Blue Origin photo

[qso1]

My hats off to them! <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>

 

[no_way]

people have gone through this parachutes vs powered landing analysis dozens and dozens of times, and performance impact wise, they are pretty close. operationally, parachutes are a nightmare. Imagine a hundred short hop test flights.. while packing chutes.<br />Operationally they also add failure modes that are hard to deal with, regulatory wise. If your computers go bonkers and deploy at high altitude, you could drift to large populated places for landing. Adding a cutaway and spare will kill the weight budget.<br />Armadillo already went through all this, and operationally and from third-party safety standpoint, powered landing won out. If you want to build a viable business, these are very important variables.<br />BO also seems to have an engine out capability, so critical failure on powered landing would mean that you lose a majority of the engines, or both your primary and redunant flight control systems. In a well engineered, debugged and tested vehicle, these things shouldnt happen very often. <br /><br />EDIT: Just to clarify on the performance aspect. You cant just take the weight of the parachutes into account, you have to remember that your structure has to support it, and you have to have shock-absorbing landing mechanism with chutes. Unless you want to go a parafoil route and flare to land like x-38. In the end, both methods will have about the same weight impact on the vehicle but with powered landing you have less parts on the vehicle, less total mechanical complexity and arguably actually less failure modes.

 

[gunsandrockets]

Interesting. From the video I counted nine exaust ports/nozzles visible in the base of the vehicle.

 

[gunsandrockets]

"Conjecture on propellant - 'm thinking Hydrogen peroxide concentrate, lot of moisture and steam from the video - any thoughts - anybody?"<br /><br />That's a damn fine conjecture then if you weren't already aware of the environmental impact report Blue Origin filed. You see that report came out a while ago and spilled the beans that indeed Blue Origin would use HTHP/kerosene bi-propellant rocket engines.

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>We are particularly looking for experienced propulsion engineers and experienced turbomachinery engineers, as well as a senior leader to head our turbopump group. Folks with turbopump or propulsion experience on large, modern, cryogenic engines such as the RS-68 are of particular interest.<p><hr /></p></p></blockquote><br />They are going for turbopumps. Time for Flometrics people to get in touch with them ?

 

[gunsandrockets]

"I like the fact that you don't have to worry about it tipping over like the DCX."<br /><br />The Delta Clipper would have reentered the atmosphere sideways as a biconic lifting body and used body flaps for flight control, thereby leaving the engines in the vehicle's wake until the final moments of landing.<br /><br />In contrast I think the smooth wide bottom of the Blue Origin vehicle indicates a straight-down base-first reentry profile. That is a simpler flight system but that also means more diffculties protecting the engines during reentry. I think there might be retractable doors in the bottom of the spacecraft hull to protect the engine ports. Of course this assumes a high performance suborbital or orbital Blue Origin vehicle would closely resemble the small scale test vehicle revealed.

 

[holmec]

Absolutely amazing! <br /><br />"Calling occupants of interplanetary craft." <br /><br />It look and behaves out of this world. <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[mrmorris]

<font color="yellow">"Operationally they also add failure modes that are hard to deal with, regulatory wise. If your computers go bonkers and deploy at high altitude, you could drift to large populated places for landing. "</font><br /><br />OK -- you're biased towards powered landings. That's perfectly OK. I happen to be unashamedly biased towards unpowered ones. However, let's try to stay within the realm of the probable. The Apollo parachute system, which underwent more testing than anything BO is liable to do, fired its parachutes based on set altitudes -- with atmospheric based backups and manual overrides possible. It worked using the <b>Apollo</b> computers which are less complicated than most Scientific calculators on the market today. The logic is simple... at 25,000 feet, fire drogues. At 10,000 feet, fire drogue cutters and deploy pilot chutes. There are exactly two computer command sequences related to the deployment of the parachute system. If you're going to pick a failure mode -- pick a better one. Especially since the powered landing will require ***much*** more complex computer control <b>all the way to the ground</b>. A failure of a powered landing that caused the craft to veer off its planned landing point into a populated area is an order of magnitude more likely than what you described. In addition, since the computer in question has 'gone bonkers' (using your terminology), it's likely to get vindictive and power-dive the capsule into a school bus filled with disadvantaged children.<br /><br /><font color="yellow">"In the end, both methods will have about the same weight impact on the vehicle but with powered landing you have less parts on the vehicle, less total mechanical complexity and arguably actually less failure modes. "</font><br /><br />If you want to argue that a powered landing allows more pinpoint accuracy than a parachute one, I'll have to agree that this is true. If you truly beleive that a powered lan

 

[spacefire]

