More on Orion to NEOs

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>Submarines, aircraft, campervans, and boats all suggest useful approaches for compact living spaces in spacecraft.<p><hr /></p></p></blockquote><br />Unfortunately, real spacecraft will be more cramped than any of those -- at least until we build Galaxy-class starships like the NCC-1701D. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[gunsandrockets]

"...a semi-quantitative WAG, I would say, based on actual historical spacecraft experience...The clearest is Figure 6-2 which gives the optimal, performance limit and tolerance limits for habital volumes from missions ranging in duration from 0 to 12 months. The curves are essentially flat after 6 months."<br /><br />Hmmm...actual flight experience beyond six months is virtually non-existant, I wonder on what basis the curve goes flat beyond 6 months?<br /><br /> "The pressurised volume limits for these are 20, 10 and 5 cubic m respectively,..."<br /><br />Interesting. The Soyuz has 9 cubic meters and the Shenzou 14 cubic meters. Depending on which numbers pan out the Orion CM has anywhere from 11 to 20 cubic meters (I bet 14). It should be possible for any of these spacecraft to accomodate two man NEO missions if provided with extra life-support consumables.

 

[gunsandrockets]

"There'll be a "Mission Module" or "Habitat Module" for the crew to live in en-route to-and-fro to the asteroid..."<br /><br />Here's a candidate habitat module for you, the 1965 Douglas MORL...<br /><br />http://www.astronautix.com/graphics/m/morlcu.jpg<br /><br />http://www.astronautix.com/craft/morl.htm<br /><br />"Length: 12.60 m (41.30 ft). Maximum Diameter: 6.50 m (21.30 ft). Mass: 13 500 kg (29 700 lb). "

 

[gunsandrockets]

"There are a couple of abstracts at the forthcoming LPSC about Orion missions to NEOs that people might find interesting."<br /><br /><br />You know for a mission like that the old Soviet TKS spacecraft concept is even better than the Orion. It has a mission module already integratred into the spacecraft. Makes me wonder if Soyuz information was the only thing the Chinese might have acquired from Russia!<br /><br />http://www.astronautix.com/graphics/t/tksside.jpg <br /><br />http://www.astronautix.com/craft/tks.htm <br /><br />"Crew Size: 3. Design Life: 7 days. Orbital Storage: 200 days. Typical orbit: 223 km x 266 km at 52 degrees inclination. Length: 17.51 m (57.44 ft). Maximum Diameter: 4.15 m (13.61 ft). Span: 17.00 m (55.00 ft). Habitable Volume: 45.00 m3. Mass: 17 510 kg (38 600 lb). Payload: 12 600 kg (27 700 lb). Main Engine Thrust: 7.840 kN (1 763 lbf). Main Engine Propellants: N2O4/UDMH. Main Engine Propellants: 3 822 kg (8 426 lb). Main Engine Isp: 291 sec. Spacecraft delta v: 700 m/s (2 290 ft/sec). Electrical System: Solar panels 17 m span 40 sq m. Electric System: 2.40 average kW. Associated Launch Vehicle: Proton 8K82K."

 

[JonClarke]

I wrote: <br /><br />Submarines, aircraft, campervans, and boats all suggest useful approaches for compact living spaces in spacecraft.<br /><br />Will wrote:<br /><br />Unfortunately, real spacecraft will be more cramped than any of those -- at least until we build Galaxy-class starships like the NCC-1701D.<br /><br />Not at all. People can't be minaturised so there are minimum volume requirements for every task.<br /><br />A bathroom unit on a camper van is an even better example. In a volume similar to an airline toilet you also have a shower as well. I doubt if a similar compartment can be made much smaller than this and still function. <br /><br />Have you ever been on a sub? I have visited several. Many are much more cramped per person than long duration spacecraft. No private cabins except for the commander and hot bunking have been the norm on many. The ISS, Mir, and even Skylab were luxurious compared to this. <br /><br />The same is true for ocean racing yachts (as opposed to floating gin palaces), which are crewed for mo ths on end under extremely cramped and spartan conditions. Hot bunking is the norm there as well. As with spacecraft, there is strong design pressure to minimise weight and volume.<br /><br />There are lots og good archiectural concepts that can be learned from considering other places were volume, power, mass etc. are at a premium.<br /><br />The NASA Mars Design Reference Mission as, as I recalled, about ~300 cubic metres of pressurised volume on the surface of Mars exclusive of inflatable additions, docking tunnels, pressurised rovers, etc. That's 50 cubic m per person for a crew of six, which excperience has shown is quite adequate.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[willpittenger]

