sixsteps.html
©Juhani Westman 2003, 2005, 2006, 2007,2013

Six Steps to Orbit
A blueprint of a Six-Stage Freighter Launch Vehicle from the Fourties.
   In the late Fourties almost every theoretician in space flight worth his salt was busy sketching Satellite Stations in orbit around the Earth, and the means of launching them. A range of uses was foreseen, most of which have been realized since the Sixties, but with unmanned satellites. At the time it was, however, considered necessary that the Stations would have to be manned, which meant rather sizable constructions, way beyond the lifting capacity of any conceivable single launch vehicle. It was clearly seen, that the creation of a Freighter Launch Vehicle would be the first order of business, as Rolf Engel, Uwe T Bödewadt and Kurt Hanisch put it in 1948:
   " At the present stage of technology...it would be great fun, to sketch up the furnishing of the Space Station, or the sleeping or workroom arrangements. Such an exercise is, however, without merit at this juncture. What is needed is an exposition of the physical and technical needs and especially the economical capabilities needed to establich such a Station."
Updated dec 28,2013. jw

Thus most of the technical discussions started with plans for multistage launch vehicles capable of attaining satellite orbits around the Earth.

Several different schools of thought can be discerned. Wernher von Braun, at the time already settled in the US, presented his monstruous three-stage "rocket-ship" in "Das Marsprojekt" 1948, /1/, at that time in a very stubby form, which he for esthetical reasons had slimmed down in the wellknown Collier’s series on space flight a few years later./2/
   The von Braun launcher architecture was straightforward, three stages in tandem, but it tipped the scales at 6 300 metric tonnes. The payload carried in the 3rd stage, to an orbit with a period of 2 hours, was to be some 33 tonnes, plus a cabin for some 10 to 12 people, explicitly "men". The stage would carry a return load of 5 tonnes plus cabin and crew. With no return payload, the load to orbit would be some 39 tonnes.
   Some years later, in 1955 -56, von Braun, for copyright reasons, had to re-sketch his launcher for the Disney company. He then used the opportunity to downsize it, to a gross launch weight of 1 280 tonnes, with a payload of some 10 tonnes. The payload lofting capacity was maximized by separating manned and unmanned flights. An insight, which later was totally lost when the US Space Shuttle was planned! The payloads consisted of either a manned return vehicle seating 14 (sic!) men, or an unmanned cargo carrier, Earth to Orbit only.

The British, the duo R A Smith, H E Ross, and the trio K.W.Gatland, A.M.Kunesch and A.E.Dixon,/3,4/ among others, looked to somewhat smaller payloads. Even so, the launch mass at first tended to be high, 2 300metric tonnes for a Winged Orbital Vehicle, doubling as a Fifth Stage, of 8,1 t total mass and 3,7 t dry mass. This was a result of a very low specific impulse, only 2 160Ns/kg, and a high construction factor, 0,2 times the propellant mass. The assumed specific impulse was heightened rather soon, not so the construction factor. In order to bring down the gross weight of the vehicles, Gatland, Kunesch and Dixon invented a system of tank staging called "Expendable Construction". See The BIS Launchers.
That idea was an outgrowth of the WW II practice of fitting drop tanks to aircraft. Nevertheless their three-stage – more correctly "three-stage with four expendable bays in stage 2"- launcher had a gross weight of some 510 tonnes, with a 5 tonne payload to a 500 st.mile i.e. some 800 kilometers orbit. It is to be noted, that, although von Braun used tandem staging for his launcher, the layout of his Mars-bound and later Moon-bound spaceships were of an expendable construction type, where the tanks used for major maneuvres were jettisoned after the conclusion of the maneuvre.

Interesting enough, no-one mentioned the other partial staging possibilities: parallell staging and motor staging. In the real world Sergei Koroljov used parallell staging in the R-7 ICBM, and Karel Bossard designed the Atlas ICBM with motor staging.