Question: Is it possible that later on an additional engine is used for the landing phase? <br />A solid rocket will provide the necessary delta-V to slow the craft down just before touchdown with the ascent liquid propellant engines used just for attitude control and fine-tuning the landing.<br />Such engine was not visible in this test but might be incorporated for high-altitude flights.<br />Firing a high powered rocket at very low altitude would create an exhaust cushion under the (wide) base of the vehicle, magnifying the braking effect. <br /><br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[mrmorris]

<font color="yellow">"Question: Is it possible..."</font><br /><br />Dunno if you're asking me or just tagging the question onto my post because it's the last one in the thread. Whichever it is... heckifIknow what they're going to do. <br /><br />My assumption would have been similar to your initial one above -- namely that they would use a parachute for initial braking, then cut it loose and use powered braking for the final descent. Otherwise the craft is essentially freefalling from 100,000 feet plus at 1G acceleration. I don't know what the terminal velocity will be but I expect it would be several machs. SS1 hit 3 mach's going <b>up</b> before coasting to a stop from gravitic deceleration. A craft coming down from that altitude will reach the same velocity on the downward side without some means of scrubbing the energy off. Once the craft hits atmosphere, heating will scrub some energy... but since the craft is simply coming straight down rather than a descending semi-ballistic curve from orbit as with an orbital capsule or a freefall-to-gliding descent like SS1 or a superheated glide like the shuttle, there will be much less time for it to do so. Plus there's not only the existing 3+mach velocity to deal with but also normal acceleration due to gravity.<br /><br />I have great difficulty believing that without a parachute, the figure that was stated in an earlier post that 10% of the capsule's mass in propellant will be sufficient to slow the craft to a soft landing. On the other hand -- if you were to add a parachute to the spacecraft to scrub off some of the velocity, then the computers are likely to go bonkers and fire it early. It's a well-known fact that computers hate parachutes.

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>However, let's try to stay within the realm of the probable. The Apollo parachute system, which underwent more testing than anything BO is liable to do<p><hr /></p></p></blockquote><br />Apollo was expendable. That nullifies your entire argument. There are totally different variables driving the optimal design of such vehicles.<br />Also, Apollo basically did not have any issues with third-party liability. They could have landed hundreds of kilometers off target through couple of skyscrapers and they would still have been heroes. Landing a SpaceShipTwo through someones barn roof will make for one rich farmer and a young industry out of business.<br /><br />I am a skydiver myself, and i would never ever use a parachute without having a reserve. Also, while i can pack my canopy in about five minutes, packing a canopy that is able to bring down several hundreds of pounds of equipment just does not fit into equation of fast turnaround and thus high flight rate ( our club's tandem canopies get packed in about half an hour and they are about twice as big as mine, packing a bigger one will get harder exponentially )<br />And believe me, parachute systems, including deployment systems, have dozens of "interesting" failure modes.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>If you truly beleive that a powered landing is less complex,<p><hr /></p></p></blockquote><br />It is less _mechanically_ complex, in that it has less parts ( chutes add at least three major systems : the canopy, deployment mechanisms, and shock-absorbing landing gear )<br />Powered landing is more complex only computationally, i.e. the control algorithms have to be more complex. On a reusable vehicle i trust increased computational complexity over increased mechanical complexity any day, software does not have fatigue and wear issues.<br /><br />So yes, you could say that i have bias against parachutes, trusting my life to them on a regular basis 6 month

 

[mrmorris]

OK -- found a note on Hobbyspace that says: <i>"The EIS says that the actual New Shepard crew module will land by parachute after an abort separation from the propulsion module rather than by its own rocket power."</i> So the New shepard *will* have a parachute. Looking through that document and searching for 'parachute' I located the following: <br /><br /><br /><i>"The New Shepard RLV would have three possible flight scenarios - two nominal scenarios and one emergency scenario. In the first nominal scenario, the New Shepard RLV would perform a vertical takeoff from the test pad; fly a suborbital trajectory nearly straight up; shut down engines after approximately two minutes and coast to an altitude in excess of 99,060 meters (325,000 feet) before descending; and restart its engines several thousand feet above the ground for a precision vertical powered landing on the landing pad. The time from engine restart to landing would be less than 15 seconds, and the propulsion module would use less than 444,822 Newtons (100,000 pounds-force) of thrust for landing. During this entire mission, the propulsion module and CC would remain attached. Total mission time from liftoff to landing would be less than 10 minutes."</i><br /><br /><i>"In the second nominal scenario, the New Shepard RLV would fly a similar trajectory as the first scenario during ascent, except that shortly after main engine cutoff, the propulsion module and CC would separate. The separation would be accomplished using a combination of springs and possibly a low-impulse RCS burn to assure collision avoidance. The small solid rocket motors used for emergency separation would not be ignited and would remain on the propulsion module as the CC separates. Both the propulsion module and CC would reach an altitude in excess of 99,060 meters (325,000 feet) before beginning their descent. The propulsion module would perform a precision vertical powered landing on the landing pad as in the previous scenario, while the</i>

