Author Topic: Raptor Upper Stage consolidated thread  (Read 123940 times)

Offline gospacex

  • Senior Member
  • *****
  • Posts: 3024
  • Liked: 543
  • Likes Given: 604
Re: Raptor Upper Stage consolidated thread
« Reply #320 on: 06/28/2017 01:58 pm »
Need for bigger payloads? Nah, not enough payloads to make it pay.

Sure about that? Just one DIVH launch costs $400m, and that is "merely" for 29ton to LEO.
You can ask for a lot more $$$ when you are the only rocket with capability.

Offline RoboGoofers

  • Full Member
  • ****
  • Posts: 1005
  • NJ
  • Liked: 869
  • Likes Given: 977
Re: Raptor Upper Stage consolidated thread
« Reply #321 on: 06/28/2017 02:08 pm »
If the stage is reusable, it could land on Mars if it is refueled in orbit with enough fuel to get there and land.  A reusable stage would have a deep throttling Raptor to land back on earth, so it could land on Mars.   Again, pre testing ITS equipment on a smaller scale.   

The Kerolox upper stage doesn't have the ISP for deep space work and fuel is heavier.  Raptor is going to be able to deep throttle, Merlin can't.

This idea is way beyond the scope of the original proposed idea, a stopgap minimal RUS to replace the Merlin US until ITS.

Go here, as envy887 sugested:
https://forum.nasaspaceflight.com/index.php?topic=43219.0
« Last Edit: 06/28/2017 02:12 pm by RoboGoofers »

Offline meekGee

  • Senior Member
  • *****
  • Posts: 14152
  • N. California
  • Liked: 14030
  • Likes Given: 1391
Re: Raptor Upper Stage consolidated thread
« Reply #322 on: 06/28/2017 02:16 pm »
RUS remains speculative even after that interview, but nobody is claiming otherwise.

The debate is whether it's a good idea, irrespective of what SpaceX eventually decides to do.
ABCD - Always Be Counting Down

Offline envy887

  • Senior Member
  • *****
  • Posts: 8142
  • Liked: 6799
  • Likes Given: 2963
Re: Raptor Upper Stage consolidated thread
« Reply #323 on: 06/28/2017 03:24 pm »
If the stage is reusable, it could land on Mars if it is refueled in orbit with enough fuel to get there and land.  A reusable stage would have a deep throttling Raptor to land back on earth, so it could land on Mars.   Again, pre testing ITS equipment on a smaller scale.   

The Kerolox upper stage doesn't have the ISP for deep space work and fuel is heavier.  Raptor is going to be able to deep throttle, Merlin can't.

The problem is not landing but entry.

The current stage (or a Raptor stage operating on the same principles) can't be modified to land on Mars with cargo, as it doesn't have a cargo area protected by TPS and it cannot generate enough lift to do Mars EDL. Even if they put a heatshield on the front, it will go splat.

If they modify it enough to do a lifting entry and have a TPS protected cargo bay, it's basically a mini-BFS.

Offline Rummy

  • Full Member
  • *
  • Posts: 126
  • CA
  • Liked: 24
  • Likes Given: 20
Re: Raptor Upper Stage consolidated thread
« Reply #324 on: 06/30/2017 07:20 pm »
One reason against RUS that I haven't seen mentioned (apologies if I missed it) is the impact on focus. SpaceX is not a small company anymore, but I'm sure they are resource constrained when it comes to major design efforts. Putting the A team on RUS means they can't work BFR. I wouldn't underestimate the impact of this constraint.

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: Raptor Upper Stage consolidated thread
« Reply #325 on: 06/30/2017 07:27 pm »
Yeah.  Can we be released from this single thread now that the Raptor on F9 is no longer speculative?

No, I feel this is working well... and I bet my post gets more likes than yours :) (not that likes mean anything)
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline Rummy

  • Full Member
  • *
  • Posts: 126
  • CA
  • Liked: 24
  • Likes Given: 20
Re: Raptor Upper Stage consolidated thread
« Reply #326 on: 06/30/2017 07:29 pm »
Although I agree with Jim wrt the likelihood of seeing a RUS on a Falcon, I strongly object to his characterization of the USAF contract as a dead end. That misses the point of early development contracts. An effort that ends up as non-viable but assists an adjacent technology should not be called a dead end. Perhaps a forking road and a cul-de-sac?

