Quote from: Lars-J on 09/28/2016 03:44 amQuote from: Lar on 09/28/2016 02:37 amMight be fun for folks to go back and edit their prediction lists to show how they did (me? not that great)I don't know if I ever made real "prediction checkbox list", but I have made several posts with the following predictions that came true: - spacecraft as integrated 2nd stage - biconic/side entry - powered by multiple raptors instead of a single one (although I was off on the count, I expected 5) - no launch abort capsule (abort the whole thing)The booster was roughly what I expected, but bigger and lacking landing gear.To be precise the BFS we were shown is cylindrical with a rounded nose and thick fins that look to hold the landing gear, not bi-conic which would involve the vehicle widening all the way down to the base, the fins can give a false sense that's whats happening but the cut-away is clear the central body is cylindrical.That said both cylindrical and bi-conic were combined on the questionnaire and the entry profile is indeed horizontal which was the more important distinction.
Quote from: Lar on 09/28/2016 02:37 amMight be fun for folks to go back and edit their prediction lists to show how they did (me? not that great)I don't know if I ever made real "prediction checkbox list", but I have made several posts with the following predictions that came true: - spacecraft as integrated 2nd stage - biconic/side entry - powered by multiple raptors instead of a single one (although I was off on the count, I expected 5) - no launch abort capsule (abort the whole thing)The booster was roughly what I expected, but bigger and lacking landing gear.
Might be fun for folks to go back and edit their prediction lists to show how they did (me? not that great)
Really, you of all people nitpicking me on the 'spaceship' predictions? Cylindrical is indeed what all my previously posted MCT drawings showed... Here are two old sketches of a side re-entering cylindrical MCT, pretty close in the end. (other than size, flipping the propellant and crew/cargo, and engine count)
Quote from: Lars-J on 09/28/2016 05:01 amReally, you of all people nitpicking me on the 'spaceship' predictions? Cylindrical is indeed what all my previously posted MCT drawings showed... Here are two old sketches of a side re-entering cylindrical MCT, pretty close in the end. (other than size, flipping the propellant and crew/cargo, and engine count)I've seen some other posts claiming the presented vehicle was bi-conic and wanted to clarify, your perdition was indeed for a cylindrical vehicle which is why I though it odd that you wrote bi-conic and that you might have been misinformed by people throwing that word around.
Also I don't see why 'I' of all people should be considered an invalid source of nitpicking even in jest, I did correctly predict nearly everything about the booster in the face of a strong opposing consensus and while I was wrong about the 2nd stage everyone else was basing their prediction on rumors and L2 information that I don't have access too. And I stick by my opinion that the massive BFS isn't workable and think the design as presented will go the way to the reusable F9 2nd stage.
My one BFR speculation was dead on. Helodriver predicts the future (again) Quote from: Helodriver on 02/25/2016 04:45 amQuote from: Chris_Pi on 02/25/2016 03:17 amA good look at those enormous rainbirds in that photo. Assuming the yellow railing is 4' high, I get a quick-and dirty estimate of the rainbirds at 57'. That seems ridiculously big.Could they be backed off from the rocket far enough that that actually makes sense? Or am I way off on the height?Pure speculation - These are oversized for an F9 family vehicle but are right sized for a larger follow on vehicle. 39A is the eventual BFR launch site.
Quote from: Chris_Pi on 02/25/2016 03:17 amA good look at those enormous rainbirds in that photo. Assuming the yellow railing is 4' high, I get a quick-and dirty estimate of the rainbirds at 57'. That seems ridiculously big.Could they be backed off from the rocket far enough that that actually makes sense? Or am I way off on the height?Pure speculation - These are oversized for an F9 family vehicle but are right sized for a larger follow on vehicle. 39A is the eventual BFR launch site.
A good look at those enormous rainbirds in that photo. Assuming the yellow railing is 4' high, I get a quick-and dirty estimate of the rainbirds at 57'. That seems ridiculously big.Could they be backed off from the rocket far enough that that actually makes sense? Or am I way off on the height?
