Battle of the Heavy Lift Launchers – Monster 200mt vehicle noted

[Integrator]

What is so special about Mars?

Planet with atmosphere (reducing radiation at the surface) plus raw materials for settlement extractable with some effort.  It is much harder to get to but it might pay off more than the Moon in the long run.

Actually Mars has a very weak magnetic field which is what deflects the solar wind, protects our atmosphere and creates the energetic particle protection on Earth.  So no help there. Electrostatically charged dust will probably be a major day to day problem on Mars. Learning underground habitation and living techniques in a reduced gravity, reduced atmospheric pressure environment of the Moon will prepare us for Mars.  Logistics of a minimum 45 million mile supply line are insurmountable at present. Anyone who thinks Mars is easy has read too much Edgar Rice Burroughs.

http://www-ssc.igpp.ucla.edu/personnel/russell/papers/mars_mag/

INTEGRATOR

[SpacexULA]

What is so special about Mars?

Analyst

1. Gives space exploration a goal mandated by Congress
2. Use the goal to generate and influence exploration policy
3. Use policy to influence budget

1.  Mars has extremely volatile weather conditions.
2.  Equipment to land on Mars would only be applicable for Mars.
3.  Coordinated dual heavy lift launch (never done before), or a strong Depot system (does not exist) are the only ways to get there.
4.  Because of high mass losses in transport, high likelihood mission will be turned into Flags and Boots by the time they get there.
5.  Constellation should have taught us that NASA's goals don't effect the budget.

[robertross]

The way these decisions are structured shows again the lack of reason for HSF. A launch vehicle first and after this we will see what - if anything - we will do with it. And maybe we will construct a lame reason too.

SMD (and ESA for instance) does it the right way:

1) Science goals.
2) Instruments to achieve these goals.
3) Spacecraft to support these instruments.
4) Launch vehicle.

Analyst

The L2 document from JSC identifies the many science objectives (namely & mainly: large telescopes), but I fail to see that as the ONLY goal for a HLV. The report was nonsense. Reading it myself, I have to say if MSFC had a hand in it, it was only to promote their own reasons for keeping a massive HLV like Ares V 10m core. SO yes, the basis from the JSC document cannot soley justify the need for this HLV. It's like evyone is tripping over their own feet trying to gain the upper hand.

PS:

I know PLF size is very important

It is not very important. It is at best secondary.

This argument again...well it's a valid argument IMO. I think many on here can agree there comes a point when throw mass gets to a point where ridiculus borders on absurd. But we also know that for spacecraft & various payloads & satellites, volume is most times the driving factor, not mass (IE: rarely do we see something with large mass AND large volume).

We know we have & can build rockets to launch large mass, or make use of propellant depots for smaller mass but get a boost in LEO, but if we are limited to 8m diameter, then we need a whole new rocket to launch it. Let's try and build something that can at least to accept a larger PLF, if required down the road, instead of limiting us by it if our needs change in the coming years. I mean, NASA always seems to think we need more mass to LEO. WHY? It's this notion that we can't do anything unless we build the biggest rocket. But if we have a rocket capable of growing to launch larger (not more massive) payloads, we gain an upper hand for future needs, and it doesn't really cost us much more to design that in now.

[robertross]

1.  Mars has extremely volatile weather conditions.
2.  Equipment to land on Mars would only be applicable for Mars.
3.  Coordinated dual heavy lift launch (never done before), or a strong Depot system (does not exist) are the only ways to get there.
4.  Because of high mass losses in transport, high likelihood mission will be turned into Flags and Boots by the time they get there.
5.  Constellation should have taught us that NASA's goals don't effect the budget.

