Orbital Pond Hopping
A Vision for the Evolution of Point to Point Travel
ASTE 527: Space Exploration Architectures Concept Synthesis Studio
Seth A. McKeen
10/16/2012
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
Potential Implications of Point to Point Travel
 World wide network of
Ultrafast Point to Point
Travel.
 Huge networks of global
hubs, all reachable
within an hour or so.
 Goal of the architecture:
get ~ 50 essentially
anywhere in the world
in less than an hour.
*Transit times are back of the envelope
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel

Global Jumper:
48 Passenger
Orbital Jumpcraft;
Used for
commercial travel
from city to fuel
depot to city.
Vertical Take off,
vertical landing
(VTVL), fully and
rapidly reusable.
Seth A. McKeen | seth.mckeen@gmail.com
Passenger deck
Custom Lightweight, Reclining Seats
Top view of a typical passenger Deck on a Global Jumper

Los Angeles Air & Space Port
One of many potential evolved
airports that could be upgraded
with P-P / Space Tourism
Concourses once the market is
booming.
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
 Simplified landing model shows
only ~3.5% of the touchdown
weight of the Booster’s worth of
propellant is needed for soft
landing for full reusability.
Seth A. McKeen | seth.mckeen@gmail.com
Alt: 50 KM (160,000 FT.)
First Stage
Separates and
Boosts Back to Los
Angeles for
refueling and reuse.
Alt: 150 KM (500,000 FT.)
In Low Earth Orbit, ΔV ~ 9200
m/s complete. Rendezvous
with Orbital Propellant Depot
Alt: 40 KM (130,000 FT.)
Out of the dense
part of the
atmosphere. Liquid
Boosters Separate
and Boost Back to
Los Angeles for
refueling and reuse.
Alt: 1 KM (3,280 FT.)
Ascent – All 3 Liquid First Stage
Boosters are Firing, using a crossfeed propellant scheme.
Take Off Fueled Weight is roughly
2,992,207 lbm
 The boosters are easily able to take
the heating descending from just
130,000 ft, and the Reinforced
Carbon-Carbon (RCC) Plug Nozzle
dissipates the heat without any
issue.
Time of Departure:
7:57 AM Pacific Time
Wait, which way to First Class?
 A typical view from any of the 48 seats on
the Global Jumper.
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel




Concept sketch by NASAS
Seth A. McKeen | seth.mckeen@gmail.com
On Orbit-Refueling
Take on ~3000 lbm of propellant for propulsive landing
Commercial business to resupply depots
Integration of Orbital Hotels
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Alt: 40 KM (130,000 FT.)
Atmospheric Reentry:
The Plug Nozzle Takes
the bulk of the Heating
Seth A. McKeen | seth.mckeen@gmail.com
 Atmospheric Reentry (Frictional
Heating) Takes away almost all of
the Orbital Energy
Alt: 200 KM
Perigee
Lowering Burn
Alt: 100 KM
Reentering the Upper
Atmosphere
 A simplified model for reentry was
created to check different
configurations for propulsive
landing. ΔV ~ 490 m/s is required
for a 48 person Jump Craft.
Alt: 10 KM (33,000 FT.)
Terminal Velocity
Reached: RetroBurn to Slow
Jumpcraft’s Descent
Begins at 50%
Throttle
Alt: 6 KM (19,000 FT.)
Retro-Firing Throttled
Down to 30% Throttle
Alt: 0 KM (5 FT.)
Precision Landing at
5% Throttle

Touchdown at Spaceport Paris. Local time is 5:45 PM,
total time of transit: 48 minutes. Time for a fresh
Croissant.
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
The Fundamental Architecture





Fully Reusable
VTVL (No Wings)
Modular (Scalable)
Upgrade to Aerospike Nozzle
Upgrade to Refuel on-orbit
Orbital Travel
Class of Vehicle for
P-P Travel
Suborbital “Lobs”
Where Are the Wings?


Heavy; useless for most of the flight
Using VTVL is also a great opportunity for maturing
landing systems for future interplanetary missions
“Wings simply add too much weight to a rocket that don't do a
thing through most of the flight. And there are plenty of other
ways to land safely than forcing your rocket to have so much
dead weight and drag for so much of its flight.”
– John Carmack of Armadillo Aerospace
Atmospheric Hypersonic
Flight
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
How do we get there from here?
NOW
VTVL R&D
Photo - Blue Origin
< 5 Years
< 5 Years
Cargo
Flights
Aerospike
Nozzles
< 10 Years
< 10 Years
Orbital
Propellant
Depots
Military P-P
Transport
< 20 Years
Global
Jumper
Photo - SpaceX
 VTVL Reusable
Launch Vehicles Are
Already Under Way
 Increase in ISP =
More Payload to
Orbit
 Decrease in Weight;
Shorter then Bell
Nozzle and use as
Heat Shield
Key technology developments
 Reinforced Carbon-Carbon (RCC) Aerospike
Nozzle
 Orbital Propellant Depots
 Technology NASA
might use for
Interplanetary
missions, used for
P-P Travel
Drive Cost Down
 By using a highly scalable architecture with
incremental technological developments,
development cost is heavily reduced.
 The better performance we get, the more payload
we can carry for a given ΔV
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Cargo Transports



