Elon Musk: "It's game over for all the other heavy lift rockets"

EdwardHeisler · 2018-02-06 20:04:51

Elon Musk: 'If we are successful in this, it is game over for all the other heavy lift rockets'
by Kevin Loria
Feb. 5, 2018
Business Insider

If SpaceX's Falcon Heavy launch on Tuesday is successful, CEO Elon Musk thinks the success will blow away the competition for launching heavy loads into space.

"If we are successful in this, it is game over for all the other heavy lift rockets," Musk said Monday evening on a press call.

The first launch is scheduled for 1:30 p.m. on Tuesday and will be broadcast live. If it succeeds, the system will not only be cheaper than any other operational heavy launch vehicle, but it'll also be the most powerful (some retired rockets, like the Saturn V, were more powerful).

Musk believes that if the Falcon Heavy can successfully get its very cool payload into space, it will no longer make sense to use other vehicles certified for heavy lift launches, like the Delta IV Heavy, Russia's Proton, or Europe's Ariane 5. That's because of the same reason SpaceX's other rockets are already revolutionizing the business of getting to space — it's a lot cheaper to reuse the rocket boosters that propel something out of Earth's gravity well than to use new ones every time.

The Falcon Heavy has three boosters attached to each Falcon 9 rocket, and SpaceX has become quite good at recovering them for refurbishment and reuse. Other existing launch systems can't recycle their boosters.

Future competitors, however, like Jeff Bezos' Blue Origin, do plan on using reusable rockets, matching SpaceX with that crucial capability.

The Falcon Heavy isn't the only high-powered rocket SpaceX has in the works — the company is also working on a system known as the BFR, which it plans to certify for crewed missions. Musk said it was designed to be reused more quickly than the Falcon Heavy.

If SpaceX wanted to make Falcon Heavy even more powerful, according to Musk, the company could bring up the power pretty close to that of the Saturn V, the most powerful rocket in history. That's because Falcon Heavy essentially takes the Falcon 9 system, which SpaceX has now launched and landed quite a few times, and adds two identical first-stage boosters (which provide most of the rocket's thrust) to the sides of the central booster, cranking up the power.

"We could really dial it up to as much performance as anyone could ever want. If we wanted to, we could actually add two more side boosters and make it Falcon Super Heavy ... I think we can crank up thrust and probably get upwards of 9 million pounds of thrust," Musk said on the press call.

For now, it appears unnecessary for SpaceX to make a rocket that powerful. It would need extra testing and provide more power than what planned future Falcon Heavy missions would require.

With launch scheduled for Tuesday and weather looking good, there's still a lot that could go wrong.

"It will be a real huge downer if it blows up, but ... if something goes wrong, hopefully it goes wrong far into the mission so we at least learn as much as possible along the way," Musk told Business Insider's space correspondent, Dave Mosher, on the call. "I'll be happy, I'll consider it a win if it clears the pad and doesn't blow the pad to smithereens."

If Falcon Heavy blows up the launchpad, rebuilding will take nine months to a year, Musk said. There are still plenty of ways for it to fail once it gets off the ground — the structure could be torn apart by supersonic shockwaves or the side boosters may not separate, since that system has never been tested, for example — but at that point, SpaceX could probably launch another Falcon Heavy within a few months.

A successful flight would prove that at least the initial design works. Musk seems hopeful.

"I'm sure we've done everything we could do to maximize the chance of success for this mission," he said.

"It's either going to be an exciting success or an exciting failure — one big boom. So I'd say tune in," Musk said. "It's going to be worth your time."

http://www.businessinsider.com/falcon-h … ors-2018-2

Oldfart1939 · 2018-02-06 21:50:59

Apparently they needed a 3 engine burn for the drone ship landing, and only one engine re-lit. Hit the water at 300 mph.

In the post mission press conference, Musk stated that the Falcon Heavy launches would still be about $93 Million, but that they were not planning on man-rating the vehicle. As an aside, I suspect that it's just too early to make that comment stick. Could be the USAF might throw some money at having a man rated Falcon Heavy.

