A future for the shuttle?

[kevinm1984]

Is there any value in leaving a shuttle(s) in orbit to be used as a support platform? This leaves the issues of launch and return stress behind but allows for the work platform advantages that you don't have with the Constellation program.

 

[docm]

No. <div class="Discussion_UserSignature"> </div>

 

[thereiwas]

One reason "no" is that it can't last that long - the expendables run out just keeping it from permanently dying. Secondly the ISS orbit is not sustainable long term due to aerodynamic drag.

 

[kevinm1984]

Those are the simple problems. Fuel could be supplied as needed. Also, the suggestion would be a gap solution until the next generation of a reusable craft would be ready.<br /><br /> I do suspect there are other issues such as the thermal stresses in orbit that would be more of a problem. I am not suggesting this 'as is' but a modified shuttle for long term orbit.

 

[nibb31]

"As needed" would be a launch every week to refuel the shuttle.<br /><br />Anything else would require a significant budget to design, test, and perform modifications to turn the shuttle into something it was not intended to be. It would be cheaper to purpose build a new module than to retrofit the orbiters.<br /><br />Besides, what is there to gain ? The internal volume of the shuttle is actually quite cramped (65 m3, for comparison the Columbus module is 75m3) and the wings, landing gear, atmospheric flight systems would be just useless dead weight.<br /><br />I would guess that leaving the MPLMs attached to ISS as storage space might make a bit of sense after their last trip, but certainly not the orbiters.

 

[MeteorWayne]

The aerodynamic drag is not a "simple" problem.<br />The immediate lack of electricity to run it is not a "simple" problem.<br /><br />There is no means to supply the fuel and cryogenics needed every two weeks, especially with no one on board.<br /><br />Welcome to Space.com! <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[SteveMick]

Of course the Shuttle could be used in this manner. The Shuttle is capable of being plugged into power at the pad so of course it could be supplied by the ISS solar panels in theory at least. The module that fits into the payload bay (is it SpaceHab? i forget) could be used for extra room.Since no manuvering fuel would be required it seems little in the way of expendibles would be needed. <br /> The best use however would be to convert it into an OTV that could use aerobraking to return to low orbit. Of course you'd need that hangar they never got around to including to maintain it, but it could service comsats in GEO.<br /> Of course since we always throw out the old when we build the new, we'll just put them in museums.<br />Steve<br />Solar Thermal/Electric Propulsion<br />First STEP

 

[annodomini2]

But nasa were spending a fortune on developing the X-38 crew return vehicle, why not just attach a shuttle and leave it there?<br /><br />One question I have regarding the shuttle, could the X33 heat sheilding be adapted for the shuttle and use a shallower entry angle (as was intended for the venture star)?<br /><br />Then as a crew delivery vehicle, fill the payload bay with fuel and oxydiser tanks, run 1 engine (much lighter and less aerodynamic drag) and obviously less fuel consumption.<br /><br />Retain solid boosters or mount atop an existing booster e.g. titan or delta etc? and get rid of the external tank. <div class="Discussion_UserSignature"> </div>

 

[kevinm1984]

The electrical power 'seems' to be a minor issue. When in stand by mode it could be attached to a power source in orbit. My thoughts were not if we could put it into orbit and leave it there but more of how much of a project would it be to modify it for that mission. <br /><br />Since it is not my field the discussion is more of a learning experience for me than a practical suggestion.<br /><br />The major issues that I thought about were; Is the structure of the shuttle something that could tolerate the environment for long term use , such as thermal stresses between sun and shade? How much can the shuttle change its orbit once it is there or is it set up at launch and only capable of minor corrections?

 

[nibb31]

"why not just attach a shuttle and leave it there? "<br /><br />Because after a week (or 10 days when attached to the ISS with the SPTSS) it's as dead as a dodo. Once the power is gone, it's gone for good and can't be restarted in orbit.

 

[nibb31]

"The electrical power 'seems' to be a minor issue. When in stand by mode it could be attached to a power source in orbit."<br /><br />It's not a minor issue. Attaching it to the ISS only adds a couple of days to its on-orbit life. You would need to double the number of solar panels on the ISS or re-engineer the shuttle to <br /><br />Both would cost more than rebuilding a purpose built module.<br /><br />Using it as a space tug is a silly idea. A space tug does not need wings. Dead weight means wasted fuel. <br /><br />Also, the shuttle cannot reach GEO.

