MEMs Rocket Arrays and next generation launchers

Though with advanced MEMs technology - 1,000 to 1 thrust to weight
ratios are achieved

http://www.me.berkeley.edu/mrcl/rockets.html
http://www.bu.edu/phpbin/news-cms/ne...=1127&id=40897
http://pdf.aiaa.org/preview/CDReadyM...V2005_3650.pdf

Costs of $1,000 per sq meter are achieved in HDTV plasma panels. MEMs
technology uses the same underlying processes. 50 metric tons per
square meter are achieved as well.

So, taking the dimensions and mass fractions of an External Tank as
representative we have;

http://www.nasa.gov/returntoflight/s...system_ET.html

Weight:
Empty: 78,100 pounds
Propellant: 1,585,379 pounds
Gross: 1,667,677 pounds

Propellant Weight *
Liquid oxygen: 1,359,142 pounds
Liquid hydrogen: 226,237 pounds
Gross: 1,585,379 pounds

Propellant Volume *
Liquid oxygen tank: 143,060 gallons
Liquid hydrogen tank: 383,066 gallons
Gross: 526,126 gallons

http://science.ksc.nasa.gov/shuttle/...ewsref/et.html

The ET is 153.8 ft long and 27.6 ft in diameter. It has a projeted
area of 598.28 sq ft. To produce 1.4 gees at lift off which is nearly
optimal for this sort of vehicle, we require 227.48 sq ft - that's 32%
of the disk area. This is an annulus around the outside rim of the
base 7.7 ft wide. Total thrust 2.33 million pounds at maximum
propellant flow rate and annulus masss 2,330 pounds installed. Total
cost is only $22,000 !! The ET is $50 million !!

Replacing the foam coating with a more permanent thermal protection
system


http://www3.interscience.wiley.com/c...TRY=1&SRETRY=0

Massing 2 lbs/ft2 the advanced TPS adds 26,672 lbs to the vehicle.
Increasing structural fraction from 4.82% to 6.30%. Landing gear and
fold away subsonic wings add another 1.70% - which bring total
structural fraction to 8% - total cost per ET rises to $70 million
which includes advanced GPS and satellite controlled guidance.

With a specific impulse of 455 seconds this advanced ET would have a
delta vee with zero payload of 37,025 ft/sec

Three such tanks arranged (1)(2)(3) with 1 and 3 feeding 2 forming a
first stage. They separate at 10,000 fps. The two empty elements are
recovered by two tow planes mid air downrange. They re-enter slow to
subsonic speed and unfold their wings to become a glider. Snagged by
a tow plane each. Element 2 continues on to orbit, carrying a 551,000
pound payload, releasing is at 27,353 ft/sec.

The 551,000 pound payload consists of an aeroshell encased tank that
is capable of carrying 410,237 pounds of liquid oxygen and liquid
hydrogen. 351,695 pounds of LOX and 58,542 pounds of liquid
hydrogen. The aeroshell is a blended wing shape that is similar to
the mars airplane designs.

http://www.universetoday.com/2007/07...rcraft-tested/

The engine are patches of propulsive skin at the back, and on the
wings - to provide STOVL capabilities like that of the JSF

http://www.youtube.com/watch?v=nXzcsF2N2Ao

At LEO the blended wing stage carries 349,740 lbs of propellant,
allowing it to carry 60,495 pounds of additional payload a total of
201,259 pounds outbound to Mars. When the vehicle is injected into
Trans Mars orbit the propellant tanks are useable as habitable
volume.

This is an old idea going back to 1964

http://www.astronautix.com/craft/satkshop.htm

The tank volume of this mars craft is about 2/3 that of the Saturn II
- which is in addition to the volume of the craft itself. 96,683
pounds are returned, 60,495 pounds stay permanently on mars. 44,080
pounds is the vehicle itself. Each person will consume 3,650 pounds
of consumables. 1,825 pounds is oxygen. Water is recycled. The
balance is food.

With 120 day flight cycle, an 490 days on Mars - each person consumes
600 pounds in transit. 300 pounds of oxygen each way. Replenished on
Mars, and provided on Mars from the atmosphere, along with return
propellant, each person requires 1,825 pounds of food, and 300 pounds
of oxygen stored on board. 2,125 pounds. Add another 75 pounds of
oxygen for spares - that's 2,200 pounds per person per flight. 25
people require then 55,000 pounds of consumables.

http://www.t-immersion.com/

A hive of cells contain the 25 astronauts. Each cell consists of a
sphere 8 ft in diameter for each person - equipped with a haptic
spacesuit, and total immersion VR suite - provides any sort of
environment and interaction betwen crew members and psychological
space sufficient for all. 268 cubic feet per person 8,702 cubic feet
for the crew of 25.

Teleoperated humaniform robots operating within and outside the
spacecraft provide a safe and convenient means to maintain operations.

http://ranier.hq.nasa.gov/teleroboti...an/chap2g.html

Inflatable domes provide habitable volume outside the spacecraft once
the vehicle arrives on mars, as well as experimental volume for mars
grown crops.

http://www.springerlink.com/content/7861x07695429514/
http://pdf.aiaa.org/preview/CDReadyM...V2007_6262.pdf

Solar power provides sufficient energy to inflate the domes, maintain
air and water supplies, and refuel the spacecraft during the stay on
Mars. Depending on the success of the crops, some settlers may elect
to stay, otherwise semiautomatic robots - driven remotely - will tend
crops during the explorers absence.

A fleet of 7 vehicle leave more the 210 tons of equipment behind - and
provide habitation for 175 people.

154 of these people have paid $84 million each, 21 are professional
crew members - the program cost is $12.9 billion.