SpaceNut · 2018-02-06 21:58:29

Not sure how to start as going with only the Falcon Heavy with no means to feed the first stages will cause a rise in its costs. So the ULA, Boeing Lockheed rockets while they will get used less will not go away anytime soon. The all are working on new rockets but if they are not able to reduce the government red tape costs from production they will still be over priced even if the Falcon Heavy does rise in cost.
The Falcon heavy is larger in payload but if all that it can launch is the size of the payload shroud then its a nothing. As the chunks for fuel need to be even larger so jumping to the BFR is not the choice to make as something is needed just a little bit larger but not as large as the bfr. By large I mean diameter of the cores with a stronger engine to drop the engine count for the new diameter. Which if we are using the Raptor for BFR why not start that production and make a stronger rocket than the Heavy.

Oldfart1939 · 2018-02-07 09:04:39

SpaceNut-

You are making the same argument that I previously made re: something intermediate like the Falcon X concept design. In that way, the development time would decrease and serve as a proof of concept for the BFR. Although, it may be too close to Blue Origin's "New Glenn" in size. At one point in the same set of concepts presented around 2011, there was also a Falcon Super heavy using 4 side boosters, not just 2. Same problem with a limited diameter, though.

Last edited by Oldfart1939 (2018-02-07 09:07:23)

kbd512 · 2018-02-07 11:25:34

Actually, I think it's "game on" for old space and new space alike. This is a good thing. Competition will foster innovation and, in turn, reduce the cost of launch services to potential customers.

I think that a larger core diameter would be useful for cryogenic chemical propulsion, but not required. Constructing a Mars or lunar mission piece by piece, same as ISS, is proven to work quite well. Storable chemical propellants will require a lot of tonnage, but not nearly as much volume as the cryogenic propellants. If we can fly once or even twice per week, then this is not a major problem.

Either way, I'm stoked. We now have true heavy lift with substantial reusability.

Void · 2018-02-07 12:11:58

I don't know if this has appeared at this site before. If so, I apologize, but here it is:
https://www.teslarati.com/spacex-fairin … very-boat/
Fairing-grabber-2-Reddit-user-vshie-e1513734085764-1024x658.jpg

A mysterious and massive piece of equipment was spotted by Redditor vshie early this morning aboard one of SpaceX’s fleet of leased ocean recovery vessels.
Captured aboard the recovery vessel Mr. Steven, the massive claw-like appendages are almost certainly linked to SpaceX’s payload fairing recovery efforts that have been ongoing throughout 2017. Despite SpaceX’s highly successful first stage recovery program, as much as 30% or more of the cost of every Falcon 9 launch can be found in the second stage and its many components that are discarded after every mission. Being able to recover the payload fairing, a major component of the Falcon 9 that costs approximately $5 million on its own or roughly 10% of the cost of a $62 million expendable launch, would lead to further cost reductions in commercial spaceflight.

So, perhaps the "Catchers Mitt"

If they eventually master that, then its legs off on the 1st stage, and a "Catching Robot" which talks to the booster as it comes down, and grabs its mountings appropriately.

My understanding is that if they can do that, the it will be possible to have enough fuel to attempt the recovery of the 2nd stage.

That would be pretty close to 100% hardware recovery when it worked.

Last edited by Void (2018-02-07 12:18:50)

Oldfart1939 · 2018-02-07 13:43:05

Building a more powerful 1st stage may be simpler than building the actual Spaceship. Construction of larger tankage should be pretty straightforward, unless they are going to try the carbon fiber/polymer route. Uprating the performance through substitution of methylox Raptor engines of roughly double the thrust rating of current Merlin engines should essentially double the orbital throw mass, if the current 9 engine octaweb layout is retained. This would essentially be the5-6 meter diameter Falcon X design, slightly modified. It's much simpler concept than the 27 engines and strap-on side booster system for roughly similar performance. Then incorporate a similar side booster layout, and voila, we have a workable BFR system. Just some re-conceptualization. Just some rambling thoughts...

