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Launch vehicles: Discussion
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Launch vehicles: Discussion
1. Short overview of future launchers
2. Set-up of discussion
3. Let's talk rockets!
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Fact:More launch vehicles are currently in
development than those that have ever beenoperational since 1957.
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Major developments
Market-focusedExpendable solids
Re-usability
Assisted launchesAdvent of small launchers
Revival of super-heavy launchers
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Themes
Overarching goal ★Reduce cost of accessing space
Other developments ★Payload-return capabilities (X-37b, ISV) ★Slowly vanishing government involvement ★Developing ecological conscience
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SLS: The new Saturn V
● Move from Ares I and V to SLS● Carries MPCV● Block I: 70 tons (LEO)
Block II: 130 tons (> Saturn V)● Shuttle-derived lower stages in Block I● Saturn V derived upper (cryogenic) stage● Below budget, ahead of schedule, passed PDR in July
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SLS: Some arguments
● SLS = “Senate Launch System”● “There should be a commercial launcher instead.”● “Cost of BN$10 too much” (> BN$1 per year)● “There is no mission for SLS. Cost unjustified.”● “Launch cadence of 1/year too low.”
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Falcon Heavy: Brute Force Rocket
● Two-stage-to-orbit● LOX-Kerosene combination● 53,000 kg to LEO (vs. Delta IV Heavy 22,950 kg)● 27 engines (N1: 30 engines), 3 x Falcon 9● Propellant cross-feed● Possibly reusable
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Falcon Heavy: Some arguments
● “Which market?”● “Customers do not want to launch multiple
payloads at the same time ( Ariane 6).”→● “Did SpaceX sell themselves to the DoD?”
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Falcon Heavy vs. SLS
● Falcon Heavy GTO: 12,000 kg (Isp = 330 s)● Ariane V GTO: 10,500 kg (Isp = 465 s)● SLS GTO: 32,500 kg (est.) (Isp = 448 s)
– Commercial customers don't care about Isp– But: Falcon Heavy single-batch exploration missions
impossible on-orbit assembly required→
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Ariane 6
● Single major concern: market needs● “Triple 7 goals”
– 7 years development– 7 tons to GTO (actually, now 6.5 t in most recent design)– 70 Million per launch
● Identical lower stages, SRBs (Vega synergy)● Not carved in stone yet
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Ariane 6: Some arguments
● “Smaller commsats? Where is the evidence?”● “Focus on commsats? What about agency missions?”● “Human missions (also ATV) impossible until the mid
2030s”● “Loose cryogenic capabilities”● “Concept not scalable and evolvable”● “Not much cheaper, merely easier to plan”
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StratoLaunch
● Initially:– 2 x 747 & SpaceX (did not want to change design)
● Now:– Scaled Composites & Orbital Sciences– mp = 6,100 kg to LEO– Largest airplane of all time (540,000 kg, 117m)
● Main goal: flexibility (not cost!)● Founded by Paul Allen (Microsoft), Burt Rutan
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Stratolaunch: Some arguments
● “What if engine fails to ignite?”(was especially of concern with initial liquid-fueled Falcon concept)
● “M$300 development cost estimate too low”● “What's your market?”
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We live in the most exciting time since Apollo
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DEBATE
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Claim #1—Super-heavy Launchers
SLS is the wrong way to go for NASA. There should be a commercial development program for a very heavy
launch vehicle, similar to CCDev.
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Claim #2—Ariane 6 focus
AR-6 should focus on satisfying current market needs rather than representing a sovereign heavy
space-access capability for Europe.
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Claim #3—Launcher Policy
Defence capability synergies with orbital rockets are still essential for the selection of future launch systems.
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Claim #4—Human Spaceflight
The AR-6 should have the possibility to be human-rated.
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Claim #5—Small Payloads
Assisted launchers for small payloadswill be a game-changer in the market.
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Claim #6—Launcher ecology
“Green” or “Bio”-Propellants should be a driver for the Ariane 6 propulsion system.
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Claim #7—Small Payloads
Dedicated small launchers will replace piggy backing for small satellites.
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Claim #8—Assisted Launches
Stratolaunch will mark a (re)naissance of air launched vehicles.
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Claim #9—Payload Return
Europe should develop the capability to return payloads from space.
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