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37439
  • Cape Canaveral Spaceport
  • Liked: 21448
  • Likes Given: 428
Re: Raptor Upper Stage consolidated thread
« Reply #327 on: 06/30/2017 07:33 pm »
It is a dead end, the USAF was never going to take it to full development

Offline Joris

  • Full Member
  • ***
  • Posts: 372
  • Liked: 24
  • Likes Given: 3
Re: Raptor Upper Stage consolidated thread
« Reply #328 on: 06/30/2017 08:33 pm »
It is a dead end, the USAF was never going to take it to full development

Because they have a rocket that does what they need and the only improvement is reliability I assume?
JIMO would have been the first proper spaceship.

Offline spacenut

  • Senior Member
  • *****
  • Posts: 5180
  • East Alabama
  • Liked: 2587
  • Likes Given: 2895
Re: Raptor Upper Stage consolidated thread
« Reply #329 on: 07/01/2017 12:17 am »
Unless the Air Force wanted a Raptor upper stage to improve F9 for GSO satellites.  Or FH.  Even if a Raptor upper state is expendable, it would still be cheaper than Delta IV heavy for big birds, and F9 may be able to launch them without FH. 

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37439
  • Cape Canaveral Spaceport
  • Liked: 21448
  • Likes Given: 428
Re: Raptor Upper Stage consolidated thread
« Reply #330 on: 07/01/2017 02:33 am »
Unless the Air Force wanted a Raptor upper stage to improve F9 for GSO satellites.  Or FH.  Even if a Raptor upper state is expendable, it would still be cheaper than Delta IV heavy for big birds, and F9 may be able to launch them without FH.

Just stop.  They don't

Offline philw1776

  • Full Member
  • ****
  • Posts: 1836
  • Seacoast NH
  • Liked: 1842
  • Likes Given: 981
Re: Raptor Upper Stage consolidated thread
« Reply #331 on: 07/01/2017 03:32 pm »
This article...

http://spacenews.com/blue-origin-retains-engine-lead-as-house-considers-limitations-on-launch-system-funding/

confirms that the AF cannot pay SpaceX to develop a raptor upper stage for F9 or FH.

"a specific prohibition against funding “the development of new launch vehicles under such program.” It also specifically defines a “rocket propulsion system” that can be funded as a first-stage rocket engine or motor. “The term does not include a launch vehicle, an upper stage, a strap-on motor, or related infrastructure,”
FULL SEND!!!!

Offline Nathan2go

  • Full Member
  • **
  • Posts: 227
  • United States
  • Liked: 112
  • Likes Given: 60
Re: Raptor Upper Stage consolidated thread
« Reply #332 on: 07/01/2017 08:48 pm »
...  F9 doesn't seem to need a new US. I am only a layman, but it seems that FH might need a better US. Not adding that for F9 means LC-40 has no need, only SLC-39 would need the mod....

Something that I saw asked at least twice, can the current US get stretched to about 2x the current F9 config?  FH may need something with more push...

Yes, I think the FH needs a heavier upper stage, because the payload capability with 3-core reuse is too low, probably only 8 tons to GTO.  Which is less than Ariane V at 10t, and Delt 4H at 13t.

Quote from: Spacenut
A 5.2m upper stage is the same diameter as the fairing, ...
While going to a 5.2m diameter would be the most aesthetically pleasing way to add more propellant, I suspect that 3.4m would be structurally doable, and much less problematic (i.e. road transportable, factory tooling, etc).  It would mean strengthening the core stage and interstage (which they are doing).  Perhaps 3x the tank volume is going too far, but a 50-100% stretch would still be helpful.


[Raptor US] ... it just doesn't seem to have any real reason for existence. Test bed for Raptor? Nah. Not needed. Makes the stage reusable? Nah, too expensive to implement and would never make the cash back.
SpaceX does not have $10B to develop ITS.  Demonstrating S2 reuse on a Falcon family rocket, and flying Raptor are both extremely valuable ways to help persuade the general public that ITS might be doable.  This will help bring in other people's money (whether thru governments or private investment).  It will serve to make SLS look obsolete, and will generate pressure for NASA to modernize their thinking (e.g. maybe help fund private companies to build SLS replacement, to duplicate the space station commercial cargo COTS program).

