Micro-Space >> Ultralight Manned Spaceflight

[rpspeck]

There is a theory that exploration has become a big budget, governmental activity, and that in space this must long remain the case.  But neither of these ideas is true!  An unusual decade, almost a half century ago, planted these ideas.  It is time to uproot them and return to reality.

I have no particular interest in far future projections using imaginary technology.  I am talking about things that can be done tomorrow, and could have been done five years ago if real adventurers had awakened to the possibility!  I don’t blame the adventurers for being dense: our media and culture have drummed into their heads the message that nothing new can be done in space without spending $100 Billion!  Tens and even hundreds of Millions of dollars are regularly spent for sporting activities and entertainment: but multiply the cost by 1000 and rational people give up hope.

$20 Million will pay for new human milestones in the final frontier.  For this price a daring adventurer can loop through interplanetary space, and come home.  Walking on another planet will cost several times as much, but I will leave that for another thread.  
 
“Accessible” air flight ($5 for the average Joe) started with the Barnstormers.  And their activity was made possible by military surplus!  We actually have rocket equivalents of the surplus “Jenny” used by yesterday’s “barnstorming” pilots.  This includes the Russian “Dnepr” and “Rokot” and the American  “Minotaur”, all adaptations of decommissioned missiles.  The already modest prices of these launch vehicles would fall farther if a steady, cost sensitive market for them were to materialize (even a few units a year would be a big step up and seriously reduce the overhead cost component).  (I confess that I haven’t been able to pull up the failure rate data for these three or the more important, “Un-survivable” failure rates.  The later assumes explosive flight termination could be delayed for seconds to allow rocket boosted escape.  As I recall, the most recent Dnepr launch failure was largely intact when it hit the ground, many miles from launch.  This probably would have permitted safe “capsule” ejection.)

SpaceX promises similar prices for new, American made launch vehicles.  I wish them well (More literally I pray for their success!).  But even before their promising strides lead to orbital success, our adventurers can start preparing expeditions.

As with any private expedition, WEIGHT COUNTS!  Launch to orbit typically costs $8,000 pre pound = the current price of Gold!  One can either dream about when this freight charge will go down, or achieve the same result now by seriously minimizing system mass!  About 1965 GE did a serious study of an “Orbital Lifeboat” they called the MOOSE.  It massed 215 kg, including its astronaut in his pressure suit!  We certainly can do better today.  The MOOSE was rolled up in a duffel bag and self inflated into a 6 foot diameter reentry heat shield (plus Oxygen, retrorocket, parachute, radios and emergency supplies).  A preformed and reinforced heat shield will weigh less and the radios are down to ounces.  An achievable target today should be 400 pounds with the astronaut.

Stick to full fare launch prices and this comes out to  $3.2 million to orbit.  SpaceX projections call for $1500 per pound in orbit, which cuts this to $1.2 Million.  This is noticeably less expensive than the current Russian $25 Million orbital price or $40 Million with EVA opportunity.  That should affect the market.

With ultralight launch the EVA comes free.  You ride up to orbit in your pressure suit, hitch your reentry unit to the space station and go in the airlock.  (I personally can’t imagine wanting to go to orbit and not “Go Outside!”  That’s like going to Hawaii and looking at the scenery out of a hotel window.)

This doesn’t reach new adventure milestones in space, but it gets you to the threshold.  I will outline the road beyond in another posting.
 
Richard P. Speck,  Micro-Space, Inc.

[Danderman]

Incredible claims require incredible proof.

[braddock]

I've started a proper Q&A thread for Mr. Speck for him to answer questions about MicroSpace.
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=7416&posts=1#M127299

[rpspeck]

Danderman - 7/4/2007  7:25 AM

Incredible claims require incredible proof.

Always true.

Anyone who thinks a MMU can’t be coupled with a reentry heat shield will need A WHOLE LOT OF PROOF!

But there have always been a lot of skeptical spectators.

[rpspeck]

Pardon me for failing to get my own multiplication right.  At $1500 dollars a pound to orbit (if that SpaceX projection proves to be accurate), launching a four hundred pound personal spacecraft/reentry module to orbit would cost only $600,000.  As noted, this price should have some impact on the adventurer market.  The spacecraft unit does add cost, but probably not more than $200,000 in production quantity.
 
All my prices are for EXPENDABLE, not reusable launch vehicles and spacecraft.  The one semi reusable launch vehicle in operation (neglecting the scrapped airliner sized external tank) costs more to refurbish after each flight than expendables with equal payload to the ISS.  Since this makes an unworkable economic model for a RLV business, all discussions of Reusable Launch Vehicle services are highly speculative. I will leave that to others.  When they succeed, the discussed “freight” rates to LEO will fall.
 