Actually, I have been on the diesel sub USS Blueback in Portland, Oregon. It is part of the Oregon Museum of Science and Industry. At first glance, you might mistake it for the USS Albacore with which it shares its shape. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[JonClarke]

"Hmmm...actual flight experience beyond six months is virtually non-existant, I wonder on what basis the curve goes flat beyond 6 months? "<br /><br />There has been a dozen flights longer than 6 months, so there is some experience to draw on. The relevant people and flights were:<br /><br />Berezovoi, Lebedev - Salyut 7 EO-1 - 211.4 days (7 months) – 50 cubic m pp<br /><br />Kizim, Atkov, Solovyov - Salyut 7 EO-3 - 237.0 days (8 months) - 33 cubic m pp<br /><br />Polyakov - Mir LD-2 - 240.9 days (8 months) - 47 cubic m pp<br /><br />Krikalyov - Mir LD-3 - 311.8 days (10 months) 87 cubic m pp<br /><br />Romanenko - Mir LD-1 - 326.5 days (11 months) - 70 cubic m pp<br /><br />Manarov, Titov - Mir EO-3 - 365.9 days (12 months) 47-70 cubic m pp<br /><br />Avdeyev - Mir EO-26/-27 - 379.6 days (13 months) - 110 cubic m pp<br /><br />Polyakov - Mir LD-4 - 437.7 days (14 months) 87 cubic m pp<br /><br />Also keep in mind that both Mir and the ISS were designed for continuous habitation by missions of indefinite duration. So they give us some baseline information for what is required as well.<br /><br />I suspect that the curve goes flat after 6 months on the diagram for a couple of reasons. Initially volume requirements go up quickly with increasing duration, as the crew needs to move round, perform experiments, etc. With longer flights more comfort needs to be built in – toilet and shower facilities, a ward room, private cabins – and of course larger and more comprehensive laboratories. This can be illustrated by sequence of Vostok (days), Soyuz (weeks) and Salyut (months). However, there are points of diminishing returns. There is a limit to the amount of work a person can do in a day, which limits the volume set aside for experiments, and there is a practical limit to the amount of space a person needs to live comfortably.<br /><br />A complicating factor is the volume needed to store consumables. Salyut, Mir and the ISS are designed for regular resupply and disposal of waste. On a lo <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[gunsandrockets]

"There has been a dozen flights longer than 6 months, so there is some experience to draw on. The relevant people and flights were:"<br /><br />I was already aware there were some flights that lasted as long as a year. By your listing there have been only 6 people on missions lasting longer than 8 months. That's pretty thin data compared to how many people have spent 6 months in space.<br /><br />"Whoops, my mistake, sorry! The 20, 10 and 5 cubic m refer to habitable volumes, not pressurised. The pressure volume is three times this - 50, 30, and 15 cubic metres."<br /><br />You made no mistake. Your original post made clear the distinction between habitable and pressurized volumes. I understood what you meant.<br /><br />"Applying this to the pressurised volumes of Soyuz and Shenzhou it means they are too small to carry out missions of more than 2-3 weeks without much larger attached modules."<br /><br />When I made references to the volumes of the Soyuz, Shenzou and Orion, I stated their habitable volumes - not their pressurized volumes. 9 cubic meters habitable volume for the SoyuzTM, 14 cubic meters for the Shenzou, and 14 cubic meters for the CEV. So it should be possible (though not comfortable) for any of these spacecraft to accomodate a two man crew in a NEO mission (if extra consumables are provided).<br /><br />http://www.astronautix.com/craft/shenzhou.htm<br /><br />Crew Size: 3. Design Life: 20 days. Typical orbit: 196 x 324 km, 42.5 deg inclinaton. Length: 9.25 m. Basic Diameter: 2.52 m. Maximum Diameter: 2.80 m. Span: 17.00 m. Habitable Volume: 14.00 m3. Mass: 7,840 kg. RCS Coarse No x Thrust: 16 x 150 N. RCS Fine No x Thrust: 32 x 5 N. Main Engine: 4 x 2500 N. Main Engine Thrust: 1,020 kgf. Main Engine Propellants: N2O4/MMH. Main Engine Propellants: 1,000 kg. Main Engine Isp: 290 sec. Spacecraft delta v: 380 m/s. Electrical System: Solar panels, 24.48 + 12.24 sq m, 36.72 sq m total. Elec

 

[onesmallstep]

I'm sure everything you are saying is true, but...It just seems to defy common sense to throw pieces of your spacecraft away as you go along. It's like driving down the road throwing parts of your car out the window trying to lighten the load until you get to the next gas station. "Hey kids, were not going to make it, throw out the back seat!" Sounds ridiculous and junks up the highway! I wish we didn't have to further junk up outer space and the moon with our disposable spaceships. <div class="Discussion_UserSignature"> </div>

