Micro-Space >> Ultralight Manned Spaceflight

[rpspeck]

A quick note: “Ultralight” does not stop with hardware.  

Below average mass humans will have a pronounced advantage in entrepreneurial spaceflight, even possible flying “two for the price of one”.  The benefit is magnified if they also make do with proportionally less food.  

(I speak from experience as a well above average size human: size makes a difference.)

Small women, for example, will have a large advantage if they can also develop the skills needed for orbital (GEO) satellite repair.  

Whenever customized space hardware is involved (and it will be for up to 100 record setting missions in cis lunar and interplanetary space) they will make markedly lower cost achievable.

[rpspeck]

An Introduction to Ultralight design: Reentry and Landing

Several decades ago I read an article in an aviation magazine on “Zero Mass Design”.  The key point was: “One should not just focus on making parts lighter. You should think carefully about what that part accomplishes, and why.  If you find that you can eliminate it, or make another part serve this purpose as well its own, then you have reduced this function to zero mass.”

Considering in recent years the problem of how I personally was going to be able to afford to go into space, I applied this thinking to reentry and landing.  What was actually needed? (I would pay the price of Gold for every pound I took into space with me.)

Yes, a heat shield is needed.  Yes an additional system to get me safely on the ground was needed.  What were practical minimums for these systems?

Start with the landing system.  Images of complex sea recovery techniques were burned into my memory, including astronauts in choppy water and a capsule sinking!  But the orbital return also used parachutes.  Deconstructing this process, and sketching out alternatives, I finally realized that thousands of people every weekend make a safe transition from high altitude to the ground with backpack systems!  Sky Diving!

OK, abandon my heat shield after human free fall velocity became subsonic, and aerodynamic heating would not melt my pressure suit. Fall free for a while.  Open the first of my parachutes at a convenient time (keeping the backup for emergencies).  Aim my path for the best available spot, keep talking to my recovery crew (who were raising dust clouds as their Suburban raced along the county roads), and set up for touchdown flying into the wind.  

Take a quick look in my “Aircraft Spruce” catalog.  Parachutes, 14 pounds each (2 for 28 pounds), about $1500.   Could it be this easy?  (No 3000 pound capsule, but 28 pounds?)


Think twice (or three and four times.)   Good weather?  Given any reasonable Oxygen supply, I could reach many reentry sites and pick one with good weather.  Backup recovery crews (or hitch hiking) would be options for secondary targets.  Water landing?  A pressure suit (with the valves closed) makes a very good floatation and survival suit.  Either keep the Oxygen reserves up, or supply outside air to the mask without depressurizing the suit.  How would they find me? Take three small GPS units, and three cell phones.  Call in accurate coordinates before you touch down, just in case.  BUT, remember to take the Sky Diving class before you go into space!

Keep thinking.  Recovery systems failure: have two (possibly three) parachutes.  Reentry failure (Columbia): that’s another problem, one at a time.  Ascent failure – survivable – (like Challenger): once clear of danger zone (in free fall or with small rocket boost), abandon heat shield when convenient and do the landing stuff.  Don’t try it too low: BASE jumping requires reflexes I haven’t got.

Update design baseline: 90% reduction in orbital weight.  The reentry heat shield, attitude control thrusters and many other systems scale with total weight.  

Update project cost: 90% reduction in launch costs (subtract $22,000,000), much larger reduction in systems design and development cost.   Move on to next problem

“Yes, but some people don’t want to land with a parachute.”   Whatever.  I am not going to pay for their trip.  
I won't spend > 22 Million Dollars to avoid that step.  

[rpspeck]

An Introduction to Ultralight design: Reentry (Part 2.  See Landing above.)

The reentry problem is more complex, but promising.  The bottom line is that blunt reentry bodies like the Mercury Capsule or the more recent Galileo Probe (for Jupiter) are practical, reliable and aerodynamically stable.  

These reentry systems, using reasonable “plastic” heat shield materials, can have an ablative material mass less than ONE PERCENT of the reentry mass.  For a 300 to 400 pound reentry system, this makes even large safety margins feasible (4 pounds min.)  

