NASA's Asteroid redirect/retrieval mission; should it be cancelled?

Oldfart1939 · 2017-01-29 00:36:36

So...for $400 Million we get approximately 15% more performance than a Falcon Heavy for 4X the price? Not to mention all the re-engineering required to make it recoverable?

GW Johnson · 2017-01-29 13:09:16

I doubt there will ever be a market for SLS as it's too colossally expensive. But there will be the occasional use. So it will be around for 1 or 2 shots a year for several years. All as a government-funded item.

I simply do not see any practical way to make much of SLS reusable, since it wasn't designed from the beginning for that. Making stages recoverable is just not something you can add-on later. It has to be there from the beginning of the design.

I suppose the SRB's could be made recoverable the way the shuttle SRB's were, except that they sometimes really weren't fully recoverable. Parachute landings of shuttle SRB's in the ocean bent a lot of steel, rendering it not reusable. 5 segments being bigger than 4 segments, the fragility and potential for damage is higher.

As for the asteroid redirect mission, I suppose one has to start somewhere, but this isn't much in the way of payoff for the expense of doing it. This has devolved into something SLS/Orion really can do, since it is not capable of voyages over 2 weeks long (voyages to NEO's are years long, like Mars), and has not the delta-vee or the lander to return to the moon's surface.

GW

Last edited by GW Johnson (2017-01-29 13:14:19)

Oldfart1939 · 2017-01-29 15:25:27

Once again, the word "Boondoggle" leaps to mind. We are building--at taxpayer expense--a giant rocket without a defined mission. These vehicles are not a "one size fits all" item, and what's happened here is it fits none of the missions of manned spacefaring requirements.

This is a direct consequence of the Obama WH cancelling the Bush WH Constellation, and a reluctant Congress with constituents screaming about the jobs and revenue "lost," insisting on keeping something for the money wasted.

SpaceNut · 2017-01-29 19:26:28

The engine work was all done under constellation, with the current srb design nothing like what was used on shuttle as it had to be modified for the new tank plus for the new 5 segment length, which was all based on the larger fuel tank of 10 m width....
As far as legs it did not tank space x hardly any time to add them to the expendable rockets design....the landing legs for this rockets design would need to be a bit more on the beefy side but if it gets 10 m chunks to LEO why not...
The next level of sls was to be able to loft to LEO a payload that would be 100 or 130 mt ton from what I remember...
So getting a BFR to loft these chunks at a lower cost sure would seem to be for the benifit of nasa at least for mars....

We talked about engine pods and many other such ways to move constellation forward over the years following 2004 through to the newmars great crash in 2008 so all of the information is still here....

Oldfart1939 · 2017-01-29 22:12:39

SpaceNut-

If ULA could add a landing system, it would become a lot more reasonable for ongoing development of the SLS. The legs aren't the only mod needed, however; reentry steering fins, along with a thruster system are also necessary.

RobertDyck · 2017-01-29 22:43:53

I wouldn't even try to make SLS reusable. Too many changes required. Instead that's our BFR. The issue is Congress didn't want to waste the time and money put into Ares V, so revived it as SLS. But ULA has treated SLS as if they're starting from scratch, ignoring all the work done on Ares V. By the time SLS launches for the first time, more time and money will have been put into it than development of Saturn V. And that doesn't include any of the time or money put into Ares V.

We need a rocket the size of SLS. But we need someone who can start knocking some heads at ULA. After all, the ULA executives and managers are the same ones that drove the cost of Shuttle up so much that Shuttle had to be cancelled. Could Trump supports in the Mars Society convince Trump to be that person? To knock some heads at ULA?

Oldfart1939 · 2017-01-29 22:48:55

Robert-

I agree completely, but we cannot ever figure out the politicians and what they'll do with the SLS.

elderflower · 2017-01-30 03:36:30

The politicians - most of them- will first do what the big party donors want, then what delivers pork from the barrel for their constituents.
Its the same over here.

