System Overview

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Trajectory to the Moon. Read more about trajectories
GLXP in brief
Google Lunar X-Prize: In brief, the First Prize contestant will win $20 million 
if their system reaches the lunar surface, travels 500 meters and transmits 
“Mooncasts” including HD video before December 31, 2012.  If not won by then, 
that prize drops to $15 million until terminating on December 31, 2014. 
The Second Prize is $5 million during the whole period until that date.
Bonuses to prizes (totaling another $5 million) are available if more 
than 5 km is traveled; if human artifacts are imaged; or if the system 
survives the lunar night.


Google Lunar X PRIZE (GLXP) is a $30 million competition for the first privately funded team to
send a robot to the Moon, travel 500 meters and transmit video, images and data back to the Earth.


Main mission status

tf(x) Space Segment Ground Segment User Segment
System Launcher Lunar Bus Lunar Lander Lunar Rovers Ground Support Systems Community
Consultants
Business
Subsystems
  • Structural Design
  • Power system
  • Propulsion
  • TT&C
  • ...
  • Structural Design
  • Power System
  • Propulsion
  • Imaging System
  • Communications
  • ...
N/A N/A
Completed*) 30% 20% 40% 60% 10% 10%
Report
in brief 		Trade study
in progres 		Engine
selection 		Mockup in
progress 		WRV1 and
PicoRover
selected for
the mission 		Looking for
help on the
review and
definition of
the GSS API 		Mission simulation
and training
in progress
Leaders
Responsibles 		Mike Barrucco
Dave Masten 		Ryan Weed Monroe King Joshua tristancho
Joerg Schnyder 		John Pritchard
Gary Stevens 		Sim Zig
Survey Joe
Business Sean
Lego Thomas
*)NOTE: Completed percentage is a subjective measurement from my point of view. --Tristancho 03:37, 18 January 2010 (UTC)

Edit Main Mission Status table

Three very different Teams 

Team FREDNET is (internally) really three very different Teams, each focused on
completing different and extremely important functions, and each of those functions
are essential to the development, success, and completion of each of the other Teams.
Namely, these Teams are:
(1) the Open Source Development Team,
(2) the Open Participation GLXP Mission Team, and
(3) the Business Development Team.
Not one of these Teams can exist without the cooperation and support of the other
Teams, and the whole of  Team FREDNET cannot succeed without the success of all three
of these essential internal sub-Teams.


Targets
Adapted from Sean Casey notes.--Joshua 07:45, 30 April 2009 (EDT)

  1. A fully developed mission plan
  2. A communications network and software control for remote operations
  3. Fully functional imagers (hardware/software)
  4. A suitable lander
  5. A suitable rover
  6. The integration and test of all of the above

Mission overview

NOTICE: This mission overview is a personal understanding of how I suppose the mission will go. Team FREDNET official vision may change --Joshua 18:08, 18 April 2009 (EDT)

The escape velocity (gravity well) is independent of vehicle (launcher), while
thrust depends on mass, propellant (Specific Impulse), number of stages, etc.,
but especially the desired orbit (Delta V). To maintain an orbit one needs a
specific speed and a fixed period.

How to escape the Earth's gravity field
Over the ground, in the equator, we have about 444 m/s (1,600 km/h) for the fact that we are rotating with the Earth. We need a velocity of 10,777 m/s (38,800 km/h) with respect to the Earth to escape from the Earth's gravity field. If we go Eastwards we have this initial velocity.

There are some efficient trajectories that allows spend less fuel in order to achieve such velocity. Orbiting a bit you have a good efficiency because centrifugal force eliminates the gravity and your thrust is spent only to add to your velocity. If you go upwards all the time you always have the gravity so your thrust (let's say 2.5 times the Earth gravity) minus the Earth gravity (1 G) only gives 1.5 G and you waste much propellant. The Earth's gravitational field ends let's say at 40,000 km above sea level. You reach 38,800 km/h in 5 minutes at a height of 300 kilometers and then you just turn off the engines and you have enough kinetic energy to escape. If you go slower you spend more propellant.

You reach the Moon at 1,111 m/s (4,000 km/h) and you spend more than two days to arrive. You don't go with constant speed because Earth's gravitational field brakes you from 38,800 to 4,000 km/h during these days. When you arrive at the Moon you have to brake. If you arrive very fast you have to spend more propellant. Then if you take an orbit is because you want to decide the point to land. If you don't care where to land as long as you arrive in the daylight near the Moon's Equator, we can go in direct landing.


How to get in the moon orbit?
See Lunar Bus Trajectory for details.