RobertDyck · 2018-02-07 14:07:04

When Dan Goldin was NASA administrator, he said we need a reusable spacecraft. Actually, NASA had worked on it in the late 1960s. The 1968 design for Shuttle was TSTO, fully reusable. It was budget cuts by Richard Nixon, and insistence from a Senator from Utah that Shuttle include SRBs that resulted in the Shuttle we had. The larger problem was major contractors for NASA were military contractors. Military thought of rockets as ammunition, and you don't reuse ammunition. Dan Goldin compared Shuttle to a passenger jumbo-jet; imagine a jet that drops off parts of itself while flying. You could never make such an aircraft affordable. Now SpaceX is making rockets affordable.

However, I think we have a long way to go. Dropping off parts in the ocean, huge ships to recover the parts? There has to be a better way. Apollo splashed down in the ocean, required an entire aircraft carrier battle group to recover. Shuttle landed on a runway at KSC, required essentially a fishing trawler to recover SRBs. SpaceX also uses a fishing trawler to recover Dragon. CST-100 Starliner is supposed to use an air bag so it can land on land. That requires a flatbed truck with a truck crane, instead of a fishing trawler. A major improvement. But Orion will still splash down. X-38 was a lifting body, it had control problems at low speed so used a giant parafoil. It would use skids to land, and the test article was tested that way. Again it would require a flatbed truck with a truck crane. HL-20 was designed to have control problems at trans-sonic speed (mach 1.1 to 0.9), so it could land on a runway like Shuttle. That meant it could land at KSC; no recovery vehicle required. Dream Chaser is based on HL-20, so it too will land on a runway. Dream Chaser will still use a rocket to launch, but it's an improvement.

VentureStar was supposed to be SSTO. It was killed when Lockheed-Martin made a last minute change of the tank from solid wall to hollow wall. Test of the tank showed it disintegrated. Obvious decision was to go back to the original solid wall tank, but no. Lockheed Martin insisted NASA pay for it, despite the fact they signed a contract that said they would share the cost of any overrun. NASA activated that clause, lawyers argued until they killed the project. At one point lawyers (not engineers) argued to use an aluminum alloy tank; not even using the aluminum-lithium alloy of Shuttle's ET, but going back to an alloy from the 1960s. It could never fly with that. It was killed by corporate greed.

Perhaps the next step is TSTO. Here were the Shuttle proposals from 1968/'69. (As with most of my posts, each image is clickable for detail.)

Void · 2018-02-07 14:24:31

I choose to look at this all with hope.

Others will know that if SpaceX can do it, it can be done.

For now SpaceX wants a method that works on multiple types of planets.

However eventually, for Earth and maybe Venus, winged re-usable spacecraft will actually appear.

SpaceNut · 2020-02-21 20:19:08

Space Exploration Technologies Corp., doing business as SpaceX, is a private American aerospace manufacturer and space transportation services company headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the goal of reducing space transportation costs to enable the colonization of Mars. SpaceX has developed the Falcon launch vehicle family and the Dragon spacecraft family.

SpaceX said to be seeking around $250 million in funding, boosting valuation to roughly $36 billion

The value of SpaceX has risen to $33.3 billion, people familiar with the company’s recent fundraising told CNBC. In an amendment of its April fundraising effort, a filing last week from SpaceX showed the company’s latest round brought in $536 million

Dayton3 · 2020-03-05 09:36:54

Personally I'm not sure that reusability is the best and most needed feature for heavy lift launch vehicles. To me reusability only becomes an asset when you're looking at a substantial number of launches and the launch rate for HLLVs will tend to be rather low.

louis · 2020-03-05 14:28:43

Not if Musk's plans come to fruition. Starship will be used for Starlink, major satellite launches, ISS resupply, orbital tourism, lunar tourism and Earth-to-Earth transport (as an alternative to long haul air flights), as well as Mars settlement (which will require 1000 Starships).