Oldfart1939 · 2017-01-30 09:30:34

President Trump seems to have Lockheed-Martin reeling in retreat from the $379 Million per copy price on the F-35, and a new negotiated price more like $600 Million less on an order for 90 aircraft. He needs to get involved in the SLS program before it destroys NASA politically.

Last edited by Oldfart1939 (2017-01-30 13:03:10)

SpaceNut · 2017-01-30 19:27:38

The larger upper stage has made it through the preliminary review on its way to being reality...

SLS Exploration Upper Stage Completes Preliminary Design Review

Slow progress but what do we expect from pork.....

Starting with that first crewed flight of SLS and NASA's Orion spacecraft in 2021, future configurations of SLS will include the larger exploration upper stage and use four RL10C-3 engines. The EUS will replace the interim cryogenic propulsion stage that will be used on the initial configuration of SLS for the first, uncrewed flight with Orion. The EUS will use an 8.4-meter diameter liquid hydrogen tank and a 5.5-meter diameter liquid oxygen tank.

kbd512 · 2017-01-31 14:28:46

Does this mean that in another decade or so, we might have a human flight-rated upper stage for SLS?

SpaceNut · 2017-01-31 18:50:24

Oldfart1939 wrote:

SpaceNut-
If ULA could add a landing system, it would become a lot more reasonable for ongoing development of the SLS. The legs aren't the only mod needed, however; reentry steering fins, along with a thruster system are also necessary.

Very true an I look to how fast they were added to the Falcon as what could be done for a time frame. All the other engines such as the RS68A or B which are cheaper could be used for cargo units saving the man rated RS25 for human flights...You could still run 2 flights of each in a year and get some big bang for the buck....

kbd512 · 2017-02-01 14:17:17

After reviewing the projected development/fabrication/assembly costs associated with the upper stage, there's no way SLS will deliver 100t+ to orbit for less than half a billion dollars. I would go so far as to say that the purpose of the Ares / SLS program is to make the new rocket every bit as unaffordable as the STS program was.

There is no practical way to make SLS a cost-effective launch vehicle and any attempt to do so will only increase development costs, lengthen the timeline required to complete development work, and further detract from all the other programs required for long duration human space flight.

Perhaps if NASA's favorite contractors work at it a little, they can ensure that the development cycle for SLS (2011-Present) is longer than the length of time that the Saturn V program (1964-1973) existed. Three years after the Saturn V program was initiated, the first rocket left the pad. Six years into SLS development, we still don't have a flight test article ready for launch and the first flight test article won't fly until 2018 at the earliest. SLS will be in development longer (2011-2021) than Saturn V was a program of record before the first human flies aboard SLS.

RobertDyck · 2017-02-01 15:05:18

kbd512 wrote:

Three years after the Saturn V program was initiated, the first rocket left the pad.

On January 10, 1962, NASA announced plans to build the C-5. April 6, 1968, Apollo 6 launched, the first unmanned test launch of Saturn V. That's 6 years, 2 months, and 27 days.

However, SLS was announced at a joint NASA-Senate presentation on 14 September 2011. If the first launch is November 2017, that will be 6 years, 2 months, and an unknown number of days. So longer than Saturn V, even without counting time and money spent on Ares V.

Oldfart1939 · 2017-02-01 15:15:42

NASA really needs to begin designing missions, and then put out requests for bids; they really need to get out of the Deep Space hardware business. Build into these requests a hard time line for completion, too.

GW Johnson · 2017-02-01 18:39:09

Look, the SLS was designed from the outset to be expendable. There are no structural locations in its first stage to mount things like landing legs, steering fins, and attitude thrusters, plus, the engines are NOT designed to be restarted in vacuum. That restart capability would require some sort of ignition torch mounted directly to the engine.

The most likely torches would be liquid injection of TEB or TEB/TEA blends, and at feed pressures well above those of a lit chamber. You WILL NOT light this thing in vacuum at the exit plane the way they do on the pad. Those liquids require an inerted high-pressure storage tank, super high pressure gaseous pressurant, feed and command controls, and the means to safely load (and unload) intensely-pyrophoric and dangerous-to-handle fluids.