  1. Get a cheap ride on the Ariane 5 to Geostationary Transfer Orbit (GTO = 36,000 km) because they have frequent launches; otherwise you have to go to a Low Earth Orbit (LEO) to GEO. This is the expensive part of the project and takes less than five minutes.
  2. Use more than one perigee burn to raise apogee to Earth-To-Orbit (ETO) and then to Moon orbit. 2.5 loops takes more than 24 hours and you apply a Delta_V = 728 m/s.
  3. Use another burn to insert the Lunar Bus into Low Moon Orbit (LMO = 1,000 km) and another for Lunar Polar Orbit (LPO = 100 km), it takes about 5 days and you apply a Delta_V = 966 m/s taking into account corrections and orbit maintenance.
  4. From Moon orbit send the Lunar Lander into descent trajectory, it takes less than one hour and you apply a Delta_V = 2,104 m/s for descent orbit insertion and lunar descent and landing.

This information is based on the Indian Moon mission Chandrayaan-1 in 2007-8 time frame and a Flemming Hansen study from the Danish National Space Center.

1. The launcher puts the Trans Lunar Injection (TLI) module in a Low Earth Orbit (LEO) 2. The Trans Lunar Injection module spin-up thrusters firing 3. The spin-stabilized perigee thruster firing in order to inject the Lunar Bus (LB) module into the Lunar Transfer Orbit (LTO)
4. The axial thrusters firing to re-orient spin axis to ecliptic normal 5. The radial thrusters firing for mid-course orbit correction 6. The axial thrusters firing to re-orient for Lunar Lander (LL) module firing
7. The spin-stabilized Lunar Orbit Injection (LOI) module inside the Lunar Lander module firing 8. Lunar Orbit Injection module separation from the Lunar Lander module
OPTIONAL: The Lunar Bus module corrects the trajectory to a polar orbit for alternate relay 		9. The Lunar Lander module starts the guided descent to the target point (guided by a laser reflector of the Apollo 15 or so)
10. The Lunar Lander module lands 500 meters near the Apollo 15 or other target point 11. The Rover Lander module deploys and starts the first mooncasting while leaving 12. First hopping starts using the Lunar Lander module as a relay direct to the Earth or the Lunar Bus module in orbit
13. The Rover Lander module runs 500 meters towards the Apollo 15 or other landing place and starts the second mooncasting while reaching to the man-made artifact (1) 14. Second hopping starts using the Lunar Bus module in orbit as a relay to the Earth or store the video until Lunar Lander will be available 15. The Rover Lander module runs up to reach the traveled mark of 5000 meters (2) looking for water ice (3) confirmed by the water radar
16. The Rover Lander module returns the Lunar Lander module to plug inside and survive the lunar night (4) and upload the pending mooncast and other information 17. The Rover Lander module leaves the Lunar Lander module in order to explore the moon for six months before disposal . 18.

Mission Architecture

We define a typical mission to the moon consisting of:


The mission architecture painted by Tobias

Earth mission

  • The Ground Support Systems need to be able to receive the weak signal from the Moon in order to receive the rover Mooncast. Also could be used for tracking the launcher if required.

Transfer mission

  • The Launcher cost is proportional to mass. An applicable approximation is 31,000 $/kg. The launcher will put this mass to LEO orbit (8600 m/s of Delta_V for about 200 km LEO) with a solid propellant stage having a 260 second specific impulse.
  • The Lunar Bus will do a number of maneuvers (elliptic transfer orbits) in order to gain 4400 m/s of Delta_V for the transfer orbit to the Moon. The Lunar Bus will use bi-propellant with a specific impulse of 320 s. Note that in some contexts we regard the Launcher and Bus as one component, the vehicle system transporting the Lander and Rover.

Moon mission

  • The Lunar Lander will do a descent maneuver in order to gain 2200 m/s of Delta_V to transfer orbit to the Moon. The Lunar Bus will use a bi-propellant with a specific impulse of 320 s.
  • The Lunar Rover will win the GLXP grand bonus traveling 500 meters from the Lunar Lander and sending the so called Mooncast, videos, pictures, emails, etc.



Operational Costs

http://wiki.xprize.frednet.org/index.php/System_Overview#Why_the_payload_mass_is_so_important.3F

Why the payload mass is so important?

In the following picture you can see the relation between the payload mass (the Lunar Rover mass) and the impact in the rest of vehicles; it is to say the required weight of the Launcher , Lunar Bus and Lunar Lander required to bring to the Moon each kilogram of Lunar Rover . We can see a numerical example. If we want to bring 10 kilograms of payload to the Moon then we need a Lunar Lander of 61 kilograms and a Lunar Bus of 593 kilograms. In addition, if we build our own launcher we need a launcher of 40,727 kilograms.