 

[holmec]

I just tried it. Its working fine for me. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[radarredux]

> <i><font color="yellow">It just seems to defy common sense to throw pieces of your spacecraft away as you go along.</font>/i><br /><br />Disposable components are concept in many areas. For example, if your hard drive, graphics card, or iPod shuffle fails, you don't pay to have them fixed. Instead you throw them away and buy a new one. The cost of replacing them is cheaper than trying to fix it.<br /><br />Likewise, for rockets, the cost of building something rugged enough for multiple uses, and all the cost to support multiple uses (e.g., tear down, inspect, rebuilld), often exceeds the cost to build throw-away components.</i>

 

[onesmallstep]

I don't throw away my hard drive, graphics card, mother board, etc., and install a new one every time I use my computer either! Neither do I tear down, inspect, or overhaul my computer, automobile, microwave oven, or blender everytime I use it. Even commercial aircraft is not rigorously inspected to this degree between each flight. There is an engineering term called MTBF, or mean time between failures, that is determined for major components or systems to help predict/determine maintenance schedules. I'm not saying that all components of the new LTS should be reusable...I just think some serious consideration should be given before we start building disposable lunar landers...again! <br /><br />It sounds like cost is the primary driving force at work here. What is the cheapest way to get to the moon, disposable or reusable vehicles?...If that is our most pressing concern, let's forget it and stay home. Sooner or later there will be an accident and people will lose their lives because it is impossible to fully functionally test a disposable vehicle, except in actual usage. This is one of the lessons of Apollo 13. All of the vehicles worked in Apollo, thankfully, except for the Apollo 13 service module. This clinker came off the disposable assembly line and no one caught the oxygen tank problem until it was put into actual usage. Challenger was lost because of faulty rubber O-rings built to be used once, then refurbished with new rings...disposable, therefore cheap.<br /><br />On the other hand, the shuttle orbiters themselves have proven to be quite hardy vehicles, flying without incident for over twenty years...save for a piece of foam that hit Columbia like it was shot out of a cannon, but that wasn't the orbiter's fault.<br /><br />I guess my point here is that the maiden voyage of any vehicle, whether it be a lunar lander, a nuclear submarine, or a toyota corolla is ususally where the bugs show up, hence the need for test pilots. Vehicles that have been in se <div class="Discussion_UserSignature"> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>All of the vehicles worked in Apollo, thankfully, except for the Apollo 13 service module.<p><hr /></p></p></blockquote><br />You forgot the Apollo 1 command module. Not surprising as it never flew. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[JonClarke]

"By your listing there have been only 6 people on missions lasting longer than 8 months."<br /><br />And your point is? <br /><br />"You made no mistake. Your original post made clear the distinction between habitable and pressurized volumes. I understood what you meant. "<br /><br />In my post of 02/04/07 12:23 AM I said <i>The pressurised volume limits for these are 20, 10 and 5 cubic m</i>. I should have said habitable, not pressurised.<br /><br />"When I made references to the volumes of the Soyuz, Shenzou and Orion, I stated their habitable volumes - not their pressurized volumes. 9 cubic meters habitable volume for the SoyuzTM, 14 cubic meters for the Shenzou, and 14 cubic meters for the CEV. So it should be possible (though not comfortable) for any of these spacecraft to accomodate a two man crew in a NEO mission (if extra consumables are provided). "<br /><br />Sure, and the best way to store those consumables is in a misison module, which will give you more room. <br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[3488]

Which NEO' would be worth visiting by an Orion CEV?<br /><br />Perhaps any of these 433 Eros, 1036 Ganymed, 1620 Geographos, 3908 Nyx, 4179 Toutatis, 4183 Cuno, 25143 Itokawa, 99942 Apophis, etc.<br /><br />The selction above are quite a range of different NEO's that may be worth visiting by a human crew. 1036 Ganymed (not to be confused with Ganymede, Jupiter's & the solar system's largest moon), is the largest NEO known to date.<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>It sounds like cost is the primary driving force at work here. <p><hr /></p></p></blockquote><br /><br />Yes, and it always will be a factor. Don't forget; it's not just the maintenance costs. Reusable parts can impose other more serious penalties as well (which is why the Shuttle doesn't even carry all of its reusable components into space; it ditches the SRBs as soon as they burn out). Rocket staging is one of the most obvious examples of this. But it can be extended past ascent. The MERs jettisoned their cruise stages before entering the Martian atmosphere not to save maintenance costs but to reduce the amount of mass that had to decelerate. They later jettisoned other components (backshell, drogue chute, heat shield, and finally the main chute with its landing rockets and avionics) for the same reason. This did save money, but it also saved risk -- which itself saves money in addition to increasing the odds of a successful mission. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[JonClarke]