EVERY SINGLE ONE of those things I mentioned is an increase in the inert weight fraction of the stage! Including providing the extra structural beef to mount the other items! The net effect is that inherently reduces practical payload fraction for the vehicle overall. SIGNIFICANTLY.

I think you can safely forget the notion of a reusable variant of the SLS. Just how many more 100's of billions of dollars do you want to spend on this boondoggle?

Sorry to bust bubbles here, but reusability MUST be designed-in from the outset. The Falcon family had some sort of landing legs, vacuum igniters, and attitude thrusters designed-in from the outset, even if those features were missing from the initial flight vehicles.

The things that got added after-the-fact were the grid fins for extra steering, and the extra hydraulic fluid to power them for long enough. Remember: multiple failures before they finally succeeded in landing one.

GW

Last edited by GW Johnson (2017-02-01 18:43:03)

Oldfart1939 · 2017-02-01 18:52:58

GW-

Check my post # 28 for the nomenclature for the SLS. For the amount of money thrown at the SLS, NASA could have paid SpaceX to do a Apollo 8 Redux AND an Apollo 11 Redux. I for one, have little interest in repeating the Moon, a far scientifically less interesting place than Mars.

GW Johnson · 2017-02-02 10:10:45

Hi Oldfart1939:

Actually, I quite agree with you. The money spent on the SLS/Orion boondoggle (in all its incarnations) could have served us better.

Remember it was mandated upon NASA by congress (ever since the presidential decision to retire the shuttle) as "pork" to maintain constituents' jobs in the states where shuttle items were built. The type of folks who typically serve in congress (there are precious few exceptions) are not known for technical competence, sometimes not even common sense.

What I was trying to address was the oft-expressed hope in these forums that SLS could be made more affordable by being modified to be reusable. It cannot. You'd have better luck modifying a 747 to fly under water.

The SLS will be around for a while. We might as well use it occasionally when there are really big things to launch. That's what the one-a-year projected launch rate is really all about. But the only outfit who will step up to the bar and pay that price will be the government. No commercial outfit in their right mind would ever propose anything that big to launch, because of the cost.

Orbital assembly from smaller chunks launched by commercial launchers is just far, far cheaper, even for the same final assembled weight. The savings with commercial launchers is so big you can afford to hire a crew and launch them to do your orbital assembly, and still save money.

What the giant rocket buys you is direct launch to Mars (or elsewhere). Except that we don't really do it that way, except with some relatively-tiny unmanned probes. For big stuff, we have always stopped in LEO, and made the precisely-timed departure burn from orbit (Apollo-to-the-moon).

If you do that, then there is simply no reason to launch it all into orbit all in one chunk. Might as well do orbital assembly. If the mission requires a 450 ton space vehicle (for whatever reason), it can built from 30 15-ton chunks docked together at today's $5.5M/metric ton (with Atlas 5 and Falcon-9) for $2.5B in launch costs.

If instead you build it out of 5 90-ton chunks launched with SLS at NASA's price of $0.5B/launch, you will also pay $2.5B in launch costs. If you believe NASA's price estimates. If instead you believe their critics, the total launch cost bill is closer to $5B, or maybe more. Which is more real, today's prices, or a future estimate made by a government agency infamous for underestimating costs?

On the other hand, Falcon-Heavy is a future estimate that is nearer-term than SLS. That same 450 ton "something" could be docked together out of 9 50-ton chunks using -Heavy, for a listed price of $90M per shot. Now the total launch cost is just under $1B! Size makes a difference, yes, but only if the launch system is designed by commercial entities, competing in a market where costs matter.

All of the above assumes the Spacex vehicles are flown fully expendable! Total launch price may or may not reduce if we do more launches with slightly-smaller chunks in order to re-use stages. Whether that promise actually pans out remains to be seen. Note that I did NOT count on it with my launch cost analysis above!

