Ares V (CaLV) - status

GCNRevenger · 2008-02-29 13:37:53

a space-spammer that always IS right

Nobody is always right, you are just grand-standing for your own amusement, and not to seriously debate or discuss. That makes you a spammer.

And Ciclops is right, all you've done is state that all of NASA's plans have problems, which at least some of them inevitably will. Thats by no means proof that you are an expert! And thats besides the fact that all your "problems" are simplistic and obvious ones that you don't need expertise to come up with. More spamming.

And again, you write your posts as a bunch of separated lines that are hard to read, and many blank lines with just periods in them that waste space and hurt the eyes. If you don't stop that, then its obvious that you are posting just to get us annoyed with you for your own amusement. Which also makes you a spammer. Less than half of your lines even have words!

And spammers should get banned

gaetanomarano · 2008-02-29 15:34:39

...seriously debate or discuss...

I do believe the ALL my discussions was/are/will be VERY serious

...makes you a spammer...

it's easier for you, since you accept everything space agencies and companies say and do without any critics hiding the fact that they do mistakes and often do changes in completely different ways than those they (and YOU) supported just a few days before...

...all you've done is state that all of NASA's plans have problems...

yes, it's easy to say that now... but the problem is that I've said that months and YEARS after the changes (from 2005) with detailed articles and posts about what and where are the problems, and MY solutions to them ...that very often are ALSO teh same problems that NASA admits and the solutions that NASA has adopted always AFTER my suggestions...

Thats by no means proof that you are an expert!

it's clearly IMPOSSIBLE, since, you are the only "expert" of the universe...

...your "problems" are simplistic and obvious ones...

so simplistic and obvious that no one have seen them before me... you included...

...separated lines that are hard to read, and many blank lines with just periods in them...

it's only your opinion, I think that spaces make it clear

...spammers should get banned...

you're right, then, please STOP post your useless comments here...

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SpaceNut · 2008-02-29 22:28:25

gaetanomarano, I am about this close to removing you or posts of the same as it is the same thing over and over again....So stop it.....

First to put a point out for the SRB harmonic oscillation that will as a function of chamber size it will change pitch as the fuel burns as the length and nozzle does not change only the open area inside as a result of its internal pressure.

Like a kids slide whistle a change of the chamber with constant pressure results in the pitch changing.

One could at intervals place side wall barriers or protrutions to interupt the harmonics much like the frets on a guitar. Yes this is a mass change but if you made it from a material that will cook away. The question is one of how many barriers and how large they would need to be.

cIclops · 2008-03-06 07:27:07

From Ares V Overview (PDF 2MB) - 26 Feb 2008

Trade space of six core engines, composite case booster and 5.5 segment motor!

gaetanomarano · 2008-03-06 18:33:03

.

HOW they can released so detailed plans, while, in the SAME time, one of their officials says in an interview that THIS Ares-5 is largely underpowered, so, it needs deep changes? (and new calculations of everything about it)

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SpaceNut · 2008-03-06 20:50:05

First gaetanomarano you have not said why changing the Loiter Time from 14 to 4 days matters so I will...
These changes effect the mass of consumed fuels for the fuel cells, the size of the fuel tanks needed for the cells, batteries or there overall capacity ect.... in other woulds we can make a bigger moon lander or have more cargo to go to the moon rather than wasting it where we do not need it in LEO....that does not even have a crew on it yet....

GCNRevenger · 2008-03-06 21:20:36

Its called "refining the design"

First you start with a rough master plan with various assumptions, and then you make more detailed plans with more detailed calculations and more realistic assumptions, which in turn requires changes to the master plan.

You have to get it through your head that the NASA Moon plans are still pretty rough, gaetano, what will actually be built probably will be different than what you see today.

Although, this is kind of making the DIRECT plan sound a little better.

cIclops · 2008-03-07 01:49:05

HOW they can released so detailed plans, while, in the SAME time, one of their officials says in an interview that THIS Ares-5 is largely underpowered, so, it needs deep changes? (and new calculations of everything about it).