 

[mrmorris]

<font color="yellow">"Apollo was expendable. That nullifies your entire argument."</font><br /><br />Um.... my argument is that if a computer glitch can mess up two command sequences to fire drogue chutes, then pilot chutes, how a powered descent which requires several orders of magnitude more computing power is *not* subject to a glitch which could put the crew capsule through Farmer Brown's roof. How exactly does this have anything to do with expendability?<br /><br /><font color="yellow">"I am a skydiver myself, and i would never ever use a parachute without having a reserve. "</font><br /><br />I'm an avid researcher of spacecraft myself and I realize that the Apollo parachute system had two drogue chutes to stabilize flight prior to main chute deployment (only one of which was required for stabilization) and three main chutes (only two of which were required to inflate for a safe descent velocity). Reserves were therefore imbedded in the system.<br /><br /><font color="yellow">"Also, while i can pack my canopy in about five minutes, packing a canopy that is able to bring down several hundreds of pounds of equipment just does not fit into equation of fast turnaround and thus high flight rate"</font><br /><br />Great -- the Apollo chutes were prepacked by a pneumatic press and vacuum stored within polyethylene bags and a wooden former to ensure they'd maintain their shape and compression for up to a year. One presumes that several sets would be packed in this fashion and pulled out as required to support whatever flight rate is required.<br /><br /><font color="yellow">"...software does not have fatigue and wear issues."</font><br /><br />Oh but when those computers go bonkers... there's just no telling what will happen.

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>New Shepard will be carrying the mass for a powered descent *plus* parachutes... but only use the parachutes in an abort or (presumably) if they have concerns with the propulsion module post-MECO.<p><hr /></p></p></blockquote><br />That makes a lot of sense. Chutes are there for just an emergency, not for normal operational use. <br />I am pretty sure you will see a BRS Parachutes logo on the vehicle, once operational, as they have already saved countless light aircraft from what would have otherwise been fatal accidents. BTW, normally BRS is not very willing to repack and reuse them, once deployed.<br />

 

[spacefire]

I still believe that the operational vehicle will use parachutes for braking.<br />In that event it makes more sense to install a brand new parachute module before each flight. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>How exactly does this have anything to do with expendability? <p><hr /></p></p></blockquote><br />Expendability has everything to do with everything. If you are building a reuseable craft that has engines on it, that are going to be reused anyways, it makes a lot of sense to use them for landing as well.<br />If you are developing an expendable landing crew module only, it makes a lot of sense not to put any fuel or engines on board it at all ( see X-38 ) <br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>my argument is that if a computer glitch can mess up two command sequences to fire drogue chutes, then pilot chutes, how a powered descent which requires several orders of magnitude more computing power is *not* subject to a glitch which could put the crew capsule through Farmer Brown's roof.<p><hr /></p></p></blockquote><br />One of these scenarios is likely recoverable by switching to redundant system without incurring additional hefty weight penalties. Guess which.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>three main chutes (only two of which were required to inflate for a safe descent velocity). Reserves were therefore imbedded in the system. <p><hr /></p></p></blockquote><br />Yes, and nobody questioned the weight penalties, because at the time, they basically had no alternatives.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Great -- the Apollo chutes were prepacked by a pneumatic press and vacuum stored within polyethylene bags and a wooden former to ensure they'd maintain their shape and compression for up to a year. One presumes that several sets would be packed in this fashion and pulled out as required to support whatever flight rate is required. <p><hr /></p></p></blockquote><br />Im definitely sure that a startup private spaceflight operator would just love to hire an army to maintain its parachute reserves. Operational costs dont mean jack to them.<br /><br /><blockquote></blockquote>

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>I still believe that the operational vehicle will use parachutes for braking.<br />In that event it makes more sense to install a brand new parachute module before each flight.<p><hr /></p></p></blockquote><br />Go ask a quote from BRS Flight systems for a brand new parachute able to bring down this DC-X clone. And then add this to your basic ticket price.<br />BTW, would you trust your life to airplanes if they had a brand new landing gear off the assembly line each flight ?

 

[soyuztma]

<blockquote><font class="small">In reply to:</font><hr /><p>6,672,000 kg-M/s applied to a mass of 4800kg would result in a dv of 1,390 meter/second. This is about mach four which makes sense for the freefall from 100km, so this is in the ballpark. I expect New Horizons is probably a bit heavier and there may be a bit less propellant. <p><hr /></p></p></blockquote><br />Mach FOUR??? <br />Genesis crashed at a speed of 322 kilometers per hour and it came from a solar orbit! Bezos is planning to land the New Shepard on the earth not on the moon and on earth we have something called an atmosphere and it slows you down a lot. For the 10% number read this page: horizontal_vs_vertical_landing <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

There's a big difference between the size of the parachute needed to land the entire craft intact and the size of a parachute needed to return a crew in a small detatched crew module alive in an emergency. The weight being parachuted is much less, and in an abort scenario it is acceptable if there is the possibility of some damage on landing, crumple zones, ect.