Hi Andrew<br /><br />How many of those are NEOs? I know that itokawa is a main belt asteroid.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[Boris_Badenov]

All of them are NEO's, except Itokawa. <br /> 1620 Geographos has a great close pass in 2015 & again in 2019. None of the others come close in the years 2014 through 2020.<br /> Do you have any idea when NASA will chose their target? Public interest will skyrocket when they do. <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[j05h]

What about Apophis as a NEO target? Potential Earth impactor and all.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[onesmallstep]

"The MERs jettisoned their cruise stages before entering the Martian atmosphere not to save maintenance costs but to reduce the amount of mass that had to decelerate. They later jettisoned other components (backshell, drogue chute, heat shield, and finally the main chute with its landing rockets and avionics) for the same reason. This did save money, but it also saved risk -- which itself saves money in addition to increasing the odds of a successful mission."<br /><br /><br />You are talking about robotic missions...that's apples and oranges compared to manned missions. It doesn't matter if they do robotic missions with duct tape and Elmer's glue! <div class="Discussion_UserSignature"> </div>

 

[willpittenger]

Both expendable and reusable systems have their advantages. Unlike the Saturn V, Ares boosters will be at least partially reusable with help from the Shuttle's SRB system. Long term, I think we will find that the Science Fiction writers have the right idea. In Star Trek, they came up with the concept of the modular "runabout".<br /><br />The original concept was something simply sized between what they writers called "shuttles" and full starships. Like the "shuttles," runabouts needed no more maintenance than your car. (I doubt anyone seriously believes they should have cars built with stages like rockets have.) But they they thought of something cool. Runabouts became modular. One runabout can handle many different missions. For instance, some runabouts were shown both with and without a special "sensor" pod. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[3488]

Hi Jon.<br /><br />25143 Itokawa is not generally thought of being a near Earth asteroid, but is does cross the Earth's orbit, although its AVERAGE distance from the Sun is within the main asteroid belt.<br /><br />Japan's Hayabusa (Muses C) was to have visited 4660 Nereus, but delays & the fact that 4660 Nereus was no longer so easy to reach, 25143 Itokawa was picked instead.<br /><br />4660 Nereus appears to not want to be visited!! It was the original target for the NEAR/Shoemaker, until mission planners decided that 4660 Nereus was too small & would probably not offer anything new, hence 433 Eros being chosen instead!!<br /><br />Andrew Brown. <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[spacester]

This is a great thread to become a solar system on, don't you think? Man, it's been a long road back, the last crash took away ~1200 posts. Never complained, not once, did I.<br /><br />Am I allowed some latitude here, you know, like on your Birthday, for my regained Solar System status? I haven't posted in a long time because I've been working on my project, which for a long time I've planned to announce on my 2048th post. I know this appears off topic and even self-promotional, but after this post I will keep it to the sigline, and I promise to return with a full answer to this question. Most likely, I will differ with NASA and y'all will have an opportunity to debate lots of sub-topics.<br /><br />My first posts here in 2001 were on NEOs and the prospects for their exploitation. <i>Mining the Sky</i> by John S. Lewis was the book that pulled me out of my lurking on space BBs and mailing lists. It was Yales who told me about the fourth class of NEOs, the Arjunas, those completely within Earth's orbit and thus impossible to observe in night skies.<br /><br />Which NEO would be targeted? <br /><br />Let me get back to you on that this summer. NASA has folks doing advanced orbital mechanics work to develop a strategy, and I am going to work on a parallel effort as part of my space program. It is one of three major projects I am developing.<br /><br />Yup, I've got my own comprehensive Space Program and I am going to share that on my new website (see sigline) with anyone interested. Also, I am going to develop my own Political Party and see if I can work with others to develop a modern cosmology based on the philosophy of Alfred North Whitehead and what I call Applied Teleology or Teleological Engineering. (Not your typical mass media website, but why be typical?)<br /><br />The Space Program and the rest are all for educational fun but they will be pursued very much in earnest, under the assumption that anything that is technically possible is politically possible. Some stuff wi <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

It must be shy! <img src="/images/icons/smile.gif" /> <br /><br />However, I would have thought, given the 60-120 day mission rule, any asteroid that makes it out to the main belt may not be that attractive from a misison lenth point of view.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[willpittenger]

Where it <i>goes</i> is irrelevant. All we care is where to intercept it. If that's close, I could care less how far away it might be at other points in its orbit. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>