GW

Last edited by GW Johnson (2017-02-02 10:15:14)

SpaceNut · 2017-02-02 19:11:24

http://space.skyrocket.de/doc_lau_fam/falcon-9.htm
look closely at images no attachment points in the original version or fins so it can not be that hard to develope....

RobertDyck · 2017-02-02 19:45:45

I found this image:

Falcon 1
Falcon 9 v1.0: Dragon v1, cargo, proposed Heavy
Falcon 9 v1.1: Dragon v1, cargo, proposed Heavy (note side boosters taller than core)
Falcon 9 v1.2 aka Full Thrust: Dragon v1, Dragon v2, cargo, proposed Heavy (note core same as side boosters)

Engine mounting was also significantly different: (v1.0 left, v1.1 with "octaweb" right)

I think it's fair to say Falcon 9 required significant redesign to be reusable. The changes from v1.0 to v1.1 were dramatic.

GW Johnson · 2017-02-03 10:59:43

The original Falcon-9's tankage and aft structure was designed from the beginning to take landing loads from a set of legs to be installed later. They went to the octaweb to make room for a better leg design than the one they started with.

But the internal "hard point" structures were always there, they just don't show on the outside , and they still don't! Appearances are deceiving. Only the presence or absence of legs shows on the outside.

In contrast, the SLS first stage lacks those internal "hard point" features to support landing leg forces, because it was not designed with that requirement imposed.

You'd have to start over on your tankage internal structural design and your buried-in-the-bottom-end engine-mounting structures, because that's where those "hard point" features are. Which means you design a new first stage from scratch!

That's just the ugly little engineering facts of life. Which almost never show in external pictures.

GW

SpaceNut · 2017-02-03 17:42:32

I still say engineering 101 for making a new tank that gives the correct structural support for reuse...and it should not take a decade to do so.....

Oldfart1939 · 2017-02-03 17:59:16

It simply makes more sense to "expend' the SLS and simply discontinue the further production. Get whatever we can from the existing hardware, but don't throw any additional money at it.

SpaceNut · 2017-02-03 18:04:29

There is truely no hardware to be worried about that has been built as they are still building the first prototype with left over RS25 engines that have been upgraded, the SRB all have been upgraded as well... There probably is only 1 or 2 finished fuel tank, a partially designed prototype upper stage and most likely not more than 3 capsules in build stages.....

SpaceNut · 2021-11-22 08:54:26

kbd512 wrote:

This is the initial technology set that would need to be developed, in order for metals to be mined from Near-Earth Objects:
Robotic Asteroid Prospector (RAP)

nasa was to bring a large bolder to the moon as the experiment into moving a large object but to give people a means to explore it close up.

I believe this is not on the plate anymore with the gateway coming into being for the SLS instead to make use of.

Instead the DART program of slamming into one is...

https://www.nasa.gov/content/what-is-na … ct-mission

New Mars Forums

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#26 2017-01-29 00:36:36

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#27 2017-01-29 13:09:16

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#28 2017-01-29 15:25:27

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#29 2017-01-29 19:26:28

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#30 2017-01-29 22:12:39

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#31 2017-01-29 22:43:53

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#32 2017-01-29 22:48:55

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#33 2017-01-30 03:36:30

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#34 2017-01-30 09:30:34

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#35 2017-01-30 19:27:38

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#36 2017-01-31 14:28:46

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#37 2017-01-31 18:50:24

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#38 2017-02-01 14:17:17

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#39 2017-02-01 15:05:18

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#40 2017-02-01 15:15:42

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#41 2017-02-01 18:39:09

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#42 2017-02-01 18:52:58

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#43 2017-02-02 10:10:45

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#44 2017-02-02 19:11:24

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#45 2017-02-02 19:45:45

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#46 2017-02-03 10:59:43

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#47 2017-02-03 17:42:32

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#48 2017-02-03 17:59:16

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#49 2017-02-03 18:04:29

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

#50 2021-11-22 08:54:26

Re: NASA's Asteroid redirect/retrieval mission; should it be cancelled?

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