These are not detailed plans, they would fill gigabytes of documents and CAD databases. These are just top level descriptions of the current design concepts, concepts that are modeled together with a lot of other flight and component data to produce the performance numbers shown. This is a design that will evolve until about 2015 (yes 2015 but hopefully earlier) when the final design version is reviewed at CDR. During that time requirements and technology will change, so expect the design to also change.

gaetanomarano · 2008-03-07 03:50:52

First gaetanomarano you have not said why changing the Loiter Time from 14 to 4 days matters so I will...

sorry, but I've written a full article about this problem in 2006 (when the Loiter Time was planned to be 95 days!) and the risk of several missions' failures due to a "sum of delays", also, the reduced Loiter Time seems mainly due to avoid too much LOX and LH2 boil off with so big tanks

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gaetanomarano · 2008-03-07 04:04:22

..."refining the design"...

a really gentle and "underpowered" (like both Ares) say for a space hardware that needs DEEP changes

...what will actually be built ... will be different than what you see today...

that's is SURE for me!

...DIRECT plan sound a little better...

despite I've suggested it FOUR months BEFORE (with my FAST-SLV article) the (FAST-SLV-like but FOUR months LATER) "Direct" is a dead end concept, no matter how big the Direct-lobby is and how many Direct-supporters runs the web... the Orion needs a rocket also for orbital missions, so, the Ares-1 is a possible solution and may work, if CHANGED from the current design to a 4-segments SRB + J-2Y superengine... this change is, also, absolutely necessary, since the twin-5-seg.SRB Ares-5 is underpowered and may need three-four standard SRB and two J-2X (or one J-2Y) to carry the planned payload (or more, that's always is better)

change the rocket(s) needs a deep change of the missions' architectures, a thing seems they don't want to do

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gaetanomarano · 2008-03-07 04:09:42

These are not detailed plans, they would fill gigabytes of documents and CAD databases.

they look enough "detailed" for a rocket that must/will be COMPLETELY different...

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cIclops · 2008-03-07 04:33:47

Latest schedule from: Ares V Overview (PDF 2MB) - 26 Feb 2008

Notes
o First test flight Ares V-Y slipped to 2018 from 2017
o First flight supporting a human lunar landing (LSAM-2) unchanged in Q2 2019
o MCR (Mission Capabiliy Review?) added in 2009

RedStreak · 2008-03-07 13:05:26

It mentions wind tunnel testing in April - this April or April 2009?

cIclops · 2008-03-07 15:21:41

Forward Work
• Support to LCCR architecture and requirements analysis - June LCCR
• Integrated Vehicle and Core Stage detailed study - Feb- July
• EDS detailed trade studies and design concepts - July 07-Oct 08
• Wind tunnel testing - April
• Ares I avionics extensibility assessment to Ares V Earth Departure Stage Instrument Unit - Jan-Oct.

This? As there's no year mentioned, the Wind tunnel testing is probably happening in 2008.

cIclops · 2008-03-20 05:52:42

J-2x engine testing in B-2 Test Facility at Plum Brook Station

Thermal/Vacuum Testing of J–2X Engine

As part of the J–2X engine test program for Ares V Earth Departure Stage (EDS) application, Glenn’s Plum Brook Station B–2 facility will be modified to perform thermal/vacuum ignition testing. Engine start and restart in conditions equivalent to the Earth Departure Stage environment will be verified in the test.
Plum Brook’s unique capability to hot fire test an engine at simulated altitude temperatures and pressures will help validate the J–2X engine’s ability to perform in space. The B-2, Spacecraft Propulsion Test Facility was constructed originally to conduct engine and stage testing.

cIclops · 2008-04-02 13:10:46

From Rob Coppinger's blog - 6 Mar 2008

Notes from an interview with exploration launch project office's advanced planning manager, John Sumrall.