Dayton3 wrote:

Personally I'm not sure that reusability is the best and most needed feature for heavy lift launch vehicles. To me reusability only becomes an asset when you're looking at a substantial number of launches and the launch rate for HLLVs will tend to be rather low.

tahanson43206 · 2020-03-05 15:24:25

For Dayton3 re #11, and history of posts going back to 2002

It is intriguing to have someone with such a long history with the forum return to view. I went back to your first posts, and conclude that you have taken sensible positions from the beginning, although they are somewhat on the cautious side, from my perspective.

I then came back to rethink my initial evaluation of Post #11 ...

For Louis ... given the costs of developing a reusable heavy lift vehicle are greater than a throwaway one such as SLS, it would seem that Dayton3 is right, if the reusable heavy lift vehicle flies only once.

Now I recognize this is an unfair comparison, because SLS is not competitive with anything, but it is still true that Falcon Heavy has only flown twice.

Despite only being flown twice, I was interested to learn that all four of the side boosters were recovered and reused.

From the history of Falcon (9 and Heavy) flights on Wikipedia, I learned today that the center core tipped over into the ocean and was lost.

Second flight of Falcon Heavy, the first commercial flight, and the first one using Block 5 boosters. SpaceX successfully landed the side boosters at Landing Zone 1 and LZ2 and reused the side boosters later for the STP-2 mission. The central core landed on drone ship Of Course I Still Love You, located 967 km downrange, the furthest sea landing so far attempted.[424][better source needed] Despite the successful landing, due to rough seas the central core was unable to be secured to the deck for recovery and later tipped overboard in transit.[425][426] SpaceX recovered the fairing from this launch and later reused it in the November 2019 Starlink launch.[427][428] Arabsat-6A, a 6,465 kg Saudi satellite, is the most advanced commercial communications satellite so far built by Lockheed Martin.[429] The Falcon Heavy delivered the Arabsat-6A into a supersynchronous transfer orbit with 90,000 km (56,000 mi) apogee with an inclination of 23 degrees to the equator.[430]

So, given that Falcon Heavy has only flown twice, and SLS has not flown at all, can you (may be too much to ask) compare the two vehicles in response to the observation by Dayton3?

The question to be answered would be: (I think) .... has it proven cheaper to fly the two Falcon Heavies and to recover four boosters, than it would have been to have flown the missions without recovering any of the components.

After all ... funds were expended refurbishing the boosters after their flight, and funds were expended on the unsuccessful landing attempts at sea.

I wonder if the accountants at SpaceX called it a wash?

(th)

SpaceNut · 2020-03-05 17:07:20

If anyone other than the space military companies were making sls it woiuld be a much lower costing rocket but with the number of companies that are marching to the same tune of over pricing or charging for the service its no surprise that sls is so expensive. We actually have a topic for this being so expensive of a rocket. In the same token under valuing the starship is also not a valid condition for comparison as well when you need to look at not just what we are calling a per launch cost billing.

louis · 2020-03-05 17:54:33

I'll grant there's logic in Dayton's comment, but on the narrow assumption that you will develop a reusable rocket to use it only once or twice which - as we all know - is not Space X's plan.

tahanson43206 wrote:

For Dayton3 re #11, and history of posts going back to 2002
It is intriguing to have someone with such a long history with the forum return to view. I went back to your first posts, and conclude that you have taken sensible positions from the beginning, although they are somewhat on the cautious side, from my perspective.
I then came back to rethink my initial evaluation of Post #11 ...
For Louis ... given the costs of developing a reusable heavy lift vehicle are greater than a throwaway one such as SLS, it would seem that Dayton3 is right, if the reusable heavy lift vehicle flies only once.
Now I recognize this is an unfair comparison, because SLS is not competitive with anything, but it is still true that Falcon Heavy has only flown twice.
Despite only being flown twice, I was interested to learn that all four of the side boosters were recovered and reused.
From the history of Falcon (9 and Heavy) flights on Wikipedia, I learned today that the center core tipped over into the ocean and was lost.
Second flight of Falcon Heavy, the first commercial flight, and the first one using Block 5 boosters. SpaceX successfully landed the side boosters at Landing Zone 1 and LZ2 and reused the side boosters later for the STP-2 mission. The central core landed on drone ship Of Course I Still Love You, located 967 km downrange, the furthest sea landing so far attempted.[424][better source needed] Despite the successful landing, due to rough seas the central core was unable to be secured to the deck for recovery and later tipped overboard in transit.[425][426] SpaceX recovered the fairing from this launch and later reused it in the November 2019 Starlink launch.[427][428] Arabsat-6A, a 6,465 kg Saudi satellite, is the most advanced commercial communications satellite so far built by Lockheed Martin.[429] The Falcon Heavy delivered the Arabsat-6A into a supersynchronous transfer orbit with 90,000 km (56,000 mi) apogee with an inclination of 23 degrees to the equator.[430]
So, given that Falcon Heavy has only flown twice, and SLS has not flown at all, can you (may be too much to ask) compare the two vehicles in response to the observation by Dayton3?
The question to be answered would be: (I think) .... has it proven cheaper to fly the two Falcon Heavies and to recover four boosters, than it would have been to have flown the missions without recovering any of the components.
After all ... funds were expended refurbishing the boosters after their flight, and funds were expended on the unsuccessful landing attempts at sea.
I wonder if the accountants at SpaceX called it a wash?
(th)