Simplified Theory:

The classic “Allen and Eggers” paper (1958, NACA Report 1381) demonstrates that the fraction of vehicle kinetic energy transferred to its heat shield is closely approximated by ½ (Cf / Cd), ½ the ratio of skin drag to the blunt form drag, where the heat shield area almost equals the blunt cross sectional area.  Note for estimates, that all of the energy absorbed in skin drag comes from the boundary layer, and that this has a thickness about 3.6* L * SQRT(Re), where Re is the Reynolds number, and L is the critical dimension used to compute that number (The radius of curvature of the blunt heat shield in this case).  For blunt (Mushroom) bodies, this thickness is about equal to the body diameter divided by SQRT(Re), with the fraction of heat transferred being about the same fraction {D/SQRT(Re)}.  With reentry Reynolds numbers running from 10,000 to 1,000,000, the heat transferred to the heat shield is thus less than one percent of the orbital energy.

This fraction (<1%) is consistent with the graphs in this report and the numbers in Regan’s “Dynamics of Atmospheric Reentry” (1993).  Using 3.11 exp +7 J/kg for the specific orbital energy, the heat load the shield must handle can be estimated.  Dividing further by the heat absorption performance of a very good shield material (“PICA”, NASA 1995, with 2.3 exp +8 J/kg), the actual heat shield mass can be calculated.  In this case the heat shield material loss from ablation would be 0.14% of the reentry mass.  Best estimate for the Mercury capsule, with this heat shield material, would be 1 kg loss.  For our vehicle (as little as 10% of the 1354 kg Mercury mass) it would be much less.

More common materials are also usable.  Huy K. Tran reports on a range of materials (1994, NASA Tech Memorandum 108798) including BALSA WOOD.  This material shows modest but reliable performance.  It would require 8 to 10 times the mass of that listed above, but the actual ablator loss (without safety factor) would still be less than 1% of reentry mass = 4 pounds for our lightweight reentry vehicle.

The biggest problem with developing this system will be arranging for unmanned tests.  Some low reliability launch systems are still available at moderate cost, as well as “piggy back” launch arrangements.  Instrumented test units can be small and light enough for these economy launches.

[rpspeck]

I was asked on another forum about MOOSE style reentry with parachute landing by an astronaut weakened by a long zero “G” interplanetary flight. This individual suggested a derivative of the Soyuz system for Mars missions.  I think the options listed below adequately address this for “non tourists”.  

I am sure you are aware that my goal is to find the lowest practical mass for a Mars and other missions, since flight costs are so high.  Doubling the mass will very likely double the trip cost and when it is very difficult to raise the necessary funds, such a factor of two likely means that you won’t go!  (Doubling the price of a new car (and used ones as well) would have a big impact on my terrestrial transportation plans!)

I don’t trust efforts to “downsize” a military product.  Stripping half the weight from a single seat F-16 would not have made it possible for me to afford pilot training in one.  The Cessna made that possible.  Several of the “Light Sport Aircraft” may make it possible for me to OWN an aircraft!  The Soyuz is a very successful 1966 spacecraft design.  But some progress has been made in technology since that time and improvements are possible.  

Thus I favor “clean sheet” approaches.  This doesn’t rule out conceptual similarities.  All my projections assume that you throw away what you don’t need at each stage, and bring little more than the astronaut back to Earth.  (No hardware we will use on interplanetary missions will be so valuable that it is worth while to return it to Earth for reuse.)

I will address the specific question of “Parachute landing after an interplanetary voyage”:

Option 1: (Tested with the GE MOOSE system), land in water with your heat shield still under you.  As in Mercury or Apollo landing, but no vehicle shell. Weight Penalty = 0.

Option 2: Same, but allowing “prairie landing” with retrorockets (See Public Domain Technology).  Very soft parachute landing: Weight Penalty =  8.0 pounds.

Option 3:  Verify adequate leg strength with calibrated exercise in lasts months before landing.  (Retains wide range of landing sites.) Weight Penalty = 0.

Option 4: Program pressure suit to simulate “gravitational” pressure differential between chest and feet (-2 psi) before landing.  Combine with exercise.  Weight Penalty = 0.

Option 5: Program pressure suit to counter gravitational pressure differential in actual landing (“G” suit mode, + 2 psi pressure on legs.)  Weight penalty = 0.

