Quote from: smoliarm on 08/31/2013 06:59 pmSaturn 1B = 1,600,000 lbfF9 V1.1 = 1,100,000 lbf1,100,000 lbf is for F9v1.0.
Saturn 1B = 1,600,000 lbfF9 V1.1 = 1,100,000 lbf
Quote from: JBF on 08/31/2013 03:08 pmThere has to be an RCS since they want to do the 3rd burn right before water. If there was no RCS they would not be able to predict orientation. How about a (small) parachute ? RCS is ineffective at low altitude.
There has to be an RCS since they want to do the 3rd burn right before water. If there was no RCS they would not be able to predict orientation.
How is it ineffective? Didn't Antares use RCS during launch?As for the original statement, why would you need to predict orientation when you can just measure it?
Anyone care to venture an opinion about the odds of any of the following happening when Cassiope launches?1. The launch vehicle at least clears the transporter erector.2. #1 plus also the first stage successfully completes its first burn (with or without one or more engines out, as long as at the point the burn completes the upper stage is in a position where it could have put the payload in the proper orbit if staging had worked and if the upper stage had functioned properly).3. #2 plus also the upper stage successfully separates from the first stage.4. #3 plus also the upper stage successfully lights.5. #4 plus also fairing separation is successful.6. #5 plus also the upper stage completes its first burn successfully (so it reaches the intended orbit of the payload).7. #6 plus also the primary payload is deployed successfully into the correct orbit.8. #6 plus also the five secondary payloads are deployed successfully into the correct orbits.9. #6 plus also the upper stage successfully restarts.10. #9 plus also the upper stage successfully burns until its propellants are depleted.11. #3 plus the first stage is successfully oriented for its second burn.12. #11 plus the first stage successfully relights three engines for its second burn.13. #12 plus the first stage successfully completes its second burn to reduce its speed before re-entering the thicker parts of the atmosphere.14. #13 plus the first stage successfully retains the intended attitude down to the altitude where the third burn is intended to begin.15. #14 plus the first stage successfully relights the center engine to start its third burn.16. #15 plus the first stage successfully completes its third burn to come to a landing just above the surface of the water.17. SpaceX recovers the first stage more-or-less intact18. #16 plus we get to see video of the stage doing its water landing.19. #7 plus #8 plus #10 plus #16 plus #17 plus #18.20. #19 plus someone on this forum says the flight was a failure and/or meaningless.
14. #13 plus the first stage successfully retains the intended attitude down to the altitude where the third burn is intended to begin.
Anyone care to venture an opinion about the odds of any of the following happening when Cassiope launches?16. the first stage successfully completes its third burn to come to a landing just above the surface of the water.*AND* 18. we get to see the video
Anyone care to venture an opinion about the odds of any of the following happening when Cassiope launches?
Quote from: edkyle99 on 08/31/2013 03:55 pmThat adds complexity to an inaugural flight. I suppose that the cold gas RCS will also have to do the ullage thrusting prior to engine restart. Still, I've seen no hint of this RCS hardware in any photos so far. - Ed KyleNo need to use the RCS for that purpose IMO. The atmosphere will do that in time. No need for braking thrust as long as the atmosphere is too thin.
That adds complexity to an inaugural flight. I suppose that the cold gas RCS will also have to do the ullage thrusting prior to engine restart. Still, I've seen no hint of this RCS hardware in any photos so far. - Ed Kyle
Quote from: ChrisWilson68 on 08/31/2013 11:50 pmAnyone care to venture an opinion about the odds of any of the following happening when Cassiope launches?1. The launch vehicle at least clears the transporter erector. 99.5%2. #1 plus also the first stage successfully completes its first burn (with or without one or more engines out, as long as at the point the burn completes the upper stage is in a position where it could have put the payload in the proper orbit if staging had worked and if the upper stage had functioned properly). 90%3. #2 plus also the upper stage successfully separates from the first stage. 89%4. #3 plus also the upper stage successfully lights. 86%5. #4 plus also fairing separation is successful. 83%6. #5 plus also the upper stage completes its first burn successfully (so it reaches the intended orbit of the payload). 78%7. #6 plus also the primary payload is deployed successfully into the correct orbit. 75%8. #6 plus also the five secondary payloads are deployed successfully into the correct orbits. 75%9. #6 plus also the upper stage successfully restarts. 70%10. #9 plus also the upper stage successfully burns until its propellants are depleted. 69%11. #3 plus the first stage is successfully oriented for its second burn. 75%12. #11 plus the first stage successfully relights three engines for its second burn. 70%13. #12 plus the first stage successfully completes its second burn to reduce its speed before re-entering the thicker parts of the atmosphere. 50%14. #13 plus the first stage successfully retains the intended attitude down to the altitude where the third burn is intended to begin. 15%15. #14 plus the first stage successfully relights the center engine to start its third burn. 12%16. #15 plus the first stage successfully completes its third burn to come to a landing just above the surface of the water. 2%17. SpaceX recovers the first stage more-or-less intact 1%18. #16 plus we get to see video of the stage doing its water landing. 2%19. #7 plus #8 plus #10 plus #17 plus #18. 0.5%
Quote from: guckyfan on 08/31/2013 05:10 pmQuote from: edkyle99 on 08/31/2013 03:55 pmThat adds complexity to an inaugural flight. I suppose that the cold gas RCS will also have to do the ullage thrusting prior to engine restart. Still, I've seen no hint of this RCS hardware in any photos so far. - Ed KyleNo need to use the RCS for that purpose IMO. The atmosphere will do that in time. No need for braking thrust as long as the atmosphere is too thin.The idea is to cancel horizontal velocity before the stage hits the atmosphere, to minimize reentry heating and reentry forces. - Ed Kyle
Everything will go perfectly and SpaceX will move up their schedule, attempting a boost back to the launch site on the next flight. ::)
Everything will go perfectly and SpaceX will move up their schedule, attempting a boost back to the launch site on the next flight.