Shuttle Replacement

[redrover]

Maybe it's unrealistic and technologically immature of me, but I have to say I'm disappointed with the design of the Shuttle replacement. I guess I was hoping for something more elegant and what I suppose would be considered futuristic. I realize design is secondary to functionality, but I wondered if anyone shared this sentiment and if you've seen or heard of other designs that are more advanced that what NASA has come up with.

 

[docm]

This time 'round they decided to design a spaceship, not a glider that can be put in orbit while doing a poor imitation of a medium-heavy lifter and cooking its crew 2% of the time. <br /><br />Orion or even Dragon is perfect for lunar trips, but for Mars something with a capsule for re-entry, a habitat and some sort of electric drive is in order; VASIMR, MPD, PIT, NanoFET...whatever. <div class="Discussion_UserSignature"> </div>

 

[R1]

I think the replacements will really be better, just got to learn them better first<br />and hope the programs get going.<br /><br />I think the worst part is having all kinds of delays, as you might have read, our manned space program will <br />stop for a few years, they don't think the new lunar capable spaceship will be ready before the year 2015<br />and the last time I read it we are counting on other countries' charity or something like that.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[jimfromnsf]

The CEV is still viable for a Mars mission.

 

[vulture2]

It's all in what you consider the goal to be. If cost is no object and only a few missions are planned, an ELV and capsule are the optimal approach. But if human spaceflight for research, tourism or other reasons is to be economically sustainable, a much lower operational cost is required. It is difficult to see how any significant improvement in operational cost can be made without a fully reusable vehicle.<br /><br />A reusable vehicle requires that non-payload mass be carried into orbit; we tend to look on this as inefficiency since it requires energy. But we should not fprget that the cost of all the energy required to get into orbit, i.e. the fuel, is less than 1% of the cost of a space shuttle (or CEV) mission. The cost of energy is minor compared to the cost of assembling or reassembling the vehicle for each flight. <br />

 

[qso1]

The vehicles being designed for the VSE are not intended as strictly shuttle replacement vehicles. They just happen to be replacing the shuttle as the primary means of crew transport because the shuttle is very expensive to operate and after two accidents, its missions were limited to ISS. ISS is scheduled for completion on or about 2010.<br /><br />NASA was unable to develop a shuttle replacement due to costs. What I call the "Cost barrier" is still a formidable barrier and exists because the general public is no longer that interested in human spaceflight as evidenced by NASAs constant budget fights and the fact the NASA budget remains at roughly 50% GDP.<br /><br />There are also technical issues that have made the pursuit of a shuttle replacement too difficult as well. A true shuttle replacement would be a vehicle that can be operated in a manner similar to what the shuttle was, be reuseable, and above all, provide inexpensive access to low orbit. At this point it appears only the private sector can develop such a vehicle but that has yet to be proven. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[robnissen]

<font color="yellow">NASA budget remains at roughly 50% GDP. </font><br />If only. NASA could do a heluva lot of research at 50% GDP. I'm thinkin its probably closer to .05% GDP.<br /><br />

 

[jimfromnsf]

Reusability doesn't come into play until 40-60 flights a years. It will be awhile before we see flight rates this high and so it will be awhile for an RLV

 

[radarredux]

> <i><font color="yellow">I have to say I'm disappointed with the design of the Shuttle replacement.</font>/i><br /><br />I would prefer something sexier, along with a dramatic drop in costs. But what I <b><i>really</i></b> want is something that works on time and within budget. NASA has had a lot of starts and stops over the years, lots of art work, lots of models, and nothing to show for it.<br /><br />So if I have a choice between dull and real versus sexy and only a vision, I will take dull and real.</i>

 

[baktothemoon]

>I guess I was hoping for something more elegant and what I suppose would be considered futuristic.<br /><br />Like what exactly? We weren't going to get the USS Enterprise to replace the shuttle, but getting a moon base is futuristic enough. In my opinion, what i would consider to be really futuristic would be a reusable space ferry, or a vehicle with nuclear engines instead of standard ones.

 

[dreada5]

<blockquote><font class="small">In reply to:</font><hr /><p>Like what exactly? We weren't going to get the USS Enterprise to replace the shuttle, but getting a moon base is futuristic enough. <p><hr /></p></p></blockquote><br /><br />Agreed. I was wondering what Redrover had in mind too...