kbd512 · 2020-03-07 18:05:10

Louis,

How does SpaceX's plan compare to what we know of how orbital or interplanetary reentry affects the reusability and therefore cost of such a vehicle?

Can you name off a single example of a vehicle with a heat shield that survived 3 or more orbital reentries that was re-flown on a subsequent flight without significant refurbishment costs, in terms of labor to inspect the heat shield and to repair it as needed to then make the determination that the heat shield was still certified for another reentry event?

I already know that this has never been done by anyone anywhere in the world on account of what the reentry does to the heat shield, so any speculation on how long a heat shield might last is just that. PICA-X is an ablator technology, which means it's not reusable. It can be replaced as required, and that's exactly what SpaceX does on their Dragon capsules after reentry. Maybe PICA-X is really cheap to make, but I bet the labor to install a new heat shield is not so cheap and I'd be really surprised if it could be done in less than a week. I'm certain that maintaining a small standing army to service the vehicles could get the job done, but that's a major part of what made Space Shuttle so expensive to operate.

Cost-wise, purchasing each Space Shuttle was exactly like purchasing a B-2 stealth bomber. I think SpaceX can reasonably reduce the marginal purchase cost of a Starship to something approximating an airliner, which is still a massive improvement worthy of high praise.

If there isn't such a thing as a heat shield that can withstand 100+ orbital reentries, never mind interplanetary reentries, then how does the cost of the heat shield technology affect the marginal cost of operating the vehicle it's protecting?

GW Johnson · 2020-03-07 21:33:04

PICA-X is good enough to survive about 4 entries from LEO (about the same as interplanetary entry at Mars). It might survive two entries returning from the moon. It will survive only one interplanetary entry returning from Mars. After that, you replace it.

The extreme-low density (fragile) ceramic tiles on the shuttle were billed as surviving 100 entries from LEO, but they never came close to achieving that level of performance. They were never adequate to survive anything faster than LEO entry, the surface temperatures get too high. Aluminosilicates undergo a solid phase transition at only 2250 F, which means they shrink and crack. That's a lot lower than their meltpoint of 3350 F. Physics and materials technology are a bitch, ain't they?

My point is this: (1) there are no known materials capable of 100 LEO entries and no hints on the horizon of any such thing existing, and (2) the only things we have capable of surviving 12-17 km/s entries off of interplanetary trajectories are ablatives (with very limited life).

And that's lateral skins, not nosetips and leading edges. Those are way worse.

GW

kbd512 · 2020-03-08 07:54:15

GW,

Thanks for the info. It would seem as if what we could expect to realistically and reliably achieve is several reentries from LEO, whereupon major heat shield components probably get tossed and replaced. I know the tile-based solution was a special PITA unto itself, but this is starting to sound a lot like a Space Shuttle, only bigger.

Any thoughts on that plasma brake / heat shield that MSNW LLC was working on? That seemed pretty promising.

