Henry:
You might want to find a bigger knothole from which to view the problem:
even if ULA were able to match SpaceX’s costs, ULA’s pension obligations
assure they could not match SpaceX's pricing. Because ULA is structurally
committed to paying higher wages than SpaceX and because SpaceX requires
more hours from it’s workers, there is no plausible investment in ULA that
makes it a viable competitor. Then there is Blue Origin.
Given that the owners have many other and better alternative investments,
liquidating ULA is the correct strategy for the owners. Indeed, it is
common knowledge that one of the owners would sell it’s share if they
could, in order to put that money to more profitable use.
Bill
On Sat, Jun 29, 2019 at 8:27 PM Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
wrote:
I agree with part of what you imply, that ULA shouldn't try to compete
with SpaceX on price.
I disagree strongly with your main assertion, that ULA obviously has no
future and that Boeing and Lockmart are correct in treating it as a
limited-life cash cow and minimizing investment in its future
capabilities. (FWIW, what they are currently investing - chiefly in Vulcan
- despite their parents apparently agreeing with you is I think explainable
in terms of their main government customer insisting on a US-engined Atlas
5 replacement.)
My point is that ULA has a window of opportunity to compete with SpaceX in
a growing new beyond-LEO market on *performance* - on superior ability to
execute complex high-performance missions in deep space. And then to
charge what the traffic will bear to those in need of those unique
capabilities - a sweet spot to be in.
But they're in growing danger of missing the window, due to deliberate
underinvestment in that specific (ACES) capability, and to SpaceX now
working toward eventual (more or less) similar capability via
LEO-repropellanted Starship.
"That kid will never amount to anything" is self-fulfilling prophecy if on
that basis you starve them and stunt their growth. "Hello? CPS?"
Henry
On 6/29/2019 6:03 PM, William Claybaugh wrote:
None of ULA’s investments are likely to beat SpaceX’s current prices, much
less their future pricing. Company B and Company L are acting
appropriately. Indeed, one wonders why they are supporting any future
investment in ULA....
Bill
On Sat, Jun 29, 2019 at 4:36 PM Henry Vanderbilt <
hvanderbilt@xxxxxxxxxxxxxx> wrote:
Yes, ACES. Which, when you get down to it, could be the first true space
ship. It'll have electric power, maneuvering jets, and main propulsion for
as long as it has LOX and LH2. And once you're able to top those up in
space, it can keep flying missions until it needs maintenance.
Too bad Boeing and Lockmart keep treating ULA as a cash cow rather than
letting them plow enough back into development to move forward with Vulcan
and ACES simultaneously. Padding the current bottom line at the expense of
ULA's near-term chance to be the dominant player for beyond-LEO ops, IMHO.
"Hello, CPS? I want to report a case of child abuse. Biological parents?
No, corporate."
As for ULA and Roush, well, as an ex-XCORian, mixed feelings. That
wasn't entirely the match we were trying to make...
Henry
On 6/29/2019 10:26 AM, John Schilling wrote:
Also a GH2-GOX auxiliary power unit running at tank pressure and
hopefully replacing the limited and sometimes troublesome batteries on the
Centaur. Which, since turbines aren't the right answer at that scale and
ULA knew they needed outside talent for this, offers the ineffable coolness
of a high-performance deep space transfer vehicle running on a flat-six
internal combustion engine out of NASCAR <https://www.roush.com>.
One more reason to lament the lack of sound in space...
John Schilling
john.schilling@xxxxxxxxxxxxxx
(661) 718-0955
On 6/28/2019 7:05 AM, Doug Jones (Redacted sender randome for DMARC)
wrote:
Frank Zegler has lead a lot of interesting work on low pressure
RCS/ullage thrusters at ULA under the integrated vehicle fluids project.
