Nuclear Thermal Rocket Enhanced Lunar Launch Fleet

1. NTR-Enhanced Lunar-Base
Supply Using Existing
Launch Fleet Capabilities
John Bess
Idaho National Laboratory
Emily Colvin
Georgia Institute of Technology
Paul Cummings
University of Michigan
Nuclear and Emerging Technologies for Space
ANS Annual Meeting, Atlanta, GA
June 14-19, 2009

2. Objective
Assess the feasibility of
employing current Earth-to-orbit
launch vehicles and a nuclear
thermal rocket engine to deliver a
21 metric ton payload to the lunar
surface
2

3. Mission Characterization
LSAM Burns to
LEO Achieve LLO
EDS Detaches from
Launch CaLV; Burns to
on CaLV Circularize Orbit &
Achieve LEO
Earth Moon
LSAM
LSAM Burns to
Lands
Descend to Lunar
LLO
Surface
TLI
EDS Burns to
Achieve TLI LSAM Detaches Delivery of 21 metric tons in
from EDS support of a lunar base
NASA’s Exploration Systems Architecture Study Final
Report. NASA-TM-2005-214062, November 2005

4. NTR-Enhanced ESAS Architecture
Substitution of
the chemical EDS
with a NTR
Increase lunar
surface payload
by 36.2%
or
Reduce IMLEO by
24.1%
Using a Nuclear Thermal Rocket to Support a Lunar
Outpost: Is It Cost Effective? STAIF 2007.

5. What Makes This Study Different?
Assume that the Ares rockets and
other proposed earth-to-orbit
launch systems will be unavailable
for use
Use only existing launch vehicles
coupled with a NTR to provide
lunar support

6. Launch Fleet Characterization
Assessed characteristics of various
foreign and domestic launch vehicles
Limitations were based on volume and
not mass restraints for delivery to LEO
¤ Liquid hydrogen propellant
Launch vehicles and facilities within
the United States were preferred
¤ Reduce security and handling concerns

7. Delta IV Heavy
 Boeing
 Launch Facilities
¤ Space Launch Complex
37B, Cape Canaveral Air
Force Station, FL
¤ Space Launch Complex
6, Vandenberg Air Force
Base, CA
 Characteristics
¤ 5-m ID, 13.8-m long
faring
¤ 50,800 lb LEO
¤ $253 M (2004) per launch

8. Atlas V Heavy
 Lockheed Martin
 Launch Facilities
¤ Space Launch Complex
41, Cape Canaveral Air
Force Station, FL
¤ Space Launch Complex
3-East, Vandenberg Air
Force Base, CA
 Characteristics
¤ 4.6-m ID, 12.2-m long
faring
¤ 27,500 lb LEO
¤ $138 M (2004) per launch

9. Rendezvous with Orbital Assembly
Six rockets needed
¤ 1 – reactor,
shielding, structural
¤ 1 – payload, LSAM
¤ 4 – liquid hydrogen
propellant
¤ NTR specific
impulse of 850 s
An Isp of 950 s
would require only
four launch vehicles

10. Nuclear Thermal Rocket Engine
650 MW
tungsten-cermet
reactor
93%-enriched
HEU-O2
45-cm-thick ZrH
shadow shield
H2 flow rate:
¤ 18.0 kg/s (850 s)
¤ 16.1 kg/s (950 s)

11. Assembly Logistics
In-orbit infrastructure
¤ Independent orbital space garage
¤ Expansion of the International Space
Station
Multi-launch coordination and timely
construction
¤ Mitigate H2 boil-off concerns
¤ Development of in-space machining and
welding that have already been
demonstrated

12. Evaluation of Launch Costs
Reported launch cost estimates for the Ares
rockets are ~$3K/lb (~$7K/kg) to LEO
¤ $875M to place 125 metric tons in LEO
~$12K/kg for Delta IV and Atlas V rockets
¤ $1.4B to launch 6 rockets
The Ares rockets use “economy of scale”
for reduced launch cost
¤ Delta II and Atlas 2AS launch costs were still
~$12K/kg
¤ Similarly, a Ares V rocket would cost $1.5B

13. Additional Launch Costs
NTR engine
¤ ~$3B for contained test facility
¤ $1B for SAFE testing
In-orbit assembly
¤ Dominated by transportation costs, which are
sensitive to demand
¤ Human assembly with associated infrastructure
to cost ~10% of total ($140M)
Extra structural materials and assembly
¤ Assumed ~$140M

14. Cost Estimate for Lunar Base Supply ($B)
ESAS Fleet of Fleet of
Cost
Mission 6 rockets 4 rockets
Mission 1.50 1.40 1.14
Assembly 0.00 0.14 0.11
Structural 0.00 0.14 0.11
NTR Engine 0.00 1.00 1.00
Total Cost 1.50 2.68 2.37

15. Additional Cost and Logistics Needs
Upgrade costs for new vehicle development
and expansion of launch facilities are
unknown
Launch costs heavily influenced by supply
and demand
Additional costs may exist for coordinating
multiple launches, especially near the ISS
Current launch systems are not man-rated
and usable only for material transport

16. Developing Space Exploration Capabilities
Establishing NTR propulsion capabilities for
other missions
¤ Mars and beyond, reusable rockets, fast transit
capabilities
In-orbit construction allows for use of any
launch vehicle system to “build” the rocket
size of choice
¤ Not limited to a single quantized vehicle type
¤ Loss of a single launch vehicle does not
jeopardize the entire mission
Extraterrestrial assembly and repair
techniques

17. Recent Developments in the News
The Orlando Sentinel (4/2/09) – Cost for
Constellation has “Ballooned” to $44 Billion
Parabolic Arc (4/4/09) – Space Frontier
Foundation Will Campaign to “Kill” Ares
¤ Fund cheapest medium-lift vehicle launcher
The Orlando Sentinel (4/23/09) – NASA’s
Internal Ares V Launch Date May Be Delayed
by Two Years
Space News (5/9/09) – ULA Considering
Ways to Alleviate “Launch Bottlenecks.”
¤ Build additional Atlas 5 launch infrastructure
¤ Purchase multiple vehicles at a time
The Aerospace Daily and Defense Report
(6/15/09) – Delta IV Cheaper than Ares (for
ISS) but at the Cost of Time

18. Conclusions
Costs have been estimated for the use
of existing launch vehicles and a NTR
to deliver 21 metric tons to the lunar
surface
¤ ~ 60-80% greater than the estimated $1.5B
cost for an Ares V rocket
¤ Development costs have not been fully
assessed for either systems
¤ Benefits of developing in-space
construction allows for the development
of a more robust, lower risk exploration
architecture
18

19. Acknowledgments
Center for Space Nuclear
Research
¤ Director Steve Howe
¤ 2006 CSNR Summer Fellows
Idaho National Laboratory
¤ Jim Werner

20. This work was performed by the Center for Space Nuclear Research under the direction of Battelle
Energy Alliance, LLC (subcontract 43238) under Contract No. DE-AC07-05ID14517 with the U.S.
Department of Energy