The smallest of them all.
   The smallest of the postwar launcher was presented in 1949, by the German trio cited above, i.e. Engel, Bödewadt and Hanisch. During those years the trio were Research Engineers in the French organisation O.N.E.R.A. The trio had cut their teeth on space technology in the late twenties and early thirties, implementing the rocket research programme of the "Verein für Raumschiffahrt",(Society for Spaceship Travel, often also referred to as the German Rocket Society). Their activities during the war years is not well known, it seems that at least Rolf Engels was active within some obscure rocket development organisation within the SS. After the German collapse the trio got themselves associated with the French. Later on Engel was active in Egypt. But back to 1948.
The influence by their personal mentor, the master of theory in German, Hermann Oberth is clearly to be discerned in their treatment of the ascent trajectory theory./5/ Their employment during the nazi years and the War was in a variety of subordinate positions within the varied rocket propulsion research establishments in Germany. Post-war they entered French employment. Later on they went their separate ways.
   They wrote up their plans in the Magazine "Weltraumfahrt" of the German post-war organisation "Gesellschaft für Weltraumforschung" (Society for Space Research), and the text was published under the name "Die Aussenstation", later included in a book by Heinz Gartmann./5/
   Their rocket – the EBH launch vehicle – would have a gross launch weight of some 220 metric tonnes, and a payload of 3 metric tonnes to a 557 kilometer orbit, with a period of 1.6 hours, giving 15 orbits per diem. The Authors also calculated the launch weights for a second orbit of two hours period, 12 orbits per diem – interesting enough getting an orbital height of 1 669 kilometers against von Brauns 1 730 kilometers for the same orbital period. That came about as a result of using somewhat differing constants for the diameter and gravity acceleration of the Earth. In those days, an even number of revolutions per diem was considered necessary for logistical planning.
The trio chose the lower orbit as basis for further calculations.

Space Station Orbits, copyright: R Oldenburg Verlag, München 1952
   Circular orbits for Space Stations, inclination of orbital plane against the equatorial plane 45°.
Sketch to scale by R.Engel, U.T. Bödewadt, K. Hanisch 1948, in Ref./5/, p.126

projection fron orbit I, copyright: R Oldenburg Verlag, München 1952
    Orbital Projection on the surface of the Earth, and the visibility zone from 557 kilometres altitude. As far as is known, this constitutes the first image of the groundtrack of a satellite on the Earth during a given amount of time, in this case during one day.
© R.Engel, U.T. Bödewadt, K. Hanisch 1948, and /6, s.127/

In order to get a size of the job at hand, Authors Engel, Bödewadt and Hanisch estimated that the "Aussenstation" would consist of 10 living units, 6 laboratory and research units, one machine shop unit, and one power generating unit. Total structure weight would be 180 tonnes. The Station would contain a total of 330 tonnes of life support and research equipment, furniture and other installations. Thus altogether 510 tonnes was to be freighted to orbit, during a period estimated to last 3 years.

The insistence on even numbers of orbits around the Earth per diem was predicated on an assumed need of regularity of appearance over ground stations, in order to facilitate orbit tracking, and as a secondary consideration, easing the scheduling and logistics of the multiple flights to build and to service the space station.

Ascent Trajectory and Launch Vehicle.
   As mentioned Engel, Bödewadt and Hanisch did a thorough study on the ascent trajectory to orbit. According to the tenets of Oberth, the initial part of the launch trajectory should be vertical, followed by a coasting "free flight trajectory", leading up to heights with rarefied air. During this free coast ascent the rocket's attitude would be tilted over towards the east, in order for the subsequent acceleration phase to take advantage of the rotation of the Earth. A more or less horizontal acceleration period would follow, so as not to carry excess amounts of propellants to unnecessarily higher altitude against the force of gravitation. The vertical velocity component would be consumed by gravity during the increasingly more horisontal acceleration, until the motion would be parallell to the Earths surface as the velocity approached circular velocity.

aufstieg, copyright: R Oldenburg Verlag, München 1952
   Ascent to the 100...557 kilometre Transfer Orbit. The reproduced page also contains various ascent data or the six stages of the Transport Vehicle.
© R.Engel, U.T. Bödewadt, K. Hanisch 1948, and ref.6, p.140/

After attaining a circular orbit at an altitude of some 100 kilometers, a second short freeflight period would follow, to be used for small corrections. A short thrust period, the "valley impulse" would raise the apogee to the final altitude, 557 or 1 669 kilometers, where a final kick maneuver, "the top impulse", would cirkularize the orbit.

Launch was to take place at an unnamed locality in Australia, into an orbit with inklination 45 degrees to the equator. The coordinates given, 22,5oS, 135o W, coincides but loosely with the coordinates of the real launch site Woomera (31,35oS, 136,50o W)

The three authors then studied the optimum number of stages for a satellite laucher, using state of the art technology of the day, and came up with an optimum stage number of six. Actually there are five Main Propulsion Stages, and the Sixth Stage was sized for the Orbital Maneuverings from the ascent orbit to the final orbit.