They've demonstrated GH2-GOX motors running at Centaur tank pressure.
https://urldefense.proofpoint.com/v2/url?u=https-3A__forum.nasaspaceflight.com_index.php-3Ftopic-3D37206.160&d=DwICaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=rPTfWqtJdrL0Ber-yr0E_hSjRXuvJH6ZmQx03u8-2as&m=oyeKvE-Ctx7THbIwvpFEy8V9Qi_PwAXdFqkzOjSG1NI&s=Xm5pQ5-eerXNuSNwzL7d3s5aZfQN6nMy2-qP9udRUmw&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ulalaunch.com_docs_default-2Dsource_extended-2Dduration_integrated-2Dvehicle-2Dpropulsion-2Dand-2Dpower-2Dsystem-2D2011.pdf&d=DwICaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=rPTfWqtJdrL0Ber-yr0E_hSjRXuvJH6ZmQx03u8-2as&m=oyeKvE-Ctx7THbIwvpFEy8V9Qi_PwAXdFqkzOjSG1NI&s=YXKfS5zGfRnKBL8_xSyDppfRB3mScZlu__EOKUWk5Z0&e=
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ulalaunch.com_docs_default-2Dsource_supporting-2Dtechnologies_space-2Daccess-2Dsociety-2D2012.pdf&d=DwICaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=rPTfWqtJdrL0Ber-yr0E_hSjRXuvJH6ZmQx03u8-2as&m=oyeKvE-Ctx7THbIwvpFEy8V9Qi_PwAXdFqkzOjSG1NI&s=FREtyHVwAizwv3nQBzAodMoGAWiBiwX4sH9P44Udvgw&e=
On 2019-06-27 6:17 PM, Keith Henson wrote:
On Wed, Jun 26, 2019 at 10:07 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
<hspencer@xxxxxxxxxxxxx> wrote:
On Wed, 26 Jun 2019, Doug Jones wrote:
Net Positive Suction Pressure (NPSP) required for most LH2 rocket
engines is in excess of 50 psia. Gossamer tanks are an accident looking
for a time to happen.
The original Centaur had quite low tank pressures, just enough for
structural needs, with boost pumps (driven by peroxide turbines) at the
tank exits to deliver adequate pressure to the engines. But the boost
pumps proved unreliable, and for other reasons the performance demands on
Centaur were relaxed a bit, and they eventually decided to ditch the
boost
pumps and accept somewhat higher pressures and thicker tank walls.
Space junk makes building power satellites in LEO and moving them out
to GEO using electric thrusters close to impossible. (They get hit
too many times which is bad, the hits make more debris which is
worse).
The current proposal (credit to Roger Arnold) is to accumulate
15-16,000 tons of power satellite parts and 5000 tons of reaction mass
in LEO then push the stack of parts and reaction mass up with chemical
propulsion via Hohmann transfer orbit to 2000 km. That puts the
construction orbit above almost all the junk. Two of these stacks are
enough for a 32,000-ton power satellite plus the reaction mass needed
to move it out to GEO.
The delta-V for the two impulses is 827 m/s. That translates into a
reaction mass fraction of slightly less than 20% for hydrogen and
slightly more than 20% for methane. This includes enough fuel to get
the tug from 2000 km back to LEO. The exhaust velocity is not so
important when the delta-V you need is small compared to Ve.
If the ground to LEO is Skylon, then hydrogen may be the least
complicated since we can pump out any leftover Skylon hydrogen and
oxygen. Methane may be better if ground to LEO rockets are using it.
Roger makes a case that we can use lightweight, low-pressure engines
and still get the same exhaust velocity since there is no atmosphere.
I don't know much about low-pressure engines.
The reaction mass would be around 20% of 21,000, call it 4200 tons.
The engines and tanks and structure should come in at about 10% of the
reaction mass, roughly estimate the tug at 400 tons.
For the normal ratio of hydrogen to oxygen, the reaction mass would be
3500 tons of LOX and 700 tons of LH2, about 10,000 cubic meters. That
gives a radius of 28.7 for a sphere or a diameter of about 57 m. It
would be subject to around 1/10th of a g and the have to carry the
entire cargo mass.
Does this make sense?
Keith
