The SkyClimber

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j05h

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That's a very interesting compromise solution. It will need some thorough vetting before use in Mars EDL. The largest advantage I see is that it uses mostly proven technology - the winch system and some software is all that is needed (relatively). <br /><br />How scalable does everyone think this would be? The anim shows it landing a small rover - so it's safe to assume light payloads first. Could it be scaled up to crew and habitat delivery?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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windnwar

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how come? due to thin atmo? <div class="Discussion_UserSignature"> <p> </p><p><font size="2" color="#0000ff">""Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." --Albert Einstein"</font></p> </div>
 
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jimfromnsf

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Exactly, parachutes can't slow the lander enough. The "climber'" would have to move several meters per second
 
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j05h

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<i>> It is very useful on Mars for small spacecraft.</i><br /><br />That's what it appeared to me as well. How scalable is it? My main interest is in the 5-20t-to-Mars-surface range. This definitely looks like it'd be good in the 500lb category. If it was my rover/payload, I'd still want it to land on a pallet of some kind. The animation showed a rover landing directly from the system, but it makes sense to have it stowed on a platform for deployment and checkout. Otherwise you are looking at checking out the during reentry? I'm thinking more of a cage than the "pyramid" the MERs landed in. Any other thoughts on it?<br /><br />j <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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thereiwas

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Several meters per second while hauling quite a bit of weight (to be useful). Strength of the cable as well as the winch will be limiting factors.
 
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rlb2

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It was originally designed for Earth applications.<br /><br />To land on mars with something more than 1800 kilogram total mass (SkyCrane + MSL = about 3 times the mass of the Viking Lander) would require more parachutes, more power etc., can be done but at what cost. Surgical tubing recoil device? Sling shot – projectile velocity 300 kilometers per hour. Build confidence in landing smaller items such as robotic rovers and Landers first. The SkyClimber can be used with other methods to save fuel for human missions to Mars and after further testing maybe land up to 10,000 kilograms. One of the question marks is the cost from the mass of the parachutes vs. the mass of the propellant needed to land by rocket thusters only??? Note on earth there have been parachute drops using as many as ten parachutes. Parachutes are a lot safer to carry to Mars than propellant. <br /><br />On earth it has a lot more applications, one of them is it can help land the Orion on land, it will add another degree of safety to the Orion capsule, maybe enough that NASA would prefer land over water. One of the big question marks there is how well would the capsule load be distributed. After testing using a fishing pole like device that flexes back to help stabilize the load as mentioned in the paper it may be more stable before landing then what they have now??? <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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jimfromnsf

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"One of the question marks is the cost from the mass of the parachutes vs. the mass of the propellant needed to land by rocket thusters only??? "<br /><br /><br />It doesn't matter the thrusters are always needed. The atmosphere is too thin to land via chutes<br />
 
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rlb2

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After testing on smaller items as is done most of the time in research, then larger more riskier and costlier test can be done. Testing builds confidence... <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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rlb2

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<font color="orange"> It doesn't matter the thrusters are always needed. The atmosphere is too thin to land via chutes.<font color="white"><br /><br />The atmosphere is thin and parachutes alone may not be enough that’s why this idea is a good one however we don’t need thrusters to land on Earth... When you use thruster you are basically doing the same as you are with the SkyClimber you are accelerating upwards to change your downwards speed to a safe enough speed to land. There are some expected unexpected positive results yet to be tested but not to be disclosed at this time that could increase the likelihood of using it for human missions to Mars...</font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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jimfromnsf

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I was referring to a martian application. The climber isn't going to generate enough acceleration
 
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holmec

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<blockquote><font class="small">In reply to:</font><hr /><p>I was referring to a martian application. The climber isn't going to generate enough acceleration<p><hr /></p></p></blockquote><br /><br />This is kind of confusing since all martian landers use chutes to decelerate, even viking.<br /><br />And don't you mean deceleration as in reference to the planet?<br /><br />"What's your vector, Victor"? <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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rlb2

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<font color="orange">The climber isn't going to generate enough acceleration<font color="white"><br /><br />For the MSL landing it needs to accelerate upwards 1 Martian G, 3.8 m/s for 6 seconds starting at an elevation of 85 m. The energy supply to accelerate upwards is only needed for 10 seconds, 6 seconds to land with 4 seconds moving upwards only changing velocity for insurance. After reaching a certain landing velocity the speed upwards or downward can be regulated just as it can be with thrusters.</font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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jimfromnsf

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Your data is wrong. The thrusters start much earlier and higher<br /><br />A winch motor is not going to have the response required. Also what is going to control attitude?<br />
 
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j05h

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<i>>> The climber isn't going to generate enough acceleration<br /> /> For the MSL landing it needs to accelerate upwards 1 Martian G, 3.8 m/s for 6 seconds starting at an elevation of 85 m. The energy supply to accelerate upwards is only needed for 10 seconds, 6 seconds to land with 4 seconds moving upwards at a constant velocity for insurance.</i><br /><br />I think Jim is inferring that the winch's torque will "yank" the parachutes downward without actually decelerating the payload that much. Mars' atmosphere is 1% the density of Earth's, it is a much different fluid to move through. 85m to 0m is not much margin for error. <br /><br />On the smaller proposed payloads, the winch is the weak point, IMHO, in terms of mass and failure points. On larger payloads, the weak point is the cabling, because there is going to be a lot of it that must work. This even assumes that it can be done.<br /><br />For lighter payloads, current techniques seem to work fine. The real question is landing items heavier than the Mars Surface Lab. How to deliver 5t to the surface, or more? Is powered decent the only way to go for crew?<br /><br />A different landing method that I've been pondering would include a ram-air airbag in a fairly standard heat shield, similar to that used on Mercury. The payload is behind this with an aeroshell around it. A small cruise stage is above. During EDL, a small drogue chute trails, eventually deploying several large chutes. Several km above the surface the aeroshell detaches and reveals several down-angled SRBs. This provides more drag (per Pathfinder) and at terminal decent the SRBs trigger until touchdown. At line-slack, the aeroshell/chute combo detaches and rockets away. The drop-down airbag cushions the landing. Off-topic but more scalable. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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j05h