Dividing the lauch vehicle into an increasing number of stages may lower the launch weight substantially, up to a point. Given the rather high values of structure mass fractions of the day used by the authors, i.e Mstr/Mprop = 0,14 for the booster stage and 0,10 for stages 2 and upwards, and also given the specific impulses used by EBH, you end up (at least I did!)with the following Gross Lift Off Weight (GLOW) for a kick stage (originally the sixth stage) mass of 5 tonnes:

Table 1. Reduction of Gross Lift-Off Mass with added number of stages.

Number of stages, inkluding booster stage

Gross Lift-Off Mass, tonnes

2 + kick stage

474

3+ kick stage

287

4 + kick stage

235

5+ kick stage (EBH)

220

6 + kick stage

216

As may be seen, the law of diminishing return sets in already when going from 3 stages to 4, but apparently Engel, Bödewadt and Hanisch felt that the added complexity, with five ascent stages and one orbital maneuvering stage, would not prove unsurmountable.

In the following tables the significant data for the EBH Launch Vehicle are presented:

E.B.H.6-steps, copyright: R Oldenburg Verlag, München 1952
   Six-stage Freighter-Rocket and an A4(V2).
Sketch to scale by R.Engel, U.T. Bödewadt, K. Hanisch 1948, in Ref./5/, p.146.

Outwardly, the launch vehicle would have the shape of a giant artillery shell, with a cylindrical afterbody, 6 metres in diameter and 7 meter high, and an ogival forebody, with a curvature radius of 55,5 metres, bringing the total length to 25 metres. The first step – or Booster Stage – would have four stabilizing fins, 0,6 metres thick and 1,5 metres broad, with a profile compatible with the final airspeed of the booster, mach 2,9 at 12,7 kilometres altitude.
  The other stages of the vehicle would be stabilized by attitude control thrusters only.

As already stated, the Launch Site would be in Australia, the position given is 22,5 degrees South, 135 degrees West. The actual position of the Woomera launch area in Australia is 31,35 S, 136,50 E. Stage 1 would ascend almost straight upward for 35 seconds, achieving a vertical velocity component of 820 metres/seconds, after which the vehicle would continue to ascend in a free-flight mode.
During this 48 second free ascent, the vehicle, consisting of Stages 2...6, would be tilted sideways into a launch azimuth carrying the vehicle into an orbit inclination of 45 o, and an attitude of 45 degrees to the horizontal. The 2:nd stage would ignite at 37 kilometres altitude at an vertical airspeed of 345 metres/sec, down from 820 metres/sec. As seen from the launch pad, the ascent track at second stage ignition would still initially be almost vertical. In actual fact, as shown in the scheme, the inertial motion would be at a slant, because of the rotation motion of the earth, around 420 metres/seconds. With the chosen orbital inclination, 45 degrees, the actual velocity gain would be some 330 metres/seconds.

Aufstieg, copyright: R Oldenburg Verlag, München 1952
   The Ascent to Transfer Orbit at 100 km altitude. The wiew is true to scale and wiewpoint is the Nort Pole of the orbital plane. The slanted line from the launch site to the ignition point of Stage II is an effect of the rotation of the Earth.
© R.Engel, U.T. Bödewadt, K. Hanisch 1948 andh ref.5, s.140/

Stage 2 would burn for 70 seconds, carrying the tilt over from some 45 degrees to zero. At Stage 2 cutoff the vehicle would be in a trajectory, ascending by inertia, at 12,7 degrees above the horizontal, at 67,8 kilometres atitude. Stages 3 to 5 would burn for 50 seconds each, during which the ascent angle would lessen to 4,5 degrees at 87,4 kilometres, 1,1 degrees at 97,8 kilometres, and finally reach zero at 100 kilometres. Stage 2 would enter the atmosphere and hit the ground still in the Australian Northern Territory, and whatever would survive the reentry of stage 3 would fall in or off Cape York Peninsula. Stage 4 would re-enter and burn up over the Coral Sea. Stage 5 would leave the vehicle with a velocity deficit of 30 metres/sec from circular velocity, to ensure that the stage would re-enter and destruct in the atmosphere somewhere over the Atlantic.