Those who insisted (pretty strenuously as I recall) on additional stages, 'pusher stages' for LEO departure, aerocapture (at Mars or Earth), early transition to SEP, and especially Mars orbit refueling were pretty much out to lunch.
From interplanetary space, the ship enters the atmosphere, either capturing into orbit or proceeding directly to landing
Quote from: GORDAP on 09/28/2016 11:52 amThose who insisted (pretty strenuously as I recall) on additional stages, 'pusher stages' for LEO departure, aerocapture (at Mars or Earth), early transition to SEP, and especially Mars orbit refueling were pretty much out to lunch.The aerocapture is on the table (see slide 38 of the presentation):QuoteFrom interplanetary space, the ship enters the atmosphere, either capturing into orbit or proceeding directly to landing
Quote from: Helodriver on 09/28/2016 04:22 amMy one BFR speculation was dead on. Helodriver predicts the future (again) Quote from: Helodriver on 02/25/2016 04:45 amQuote from: Chris_Pi on 02/25/2016 03:17 amA good look at those enormous rainbirds in that photo. Assuming the yellow railing is 4' high, I get a quick-and dirty estimate of the rainbirds at 57'. That seems ridiculously big.Could they be backed off from the rocket far enough that that actually makes sense? Or am I way off on the height?Pure speculation - These are oversized for an F9 family vehicle but are right sized for a larger follow on vehicle. 39A is the eventual BFR launch site.Come on. You couldn't even predict that you yourself will be at the Grand Mars Reveal.
Quote from: mme on 06/10/2016 04:56 pmQuote from: starsilk on 06/10/2016 04:02 pma few more teasers before the september reveal:https://www.washingtonpost.com/news/the-switch/wp/2016/06/10/elon-musk-provides-new-details-on-his-mind-blowing-mission-to-mars/1 red dragon in 2018, 'at least 2' in 2020, then first flight of MCT in 2022...Bold mine.From the article:QuoteThen in 2022, Musk said he hoped to launch what the company now sometimes refers to as the Mars Colonial Transporter, designed to bring a colony to Mars.I'm sorry, but this is nuts somewhat optimistic. You all realize that 2022 is only six years away, right? Regardless of the fact that Dragon v2 hasn't flown yet
Quote from: starsilk on 06/10/2016 04:02 pma few more teasers before the september reveal:https://www.washingtonpost.com/news/the-switch/wp/2016/06/10/elon-musk-provides-new-details-on-his-mind-blowing-mission-to-mars/1 red dragon in 2018, 'at least 2' in 2020, then first flight of MCT in 2022...Bold mine.
a few more teasers before the september reveal:https://www.washingtonpost.com/news/the-switch/wp/2016/06/10/elon-musk-provides-new-details-on-his-mind-blowing-mission-to-mars/1 red dragon in 2018, 'at least 2' in 2020, then first flight of MCT in 2022...
Then in 2022, Musk said he hoped to launch what the company now sometimes refers to as the Mars Colonial Transporter, designed to bring a colony to Mars.
, and regardless of the fact that FH hasn't flown yet; NOTHING concrete about BFR/MCT has even been released, and Musk is talking about launching one in six years. Six. Years.
Six years to get BFR off the ground, literally. To build a factory on the scale of Michoud (only bigger) for fabrication and assembly of BFR and MCT. To build a huge HIF to handle the 12.5m or 15m cores, or heck even to lease one of the VAB high bays and get it fitted out for BFR. To build all of the ground support infrastructure and ground transportation.
To get the entire Raptor engine (not just components) off of the drawing board and into the test stands and validated.
Heck, you guys are still arguing over where the thing will be built and launched from. Do you think that would really be the case if they were going to be rolling off the assembly line in less than six years?