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<i>> It doesn't matter the thrusters are always needed. The atmosphere is too thin to land via chutes </i><br /><br />IIRC, the terminal descent speed for chutes and current Mars payloads is a couple 100km/hr. Compare to 10s of km/hr on Earth. Rockets of some kind are needed. <br /><br />Jim, what do you think of an all-propulsive method? No chutes (drogue, ballute, etc), just thrust and a decent heatshield. Obviously this is best once ISRU is available, but could be done with hypergolics now. Thoughts? <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>
 
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rlb2

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<font color="orange">I think Jim is inferring that the winch's torque will "yank" the parachutes downward without actually decelerating the payload that much.<font color="white"><br /><br />If that happens the drag from the parachute would increase providing more resistance not less. <br /><br /><font color="orange">A winch motor is not going to have the response required. Also what is going to control attitude?<font color="white"><br /><br />Electric response time is many times faster than chemical rocket thruster response time.</font></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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holmec

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<blockquote><font class="small">In reply to:</font><hr /><p>A winch motor is not going to have the response required. Also what is going to control attitude? <p><hr /></p></p></blockquote><br /><br />As far as the winch function is concerned, you could design it so that instead of a motor you use a breaking system and let gravity and the rockets extent the cable. Actually you may be able to eliminate the cable around a drum bit and just have the cable feed through a breaking system if the cable is coiled around stationary spool. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
 
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jimfromnsf

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"If that happens the drag from the parachute would increase providing more resistance not less. "<br /><br />not when moving several 100 km/hr.<br /><br />"Electric response time is many times faster than chemical rocket thruster response time. "<br /><br />Not so. valves on thrusters can open and close several times a second (see hovering missile kill vehicles). A winch is going to have inertia working against it and will haved a slower response time
 
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jimfromnsf

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I think chutes are always needed since they are lighter than prop. But thrusters are always needed for the "last mile" on mars
 
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rlb2

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<font color="orange">not when moving several 100 km/hr.<font color="white"><br /><br />Its not several 100 km/hr with three parachutes the size as mentioned at the website, do the math...<br /><br /><font color="orange">Not so. Valves on thrusters can open and close several times a second <font color="white"><br /><br />Several times a second is faster than circuits that can open and shut in less than a millisecond, wow that is a lot faster??? Electric motors are 85 to 95 percent efficient.<br /><br />An electric vehicle has very fast response time however an electric winch like winding device will have a faster response time, less gears, an electric vehicle just broke the land speed record for electric autos going from 0 to 100 mph in 6.3 seconds....</font></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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jimfromnsf

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"Its not several 100 km/hr with three parachutes the size as mentioned at the website, do the math... "<br /><br />Did you do the math? The math is not 3x parachutes is 3x less descent rate on Mars<br /><br />"Electric motors are 85 to 95 percent efficient"<br />Has nothing to do with winch response time. <br /><br />6. 3 seconds to 100 mph is not valid. It is on vehicle that has a large batteries and large motor<br /><br />Your concept shows complete disregard for physics. <br />Just graphics without engineering data to back it up. The paper has no engineering data <br />Don't respond with earth related hardware, it is at Mars<br /><br />1. The wings won't work. too small. It is the parachute that determines where the object goes. On earth ( where the atmosphere is thicker) , there is no control surfaces on the object while being parachuted.<br /><br />2. 3 parachutes aren't going to make it slower. Why do you think JPL hasn't used them? Because is doesn't help<br /><br />3. Your system is subjected to winds and has no way of countering them. A gust would drag your rover across the surface. Pathfinder and MER didn't care as much since they were in airbags. MSL thrusters can counter the wind
 
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rlb2

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<font color="orange">Did you do the math?<font color="white"><br /><br />Yes I did the math, and if you knew how to do it you would know...<br /><br /><font color="orange">Your concept shows complete disregard for physics. <br />Just graphics without engineering data to back it up. Don't respond with earth related hardware, it is at Mars<font color="white"><br /><br />Whattttt...... <br /><br /><font color="orange">The wings won't work. too small. It is the parachute that determines where the object goes.<font color="white"><br /><br />Again read what was said and presented at the conference, the wings are for guidance only and that was already acknowledged. The wings were retracted out when using one parachute to take advantage of the speed at that time which was over 300 km/hr but even going at that speed it didn’t provide much lift, but it is a great guidance tool and can be constructed of very light material since it doesn’t have to go through the sound barrier. When you travel over 100 million miles to get there it would be nice to land at the landing site instead of 20 kilometers away.....<br /><br />With wings attached to a fast ascending parachutes it opens up a lot more places that can be explored on Mars, you don’t have to count so many large rocks at the landing window….</font></font></font></font></font></font> <div class="Discussion_UserSignature"> Ron Bennett </div>
 
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jimfromnsf

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Try to talk your way out of # 2 and #3 of my post. Try to explain why a world class organization like JPL chooses to not use more parachutes to allow braking until touchdown when this would reduce both complexity and weight for Mars missions.
 
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