Well, as heated as this debate is sure to become, I to leave to hop on a decidedly "cooler" (at least in the thermal sense of the word) jet to Penn's Woods. I'll be Bach at the end of the week, and who knows, maybe even Beethoven. I'll ask around to see if any Steelers have the solution to our thermal management problem.

louis · 2020-03-08 08:21:55

I never said "without significant refurbishment costs".

How things will be organised, I don't know. Maybe you can have detachable heat shields. Who knows? That could bring down costs substantially.

But it is certainly Musk's stated aim that the Starship should be able to undertake up to 3 flights per day.

kbd512 wrote:

Louis,
How does SpaceX's plan compare to what we know of how orbital or interplanetary reentry affects the reusability and therefore cost of such a vehicle?
Can you name off a single example of a vehicle with a heat shield that survived 3 or more orbital reentries that was re-flown on a subsequent flight without significant refurbishment costs, in terms of labor to inspect the heat shield and to repair it as needed to then make the determination that the heat shield was still certified for another reentry event?
I already know that this has never been done by anyone anywhere in the world on account of what the reentry does to the heat shield, so any speculation on how long a heat shield might last is just that. PICA-X is an ablator technology, which means it's not reusable. It can be replaced as required, and that's exactly what SpaceX does on their Dragon capsules after reentry. Maybe PICA-X is really cheap to make, but I bet the labor to install a new heat shield is not so cheap and I'd be really surprised if it could be done in less than a week. I'm certain that maintaining a small standing army to service the vehicles could get the job done, but that's a major part of what made Space Shuttle so expensive to operate.
Cost-wise, purchasing each Space Shuttle was exactly like purchasing a B-2 stealth bomber. I think SpaceX can reasonably reduce the marginal purchase cost of a Starship to something approximating an airliner, which is still a massive improvement worthy of high praise.
If there isn't such a thing as a heat shield that can withstand 100+ orbital reentries, never mind interplanetary reentries, then how does the cost of the heat shield technology affect the marginal cost of operating the vehicle it's protecting?

GW Johnson · 2020-03-08 10:30:38

Having been out of circulation for many years, I'm not up on the latest and greatest stuff. I did search out "MSNW LLC plasma brake / heat shield". That kind of thing is outside of my comfort zone, but I did get the impression from the writeup that this thing is at the academic bench-top possible-feasibility stage of development. Promising, but likely a very long way off.

I did post a discussion of the related topics of entry speeds, heat shield materials, and substrate materials over in the Human Missions topic area. I forgot exactly which thread. Tough, strongly-coupled subjects.

The substrate likely serves more than one function, since it most likely sees at least some of the thermal wave percolating inward after the entry heating peak. For low density ceramic shields, the substrate has to absorb all of this wave, it IS the heat sink.

In the case of Spacex's "Starship" design, that substrate serves still another function: it is also the propellant tank wall, and must survive alternating cryogenic and entry heating temperature exposures. The only feasible choice for all of that is a 300-series stainless steel. No carbon-resin composite could ever take the entry heating exposure, even if only part of the thermal wave percolating inward. They're ALL junk at ~200-220 F. Nor could any of the aluminum alloys, they're all "butter" at 350-400 F. Neither is titanium useful, it is junk at about 750-800 F. 300-series stainless still has some strength at 1200 F, some few of the alloys even survive at 1600 F, but are just as weak at 1200 F as the others.

Given the required return to Earth direct from the interplanetary trajectory, I think the current Spacex notion of a heat shield only on the windward side is nonsense. They haven't looked past LEO entry speeds of 8 km/s and Mars arrival entry speeds of 7.5 km/s, yet. Earth return is in the 12-17 km/s range. Even return from the moon is 11 km/s. Out of reach with exposed metal. Even 300-series stainless. There will eventually be heat shielding all around this vehicle, just thinner on the leeward side. If nothing else, that will be the solution after a vehicle is destroyed attempting a lunar-class entry.

And, I have yet to see any hint from Spacex about the fin leading edges, or that nose tip. Those WILL require protection, even from just LEO at 8 km/s. They hit that before they ever reach LEO. It may cost them a vehicle if they don't address it first.