Option 6:  Ignore possibility of inept water touchdown, like uncoordinated parachute student, count on pressure suit for air and flotation.  Weight Penalty = 0.  

Option 7:  Ignore possibility of inept land touchdown, like uncoordinated parachute student, count on pressure suit for abrasion protection.  Weight Penalty = 0.  

All of these options seem preferable to raising your trip cost from two to ten times (by adding an unnecessary shell) and risking drowning with a sinking “Mercury Capsule”.

[rpspeck]

Ultralight: The Bottom Line.

Ultralight spaceflight is not intended as a stunt.  Its purpose is to get people into space who otherwise couldn’t afford to go.  In this it is identical to SCUBA diving for people who can’t afford to buy or rent a submarine. It will push the price of human ORBITAL access below $600,000 short term, falling to $200,000 mid term.  Prices for Moon landings must be 20 times higher; $12 Million short term, falling to $4 Million midterm.

These prices assume no new technology (or “unobtainium”), just good engineering.  They also do not assume “reusable spacecraft”, since no one has demonstrated the ability to make an orbital system with even maintenance costs per flight competitive with “throwaway rockets”.  The prices for lunar landing will drop further when partial hardware reusability is demonstrated.  

The short term prices assume that SpaceX, or others will be able to match the Orbital cost delivered by the Russian Dnepr: $1500 per pound.  On top of this it assumes that the hypersonic tested MOOSE concept will be completed and updated to produce a 400 pound reentry vehicle including its astronaut.  When you consider the proven adequacy of Balsa Wood for a heat shield (4 pounds plus safety factor), and advanced materials at a fraction of this weight, even this mass looks high.  I will detail the ease of producing a “fail safe” pressure suit” in this forum soon.  Life support for 48 hours, either bracketing a space station visit or leading to early return from orbit, adds less than 10 pounds to the payload.  

The $200,000 ORBITAL price assumes that production prices for aerospace hardware can be reached with small, expendable rockets.  A few years ago, the production Cessna 172 aircraft had a list price of $160,000.  This reliable unit has a 1600 pound dry weight, giving $100 per pound of certified aerospace hardware: a mix of motor, controls, instruments and fabricated aluminum, assembled, tested and insured (with product liability insurance being a large cost).  Air transport aircraft (737, 747), built in smaller quantity, run roughly twice this cost per pound, with their very sophisticated jet engines and multiple redundant electronic systems.

Keep in mind that good rocket motors often have no moving parts (unlike aircraft engines). Also keep in mind that the safest and most successful launch vehicle flying today was developed - with its design frozen – in 1966. The control system, a daunting challenge at that date, is a trivial computer task today.  Knowing both aircraft and rocket needs well, I believe the lower, aircraft “cost per pound” number is appropriate for what is primarily a flying fuel tank: the lightweight rocket.

Putting 400 pounds (astronaut, life support, pressure suit and full reentry and landing equipment) into orbit with a multistage rocket using reasonable, hydrocarbon fuel requires a “mass ratio” somewhat less than 40.  Nearly 16,000 pounds, mostly fuel, must leave the launch pad.  With good construction (composite in our designs) the dry mass of this assembly will be less than 10% of this total, or less than 1600 pounds.  To put one human into orbit with an expendable rocket, you are “throwing away” a Cessna 172.  I have rounded this total flight cost up from $160,000 to $200,000, which will more than cover the special equipment.  

Note that the 16,000 pound takeoff mass includes 14,400 pounds of fuel – actually about 4080 pounds (680 gallons) of gasoline or equivalent, and 10,320 pounds of low cost liquid Oxygen.  I have noted that this is the gasoline used by a typical family SUV every year.  Even with today’s prices, the fuel will cost only $2400, but no one knows how to approach this as a launch cost.  

It may seem wasteful to throw away a launch vehicle, but anyone who has lived more than a few decades knows that “reusable” cars and trucks are regularly “used up” and scrapped.  Before the Alcan Highway was paved, it was typical to buy a new RV, take a long vacation in Alaska, then sell the RV after returning home.  The RV, while it was still fairly new, was in reality nearly “used up” by hammering on rough roads.  More to the point for space pioneers and adventurers, few if any “Covered Wagons” used on the Oregon Trail ever completed a second trip!  