But S2 reuse is a different question than engine-swap/tank-stretch.   As a business, it really depends on finding sufficient LEO payloads, since reuse for GTO will be much harder (will likely require on-orbit refueling).  Perhaps the SpaceX LEO sat constellation will happen, and be a driver for S2 reuse.
« Last Edit: 07/01/2017 08:57 pm by Nathan2go »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25223
  • Likes Given: 12114
Re: Raptor Upper Stage consolidated thread
« Reply #333 on: 07/01/2017 09:13 pm »
But SpaceX does have access to some money to build a smaller ITS. That is a more logical approach. Jim is probably right.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline gospacex

  • Senior Member
  • *****
  • Posts: 3024
  • Liked: 543
  • Likes Given: 604
Re: Raptor Upper Stage consolidated thread
« Reply #334 on: 07/02/2017 12:49 am »
Quote from: Spacenut
A 5.2m upper stage is the same diameter as the fairing, ...
While going to a 5.2m diameter would be the most aesthetically pleasing way to add more propellant, I suspect that 3.4m would be structurally doable, and much less problematic (i.e. road transportable, factory tooling, etc).

SpaceX wants to start building wider rockets anyway. Ergo, it will need a new factory with new tooling and with access for waterway transportation, regardless of RUS materializing or not.

Offline MATTBLAK

  • Elite Veteran & 'J.A.F.A'
  • Senior Member
  • *****
  • Posts: 5362
  • 'Space Cadets' Let us; UNITE!! (crickets chirping)
  • New Zealand
  • Liked: 2238
  • Likes Given: 3883
Re: Raptor Upper Stage consolidated thread
« Reply #335 on: 07/02/2017 01:41 am »
What if Elon leased part of Michoud for 20 years or so? And the associated barges etc. Must be plenty of room in there even with the SLS activities. And if SLS gets canned - Elon might look like a prescient hero; saving jobs and infrastructure etc.

Or how feasible would it be to establish factory facilities eventually at Mcgregor, Texas?
"Those who can't, Blog".   'Space Cadets' of the World - Let us UNITE!! (crickets chirping)

Offline envy887

  • Senior Member
  • *****
  • Posts: 8142
  • Liked: 6799
  • Likes Given: 2963
Re: Raptor Upper Stage consolidated thread
« Reply #336 on: 07/02/2017 02:20 am »
What if Elon leased part of Michoud for 20 years or so? And the associated barges etc. Must be plenty of room in there even with the SLS activities. And if SLS gets canned - Elon might look like a prescient hero; saving jobs and infrastructure etc.

Or how feasible would it be to establish factory facilities eventually at Mcgregor, Texas?
Even Hawthorne is better than McGregor for building large rocket stages. Much closer to barge transport.

Iirc Elon did say they looked at Michoud though.

Offline alang

  • Full Member
  • ****
  • Posts: 404
  • Liked: 213
  • Likes Given: 7
Re: Raptor Upper Stage consolidated thread
« Reply #337 on: 07/02/2017 02:31 pm »
But SpaceX does have access to some money to build a smaller ITS. That is a more logical approach. Jim is probably right.

If Mr Musk makes a lot of money from his other business interests then the game will be very different as I am confident he would spend it on rockets.
This coming year will therefore be very important for SpaceX but in ways we're not allowed to discuss on this site.
If it all goes wrong for him financially elsewhere then some of these dreams could come to nothing.
Most likely outcome is moderate success and slow implementation of a Mars architecture, but it could be a lot better or a lot worse.
« Last Edit: 07/02/2017 02:34 pm by alang »

Offline spacenut

  • Senior Member
  • *****
  • Posts: 5180
  • East Alabama
  • Liked: 2587
  • Likes Given: 2895
Re: Raptor Upper Stage consolidated thread
« Reply #338 on: 07/02/2017 07:28 pm »
Raptor upper stage could very well be a dead end.  Remember NASA developed the J2X and shelved it.  They also shelved the RL-60.  They spent a lot of time trying to figure out how to make SSME air startable for Aries I.  They also used the J2 turbopump system and developed a plug nozzle engine that was tested but never used.  They developed a NERVA nuclear engine and tested it, but never used it in space. 

SpaceX did use the money wisely and developed the sub scale Raptor.  SpaceX also used money to help develop the F9 and the Dragon.  Others who got money never made it as far as SpaceX has come. 
« Last Edit: 07/02/2017 07:30 pm by spacenut »

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39270
  • Minnesota
  • Liked: 25223
  • Likes Given: 12114
Re: Raptor Upper Stage consolidated thread
« Reply #339 on: 07/02/2017 08:07 pm »
I don't know that SpaceX has done really any work on a Raptor upperstage other than like an afternoon's worth of graphics for a PowerPoint somewhere. Raptor, though? Absolutely. They've definitely invested in that, and continue to. Not at all a dead end.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0