With ESAS there was an Ares V with five-segment SRBs, a 8.2m (27ft) core with two Apollo era J2S+ engines on the Earth departure stage (EDS). The ESAS design had a 45,000kg lander and a trans-lunar injection (TLI) capability with margin but there was no loitering in orbit. At the end of ESAS they were able to show a 73,000kg TLI throw weight though only declared 65,000kg capability. However the TLI deltaV budget was not great and they had to add flight performance reserve to that. Other mission requirements also ate into the TLI capability
The Ares team were given a 29degree orbital plane to widen the launch window but that cost them 7,500kg in payload margin
The decision to allow the Lander to go anywhere also meant a need for lots of deltaV capability as the further away from the lunar equator you get, it drives up that deltaV. As does a need to come back “anytime form anywhere” capability. There was also a decision to be able to inject 130,000kg into low Earth orbit, up from ESAS's 125,000kg
Separately the Lunar Architecture Team (LAT) realised they needed to be able to send 6,500kg to the Moon and not the 4,500kg they originally envisaged. There was a consideration of a 55,000kg to 60,000kg lander but that was rejected and the LAT team was told to go back and they eventually settled on accepting a 2,000kg cargo capability
Another decision that reduced the Ares V’s capability was to change the core stage's engines to the Pratt & Whitney Rocketdyne RS-68 engines used on the Boeing Delta IV rocket. That decision meant that they had an engine 40s slower in specific impulse (ISP) than the Space Shuttle Main Engine (SSME) and it meant they lost 10,000kg payload capability
But RS-68 has one advantage, it has a lot more thrust than the SSME and a big reason for choosing the engine was that it was so much cheaper, it could be produced at a rate of 50 a year for a fraction of the cost of the SSMEs. Now selected there are still technical changes that have to be made to the RS-68 and Sumrall identified two
They want to cut down on the amount of pressurisation helium used by the RS-68, which he thinks the RS-68A, being developed with the USAF, could resolve that, but they also have to reduce the “excess amount of hydrogen” used due to the RS-68s start up process
This start-up creates the huge fireball up the side of the booster seen during Delta IV launches and NASA has decided that that is unacceptable. Because the RS-68, on the Delta IV, only runs for 140s and on Ares V it will need to run for 205s there are also issues with the engines ablative nozzles
The adoption of six engines is another choice to make but there are problems with nozzle clearence and turbine exhaust duct interference; manifolds are a solution
Other changes that occurred due to the TLI throw weight limitations were an initial move to a 10m wide core stage and then that has been extended to the entire length of the vehicle. The 8.2m to 10m widening was triggered by the team remembering that the Saturn 1-C was 10m wide and it was made at the Michoud Assembly Facility.
And they wanted to make the vehicle taller, to lengthen the core stage and allow it to have more propellant and more capability. This would mean adding a half segment spacer (its actually one SRB casing as two casings make up one segment) to have 5.5 segment solid rocket boosters (SRB).
Sumrall explained that while this would get more impulse out of the SRBs it still won’t get them the 9,000kg flight performance margin they want, but it gets “over five tonne”. As well as lengthening the SRBs the fuel can be changed to HTPB instead of the Ares I crew launch vehicle’s PBAN fuel and filamount wound casings would also enable a higher internal rocket motor pressure they think Ares V needs for thrust.
Sumrall said that Griffin gave his approval for the introduction of new technology for Ares V and [Steve] Cook was ready to accept that as a future change to Ares I
As the SRBs would be load bearing structures, just as they are on Shuttle, and they ensure the EDS and payload doesn’t crush the core stage, so the length of the core stage is determined by the height of the SRBs. Another option is to have longer segments and just have four of them
Sumrall and his team came up with an extension that gave a total rocket length of 112.8m (370ft). This was achieved by shortening the EDS and shroud. But Ares V couldn’t be much taller anyway as Griffin had said at a review that Ares V had to fit into the existing infrastructure - the VAB gives any rocket a height limitation of 118.9m
Sumrall also spoke of the consideration of a stage between the core and EDS. The three-stage Ares V was dropped as an option because you ended up with a 122m rocket and there were also additional costs involved in developing that third stage
The EDS also changed after ESAS as they found that they could go to one engine instead of two. That saw a saving of 700kg of mass and improved the performance of the EDS. Another reason to drop the second J2S+ was that there was an issue with the power from a two engine EDS during TLI; it would actually damage the Low Impact Docking System that linked Altair with Orion
After all this, once the EDS and Altair were in orbit there was a 95-day loiter in Earth orbit for the concept of operations. That was changed from 95-days when Griffin said it was not acceptable. Instead the new target date was four-days and this may also assume a launch of the Orion CEV prior to Ares V
Reasons for the four-day change are propellant boil off and electrical power requirements. For four-days fuel cells are sufficient and solar arrays not needed. Less than four-days and batteries could be used for EDS power. During Apollo they had 15% boil off over 3h so over several days Ares V would lose a lot of propellant. To stop boil off the choice is a passive system and “we have to eliminate heat leaks”. The solution to boil off is seen as multi-layered insulation as they want to reduce the boil off losses to 1-2%, but MLI is very expensive in terms of money, not payload margin.