The pilots in Stage 6 would perform a first burn immediately after separation from Stage 5, making good the 30 m/s deficit for injection into the low-altitude, i.e. 100 km parking orbit. After guidance updating, and suitable corrections, the pilots would ignite their 1,5 tonne throttleable motor for a second burn, accelerating with 133 m/s, and entering the ascent half-ellipse. After ascent to final orbital altitude, 557 km altitude, a third, circularization burn, the "apogee kick" of 133 m/s, would inject the spacecraft into the orbit of the space station.

Stages.
  All the six stages would be using liquid oxygen as oxidant and methyl alcohol as fuel – as the A4 (V2). Thermodynamical calculations will show that the given specific impulses in stages 2 to 6 are on the high side, but not excessively so. Stage 1 would have a chamber pressure of 50 bar, expanded to sea level ambient. In stages 2 and 3 the chamber pressure would be 36 bar, expanded to 0,2 bar. The methyl alcohol fuel would be diluted to 75 %.
In the 3 upper stages, the methyl alcohol would be undiluted, i.e 92...96 %. The chamber pressure would be lower, only 25 bar, in those days high enough, as the A4-motor had a Pc of 15 bar.
   Structural materials would be steel for the engine, duraluminium and aluminium for tanks and hull. The principles of design would be the same as for the A4, with load-carrying stringers and longerons stiffening the more or less non-load-carrying skin.

Both the booster stage and the kick stage were to be manned. In 1948 the automatic ascent guidance system, being a developed version of the mechanical gyroscopes-and-integrating accelerometer-type of the A4(V2), could not be relied on to handle the delicate maneuvers needed for rendezvous and docking in orbit. Thus the sixth stage would carry two men. After the ascent to orbit, the men would serve as part of the working crews, buildling, and later manning the Space Station.
The booster stage was to be landed and re-used again and again, so it was considered that a pilot would be needed to guide and control it during the descent and landing.
   The pilot in the booster stage would have a hair-raising flight. He would be sitting in a cylindrical cabin, 2 meters in diameter and 1,8 meter tall, with a plexiglass cupola protruding into the nozzle of the second stage. To gain entry into this cabin, he would have to climb through a passageway alongside the booster thrustchamber-nozzle assembly, inside the annular four-section fuel-and-oxidizer tanks. He would ride the thrusting booster stage in darkness for the 35 seconds until stage separation. He then would have 48 seconds to turn his craft away and "get the hell out from under", before the second stage would commence firing. For the descent phase he would have a set of steering thrusters to stabilize his horribly unstable vehicle, and a propellant reserve giving him some 300 meters per second maneuvering leeway for a soft landning, somewhere in the Australian Outback, a couple tens of miles from the launch pad.

Stages 2 to 5 would be unmanned, with guidance inputs coming from the cabin in stage 6. Like stage 1, Stage 2 and 3 would have sectioned annular tanks around the hull and the engine assembly in the middle.
Stages 4 to 6 would have spherical tanks inside the hull structure. The layout of these stages would not be unlike that of the EPS Upper Stage of Ariane-5.

Upstairs in the sixth stage – the kick-stage whick would attain the final 557 kilometre orbit – would contain a cabin for two pilots, and a payload, consisting of 1 tonne propellants and 1,5 tonnes dry load. Here we may discern a fudge factor: the authors assume that 0,5 tonnes of the stage itself would be usable for the space station construction, thus adding up to the advertized 3 tonne total payload.
Actually, when calculating the transport capacity needed for the Space Station, the Authors state that 0,3 tonnes of the 2 tonne dry cargo mass consists of consumables for the crew and 1,7 tonnes is material for the Station.

Bouncing Return from orbit.
   As the Freighter Sixth Stage would be dismantled in orbit and used up to meet the needs of the Station, there remained the problem of returning the crews from the orbital station. In 1948 nothing much was known of the re-entry problem, and the Authors invoke the best authority there was, Dr.Ing. Eugen Sänger, who during the war had headed his own research establishment at Trauen in Germany. Engel, Bödewaldt and Hanisch declared that the pilots "would be returning in a special vehicle, built to fly on the lines of the projected Sänger Antipodal Glider".    Now that craft, a single-stage catapult-lauched reusable rocket glider, built on the lines of a hypersonic glider aircraft with rocket propulsion, was in principle as diametrially different from the six-step arrangement as a spacecraft can get. What mattered, however, was the aerodynamic principle.