 

[j05h]

Future for the Shuttles: lawn ornaments after 09.2010<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[SteveMick]

A space tug is hardly a silly idea - but your comment ignores my point - AEROBRAKING!!!!<br /> For that the wings are fairly well suited. The amount of propellant saved by aerobraking upon return to Earth or arrival at say Mars will make up for the mass of the wings. The problem with the Shuttle for this type of mission is its large mass. The amount of propellant needed to get it to Mars is quite large - arguably a showstopper - but the amount of payload it could return from say Phobos to LEO could be in excess of a million pounds if there is ISRU to make propellant at Phobos. Once this was accomplished the shuttle could become an excellent Phobos/Deimos mining vehicle.<br />Steve<br />Solar Thermal/Electric Propulsion<br />First STEP

 

[SteveMick]

How are you determining the power requirements? What consumes power when the Shuttle is sitting inert at the ISS and does not ever need to fly again? If the Shuttle with Spacehab were totally de-powered and still attached to the ISS what would happen? Would the ISS systems be unable to handle the additional volume of living space? Could they be modified to do so? Are systems from the other modules usable additions to the Shuttle systems. You know somehow, by some miracle or magic other modules with even more volume have been added. How can that possibly be? Well I guess the laws of Physics are suspended for the Shuttle.<br />BTW - I found that smartass remark about meaning the Orbiter as opposed to the Shuttle really annoying.<br /> Reading your "Can't do" post I'm glad you weren't working on Apollo 13!<br />Steve

 

[MeteorWayne]

You seem to ignore that the velocities are far different for an orbital return compared to an interplanetary mission.<br />The Orbiter would fry in an instant or bounce off the atmosphere.<br /><br />The capsule shape gives the largest (hence safest) margins on approach angles. The Orbiter would have to be accurate to an arcsecond of angle.<br /><br />The capsule shape can accomodate a few degrees of angular offset.<br /><br />Since the orbiter enters from a LEO, the angles are far less critical.<br /><br />For an interplanetary mission return, if someone sneezed in the orbiter it might doom it. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[j05h]

Shuttle and ISS are very specific pieces of hardware that can only do certain things (very well). The Orbiter is a specific part of the Shuttle. shuttle_guy works on STS and is one of our most respected posters, you should reflect on his opinions, dust. IIRC, he's not quite old enough to have worked Apollo 13 - but would have performed marvelous if he had. <br /><br />The Orbiter would be a 70t dead weight with bad CG and cross-section as soon as the fuel cells died. It requires 100s of technicians to service the Orbiter after power-down, impossible at ISS. it's not "can't do" it is realism.<br /><br />STS as a whole becomes lawn ornaments in October, 2010. There is a chance some of the technology will continue in other launchers, but that depends on how NASA handles the next few years. There are other, better solutions to what you requested initially. In-space tugs, custom-built modules and automatic rendezvous hardware are what you are really asking for. The "Shuttle" isn't flying to the Moon or Phobos, nor will it be docked to ISS like two single-wides, just add some tarps and christmas lights. The ISS is not going to the Moon, either.<br /><br />This isn't negative, it's actually progress. There are better solutions.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[eniac]

<blockquote><font class="small">In reply to:</font><hr /><p>BTW - I found that smartass remark about meaning the Orbiter as opposed to the Shuttle really annoying.<br />Reading your "Can't do" post I'm glad you weren't working on Apollo 13!<p><hr /></p></p></blockquote>Shuttle_guy's remarks are generally well-founded and well-reasoned. The only smartass remarks in this thread, so far, are yours:<br /><blockquote><font class="small">In reply to:</font><hr /><p>You know somehow, by some miracle or magic other modules with even more volume have been added. How can that possibly be? Well I guess the laws of Physics are suspended for the Shuttle. <p><hr /></p></p></blockquote><br /><br /> <div class="Discussion_UserSignature"> </div>

 

[kevinm1984]

Ok, this is going a bit off track from where I wanted to go with it. My thought was not to change the mission of the Orbiter but to extend it without the stresses of launch/return.<br /><br />Is there an alternative for the equipment repair missions?<br /><br />I still have trouble accepting electrical power as the primary problem. Fuel cells have a short consumable life, I also searched around and found information indicating the fuel cells have a replacement life of 2000 hours. It would seem to me that placing a power source into orbit is not a task that is near the scale of a replacement for the Orbiter. Of course that still leave a needed solution for mission power.<br /><br />The delta V info supplied seems to be enough energy to make changes in the orbital path, is that a correct assumption?<br /><br />Am I over estimating the value of the repair work capabilities of the Orbiter and the arm?<br /><br />This is a discussion that came up on another message board but although it is a group of bright people there was not enough knowledge in the group to make any reasonable assessment. So far I am happy with the response here, very good for a public message board.