The modest Orbital and Lunar prices I am quoting do not require that you wait for technological advances (and monstrous financial investments) comparable to the development of the western railroads.  They assume that you are willing to pass SCUBA like equipment training, and fly today on an affordable, lightweight expendable rocket.  

[rpspeck]

UPDATE, Ultralight Life Support

Our Rebreather system is now operating well, with demonstrated operation to over the 1.5 hour of a single global circuit in orbit.  We are arranging a larger CO2 absorber cartridge to allow 5 hour operation, for a John Glenn style 3 orbits.  (More important than the larger canister, we need to set up a DVD player so I can watch old movies for this long boring test.)  The 5 hour procedure will consume 130 grams of Oxygen and 180 grams of Lithium Hydroxide.  Much larger supplies of both, as reserves, are practical in even the lightest system.  The 1 kg mass of the rebreather hardware also makes dual, redundant systems affordable and these are needed for our “fail safe” pressure suits.

Our work with this system has revealed a number of problems which are not present in a underwater diving system of this type, but must be addressed for emergency use in an aircraft or space vehicle.  We have adequate solutions to these problems in operation.

In related news, our MEA (Monoethanolamine) solution – used as a long life, regenerable CO2 absorber in nuclear submarines – shows no damaging reactions with the micro porous membranes we have been using to control dissolved gas levels in solutions (and prevent bubble formation).  Thus we are ready to assemble a Zero G, long life CO2 absorber system.          

R. P. Speck  Micro-Space, Inc.

[tnphysics]

rpspeck - 29/5/2007  5:34 PM

Ultralight: The Bottom Line.

Ultralight spaceflight is not intended as a stunt.  Its purpose is to get people into space who otherwise couldn’t afford to go.  In this it is identical to SCUBA diving for people who can’t afford to buy or rent a submarine. It will push the price of human ORBITAL access below $600,000 short term, falling to $200,000 mid term.  Prices for Moon landings must be 20 times higher; $12 Million short term, falling to $4 Million midterm.

These prices assume no new technology (or “unobtainium”), just good engineering.  They also do not assume “reusable spacecraft”, since no one has demonstrated the ability to make an orbital system with even maintenance costs per flight competitive with “throwaway rockets”.  The prices for lunar landing will drop further when partial hardware reusability is demonstrated.  

The short term prices assume that SpaceX, or others will be able to match the Orbital cost delivered by the Russian Dnepr: $1500 per pound.  On top of this it assumes that the hypersonic tested MOOSE concept will be completed and updated to produce a 400 pound reentry vehicle including its astronaut.  When you consider the proven adequacy of Balsa Wood for a heat shield (4 pounds plus safety factor), and advanced materials at a fraction of this weight, even this mass looks high.  I will detail the ease of producing a “fail safe” pressure suit” in this forum soon.  Life support for 48 hours, either bracketing a space station visit or leading to early return from orbit, adds less than 10 pounds to the payload.  

The $200,000 ORBITAL price assumes that production prices for aerospace hardware can be reached with small, expendable rockets.  A few years ago, the production Cessna 172 aircraft had a list price of $160,000.  This reliable unit has a 1600 pound dry weight, giving $100 per pound of certified aerospace hardware: a mix of motor, controls, instruments and fabricated aluminum, assembled, tested and insured (with product liability insurance being a large cost).  Air transport aircraft (737, 747), built in smaller quantity, run roughly twice this cost per pound, with their very sophisticated jet engines and multiple redundant electronic systems.

Keep in mind that good rocket motors often have no moving parts (unlike aircraft engines). Also keep in mind that the safest and most successful launch vehicle flying today was developed - with its design frozen – in 1966. The control system, a daunting challenge at that date, is a trivial computer task today.  Knowing both aircraft and rocket needs well, I believe the lower, aircraft “cost per pound” number is appropriate for what is primarily a flying fuel tank: the lightweight rocket.

Putting 400 pounds (astronaut, life support, pressure suit and full reentry and landing equipment) into orbit with a multistage rocket using reasonable, hydrocarbon fuel requires a “mass ratio” somewhat less than 40.  Nearly 16,000 pounds, mostly fuel, must leave the launch pad.  With good construction (composite in our designs) the dry mass of this assembly will be less than 10% of this total, or less than 1600 pounds.  To put one human into orbit with an expendable rocket, you are “throwing away” a Cessna 172.  I have rounded this total flight cost up from $160,000 to $200,000, which will more than cover the special equipment.  