Sänger-Bredt Antipod Rocket Bomber 1944, copyright: Dr Irene Sänger-Bredt
   Antipodal Reach Rocket-Glider by Eugen Sänger and Irene Bredt. The line drawing is original, the captions were later translated from German into English and substituted. (Sänger-Bredt: "Über einen Raketenantrieb für Fernbomber", secret report Ainring, august 1944. © Irene Sänger-Bredt).

In a report, innocuously titled "Über einen Raketenantrieb für Fernbomber", (On a Rocket Propulsion System for Long Range Bombers), and immediately upon completion stamped "Secret" by the nazi authorities, the rocket practitioner, Dr.Ing. Eugen Sänger and his assistant, later wife, the Doctor of Matematics Irene Bredt, had sketched a rocket glider to reach antipodal distances.The 100-ton "Rabo"-vehicle (RAketenBOmber)was to be launched from a catapult rail by a rocket-driven sled, attain a velocity of 6 000 metres per second, enough to cause it to rise to an altitude of 260 kilometers and attain a ballistic range of 4 500 kilometres. Using the enormous amount of kinetic energy bestowed upon it during the acceleration and ballistic phase, the vehicle then would re-enter the atmosphere and bounce off again, for nine times, until a slowly descending level glide would carry the craft to some landing site, 23 500 from the starting point./4,7/
   In the Report there was a sequel to the Antipodal Glider. Sänger and Bredt suggested raising the Isp to 4 000Ns/kg using metal - Aluminium or Lithium - dispersion in the fuel oil. In this case the end velocity could be raised to 7 000 metres per second, not far from circular velocity, and the range in a "bouncing" flight would be streched accordingly, level glide would commence at a distance of 27 500 kilometres and end at the starting point after 3 hours and 40 minutes./4,7/
Trajectory of Sänger-Bredt Global Rocket Bomber 1944, copyright: Irene Sänger-Bredt/ref7
   Trajectory of Global Reach Sänger-Bredt Rocket Glider, from the Sänger-Bredt-report august 1944, © Irene Sänger-Bredt, and Ref 7).

   As a matter of fact the Sänger-Bredt pair was living in post-war France at the same time as Engel, Bödewadt and Hanisch.
    The Engel-Bödewadt-Hanisch Personnel Return Vehicles would, however, not be full-sized Sänger-Bredt Rocket Gliders, but dedicated payload-sized little craft, carried into orbit with wings and appendages folded under a shrouding, to be extended in orbit. Total mass would be equal to the ordinary Sixth Stage incl. Payload, i.e. 5 tonnes. We do not know what the Personnel Return Vehicles would look like, but we may surmise a winged shape like a radically shortened version of the Sänger-Bredt Glider. A Personnel Return Vehicle would consist of a cabin, thermal protection skin, wings and empennage, rocket engines and tankage for the return burn. During ascent only the 2 Ascent Pilots would be on board, and it would carry propellant only enough for orbital rendezvous with the Station. After tanking in orbit, the braking burn would cut the orbital velocity by some 300 metres/sec, enough to start re-entry down to about 40 kilometres. The procedure during re-entry would then closely follow the Sänger Global Rocket Glider trajectory.
   The Personnel Return Vehicles would be expendable i.e. single use vehicles. There would be room for the 2 pilots and 8 passengers during the return. Some of the propellants carried by the freighters as cargo, was to be used by the Return Vehicles. The Personnel Return Vehicle would be launched into orbit using a slightly modified version of the Freighter Launch Vehicle, and in the words of the Authors, these would be fed into the launcher stream att appropriate intervals.
   A dry mass of 5 tonnes for a craft to carry ten people, that sounds awfully small today, but at the time the mass allocation per person was normal, indeed rather generous. von Braun estimated the dry mass of a 14-people winged return vehicle including payload as 9,2 tonnes, as late as 1956.