 

[SteveMick]

Of course the Orbiter as is cannot mine Phobos without considerable modification and one of the mods would have to be adding appropriate propellant tankage. <br /> To be honest, all I was thinking about was the wings' utility for slowing a payload from Mars to LEO via aerobraking. Depending on the arrival velocity, the mass that could be braked to orbit would be limited by the speed reduction needed to enter a highly elliptical orbit which could then be further reduced on subsequent orbits. Since the Orbiter can slow itself and in theory a payload from what nearly 18,000mph to 200 or so, I just guessed that a huge payload could be slowed to orbit from Phobos. <br /> As for propellant, the only readily available engine ithat can re-start on-orbit that I could think of is the RL-10. Therefore H2 and O2 would be what you'd want to produce from Phobos regolith. In the half-baked scenario I imagined, The SSME's would be removed after orbit was acheived and a seperate RL-10 based system would extend somehow from the payload bay with its own tankage and on-orbit refueling system. After additional propellent is brought up, and a solar power system modeled on the one they came up with for the Orbiter to increase its time on orbit per flight in the Eighties but never built is unfurled, the Orbiter would use a couple perigee thrusts to build up speed to Mars injection. Upon arrival at Mars, it would aerobrake to orbit and get to Phobos. ISRU systems would then slowly re-fill its tanks while the (2?)astronauts operated rovers on the surface. Another couple perigee thrusts and it would head back to aerobrake to LEO. It would be carrying plenty of propellent to carry a lander or sample return craft back to Mars.<br /> If both Orbiters were used it would not only be safer but they could use a tether between them for artificial gravity.<br />Obvoiusly this is only half-baked, but if a "can do" attitude is operant much better schemes can be realized or one similar to this done much bet

 

[SteveMick]

Higher initial velocity can be accomodated - the current Mars orbiters have even been able to use the technique to a great extent and they are about as fragile as you can get.<br /> No the obvious answer is to control the altitude to control the braking force. Since your desire is to get to orbit and not the ground, the slow-down initially only has to brake you to a highly elliptical orbit and if a little rocket thrust is required because you couldn't use aerobraking for all the slow down; so be it - you've still saved a lot.<br /> As an editorial opinion - a rocket engineer when asked if something can be done should respond "no" only after she has used all her creativity to attempt to make the idea work. The reply should most often be:"Yes you can but it's quite difficult - here's a better way to do it" <br />Steve<br />Solar Thermal/Electric Propulsion<br />First STEP

 

[SteveMick]

Fair enough. I regretted writing that it was annoying shortly after I did. My interest in and knowledge of the Shuttle is not what it should be for me to act like I know what I'm talking about.<br /><br /> That was a clever response and I deserved it.<br />My apologies.<br />Steve

 

[SteveMick]

In response the response to my calling it annoying to point out the "Orbiter" is the proper ref. not the "Shuttle":<br /><br />Smartass perhaps but motivated by frustration. My frustration was with the "Can't do" attitude that pervades the entire space "culture" these days and is certainly not limited to shuttle guy. <br />Steve

 

[SteveMick]

Realism heh?<br /> What if the power was allowed to run out by itself?<br />What would happen?<br /> Your post suggests that the Orbiter would continue to run forever because no technicians were there to power it down. The procedures in place now preserve the Orbiter for flight. As I said if there's no need to fly again, the Orbiter can be allowed to become an air filled can attached to the ISS right? How is it then different from any other module? Somehow they are maintained. How can that be?<br /> The Apollo 13 reference was of course about doing what you have to do with what you have. With current attitudes, I fear they would have crunched the numbers, said survival was impossible and never made the adapter for the CO2 scrubber that saved them or never been able to preserve enough battery to power up the CSM.<br />Steve

 

[j05h]

<i>> Realism heh?<br />What if the power was allowed to run out by itself?<br />What would happen? </i><br /><br />if the power on an Orbiter was allowed to run down, it would become a freezing cold, dead-weight hanging off the back end of ISS. It's cross-section, funny shape and sheer mass (around 1/6th the ISS) would make controlling the station much harder. All the current modules are not "air filled cans" - they all do things and have purposes.<br /><br />We've been through this hundreds of times with newbies, it's not gonna happen. Purpose-built modules are the best solution. If you want more living space on ISS, put new modules up. Attaching Orbiters is the wrong solution.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[mcs_seattle]

Steve...<br /><br />Ask shuttle_guy how much 'fuel' is on the 'shuttle'.<br /><br />;-)<br /><br />