Image:Payload_Mass_Impact.jpg
Launcher, Bus and Lander masses vs rover mass [kg]
  • The Launcher mass is composed by the payload (Bus+Lander+Rover) mass, the propellant mass and the structure mass. In this context we assume that the Launcher mass is 2% of the total mass. But in the end we will pay for the whole launcher if we can't have a relay with other satellite in the same launcher. The structure is 80 times the Lunar Rover mass because solid propellant is used.
  • The Lunar Bus mass is composed by a payload (Lander+Rover) mass, the propellant mass and the structure mass. We assumed that the Lunar Bus mass is 17% of the total mass because bi-propellant engine is used and navigation instruments are required. The structure is 10 times the Lunar Rover mass.
  • The Lunar Lander mass is composed by the payload (Lunar Rover) mass, the propellant mass and the structure mass. We assumed that the Lunar Lander mass is 33% of the total mass because bi-propellant engine is used, navigation instruments are required and thrusters are required for attitude control. The structure is 2 times the Lunar Rover mass.
  • The Total propellant mass required is about 97.72% of the total mass and is 3,980 times the Lunar Rover mass.
  • Finally, for each Lunar Rover kilogram, you need at least 3,933 kilograms of propellant. The Lunar Rover cost is USD1.838M/kg.


Image:Payload_Mass_Sheet.jpg
Gray: Structure mass. Yellow: Propellant mass. Orange: Total mass [kg]. Cost for a self-developed launcher ($M)


Example #1 of real cost

Following we present an Example of real cost for a FALCON 1 launcher. Space X launchers are a preferred GLXP provider. This study is extensible to other launchers but it is focused on the cheaper ones.

The FALCON 1 is a partially reusable launch system designed and manufactured by SpaceX


Some numbers for the launcher FALCON 1 will be as follow:

  • Extra Lunar Rover kilogram cost greater than 1,116,024 $/kg. This is what we pay for each kilogram attached to the Lunar Rover.
  • Extra Lunar Lander kilogram cost 1,116,024 $/kg. This is what we pay for each kilogram attached to the Lunar Lander or deployed on the Moon.
  • Extra Lunar Bus kilogram cost 558,012 $/kg. This is what we pay for each kilogram attached to the Lunar Bus or deployed in TLI orbit.
  • Extra GTO orbit Lunar Bus kilogram cost 111,602 $/kg. This is what we pay for each kilogram deployed by the Lunar Bus in the GTO orbit.
  • Extra launcher kilogram cost 18,810 $/kg. This is what we pay for each kilogram attached to the FALCON 1 launcher or deployed in LEO orbit.


Since we have to pay the whole launcher (USD7.9M) we have 400 kg of payload then we can offer one of the following products:

  • Maximum Lunar Rover weight 6.742 kg. We can offer 4.2 kg of payload landed in the Moon.
  • Maximum Lunar Lander weight 40.791 kg (Lunar Rover and propellant included). We can offer 25.6 kg of payload orbiting the Moon.
  • Maximum Lunar Bus weight 400.000 kg (Lunar Rover, Lunar Lander and propellant included). We can offer at least(*) 25.6 kg of payload orbiting the Earth in GTO orbit.
  • Maximum launcher weight 27,670.000 kg. We can offer 251 kg of payload aboard the Launcher or orbiting the Earth in LEO orbit.


See our business products.

NOTICE: These numbers are approximations based on cost to the launch provider, and are for reference only. More accurate calculations will be done in the Detailed Design Phase. Extra cost will be added due to the Lunar Bus and Lunar Lander development. Please contact Team FREDNET for any particular offer.

(*) Maximum GTO payload to be calculated.

Example #2 comparation between launchers

In this case we present a comparison of three very different launchers: FALCON 1 , Delta II and Ariane-5 . These calculations are based on public information but launcher providers may change these values depending on the customer so use only for reference.

Three very different launchers: Falcon-1, Delta-II and Ariane-5
Lunar
Rover
(kg)
 Lunar
Lander
(kg)
 Lunar
BUS
(kg)
 FALCON 1 Delta II Ariane-5 Parameter
- - - USD7.9M USD35M USD254M Approx. launcher cost
- - - 420 kg 2,691 kg 20,000 kg Max. payload to LEO
- - - 18,810 $/kg 13,006 $/kg 12,700 $/kg Launcher cost per kg of payload
- - - 27,670 kg 231,870 kg 780,000 kg Launcher weight
- - - 286 $/kg 151 $/kg 326 $/kg Cost for each kg of launcher
- - - LEO LEO LEO Delivery orbit
0.5 kg 3.0 kg 29.7 kg $558,000 $386,000 $377,000 Mass distribution and cost
1.0 kg 6.1 kg 59.3 kg $1,116,000 $772,000 $754,000 Cost for 1 kg Lunar Rover
4.0 kg 24.2 kg 237.3 kg USD4.46M USD3.09M USD3.01M Cost for 4 kg Lunar Rover
7.1 kg 42.8 kg 420.0 kg USD7.9M USD5.5M USD5.3M Cost using Falcon-1 max. payload
45.4 kg 274.5 kg 2,691.0 kg - USD35M USD34M Cost using Delta-II max. payload
337 kg 2,040 kg 20,000 kg - - USD254M Cost using Ariane-5 max. payload



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