Very good points, but on 1, Mars has challenging weather conditions, ones I would say are precisely the type we need to 'bite our teeth into'. These are good challenges, much like the challenges of dust on the moon, or raditation BEO, or the like. On 2, the equipment we design for Mars can be well used for other places, like asteroid missions, or very close to the requirements of the moon (if not perfectly if we so choose). We need to stop designing 'specifically' for one location, but for multiple locations, much like Orion is to be designed for. Sure, some of the outfitting would be unique, but the baseline architecture/capsule should be at least 50% common. That's what will help us reduce costs in the long run, because with (granted some luck) the lessons learned will only affect certain areas and not require a complete re-design of our systems. Anyone thinking a re-design along the way isn't required doesn't understand the whole notion of exploration, design & engineering.

[Serafeim]

Block I means the Manned version,and Block II the cargo?

[kyle_baron]

This idea is obviously a Trojan Horse, with a much more reasonable, Ares V (Lite) inside.

[robertross]

Block I means the Manned version,and Block II the cargo?

As I have learned, it depends on the reference. Something Jorge had educated me on:

"There are Block I (obsolete) and Block II (current) SSMEs, and Block I (current shuttle avionics) and Block II (new avionics) HLVs. But the two terms are not related. Both the Block I and Block II HLVs under study would use Block II SSMEs."

I believe the current reference is the avionics.

[MP99]

Block I means the Manned version,and Block II the cargo?

As I have learned, it depends on the reference. Something Jorge had educated me on:

"There are Block I (obsolete) and Block II (current) SSMEs, and Block I (current shuttle avionics) and Block II (new avionics) HLVs. But the two terms are not related. Both the Block I and Block II HLVs under study would use Block II SSMEs."

AIUI they're just a synonym for version numbers. "Version I" SSME's are obsolete because they were replaced by "Version II" types.

The Block I Ares seems to be "minimum cost everything" - no core stretch, 4-seg SRB's, RL-10's. As per Ross's recent post, RL-10 may be a problem for a crewed vehicle.

When the Block II comes online it will use 5-seg SRB's, and 4-segs won't be available anymore. I guess NASA could operate a Heavy version of block I, but what would be the point? Better to just have a common vehicle, and get the greatest amount of flying experience possible on that vehicle.

I believe the current reference is the avionics.

Block I = 4-seg, no stretch, 4x RL-10.

Block II = 5-seg, stretch, 1x J-2X. Really quite a substantial rebuild from Block I.

cheers, Martin

[MP99]

The article mentions that the inline block 1 is similar to a Jupiter 244.  But I thought the 244 had an RL-60 engine (which isn't under consideration AFAIK), not an RL10.  Have the numbers been worked up for a four engine RL10?  I hope the performance of the inline design is not getting watered down ...

Of course, I can dream that the 4-engine upper stage might be some version of ACES...


Compare J-246a vs J-247a (just for speculation purposes).

With 86% of the thrust, it achieves 97% of both mass to LEO, and mass through TLI. Same for the heavy variants. I suspect this is something to do with the good SSTO performance of SSME.

4x RL-10 must have quite an impact on overall performance, but if NASA don't want more than four engines for complexity / LOM reasons, it's more a question of how it performs in absolute terms, rather than whether six or seven would be better.

cheers, Martin

[notsorandom]

I have been doing a bit more thinking on the four RL-10 upper stage. The time versus altitude charts on the baseball cards of the Jupiter-246 show a pretty linear clime once the JUS starts. Assuming the upper stage has the same amount of propellant could the more powerful core send it on a lofting trajectory like the Delta IV flies to make up for less thrust?

[sewand]

So block 1 is not stretched?   I wonder why not?  Seems wasteful to implement two core stages. 
I'd think that 4 RL-10's would have worse LOM numbers than 5 or 6 RL-10's.  Given the cost of the mission, why not have the additional margin?

[MP99]

So block 1 is not stretched?   I wonder why not?  Seems wasteful to implement two core stages. 
I'd think that 4 RL-10's would have worse LOM numbers than 5 or 6 RL-10's.  Given the cost of the mission, why not have the additional margin?