Return on Investment
As soon as VTVL is fully developed, could begin
sending high-priority cargo across country –
package door to door in an hour.
Sub-Orbital (low Delta V, good starting point).
Start Regional and move to Coast to Coast
VTVL R&D
Cargo
Flights
Seth A. McKeen | seth.mckeen@gmail.com
Aerospike
Nozzles
Military P-P
Transport
 Again, by using a highly scalable architecture, we
could immediately start performing “flea hops”
carrying cargo city-to-city, this is earning capital
to cover investment costs but at the same time is
maturing the system before its used for Humans.
Orbital
Propellant
Depots
Global
Jumper
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Aerospike Nozzles


NASA “Pulled the Plug”
Altitude Compensating Nozzles were originally developed in the
1960’s.
By automatically correcting plume expansion to ambient
temperature, a net increase in mission average ISP allows more
useful payload to be carried.
Lighter, more efficient
 A truncated plug nozzle is also shorter than a bell
nozzle, making it lighter.
 A Carbon-Carbon nozzle could be actively cooled
with propellant running through a channel and
utilizing bleed holes – it could then be used as a
primary heat shield on reentry, grossly reducing
weight
VTVL R&D
Cargo
Flights
Seth A. McKeen | seth.mckeen@gmail.com
 Though there have been years of static testing,
notably by Rocketdyne, on both annular and
linear aerospike nozzles, NASA canceled all
research before flight time was ever achieved.
Courtesy Pratt & Whitney
Aerospike
Nozzles
Military P-P
Transport
Orbital
Propellant
Depots
Global
Jumper
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
Military P-P




Programs such as SUSTAIN and Hot EAGLE could use initial
manned Jumpers to carry 16 passengers anywhere in the world in
under an hour
1 passenger deck, integrated life support (easily scales up).
Orbital trajectories using Aerospike cluster for reentry
Ideal for emergency relief (hurricanes, etc.)
VTVL R&D
Cargo
Flights
Aerospike
Nozzles
Military P-P
Transport
Orbital
Propellant
Depots
Global
Jumper
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
Global Jumpers

Building off of its younger brother, the military transport model
and incorporating on-orbit refueling, 48 passengers can now travel
anywhere in the world in under an hour.
VTVL R&D
Cargo
Flights
Aerospike
Nozzles
Military P-P
Transport
Orbital
Propellant
Depots
Global
Jumper
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
Merits & Limitations
Merits
 Doesn’t use any exotic propulsion
 Opens up commercial market for
propellant depot refueling
 Matures technologies for
Interplanetary Space Travel
o Propulsive Landing
o On-Orbit Refueling
 Highly Scalable
 Could Start Now
 Potential usage: Military, Business,
Space Tourism, Time Sensitive
Packages
Limitations
 Potentially launching rockets over
urban areas
 High delta V for orbital flight
 On demand flight vs. scheduled?
 How many propellant depots in orbit,
how spaced? (Rendezvous problem).
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Future Work




Hard #’s on Price per Ticket
Trajectory Optimization
Preliminary Layout and Design
200 person vehicle using Rocket-Based
Combined-Cycle Propulsion (Mission
Average ISP ~ 1500s)
Seth A. McKeen | seth.mckeen@gmail.com
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
Many, many references…
http://www.spacefuture.com/archive/single_stage_to_orbit_vertical_takeoff_and_landi
ng_concept_technology_challenges.shtml
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20010017162_2001017589.pdf
http://reference.kfupm.edu.sa/content/s/c/sccream_(simulated_combined_cycle_rocket_1
25726.pdf
http://en.wikipedia.org/wiki/Reaction_Engines_Skylon
http://en.wikipedia.org/wiki/Precooled_jet_engine
http://en.wikipedia.org/wiki/Scramjet
http://www.strutpatent.com/patent/06591603/pintle-injector-rocketwith-expansion-deflection-nozzle#!prettyPhoto[patent_figures]/4/
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA539802
http://www.engr.sjsu.edu/nikos/MSAE/pdf/Munoz.S11.pdf
http://hartogsden.com/files/AIAA-2011-2229.pdf
http://utsi.academia.edu/NehemiahWilliams/Papers/1414394/A_P
erformance_Analysis_of_a_Rocket_Based_Combined_Cycle_RBCC_
Propulsion_System_for_Single-Stage-To-Orbit_Vehicle_Applications
Orbital Pond Hopping: A Vision for the Evolution of Point-to-Point Travel
Seth A. McKeen | seth.mckeen@gmail.com
http://isulibrary.isunet.edu/opac/doc_num.php?explnum_id=95
http://www.technewsworld.com/story/57516.html
http://www.spacetourismsociety.org/STS_Library/Reports_files/SpaceTou
rismMarketStudy.pdf
http://www.spacefuture.com/archive/flight_mechanics_of_man
ned_suborbital_reusable_launch_vehicles_with_recommendatio
ns_for_launch_and_recovery.shtml
http://www.nss.org/transportation/Suborbital_Reusable_Vehicle
s_A_10_Year_Forecast_of_Market_Demand.pdf
http://web.archive.org/web/20110615104534/http://www.reactionengines.co.uk/download
s/JBIS_v57_22-32.pdf
http://web.archive.org/web/20110615133300/http://www.reactionengines.co.uk/downlo
ads/The%20SKYLON%20Spaceplane-Progress%20to%20Realisation,%20JBIS,%202008.pdf
http://web.archive.org/web/20110615104428/http://www.reactionengines.co.uk/downlo
ads/JBIS_v56_108-117.pdf
http://web.archive.org/web/20110615104439/http://www.reactionengines.co.uk/downloa
ds/JBIS_v54_199-209.pdf