Note that the 16,000 pound takeoff mass includes 14,400 pounds of fuel – actually about 4080 pounds (680 gallons) of gasoline or equivalent, and 10,320 pounds of low cost liquid Oxygen.  I have noted that this is the gasoline used by a typical family SUV every year.  Even with today’s prices, the fuel will cost only $2400, but no one knows how to approach this as a launch cost.  

It may seem wasteful to throw away a launch vehicle, but anyone who has lived more than a few decades knows that “reusable” cars and trucks are regularly “used up” and scrapped.  Before the Alcan Highway was paved, it was typical to buy a new RV, take a long vacation in Alaska, then sell the RV after returning home.  The RV, while it was still fairly new, was in reality nearly “used up” by hammering on rough roads.  More to the point for space pioneers and adventurers, few if any “Covered Wagons” used on the Oregon Trail ever completed a second trip!  

The modest Orbital and Lunar prices I am quoting do not require that you wait for technological advances (and monstrous financial investments) comparable to the development of the western railroads.  They assume that you are willing to pass SCUBA like equipment training, and fly today on an affordable, lightweight expendable rocket.  

How will you get any samples back?

[A_M_Swallow]

Small amounts of delta_v between a spacestation and incoming person or capsule can be handled by catching the person in a net and using the mass of the spacestation to slow them.  You may need to winch out the net to keep the acceleration down.


SpaceX are currently charging $8.5 million for a Falcon 1.  This can lift 723 kg (1590 lb) to 200 km circular.

Using a figure of 400 lb per person + equipment the rocket can lift 1590 / 400 = 3.975 people
Taking that as 3 people $8.5 million / 3 = $2.83 million per person

On a 4 times material cost the trip ticket price is $2.83M * 4 = $11.3 million

With careful planning you may be able to reduce the 400% overhead charge.

Note $8.5M seems low for a firm employing 500 people and launching 10 times a year.  $40M is a more likely price, depending on their overheads.

[rpspeck]

tnphysics - 8/9/2007  10:57 PM

rpspeck - 29/5/2007  5:34 PM

Ultralight: The Bottom Line.
...  

How will you get any samples back?

In a bag.  Actually, for each 300 pounds of lunar samples you want to bring back, you supply an extra landing unit at 1/2 the expedition cost of adding an additional person.  Each person will use two landing units, one to land on the Moon, and a second (actually landed and verified first) to land the necessary return fuel.  A single landing unit can carry down its own return fuel and carry 300 pounds of payload back to lunar orbit. Multiple extra landing units provide spares to bring back the travelers if  any units are defective or questionable on arrival.  The questionable units can still bring back low priority samples.  A modest increase in return and reentry requirements for the samples will be covered by the unnecessary life support for "sample substitute" expedition planning.

[rpspeck]

A_M_Swallow - 9/9/2007  7:43 PM

Small amounts of delta_v between a spacestation and incoming person or capsule can be handled by catching the person in a net and using the mass of the spacestation to slow them.  You may need to winch out the net to keep the acceleration down.


SpaceX are currently charging $8.5 million for a Falcon 1.  This can lift 723 kg (1590 lb) to 200 km circular.

Using a figure of 400 lb per person + equipment the rocket can lift 1590 / 400 = 3.975 people
Taking that as 3 people $8.5 million / 3 = $2.83 million per person

On a 4 times material cost the trip ticket price is $2.83M * 4 = $11.3 million

With careful planning you may be able to reduce the 400% overhead charge.

Note $8.5M seems low for a firm employing 500 people and launching 10 times a year.  $40M is a more likely price, depending on their overheads.

I won't use a travel agent who quadruples their direct cost for the largest portion of of my journey.  

Counting vehicle, fuel , licensing and launch services as "material cost", as if it were raw material input to a manufacturing operation, is a strange accounting concept.

A four person "interface structure" to fit atop the Falcon 1 might cost more than a four place Cessna, but isn't going to cost 10 times a much ($1.5 Million).  Adding that to the SpaceX full service price gives $2.5 to $3.3 Million per person orbital travel cost.  Add a 10% travel agent's commission if you can't get a SpaceX quantity discount.