 

[radarredux]

> <i><font color="yellow">Agreed. I was wondering what Redrover had in mind too...</font>/i><br /><br />Probably almost anything that didn't look like vintage 1960s hardware.<br /><br />The Venture Star would have been cool looking, but it wouldn't support the payload capability and re-entry needs for a Lunar program. I think the key here is the phrase "shuttle replacement", which Ares/Orion are not. They are designed to support very different missions.</i>

 

[dreada5]

Blame the media? <img src="/images/icons/rolleyes.gif" />

 

[marcel_leonard]

I agree w/ you 100% NASA could developed a better shuttle then simply putting a 7 manned space capsule on top of a Delta V. As a matter of fact they should build an upgraded shuttle based on the current model and remove the bugs from the current system. Then create a separate but equal team at NASA for the Moon/Mars missions… <div class="Discussion_UserSignature"> "A mind is a terrible thing to waste..." </div>

 

[jimfromnsf]

"As a matter of fact they should build an upgraded shuttle based on the current model and remove the bugs from the current system."<br /><br />There is no need nor the flight rate to support a shuttle II. <br /><br />1. Cargo and unmanned spacecraft are better served by ELV's<br />2. There is little need to return large masses from orbit<br /><br />3. Servicing spacecraft is not really cost effective by a manned spacecraft. Most of the spacecraft are in orbits that are unreachable and the ones that were placed in shuttle orbits, had their "real" mission requirements altered to do so. <br />4. Since cargo is not flying with a crew (a no no), the manned spacecraft can be much smaller.<br />5. ELV have more efficient in delivering spacecraft (better upperstages, less safety requirements, less ASE, etc)<br /><br />6. The currrent and out year flight rates don't support the costs to develop and operate a reusable vehicle. Need 40-60 flights a year

 

[dreada5]

<blockquote><font class="small">In reply to:</font><hr /><p>I agree w/ you 100% NASA could developed a better shuttle then simply putting a 7 manned space capsule on top of a Delta V. As a matter of fact they should build an upgraded shuttle based on the current model and remove the bugs from the current system.<p><hr /></p></p></blockquote><br /><br />Marcel, I think you meant Delta IV, but in any case they won't be using one with the crew capsule. It'll be a modified shuttle solid rocket booster.<br /><br />Check out the following link (section at bottom of page called "Looking Ahead"). It provides some info on how/why NASA are moving away from the current shuttle system:<br /><br />http://en.wikipedia.org/wiki/Criticism_of_the_Space_Shuttle_program <br /><br />Although most of the key reasons have been covered above.<br /><br />I'd agree with others, it might not <b>"look"</b> as sexy, but CEV allows NASA to do far more safely in the future than could be achieved by possible upgrades to the current shuttle system.

 

[radarredux]

Out of intellectual curiosity, I wonder if the requirements were:<br /><br />(1) Small payloads (around 4 people, or unmanned cargo)<br />(2) Limited cross range capability<br />(3) LEO-only missions<br /><br />What would be possible for a reusable spacecraft with today's technology? For example, I've read that the composite tanks for the X-33 were largely resolved by the time it was cancelled. And the linear aerospike engine has been ground tested a number times.<br /><br />Anyone have an estimate on feasibility?

 

[jimfromnsf]

X-33 concept had two strikes against it<br />It tried being an RLV and a SSTO.<br /><br />Remember, the X-33 was only a suborbital test vehicle

 

[vulture2]

>>The currrent and out year flight rates don't support the costs to develop and operate a reusable vehicle. Need 40-60 flights a year<br /><br />The number of flights we need is highly sensitive to cost, At $20 million per seat, there is a market for ~2 seats per year to the ISS for tourism and perhaps a couple more for research. At $2 million per seat we could probably easily sell 50 flights per year. If we want to see more human spaceflight, the cost must be lowered considerably. But the CEV will cost at least $50 million per seat, even for ISS flights, not including cargo. Neither research nor tourism can justify human spaceflight at that price. <br /><br />This leaves us in an endless search for a magical justification for human spaceflight at any cost. But there is none. China will not race us to the moon again. We can continue to make a handful of flights a year for national prestige, but no more. Is that what we visualized in 1957? How our dreams have shrunk!<br /><br />If we go to the moon again with 1960's technology, after 10 years we will have some fond memories and be out roughly $100 billion. If we spend the money on technology development, at the end of the program we will have the technolgy for human spaceflight at a cost that can be justified.