On the other hand, the spacecraft systems I am discussing are not speculative at all.  We have operational prototypes of the life support systems, attitude control systems, retro rockets, radios, navigational gear and structures.  The parachutes are off the shelf.  We have prototyped portions of the reentry heat shield, using materials well documented in NASA studies.  Operational testing of these is the biggest economic problem, although less of an issue than one might expect.  

The blunt reentry vehicle has a zero failure rate history, and – as was demonstrated in the 1959 “Big Joe” launch, even a heat shield of 8% of reentry mass provides a large safety margin.

These launches of course will go to a space station, but not to the ISS.  No American flag manned space launch will carry private citizens to the ISS (unless the laws and policies change).  Only the Russians will carry them to that destination.  Those who have seen some $100 Billion of their tax dollars going into this assembly may not be happy about this fact.  

But that is not a problem.  The “miniature” Bigelow “Genesis 1” is 8 feet in diameter and 14 feet long.  This is the same diameter and 2/3 of the length of the DC-3 main cabin, and that airliner held up to 32 passengers.  By mountaineering standards, this first “experiment” is a roomy habitat for 12 adventurers (>10 foot by 24 foot floor/wall space).

[rpspeck]

The “Dnepr” quotes a 97% reliability.  This is very close to the STS, Shuttle, and spacecraft for the Dnepr could be provided with escape systems for a significant fraction of its failures (unlike the STS).

The Dnepr promises >3200 kg payload to ISS altitude and 2600 kg to the Genesis 1 altitude.  A Hubble repair mission would require a major plane change maneuver, and for this a SpaceX, near equatorial launch would be more attractive.  For Lunar and interplanetary missions, this is not a big factor.  

Quoted prices run in the $12 Million range.

[Space Lizard]

rpspeck - 6/4/2007  9:29 PM
Anyone who thinks a MMU can’t be coupled with a reentry heat shield will need A WHOLE LOT OF PROOF!

So you want to rendezvous a space station with 8 hr of life support autonomy and almost no ?v capability?

[Kayla]

The concept of reducing the ancillary weight that is taken to orbit is critical.  The Space Shuttle costs actually aren’t that horrendous based on weight taken to orbit, ~250,000 lb (orbiter + payload) @ ~$1B/launch = $4,000/lb.  However, based on the useable payload of 40,000 lb this cost sky rockets to $25,000/lb. (36,000 lb/person)

Orion won’t be much better with ~50,000 lb space craft for 6 people (8,333 lb/person)

Soyuz is a bit better At 16,000 lb for 3 people (5,333 lb/person)

With the high costs of rocket launches it is absolutely critical that the bus taking people to orbit be of minimal weight.  Can one get all the way down to the stated 473 lb (215 kg) /person, an order of magnitude reduction from Soyuz, I don’t know.  But less mass is certainly in the right direction, and until one tries to push the envelop you never know what is feasible.

[rpspeck]

Space Lizard - 8/4/2007  3:32 AM

rpspeck - 6/4/2007  9:29 PM
Anyone who thinks a MMU can’t be coupled with a reentry heat shield will need A WHOLE LOT OF PROOF!

So you want to rendezvous a space station with 8 hr of life support autonomy and almost no ?v capability?

I plan to orbit with 48 hour life support supply (1 liter of LOX + 4 kg LiOH), equipment to reenter at will and Delta V capability (the mass for which also scales linearly with spacecraft mass) as necessary depending on how sloppy the launch vehicle is.  

The Dnepr quotes +/- 4.0 km altitude, +/- 0.04 degree inclination (= 5 km lateral).  With 6 kg (3% 0f 200 kg vehicle mass) of modest performance fuel  I can correct far more than this error: +/- 70 km altitude,  +/- 0.3 degrees inclination.  Using that 70 km altitude correction, I can correct orbital phasing by 1.5% = 1.35 minutes per orbit.  If the Russians can launch this vehicle within one minute of schedule, orbital rendezvous won’t take long.  (I will also be using GPS so that orbital parameters and relative position will be known in minutes to very high accuracy.)

Richard P. Speck,  Micro-Space, Inc.

[Jim]

rpspeck - 7/4/2007  2:51 PM

Space Lizard - 8/4/2007  3:32 AM

rpspeck - 6/4/2007  9:29 PM
Anyone who thinks a MMU can’t be coupled with a reentry heat shield will need A WHOLE LOT OF PROOF!