Cost analysis.
   There was also a cost analysis. It started from a sketch of the size and mass of the Space Station itself, which may be summarized in tabular form, thus:

The EBH Space Station:

Living Units
Laboratory Units
Research Volume Units
Machine Shop Unit
Power Generating Unit
Station Complex

10 units
  4 units
  2 units
 1 unit
 1 unit
18 units

Structures
Installations
Total Mass
Crew

180 ton
330 ton
510 ton
20 men

  Now for the Launch vehicle costs. When looking at the numbers one has to remeber that the dollar cited was a dollar worth real money, not yet stricken by the postwar inflation, and as such, worth certainly more than 20 times, and maybe 100 times more than at the end of the century. The Authors started from the dry mass, and estimated the time and cost of producing it from the known amount of time needed to produce A4(V2) missiles, i.e 1,6 working hours per kilogramme of structure. Likewise they estimated the work amount of producing the propellants as 0,06 working hours per kilogramme of LOX and alcohol. Multiplying these amounts of work with a cost of labour somewhat higher than then current aviation production costs ( $ 24,-/hour instead of $ 15,-/hour, mid-1949 wage level!) , the authors arrived at a serial production cost of $ 73 000, (1949!!) for the A4 and $ 702 000 for the EBH launch vehicle, including propellants, but excluding payload.

This approach is deceptively simple, and in fact simpicistic, it does not account for the fact, that a six-step vehicle constitutes at least a sixfold increase in complexity. The stages will naturally have to be integrated into a single vehicle after being produced separately. The multiplied complexity should be seen as multiplying costs, too.

In these calculations all of the vehicles, including the Personnel Return Vehicle, were regarded as expendable. Whatever savings there would be from the recovery of the Booster Stages was regarded as leeway. Standing purely for manufacturing costs these numbers probably were as accurate for their day as could be expected.

Determining the ballpark size of the development costs was done by stating that the then aviation cost of prototype was running in the ratio of 10 to 15 times the serial unit production cost, and concluding that the state of the art in rocketry demanded a rather greater amount of basic development for each new launch vehicle, than was the case in aviation. The Authors ended up with an estimate that their six-stage vehicle, with six different rocket motors, propellant system, control agents etc, to be developed concurrently, would have a tenfold development cost per completed unit compared with that in aviation, i.e 100 times the cost of producing one vehicle.
The unit cost of the Passenger Return craft, including Launch Vehicle, would be $ 1,3 million per unit, including launch vehicle, presumably the development cost was absorbed in the overall $ 70 million for development.
   The mean manufacturing cost of the payloads, 510 tons of Space Station structure and equipment was taken as $ 80,-/kg.
The costs of preparing the vehicles for launch, and all other operating costs, like tracking, communications etc, were estimated as costs for personnel: The Authors estimated, that 1 000 men would be needed for the launch operations, 400 would be manning the 30 tracking stations around the world, 100 men were employed as "flying personnel", and 165 persons in administrative duties. A mean yearly outlay of $ 6 000,-/person for this total of 1 665 employees gave the yearly personnel outlay: $ 10 million.

Ground Support Infrastrructure was estimated at $ 50 million. Each of the tracking stations would cost $ 1 million to establish, for a total of $ 30 million, and the cost of establishing the launch centre "would certainly not be under-estimated" at $ 20 million.
Using the information in the text we may tabulate the total costs of the Station Project thus:

The Space Station Programme Costs, millions of $$

Development of LV
Build 375 vehicles
Launch site
30 Tracking Stations
Personnel costs
Space Station constr

70 mill USD
310 mill USD
20 mill USD
30 mill USD
30 mill USD
40 mill USD

Total, for 3 yrs

500 mill USD

   In the end the Authors came up with a cost of $ 500 million for their 3-year space station program, wherein 510 tons of station with 20 men aboard would be established during 3 years, using 300 Freighter Launch Vehicles and 75 Passenger Return Launch Vehicles. That means 3 x 125 = 375 annual flight opportunities, whereof 250 to orbit and 125 in the Booster Stage. The flying personnel of some 100 men would certainly be fully employed, every third mission being the brief, but horrible, first stage piloting job.

Those $ 0,5 billion were 1948-49 dollars, the purchasing worth of which was at least 50 to 100 times the worth of a dollar of the Clinton or Bush Junior administrations.