 

[rocketman5000]

it is quite possible that the CC and the propulsion module will weigh in around 24000, remember the first landing option still has the propulsion module attached. It also has landing gear, solid rocket motor, and emergency parachute systems. <br /><br />Assuming it has enough dV to preform its mission it appears to be a very robust system designed for multiple redundency. It would have to have 3 complete failures of recovery systems to have an accident resulting in LOV. I like that amount of backup. SRM in emergency seperation comforts me as they typically are much easier to get started the first time without delicate startup procedures or nasty hypergolic chemicals.

 

[no_way]

yep, SRMs for an emergency separation and deployment are pretty much a no brainer as pretty much all of the light aircraft recovery systems and military plane catapults already use them with good track record.<br />

 

[josh_simonson]

They might use an off the shelf balistic recovery system for a small plane on their crew cabin. It's likely to weigh about the same as the light planes that these are made to return to ground in a (better than crash landing) manner.

 

[mrmorris]

<font color="yellow">"Genesis crashed at a speed of 322 kilometers per hour..."</font><br /><br />It's a very good thing that you have no relationship with any NASA team that deals with aerobraking.<br /><br />Some facts for you:<br /><br />Earth's Diameter at the Equator is 7926 miles. At 65,000 feet (12 miles) you're above 95% of earth's atmosphere. Put another way -- let's envision the earth as an orange with the 'flesh' being the solid matter of the planet, and the 'peel' being the atmosphere. Given a diameter of the 'flesh' of 3 inches, the 'peel' would be about .0045 inches thick. That's a *really* thin peel!<br /><br />Spacecraft don't appreciably slow due to atmospheric braking on a trajectory going straight down. Spacecraft on re-entry from orbital velocities enter the atmosphere almost at a tangent, travelling a considerable distance around the globe as they burn off velocity in the form of heat. A re-entry trajectory that travels around a third of the circumference of the Earth will travel through over 8,000 miles of atmosphere... as opposed to 12 going straight down. This makes a wee bit of difference in the final velocity.<br /><br />So... yes. Mach 4. Ballpark.

 

[mrmorris]

<font color="yellow">"One of these scenarios is likely recoverable by switching to redundant system without incurring additional hefty weight penalties. Guess which. "</font><br /><br />Oooooh. I see. Like you have two or three avionics systems. And if one goes haywire on your powered landing... you just switch to the secondary or tertiary. Cool. It's too bad that this has no parallel to a parachute-based landing. Oh like say... you have two or three avionics systems, and if two of the three don't agree on when to pop the chute, a human-in-the-loop input is requested. Dang I wish that'd apply to chutes so that they too could have redundancy without incurring hefty weight penalties.<br /><br /><br /><br /><font color="yellow">"In the end, both methods will have about the same weight impact on the vehicle<br /><br />Yes, and nobody questioned the weight penalties, because at the time, they basically had no alternatives<br /><br />Redundancy in computer systems does not have weight penalties in ballpark of redunant parachute systems."</font><br /><br /><br />Weight Weight Weight. I'd wonder if you read my post calculating the mass of the propellant oxidizer mass -- except that you replied to it, pleased that BO was planning to have parachutes imbedded for redundancy and aborts.<br /><br />So... ignoring my calculations on propellant mass for the moment... you're arguing that the powered landing will not have the weight penalties of chutes *and* will have about the same mass as a parachute based deceleration system, and lambasting the mass requirements of redundant parachute systems <b>despite</b> the fact that the current design of NS as a powered-descent craft *has* a parachute system as a backup. You're arguing that <i>"If you are building a reuseable craft that has engines on it, that are going to be reused anyways, it makes a lot of sense to use them for landing as well."</i> You don't see the irony in the fact that the craft is going to have parac

 

[mrmorris]

<font color="yellow">"it is quite possible that the CC and the propulsion module will weigh in around 24000"</font><br /><br />There is <b>absolutely no way</b> that the mass to be decelerated to a landing is going to be 24,000 kg. If that were to be the case, the propellant required to lift that mass up to 100km would be prohibitive. I may try to work out tomorrow what the propellant requirements would be to lift 5,000 kg to 100km. <br /><br />Probably not -- I'm really not all that interested. I'm sorry I ever made my first post. Re-read it. All I said was that IMO, the concept won't work, but I really hope it does. I wasn't soliciting gratuitous attacks by members of the Holy Order of Powered Descent. I'm a space enthusiast. I just happen to be enthused more by other engineering directions than the one BO is currently taking.