So you want to rendezvous a space station with 8 hr of life support autonomy and almost no ?v capability?

I plan to orbit with 48 hour life support supply (1 liter of LOX + 4 kg LiOH), equipment to reenter at will and Delta V capability (the mass for which also scales linearly with spacecraft mass) as necessary depending on how sloppy the launch vehicle is.  

The Dnepr quotes +/- 4.0 km altitude, +/- 0.04 degree inclination (= 5 km lateral).  With 6 kg (3% 0f 200 kg vehicle mass) of modest performance fuel  I can correct far more than this error: +/- 70 km altitude,  +/- 0.3 degrees inclination.  Using that 70 km altitude correction, I can correct orbital phasing by 1.5% = 1.35 minutes per orbit.  If the Russians can launch this vehicle within one minute of schedule, orbital rendezvous won’t take long.  (I will also be using GPS so that orbital parameters and relative position will be known in minutes to very high accuracy.)

Richard P. Speck,  Micro-Space, Inc.

GPS doesn't help find the station.  

The ISS would not allow that type of fast approach.

[Marsman]

So essentially you are proposing an astronaut in an EVA suit strapped on their back to a blunt reentry shield? Also, how are you planning on docking to your station? Manual, Automated?

[sammie]

Moderators, is it possible to merge this thread together with the Q&A.
Just to keep everything tidy and organized.

[Christine]

Marsman - 7/4/2007  2:54 PM
Also, how are you planning on docking to your station? Manual, Automated?

Scuba tank and a prayer.  

[rpspeck]

As I recall, both the current EVA astronauts and the MMU users actually got back in after their EVA exploits.  Follow them in.  Tie your reentry module to a hitching post outside (most likely with a couple of carabineers) so that it doesn’t drift away.   (Yes, I know that the ISS EVA ports are so hardware specific that the Russian and American spacesuits can’t be used through the same door.  Bigelow isn’t required to follow this design philosophy.)  

I am certain that these adventurers will never be allowed to use or visit the ISS.  

GPS won’t help you find the ISS unless somebody happens to know where the ISS actually is.  Space stations used by these astronauts can provide short range (Wi Max?) transmissions to produce differential GPS information.  With carrier phase detection, and using the 10 MHz BPSK data, differential GPS usually provides relative positions accurate to 10 cm.  I don't think it is easy to overlook the ISS, or even the smallest Bigelow space station, at 10 cm distance.  

[Jim]

Differential GPS on a moving platform?

[dbhyslop]

What happens if (when) a tourist throws up in his helmet?

[Danderman]

When is the next MicroSpace launch?

Jim - 7/4/2007  2:04 PM


GPS doesn't help find the station.  

The ISS would not allow that type of fast approach.

Mini-AERCam used GPS, if I recall correctly.

[rpspeck]

dbhyslop - 9/4/2007  7:22 PM

What happens if (when) a tourist throws up in his helmet?

This is a very real problem.  Aspiration of these fluids into the lungs can be deadly (both short and longer term - by triggering pneumonia).  This is the largest cause of death during surgery, and a primary cause of death by alcohol abusers. I don't have the NASA answer.  If the cabin is pressurized, you can open the helmet long enough to clean out the mess - although this is much harder in zero g.  

For long duration suit use, or if this occurs following cabin depressurization, my answer is to use a third "port" on the face mask to clean out fluids by vacuum aspiration (excess saliva, and mucus included).  (The other "two" ports are Oxygen inlets (actually multiple in the ultimate system) and exhalation outlets.) If a participant considered this a possibility, he can insert an aspiration tube into this "third port" "just in case", and draw out the material while he holds his breath.  Some of course would automatically flow through the exhalation valves.  Alternately, it is feasible to “suck Oxygen” through a small tube inserted directly into the mouth in spite of material in the mask and helmet. In zero G this remains a dangerous situation.  

The third port is otherwise used for water or other liquids and gel foods.

[rpspeck]

Jim - 9/4/2007  6:51 PM

Differential GPS on a moving platform?

There is no inherent difficulty in retaining carrier phase information (as well as all modulation signals) on GPS in orbit.  This is of course done with standard “Phase Locked”, “Coherent” control/telemetry links.  These offer line of sight distance to a launch vehicle limited only by uncertainty about the speed of light in the intervening atmosphere.  

Retaining carrier phase information allows full differential GPS performance in any environment.  The position difference between the two comparison points of course means that they will see slightly different errors, and the resulting 3 dimensional relative position vector has an increasing uncertainty, possibly as high as 10 parts per million.