I don't think SpaceX is paying their employees $800,000/yr each, even when overhead is included. But even if their Falcon 9 jumps to that price (with 10 per year - and they are building  engines and tanks for those vehicles with that staffing) I will be a customer.  I need the bigger rocket for "affordable" interplanetary expeditions.      

[A_M_Swallow]

rpspeck - 11/9/2007  8:49 PM
A four person "interface structure" to fit atop the Falcon 1 might cost more than a four place Cessna, but isn't going to cost 10 times a much ($1.5 Million).  Adding that to the SpaceX full service price gives $2.5 to $3.3 Million per person orbital travel cost.  Add a 10% travel agent's commission if you can't get a SpaceX quantity discount.

I don't think SpaceX is paying their employees $800,000/yr each, even when overhead is included. But even if their Falcon 9 jumps to that price (with 10 per year - and they are building  engines and tanks for those vehicles with that staffing) I will be a customer.  I need the bigger rocket for "affordable" interplanetary expeditions.      

I do no think SpaceX pays its employees $800,000/yr either.

However to put this in context in 2006 Boeing, according to its website, had a turnover of $61.8 billion in 2006.  In August 2007 it employed 158,018 people
Turn over per person is approximately $61,800,000,000 / 158,018 = $391,095

So $400k/year/person is within the cost range of an established aerospace company.

SpaceX costs could be twice that or half that.

[rpspeck]

The ratio is very sensitive to the level of vertical integration, or alternatively, subcontracting.  The ratio will be much lower for a company which develops and builds it own own motors (which SpaceX does and Boeing does not.) Similarly, a lot of international aerospace sales today have "contribution" arrangements in which the customer nation gets to do part of the manufacturing.  This pushes the subcontracting level beyond even the cost break even level.  SpaceX has none of this and apparently subcontracts very little.

These observations point to a much lower $$/worker ratio for SpaceX with a factor of two being a conservative estimate.  (est $200,000 per worker sales breakeven point).

[tnphysics]

What kind of LV would be needed to land 6 men on Mars, using your technology?

[tnphysics]

What kind of hab will the crew have for a Mars mission?

[rpspeck]

tnphysics - 14/9/2007  9:14 PM

What kind of LV would be needed to land 6 men on Mars, using your technology?

I have been a lot more focused on getting travelers BACK from the surface of Mars than in landing.   For ASCENT I intend that 6, one person units would be used (one each, like bicycles).  This reduces development cost and modern systems often have very low economies of Physical scale.  Most "economies of scale" actually realized today are from Quantity = Production Volume.  Six units of course increases the chance of One Death, but far reduces the chance of All Dead.  Pick your philosophy.  The ascent system would be a version of our ultralight "Lunar Lander" with bigger fuel tanks: mass ratio 4 instead of 2 for the Moon.  

Landing would use an "Aerodynamic Decelerator" (aka Parachute) combined with small solid fuel braking rockets.  It is hard to get parachute descent on Mars much below 30 meters/sec and this needs to drop by at least a factor of 5 before surface impact.  A cluster of 6 grain Pro 38 motors (a small, reliable motor used in TRA amateur rocket flights) would produce 1.5 g deceleration for 2 seconds to counter the parachute descent velocity.  This rocket pack would weigh 3% of the payload mass: 3 kg total for a traveler in a pressure suit.

It is ridiculous to imagine that Mars landings are anything like Moon or other vacuum landings.  Combined with a parachute and aerobraking, the rockets need to provide only 3 g*sec of thrust, compared to about 180 g seconds to descend from lunar orbit.  With only 1.7% of the required impulse the retro-rockets are almost vanishingly small.  

The HABITAT on Mars is very much a question of the expedition style and objectives.  Many expeditions will be made to Mars.  At one extreme there will be no habitat and the traveler will remain for only a day or two in his pressure suit.  Your 6 man question probably calls for a sizable, but light weight, "inflated tent" habitat.  Another expedition we are talking to - with two travelers - really wants a compact, inflated habitat, probably on wheels, that they can drag over the Martian surface to extend the area that they can personally explore.