I guess it can just be built quicker. It also fits with the 4-seg SRB without having to design & qualify a dummy segment.

cheers, Martin

[sdsds]

FWIW though, Analyst, I agree with you that building a gigantic LV just because the prevailing power blocs at NASA want a gigantic LV is somewhat foolish.  Unless they are planning to build multi-hundred tonne interplanetary spacecraft, such launch capacity isn't needed and will quickly prove unsustainable. 

Yes.  But note what some "power blocs at NASA" want isn't to have a gigantic LV.  They want to be (more or less constantly) designing a gigantic LV. 

From that perspective once a vehicle is flying the good times are mostly over; there's a long dry spell until the next push to develop a vehicle.  The ideal situation from that perspective is to be constantly designing -- but never building or flying -- impressive-looking systems that bring them both prestige and dollars.

[ChuckC]

If the options are really down to these three then Direct is most likely winner. If for no other reason it’s the one that has been discussed and dissected enough for an informed decision. 

This 200mt vehicle not even a paper rocket let lone a reasonable proposal. They could even provide a design concept. As a kid I came up with designs for all sorts of space craft including some faster than light craft that got further than this seems to be. It sounds more like a wish list than real concept.

The Sidemount design is at least an actual design that can be evaluated for strengths and weaknesses. By the way one advantage is that it does have is that it does not eliminate the possibility of going to a Direct type vehicle some time in the future, after all it would be no harder than going  Shuttle to Direct. It's main problem is that its reliance on a sidemounted vehicle, this limits is expansion options and causes needless risk with the escape tower.   

[Nathan]

What is so special about Mars?

Analyst

Easier access to basic resources such as water, oxygen, nitrogen, sunlight and thus it is cheaper and easier (not easy) to survive and thrive. The 24hr day is a major advantage for greenhouses.  Atmosphere protects against radiation (still need uv blockers). Greatest potential for economic growth.

The moon is composed primarily of the contents of a vacuum cleaner bag.

And no - we don't need 200mt rockets to do Mars. Just need a smart lightweight plan. Send 2 people at a time!

[StarGeezer]

As far as I'm concerned, as a shuttle amazing people, anything that uses the ET as the focal point of its design that could potentially use (a) new or refurbished shuttle(s) is the way to go.

[kraisee]

It is interesting to see four RL-10s as opposed to Jupiter's six. With the Jupiter-246 there would have to be a significant performance hit with only 2/3rds of the trust available in the upper stage. Here is a question for anyone who would know such things. Does the extra performance from the stretched core, and 5 segment boosters make up for the loss of the two RL-10s?

Actually the difference is engine-out situations.

The Jupiter is actually designed for 4 *working* engines -- which allows two to experience failure and still continue with the mission unhindered.

Ross.

[robertross]

And no - we don't need 200mt rockets to do Mars. Just need a smart lightweight plan. Send 2 people at a time!

2 persons is not viable to operate a complex mission for that length of time, at this point in our 'infancy'. Zubrin made a good case for 4, but NASA had insisted on 6, which is why the Orion was being designed for 6 to Mars.

[Cbased]

still too vague at this stage... Could it be just a requirement for whichever program/variant NASA moves ahead with to have an architecture flexible enough to accomodate different LVs upto 200mT?

[MATTBLAK]

And no - we don't need 200mt rockets to do Mars. Just need a smart lightweight plan. Send 2 people at a time!

2 persons is not viable to operate a complex mission for that length of time, at this point in our 'infancy'. Zubrin made a good case for 4, but NASA had insisted on 6, which is why the Orion was being designed for 6 to Mars.

For Mars Missions, I'd hedge my bets and say 5 people: 5 crew uses about 16-to-18% percent less consumables than 6 and gives you, er, 25% percent more personnel redundancy than 4x folk. In the case of a crewmember getting ill or dying -- the mission could still be fulfilled quite well with four people. Because with a crew of four; if you lost one person the workload would be pretty high. Also, I've read that many psychologists reckon having uneven crew numbers means that during conflicts and arguments, its much harder for warring crewmembers to takes sides on very long, stressful missions.