Landing an Orion capsule

[willpittenger]

Since the CEV design is supposed to land-based touchdown, I keep having this nightmare of a capsule landing in downtown Houston during rush hour on I-10. Would anyone care to offer relief? <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>

 

[nacnud]

Well it's supposed to land at Edwards...

 

[greythanis]

I have read that an Orion capsule is reusable up to ten times but that the heatshield is jettisonned. true/false?<br /><br />PS; i'm not sure

 

[mattblack]

True. Developing a one-piece, re-usable heatshield of that size and shape would be punishingly expensive. Better to expend an ablative shield each time. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[vulture2]

True, but the method of shipping the capsule back and the economics of capsule reuse have not been clearly explained. One Gemini capsule was flown twice, but the airbag touchdown on the ground may be a little harder than water landing. The Soyuz has used land recovery for years with only a few problems, but is not reused. The Apollo type heatshield was not reusable but was simple and rugged, consisting of a honeycomb of very thin stainless steel sheet with the spaces filled with ceramic. The steel honeycomb was lightweight and allowed the whole heatshield to be tough and flexible, though of course it melted away slightly during entry. This system could probably be replaced for less than the cost of inspecting and repairing tiles. It's difficult to see how an airbag could be inflated without jettisoning the heat shield. The original Mercury capsule also had an airbag for possible ground landing, but after the false heat shield separation signal on Glenn's flight this was deleted.

 

[PistolPete]

With a big enough hypersonic L/D ratio to hit Edwards, you'd think that they could get it to hit the sound behind the cape. That way you could get a water landing without having to send out a Navy flotilla, and it would be close to the reprocessing center, so you wouldn't have to ship it across the country. <div class="Discussion_UserSignature"> <p> </p><p><em>So, again we are defeated. This victory belongs to the farmers, not us.</em></p><p><strong>-Kambei Shimada from the movie Seven Samurai</strong></p> </div>

 

[darkenfast]

The ESAS report covers this. The landing site requirements include safe disposal of the Service Module. It must impact a safe distance offshore, which means a west coast landing site to allow a sufficient amount of options for both return from orbit and return from the Moon. The two sites most often mentioned are Moses Lake, Washington and Edwards AFB, California.

 

[spacefire]

They'll have to merge in with traffic like everyone else.<br />It'd be better if they landed on I95 right by the Cape to save money on tranport. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[bdewoody]

Last time I checked there's a big ocean just east of KSC. <div class="Discussion_UserSignature"> <em><font size="2">Bob DeWoody</font></em> </div>

 

[lampblack]

<font color="yellow">Last time I checked there's a big ocean just east of KSC. </font><br /><br />That's not an option, as it would have the service module impacting on land. <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[henryhallam]

All orbital missions and some or most types of lunar missions will reenter travelling from West to East. Since the crew module will have a certain amount of lift it will travel further to the east than the service module, which is on a pretty much ballistic trajectory until it breaks up and will then rapidly decelerate.<br /><br />So "by default" the crew moudle will land further to the east than the service module impact site, implying a west coast landing. Perhaps the service module can separate at a higher altitude and perform some manouvers using its RCS and/or main engine in order to bring its impact site further east. But it would require a relatively major change in the orbit to do so, particularly if returning on a fast hyperbolic trajectory from the moon. So there is some mass penalty and increased risk of failure if this is done. I'm not sure how much the mass penalty would be... probably not too much.

 

[radarredux]

> <i><font color="yellow">I have read that an Orion capsule is reusable up to ten times but that the heatshield is jettisonned. true/false?</font>/i><br /><br />One suggestion I have read recently is that much of the insides (e.g., avionics, life support systems, etc.) would be reused, but a new outer shell would be used for each flight.</i>

 

[radarredux]

> <i><font color="yellow">So "by default" the crew moudle will land further to the east than the service module impact site, implying a west coast landing.</font>/i><br /><br />Florida has a pretty substantial west coast too.</i>

 

[rybanis]

<blockquote><font class="small">In reply to:</font><hr /><p>The ESAS report covers this. The landing site requirements include safe disposal of the Service Module. It must impact a safe distance offshore, which means a west coast landing site to allow a sufficient amount of options for both return from orbit and return from the Moon. The two sites most often mentioned are Moses Lake, Washington and Edwards AFB, California.<p><hr /></p></p></blockquote><br /><br />Moses Lake would be great, as its only about 2 hours west on I-90 for me. It'd be quite fun to watch returns <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[henryhallam]

Good point... the Gulf is more heavily populated by people and oil rigs etc than the Pacific but maybe it's still sparse enough to serve as a drop zone.

 

[willpittenger]

That design probably saved weight. <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>

 

[willpittenger]

Unlike shuttles, a capsule's landing point will probably not be that predictable. Most likely, you will wait for something out of sight. <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>

 

[willpittenger]

Would you put any bets on the CEP?<br /><br />(CEP is a military term for "Circular Error of Probability." In their context, it refers to what percentage of warheads will come within X distance of the target. X would be set by the design specs for the warhead. With WWII iron gravity bombs, X was measured in miles and the percentage was low. That is one reason why the British resorted to bombing cities. It is also why we massed our bombers in the hundreds. Today's laser and GPS guided bombs do much better. Some are predicted to hit within 10-20 of the aim point.) <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>

 

[PistolPete]

What if the CEV had the parasail from the X-38? Then the CEP would be measured in feet. As accurate as a JDAM. <div class="Discussion_UserSignature"> <p> </p><p><em>So, again we are defeated. This victory belongs to the farmers, not us.</em></p><p><strong>-Kambei Shimada from the movie Seven Samurai</strong></p> </div>

 

[henryhallam]

$100 says a delivered CEP of less than 400 meters.

 

[edkyle98]

""Last time I checked there's a big ocean just east of KSC.""<br /><br />"That's not an option, as it would have the service module impacting on land."<br /><br /><br />Just east of Florida wouldn't work, but further out in that big Atlantic would do just fine. Apollo 7 landed southeast of Bermuda.<br /><br /> - Ed Kyle<br />

 

[rybanis]

I'm putting my money on Moses Lake <img src="/images/icons/smile.gif" /> Lots of open land out there, and there is a HUGE airport for taking the capsule back to KSC. <div class="Discussion_UserSignature"> </div>

 

[henryhallam]

<font color="yellow">Just east of Florida wouldn't work, but further out in that big Atlantic would do just fine. Apollo 7 landed southeast of Bermuda. </font><br /><br />That does mean a decent sized fleet if not a whole naval task force for recovery. The main advantage of landing on land or a lake is reduced costs of recovery.

 

[edkyle98]

""Just east of Florida wouldn't work, but further out in that big Atlantic would do just fine. Apollo 7 landed southeast of Bermuda.""<br /><br />"That does mean a decent sized fleet if not a whole naval task force for recovery. The main advantage of landing on land or a lake is reduced costs of recovery."<br /><br /><br />Costs could be reduced by using smaller, specialized recovery vessels. At any rate, ships will have to be posted on-station to cover emergency ocean recovery zones even if a land-landing mode is used.<br /><br /> - Ed Kyle

 

[Boris_Badenov]

I read on these message boards that the furthest a capsule landing took place from it's intended target was a Gemini mission that was a fraction of a degree off in it's reentry vector, pulled 5 g's, & landed 2 miles from it's designated landing zone. <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>