cIclops · 2008-04-30 03:17:03

Application to Solar System Scientific Exploration (PDF) - January 2008

Preliminary performance assessments indicate that Ares V could deliver 5 times the payload to Mars as compared to the most capable US launch vehicle available today, the Delta IV Heavy (Delta IV-H). Beyond Mars, the outer planets offer a number of high-priority investigations with compelling science as identified in the National Research Council (NRC) Decadal survey [1] and Solar System Exploration Roadmap [2]. Presently, missions to these destinations are only achievable using indirect flights with gravity assist trajectories and, in many cases, suffer from long flight times. An Ares V with an upper stage could capture these missions using direct flights with shorter interplanetary transfer times that would enable extensive in situ investigations and possibly the return of samples to Earth.

RedStreak · 2008-04-30 12:06:58

From the jist of the paper about the only things this rocket couldn't launch would be like a Triton or Pluto orbiter, but considering it could likely launch the equivellant of Cassini to Neptune I think that'd certainly be more than sufficent there.

This would certainly be an ideal rocket for sample returns or planetary networks, obviously Mars but they implied the same could be done to either Jupiter or Saturn.

MAN now I have a reason to definetely return to college so when the 2010s come I can possibly be part of it, getting right degrees of course beforehand!

JoshNH4H · 2008-04-30 13:51:21

would it be possible, to make a super HLLV, to replace the cargo with, say, a S-II or an S-III for a third stage?

RedStreak · 2008-04-30 14:08:59

I imagine that'd depend on the needed mass. The Ares V will already be pushing mass limits from NASA equiptment in existance. I imagine the 'nominal' configurations would be the the Ares V Core/EDS or Core/Centaur combinations. A small solid third stage probably wouldn't cause too much of a rukus but a Centaur atop the EDS atop the Core would be too tall for the VAB as well as too massive for the transporter to support...unless someone has numbers to crunch that show otherwise.

JoshNH4H · 2008-04-30 14:14:34

but ignoring the VAB's dimensions, just for what is possible in a rocket, specifically the ares V. Could the structure etc. support a heavy third stage?

cIclops · 2008-04-30 14:25:12

Remember this? That fairing can hold a good size upper stage of around 130 MT mass. Depending on the payload mass, that would give it a big kick out of LEO. For lunar missions it's currently about 65 MT TLI, Mars would be a bit less. Beyond, well it depends how quickly you want to get there.

JoshNH4H · 2008-04-30 14:30:25

Oh, yea. So, basically, it could support another stage if really needed, but no one needs the extra mass?

cIclops · 2008-04-30 14:32:09

Lunar and Mars missions want as much payload as possible.

RedStreak · 2008-04-30 22:43:42

Lunar and Mars missions want as much payload as possible.

Sounds right, so whether or not there's a third or fourth stage involved depends on the distance to fly and the mass of the spacecraft. I imagine the only things that might need up to a fourth stage would be a Neptune/Uranus orbiter, a TAU-Heliopause mission, a Jovian/Saturnian sample return, or a Jovian/Saturnian Prometheus-style mission.

I imagine using the EDS that'll already be part of the Ares V system pretty impressive payloads could be sent to Venus, Mars, the asteroid belt, and Jupiter for certain.

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