The building costs for launch pad and tracking station may be taken as infrastructure, the costs recuperated in the budget for the establishment of the Space Station. The overall Launch Vehicle Costs during the establishment phase will then be:

Overall Launch Vehicle Costs, millions of $$$

Dvlp Costs recuperated during 3yr Progr

Development of LV
Build FLV
Build PRLV
Share of Personnel Cost,FLV

0,187 mill USD
0,702 mill USD
1,300 mill USD
0,081 mill USD

Cost of FLV launch&ops

0,970 mill USD

Share of Personnel Cost,PRLV

0,083 mill USD

Cost of PRLV launch&ops

1,570 mill USD

   After the Space Station had been built, it had to be maintained. Consumables had to be freighted up and the crew must be exchanged. The following estimates of the size and cost of Station Maintenance are done by this Author. Using the Station Crew size of 20 and the number of pilots needed for the transportation flights as Station Crew we get:

Yearly costs of maintaining Station

Consumables, daily
Consumables, yearly

12,3 kg/man
90 ton(metric)

Transport flights
Crewmen to Station
Tour of duty
Passengers on return flight
Crew Return Flights

45 full loads
90 pilots
81 days
8 men
11 flights

Freight Vehicles FLV
Return Vehicles PRLV
Personnel
Payload cost

31,6 mill USD
14,3 mill USD
10 mill USD
7,2 mill USD

Cost/year excl. research

63,1 mill USD

   In this phase the Launch Vehicles may be considered available for other research programmes and commercial launches. Launch costs then may be presented as follows:

Overall Launch Vehicle Costs, M$

Dvlp Costs already recuperated

Build FLV
Share of Personnel Cost,FLV
Cost of FLV launch & ops

0,702 mill USD
0,179 mill USD
0,89 mill USD

Build PRLV
Share of Person. Cost,PRLV
Cost of PRLV launch&ops

1,3     mill USD
0,179 mill USD
1,48 mill USD

Wernher von Braun, with hindsight from more than a decade of grabbing and spending government funds at Peenemünde, estimated the unit costs of his 25 re-usable 3-stage "rocket ships" as $ 4 million/unit, and propellant costs per flight as $ 0,5 million, but then he just grabbed a symbolic all-inclusive sum: from first planning to an operative space station 10 years later, 4 billion USD 1948-52, or a sum twice that of the Manhattan Project 1942-45./2/

Engel, Bödewadt and Hanisch end their exposition by stating, that their sketch should not be construed as a factual blueprint for any development effort, but as an example of what kind of launch vehicle to what costs it would be possible to develope and operate, using state-of-the-art technology in 1948-49.

The Legacy.
   In its day, the EBH vehicle was hailed as the most realistic forecast to date. The size of the thing was not too daunting, the propellants were well known, and the construction parameters and the specific impulse, although higher than those used by, for example, Ross and Smith in the BIS, seemed achievable. The costs seemed to be realistically estimated - the complexity of six stages instead of fewer conveniently forgotten - and affordable.
   Today this sketch is all but forgotten, and so are the Authors. In contrast the much more futuristic monster rocket by von Braun, with it’s then exotic propellants, nitric acid and hydrazine, which never inspired any actual project, crops up in most recapitulations of the prehistoric eras of astronautics. The reason for this, of course, lies in the fact that the well-illustrateds articles in Collier´s, and the books derived from them, were widely read in the English-speaking world, and also were widely translated and spread. The Engel-Bödewadt-Hanisch report was published in German in an internal periodical of the "Gesellschaft für Weltraumforschung", and later in a book published by that Society. As far as this Author knows, Engel-Bödewadt-Hanisch never were translated for publication, into for example, neither English, French or Russian. /ref 6/ The references in litterature to the EBH work are also confined to works in German, of which few have been translated into other languages.
     Nevertheless, it attracted the notice of experts, aficionados and "armchair astronauts" in Germany and abroad, but it never got into the general public eye like the Collier´s articles.

The number of stages, six to orbit, actually 1+4+kick, may seem excessive today, but it is well to remember the Smith-Ross five stager Behemoth, and also that in the post-war studies in the US, a four-stage vehicle vas one of the options for an unmanned satellite launcher. The Experimental World-Circling Spaceship, proposed by the RAND think-tank in 1946 for the then USAAF in 1948, had four stages, a launch mass of 106 tonnes, and a satellite payload of 225 kg into a 450 km orbit./8/
   Also, the in those days oft-cited report by Frank J.Malina and Martin Summerfeld, listed possible 5 to 10-step-rockets for Earth Escape Missions without compunction./9/
  The first US satellite Explorer I was launched ten years later by a four-stage vehicle, the Jupiter-C/Juno I. The larger Juno-II was likewise a four-stage vehicle, as was the small launcher workhorse Scout.