Approaching 30 days from what (we hope) is the big reveal, I thought it a good time to revisit and post revised BFR/MCT speculation before any info leaks out. Trying to stay within the parameters of what Musk has said as I best understand. A TSTO vehicle launched by a re-useable, single core BFR that puts the BFS a.k.a. the MCT into LEO where it is re-fueled, travels to and lands on Mars where it is again refueled for the journey back to Earth carrying a quarter of the outbound “cargo” mass. The outbound cargo masses 100 tonnes which I assume means either cargo or people or a combination thereof. BFS/MCT mass not included in the 100T.Correct mission profile. Most here with a few notable exceptions agreed with this, so no great insight.Myriad unknowns led by the dry mass of the BFS. Rocket equation dictates various mass assumptions here can produce wildly different answers.My predictions, metric unless otherwise stated:1. Entire launch vehicle BFR+BFS masses under 5,000T. Guestimate ~4,500T.WAY off!2. BFS dry mass < 100T, my pick is 85T carbon composites BUT heavier than some predictions because ruggedized to allow for minimal maintenance.WAY off3. BFR absolutely > 10m diameter to fit enough engines. Likely between 12.5 and 15m. My guess 15m. Allows addition of more engines in the future.Another miss as I was confident of 12.5m or greater. Not counting 17m flare outs on ITS craft.4. My guestimate BFR+BFS stack <100m height. Certainly <125m.Barely made my "certainly under 125m but missed on 15m. Skinny rocket 12m increased height.5. Sticking with the “over 230T” Raptor thrust Elon mentioned, I get 25-27 engines. My guestimate is 26 with “over 230T” as 235T in my spreadsheet. Around 13.5 million Lbs force.Engine # most likely wrong because…I was right that I was wrong 6. Predict that Raptor engine design goal thrust changed to higher than 230T previously stated, but only by several 10s of tonnes, not hundreds.Hit! I was confident that more detailed design would increase Raptor SL thrust by several 10s of tonnes. It helped that Bezos BE-4 thrust was higher than Elon's earlier 230T for Raptor. That shall not stand! 7. BFS with 5 Rvac enginesClose but no cigar.8. RTLS minimizes cost, turnaround time, effort. Changed my opinion from max payload ASDS for those reasons. Just make the BFR bigger. Stages low and slow ~2.2 Km/sec. “Easy” recovery & re-flight vs F9 GTO flights.Hit!9. Initial BFR test flights likely equipped with less engines and less payload.Unknown10. Large crew volume design >2,000m3. Initial flights with less people & people space but more cargo space.I believe crew volume is ~3,000 m3 so this is a hit. Felt that nuclear sub range 20 something m3 was the goal. Never agreed with those in the 10m3 and under range. You know who you are.11. Initial crewed Mars mission will carry 6-12 people. 10 is my latest #. Why? NASA & other nations will buy seats. http://forum.nasaspaceflight.com/index.php?topic=40683.msg1557261#msg1557261Unknown12. SEP still under development awaits later opposition cargo transits Scoring as a miss in that not mentioned13. BFS will have “exotic” upper mounted engines for rough terrain Mars landing &takeoff (just echoing others’ analysis here)Big miss. I am concerned about SX's approach here.14. BFS will be a lifting body for EDL, but not a scaled up Dragon capsule shape. It will look badass.HIT!You know we’re totally screwed trying to predict Musk because he already warned us, “When it looks more like an alien dreadnought, that’s when you know you’ve won.”I’ve attached a spreadsheet showing different assumptions, BFS mass, etc.Anyone else want to update their speculations?