 

[dreada5]

Vulture, I'm guessing you are one of those that believe we should be spending the majority of human spaceflight budget on things like air-breathing rockets, space nuclear power/propulsion, SSTO research, advanced life support systems etc with minimal LEO/ISS missions as opposed to taking what we have now and venturing out of LEO?<br /><br />I've thought about this for a while now, and I guess my personal take on it goes something like the problem with committing the bulk of NASA resources to technology research for say the next 10-15 years, is that whilst NASA is throwing huge sums of money at "investigating" whether some of these advanced concepts will work effectively, other nations like China will be off to the moon and grabbing all the international limelight for its exploits on other worlds. They will seen to be the new world space leader by many.<br /><br />At the end, we may come out with what apepars to be "Starship Enterprise", but it will have been at the expense of all those uninspired young people who walked away from sci/eng because of NASA's years of behind-the-scenes research and loss of national prestige. Plus imagine, if after all that our new spaceflight technology didn't live up to expectations?! <img src="/images/icons/frown.gif" /><br /><br />IMHO, its better to go to the moon now, with what we have and as we learn, identify challenging requirements for advanced operations/missions, industry (not NASA) will research and come up with the best possible solutions to meet those requirements. It might mean we stay with what appears to be 60's technology for longer, but long-term we'd be getting more value (on every front) from the human spaceflight program.

 

[rocketman5000]

Thank you I had never known that before, So what is this Venturestar thing people seem to talk about.....<br /><br />

 

[docm]

http://www1.dfrc.nasa.gov/gallery/photo/X-33/HTML/EC96-43631-2.html<br /><br />http://en.wikipedia.org/wiki/Venture_Star <div class="Discussion_UserSignature"> </div>

 

[rocketwatcher2001]

<font color="yellow">This time 'round they decided to design a spaceship, not a glider that can be put in orbit while doing a poor imitation of a medium-heavy lifter and cooking its crew 2% of the time.</font><br /><br />No, they decided that they didn't want the capability that the Space Shuttle offered because we are going to have a very unambitious space program for the next 20 years. There will not be a need to transport anything bigger than a loaf of bread back from space, and we won't be sending any more than 4 or maybe 6 astronauts in space at any one time, or doing any major construction in LEO.<br /><br />If we had the space program that a properly funded shuttle program could have delivered, we could have had a moon base with 500 people living there full time, and building the spacecraft that would move us through the solar system. Instead we wussed out, and are building the wuss-mobile.<br /><br />Apollo killed a greater percentage of it's crew than the Space Shuttle, and there have been 4 catostophic failures of Soyuz, two of which killed it's crew. Saying that the Space Shuttle fries 2% of it's crews may be true, but that wouldn't be true the longer we used it, and what should have evolved from in Space Shuttle II. I like the fact that we are building Orion and Aries, but they would be a good compliment to the Space Shuttle, and are in no way a replacement. <div class="Discussion_UserSignature"> </div>

 

[rocketman5000]

That was sarcasm, I am well aware of the capabilities of the X-33 and venturestar

 

[docm]

<font color="yellow">Apollo killed a greater percentage of it's crew than the Space Shuttle</font><br /><br />All at once and on the ground during tests; not as a result of normal flight ops. Apollo 13 doesn't count; no fatalities and the failure wasn't of the capsule. If anything it and the LEM saved their bacon.<br /><br /><font color="yellow">Saying that the Space Shuttle fries 2% of it's crews may be true, but that wouldn't be true the longer we used it</font><br /><br />Just what are you smoking?? STS has terrible failure modes as a result of its very design; sidesaddle mounted, making it vulnerable to its own boosters insulation. It's also so large that linear mounting to eliminate the problem is out. <br /><br />Then there's the wings, useless in space and requiring carbon-carbon leading edges that if they fail (foam, space junk, whatever) you lose the crew and ship. At least a capsules TPS can be covered and is much small affording it better odds of escaping damage before its needed.<br /><br />A "space truck" is not what we need. That comes down to reliable capsules for up/down and a refuelable "space tug" for moving things around and providing a solid base for mounting robotic arms. <br /><br />Get the heavy loads in space by conventional means, get the crew up/down using capsules and do the rest with the tug. My dad used to call it using the right tool for the job. <br /><br />The STS model is like using an over-priced/under-capable/poorly-designed multi-tool bought off late night TV. <div class="Discussion_UserSignature"> </div>