Jupiter-C, copyright: IAA 89-740, M R Sharpe, B B Buchhalter and NASA
    Four-Stage Satellite Launch Vehicle Jupiter-C/Juno I. © NASA

Furthermore, the principle of a launch trajectory with a free-flying phase, with tilting between lofting to altitude and acceleration to orbit, was cited in the literature often enough, and also adhered to in both the Vanguard, and the two versions of Juno vehicles.

Vanguard-start, copyright: NRL
    Vanguard launching trajectory.
© Project Vanguard, NRL

We may further take note of the fact, that both the US Shuttle and the ESA Ariane-5 use an ascent trajectory not unlike that of the EBH. The first free-flight phase is of course lacking, but the SRB-s in both STS and Ariane do a fair amount of lofting the whole vehicle, which then is accelerated into circular velocity in a more or less horizontal flight attitude above the dense parts of the atmosphere. The Shuttle MECO and ET separation, and the Ariane Lower Composite separation, occurs at a just slightly less than circular velocity. The Shuttle gets the final kick into low Earth orbit by its Orbital Maneuvering System. The Ariane-5 Upper Composite is responsible for attaining of the final orbit, whichever it may be.

Looking at the numbers, one could imagine a vehicle with solid propellants for the five main stages giving a equal performance as the EBH. Of course the visible layout of the vehicle vould be quite different from the nicely aerodynamical flying artillery shell imagined by Engel, Bödewadt and Hanisch.

Finally it may be noted, that the plans for the reusable launch vehicle Kistler , envisions a Launch Assist Module , rather like the booster stage of the EBH launcher, and the ascent trajectory plan also includes an initial free-flight phase following the LAM burn, aimed at achieving operating altitude for low-pressure expansion of the re-usable Orbital Stage engine.


Notes and Bibliography:

Notes on Sources.
1.Wernher von Braun: "The Mars Project", University of Illinois Press, Urbana and Chicago 1953, 1991. Orig: Wernher von Braun: "Das Mars-projekt," Bechtle Verlag, Esslingen 1952.
2. Cornelius Ryan (ed): "Across the Space Frontier",Viking Press, New York 1952
3. Bob Parkinson:  "High Road to the Moon, the Collected Pictures of R.A.Smith   " The British Interplanetary Society, London 1979; and "Evolution of Winged Space Vehicle ..."Space Chronicle, JBIS Vol 59, Suppl.2, 2006, pp 71...78, especially Fig.3. Also personal contact. 4. Kenneth Gatland, Anthony Kunesh:"Space Travel", Allan Wingate, London 1953.
5. Hermann Oberth: "Die Rakete zu den Planetenräumen", Verlag R. Oldenbourg, Müchen und Berlin 1923.
6. Rolf Engel, Uwe T Bödewadt, Kurt Hanisch: "Die Aussenstation", in H Gartmann (ed)"Raumfahrtforschung", Verlag von R.Oldenbourg, München 1952, pp 117...165, especially "Das Stufengerät für die Bahn 1" pp 142...152.
7. Werner Buedeler: "Geschichte der Raumfahrt", 1979 Sigloch Edition, Künzelsau, Thalwil, Strassburg, Salzburg, pp 275...277.
8. Kenneth Gatland(ed) "The Illustrated Encyclopedia of Space, 2nd Ed." Salamander Books, London 1989, p. 26
9. K. Gatland: ""Development of the Guided Missile" Iliffe&Sons Ltd London 1952, p 198.

General:

Michael Rycroft (ed) "The Cambridge Encyclopedia of Space" Cambridge University Press, Cambridge 1990
H. Ulv Mai: "Rakettitekniikan Perusteet", PIK 1967.
George P Sutton: "Rocket propulsion Elements, 6th Ed.", John Wiley&Sons, New York 1992
H.H.Koelle(ed)"Handbook of Astronautical Engineering", McGraw-Hill, New York 1961


Links:

Mark Wade's Encyclopedia Astronautica
European Space Agency,   ESA.
National Aerodynamics and Space Administration,    NASA.
Tähtitieteellinen yhdistys    Ursa.
Suomen Avaruustutkimus-Seura - Sällskapet för Astronautisk Forskning i Finland - Finnish Astronautical Society     SATS - SAFF


e-mail your Comments to: juhaniwestman@gmail.com


Read more about the prehistory of Space Flight in
The BIS Launchers,
Global Bounce,
 and
Was there a Nazi Space Program?

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