Quote from: GORDAP on 09/12/2016 06:32 pm1) Overall Launch Architecture a) MCT is composed simply of a BFR 1st stage and BFS 2nd stage/spacecraft b) Boost phase consists of 2 stages, which put the BFS into orbit c) Other: 3rd stage, 'half' stages, drop tanks, etc.Going with (a)Hit2) Number of Raptor Engines on BFR (1st stage)< 30, my best estimate is 25-27 if thrust stays close to 230 tonnes rangeMiss3) Diameter of BFR (1st stage)Range 12.5m-15m, best estimate 15m 1st stageMiss4) Total Raptor 1st stage thrust (sl)60 Meganewtons and T/W > 1.3Miss5) LAS Architecture a) No LAS - BFS is the escape mechanism b) Traditional LAS - above BFS and is nominally jettisoned during launch phase c) BFS contains smaller 'ejection pod' where humans reside during launch d) Other, non-traditional LAS designBest guess is (a)HIT!!!6) Shape and Landing Mode of BFS a) Capsule (perhaps elongated), w/ TPS on base b) Cylindrical or biconic - horizontal landing c) Cylindrical or biconic - vertical landing d) OtherGoing with (c), definitely no horizontal landingHIT!!!7) Mars and Earth return a) BFS does direct entry into Mars and Earth atmosphere b) BFS does orbital capture before performing entry burn and landing c) Same as b, but upon Earth return, stays in orbit for next synod(a)HIT Use of non-chemical thrust a) Not part of the plan b) Will use SEP for some/all of the big transits c) All chemical for now, but plans to incorporate SEP down the road(c) strongly favora seems more correctCan anyone think of more/better questions?Predict Musk will miss 1st crewed landing by >= 3 synodsUNKNOWN but too easy5-6 Rvacs on BFS stage 2HIT sort of. Missed on R SL engines. frakked at self for not seeing that.Raptor sea level will have 10s of tonnes thrust more than the 230 tonnes mentioned by ElonHIT!!!Entire BFR/BFS GLOW masses under 5.000 tonnes; my estimate ~4,500BIG miss!Height of BFR/BFS stack under 120m; my estimate <100mMISSCargo version, tanker version, crewed version of BFSHIT1st crewed landing on Mars 8-12 humans plannedUNKNOWNJust over 48 hours until Musk makes fools of usGot that right!
1) Overall Launch Architecture a) MCT is composed simply of a BFR 1st stage and BFS 2nd stage/spacecraft b) Boost phase consists of 2 stages, which put the BFS into orbit c) Other: 3rd stage, 'half' stages, drop tanks, etc.Going with (a)Hit2) Number of Raptor Engines on BFR (1st stage)< 30, my best estimate is 25-27 if thrust stays close to 230 tonnes rangeMiss3) Diameter of BFR (1st stage)Range 12.5m-15m, best estimate 15m 1st stageMiss4) Total Raptor 1st stage thrust (sl)60 Meganewtons and T/W > 1.3Miss5) LAS Architecture a) No LAS - BFS is the escape mechanism b) Traditional LAS - above BFS and is nominally jettisoned during launch phase c) BFS contains smaller 'ejection pod' where humans reside during launch d) Other, non-traditional LAS designBest guess is (a)HIT!!!6) Shape and Landing Mode of BFS a) Capsule (perhaps elongated), w/ TPS on base b) Cylindrical or biconic - horizontal landing c) Cylindrical or biconic - vertical landing d) OtherGoing with (c), definitely no horizontal landingHIT!!!7) Mars and Earth return a) BFS does direct entry into Mars and Earth atmosphere b) BFS does orbital capture before performing entry burn and landing c) Same as b, but upon Earth return, stays in orbit for next synod(a)HIT Use of non-chemical thrust a) Not part of the plan b) Will use SEP for some/all of the big transits c) All chemical for now, but plans to incorporate SEP down the road(c) strongly favora seems more correctCan anyone think of more/better questions?
everyone else was basing their prediction on rumors and L2 information that I don't have access too.
Yes, I meant cylindrical. Although the three "fins" do alter the shape slightly, so I wonder if they have seen some aerodynamic benefit of stretching them so far forward.
Although I never came out and specifically said so, I've favoured what I called a "semi-lifting body", that is something that gets some lift from its body shape and maybe has small fins but is not a traditional lifting body shape.It looks like the Ship qualifies as a semi-lifting body.
I underestimated the Tanker fuel load so expected 5-8 Tanker flights to refuel the Ship.