overall launch market fast enough so 
> overall revenue rises despite dropping prices.  At that point, further cost 
> reductions pay for themselves and more, and the sky's (no longer) the limit.
> 
> Henry
> 
> On 4/2/2014 10:49 AM, marsbeyond@xxxxxxxxx wrote:
>> Kieth,
>> 
>> When is Skylon supposed to fly? In less than two years, SpaceX will
>> be using propulsive recovery to re-use the first stage, second stage,
>> and capsule, and their cost to LEO will drop to $100 a pound!
>> 
>> Sent from my iPhone
>> 
>> On Apr 2, 2014, at 9:27 AM, Keith Henson <hkeithhenson@xxxxxxxxx>
>> wrote:
>> 
>>> http://theenergycollective.com/keith-henson/362181/dollar-gallon-gasoline
> $350 million committed so far to the Skylon engines.
>>> 
>>> Keith
>

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