Nor have I seen ANYONE question whether a Coanda-effect jet will form over that nose between the lateral vortices, which will impact all those windows they show on the lee side of the nose. That effect was VERY real on the Space Shuttle. The vulnerability of its cockpit windshield to that effect is why entry AOA was STRICTLY LIMITED to 20 < AOA < 40 degrees. "Starship" is said to enter at AOA ~ 60 degrees. It takes hypersonic wind tunnel testing to find this out. Such as that which I worked on, when a graduate student, for the shuttle. That was now almost half a century ago.

GW

Last edited by GW Johnson (2020-03-08 10:40:02)

RobertDyck · 2020-03-08 12:18:23

MSNW LLC plasma brake / heat shield. Very interesting!
Geek Wire: MSNW’s magnetoshell aerobraking system gets in on NASA’s way-out research fund

NASA: Magnetoshell Aerocapture for Manned Missions and Planetary Deep Space Orbiters

This is by the same company that proposed a Magnetic Parachute. That one was for atmospheric entry; it would provide drag by interacting with plasma generated during the thermal phase of atmospheric entry. Particularly useful to land a large probe on Mars.
New Scientist July 2014: Magnetic bubble may give space probes a soft landing

As GW can explain, you have to do something about ballistic coefficient to land a large payload. The cube-square law means a simple aeroshell is not good enough for anything larger than Curiosity. As the probe increases in size/mass the surface area of the heat shield increases as the square of the radius, but the volume and mass increases as the cube. Which means a larger probe would descend too deeply into the atmosphere before it slowed enough to open a parachute. ADEPT opens like an umbrella to increase surface area; that was included with Mars Direct. HIAD is an inflatable that opens for the same purpose. But the magnetic parachute would use plasma for the same purpose.

Mark Friedenbach · 2020-03-09 10:45:21

You are only considering passively cooled designs. Starship will be using plain stainless steel with active cooling. If it works, it would require very little servicing, not much more than an aircraft (they claim).

GW Johnson wrote:

My point is this: (1) there are no known materials capable of 100 LEO entries and no hints on the horizon of any such thing existing, and (2) the only things we have capable of surviving 12-17 km/s entries off of interplanetary trajectories are ablatives (with very limited life).

Last edited by Mark Friedenbach (2020-03-09 10:49:13)

Spaniard · 2020-03-09 11:37:24

Mark Friedenbach wrote:

You are only considering passively cooled designs. Starship will be using plain stainless steel with active cooling.

I think that the active cooling has been discarted from the first version of the Rocket.

elderflower · 2020-03-10 04:45:26

Have porous materials with coolant transpiration been tried for this kind of application?

GW Johnson · 2020-03-10 11:18:29

This porous-surface evaporative cooling issue has been discussed in "human missions"/"an important article". What was said there applies here. It's exactly the same issue and the same application.

GW

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#1 2018-02-06 20:04:51

Elon Musk: "It's game over for all the other heavy lift rockets"

#2 2018-02-06 21:50:59

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#3 2018-02-06 21:58:29

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#4 2018-02-07 09:04:39

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#5 2018-02-07 11:25:34

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#6 2018-02-07 12:11:58

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#7 2018-02-07 13:43:05

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#8 2018-02-07 14:07:04

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#9 2018-02-07 14:24:31

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#10 2020-02-21 20:19:08

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#11 2020-03-05 09:36:54

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#12 2020-03-05 14:28:43

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#13 2020-03-05 15:24:25

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#14 2020-03-05 17:07:20

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#15 2020-03-05 17:54:33

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#16 2020-03-07 18:05:10

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#17 2020-03-07 21:33:04

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#18 2020-03-08 07:54:15

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#19 2020-03-08 08:21:55

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#20 2020-03-08 10:30:38

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#21 2020-03-08 12:18:23

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#22 2020-03-09 10:45:21

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#23 2020-03-09 11:37:24

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#24 2020-03-10 04:45:26

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

#25 2020-03-10 11:18:29

Re: Elon Musk: "It's game over for all the other heavy lift rockets"

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