[savuporo]

rpspeck - 18/9/2007  10:11 AM
I have been a lot more focused on getting travelers BACK from the surface of Mars than in landing.

Er .. last i heard, MicroSpace was supposed to win the Lunar Lander Challenge this year ? So you completely skipped that stage and went straight to mars ?

[rpspeck]

Micro-Space will not be flying in the Lunar Lander competition this year.  It became obvious earlier that it would be impossible to get the required FAA experimental Launch permit by the required time.  We are actively working on all three Lunar Lander vehicles: the lightweight 90 sec version, the 180 second version with a much larger tank cluster, and the split tank cluster configuration which can transport a Rover to the lunar surface or - with high grade peroxide and the higher ISP in vacuum - can actually carry a human traveler.  

Our deep space focus actually started with our original X Prize work.  At that time we were perfecting the propulsion modules we continue to use, but recognized that there were important LIFE SUPPORT issues for an ultralight vehicle, both in normal flight and in emergency modes.  (Many of these issues have never been successfully addressed with the Space Shuttle).  Since this work tapped into research in Pulmonary Physiology I did years ago, it was not a stretch to adapt and apply the required technology. We have succeeded in producing several, fail safe, life support backpacks.  These, combined with modern high altitude technology, also provide far lighter and safer "pressure suits" than NASA standards.  

Beyond this, as a successful small business, we know the importance of choosing "right sized" goals.  In this arena, a goal with high public interest is easier to fund.  The final stage of an interplanetary spacecraft has more than 100 times less mass that its initial launch vehicle. Many are no bigger or heavier than a homebuilt airplane.  Launch to orbit is a commodity service and, for a very lightweight human mission, is affordable.  We added up all these factors and chose ultralight human Mars expeditions as an achievable goal.  

Bear in mind that the terrestrial Lunar Lander simulation has exactly zero follow on potential.  The Google Lunar X Prize adds real follow on potential, as do the human Moon and Mars adaptations.  As a business strategy it is important to keep these in mind and not pursue technology short term which will preclude such uses.  

[tnphysics]

Would you have an abort option during descent?

Retro failure, violent winds causing parachute failure, etc. for a Mars mission.

DPS failure for a Moon mission.

[savuporo]

Let me get this straight. You, as a small business, decided that its not worth your while to pursue the $2 Million purse of Lunar Lander Challenge, and are focussing on manned mars exploration instead ? All the while still "actively working on lightweight 90sec lunar lander" which has no relevance to manned martian missions as such ?

[tnphysics]

rpspeck - 20/9/2007  4:58 PM

Micro-Space will not be flying in the Lunar Lander competition this year.  It became obvious earlier that it would be impossible to get the required FAA experimental Launch permit by the required time.  We are actively working on all three Lunar Lander vehicles: the lightweight 90 sec version, the 180 second version with a much larger tank cluster, and the split tank cluster configuration which can transport a Rover to the lunar surface or - with high grade peroxide and the higher ISP in vacuum - can actually carry a human traveler.  

Our deep space focus actually started with our original X Prize work.  At that time we were perfecting the propulsion modules we continue to use, but recognized that there were important LIFE SUPPORT issues for an ultralight vehicle, both in normal flight and in emergency modes.  (Many of these issues have never been successfully addressed with the Space Shuttle).  Since this work tapped into research in Pulmonary Physiology I did years ago, it was not a stretch to adapt and apply the required technology. We have succeeded in producing several, fail safe, life support backpacks.  These, combined with modern high altitude technology, also provide far lighter and safer "pressure suits" than NASA standards.  

Beyond this, as a successful small business, we know the importance of choosing "right sized" goals.  In this arena, a goal with high public interest is easier to fund.  The final stage of an interplanetary spacecraft has more than 100 times less mass that its initial launch vehicle. Many are no bigger or heavier than a homebuilt airplane.  Launch to orbit is a commodity service and, for a very lightweight human mission, is affordable.  We added up all these factors and chose ultralight human Mars expeditions as an achievable goal.  

Bear in mind that the terrestrial Lunar Lander simulation has exactly zero follow on potential.  The Google Lunar X Prize adds real follow on potential, as do the human Moon and Mars adaptations.  As a business strategy it is important to keep these in mind and not pursue technology short term which will preclude such uses.  

What where the life support issues?