LIQUID HYDROGEN AS A PROPULSION FUEL,1945-1959

 

PART III : 1958-1959

10. Early High-Energy Upper Stages

 

 

NASA Plans, ARPA Acts

 

[195] The ink was hardly dry on the President's signature establishing NASA on 29 July 1958 when Abe Silverstein established a committee to coordinate government plans for propulsion and launch vehicles. He called it an informal technical advisory committee for propulsion with himself as chairman. It had a flexible membership to meet the needs that arose.*

 

At the first meeting on 7 August 1958, the agenda included high-energy upper stages. Recognizing that a choice of the best high-energy propellant combination depended upon the application and stage design, a working group was appointed to review available information and present it to the committee for evaluation. Headed by A.O. Tischler, a propulsion researcher Silverstein recruited from the NACA Lewis laboratory, the working group was instructed to give particular attention to hydrogenoxygen and hydrogen-fluorine.** In so doing, the Silverstein committee also agreed to defer a contract then under consideration by the Air Force to develop a hydrazine-fluorine engine of 356 kilonewtons (80 000 lb thrust).15

 

At the second meeting of the Silverstein committee on 14 August, discussion of the high-energy propellant stages centered around a hydrazine-fluorine engine of 53 kilonewtons (12 000 lb thrust), being developed by Bell Aircraft for the Air Force, and a contract just awarded by Wright Field to Aerojet-General to study the feasibility of a hydrogen-oxygen engine of 445 kilonewtons (100 000 lb thrust). However, no actions were taken on these.16

 

By the time of the third meeting of the Silverstein committee on 28 August 1958, the Tischler working group on high-energy upper stages reported progress.*** Hydrazine-fluorine engines in thrust ranges from 27 to 90 kilonewtons (6000 to 20 000 lb) were, marginally superior to hydrogen-oxygen engines for a well-designed stage using tank pressurization to force propellants to the engine. A hydrogen-oxygen engine using a turbopump, however, was superior to a hydrazine-fluorine engine of the same thrust using tank pressurization instead of pumping. Hydrogen-fluorine engines were lighter than engines using the two other propellant combinations.17

 

According to Silverstein and Tischler, this meeting provided the impetus for final actions by ARPA on a hydrogen-oxygen engine. Cesaro reportedly slipped out of the meeting and telephoned his associates to move fast on the Centaur proposal.18 [196] Whether for this reason or by coincidence, ARPA issued order 19-59 the following day (29 August), directing the commander of ARDC to initiate a high-energy fuel stage for use with a modified Atlas missile. The propellants were to be liquid hydrogen and oxygen. The propulsion system was to be either pressure-fed or pump-fed, with a total thrust of 133 kilonewtons (30 000 lb) in single or multiple units. The final design would be determined after detailed studies were made by the propulsion and vehicle contractors and review by ARPA. Preliminary flight rating testing was to be 18 months from go-ahead. The sole source for the engine contract was Pratt & Whitney Aircraft Division of United Aircraft Corporation, and the sole source of the vehicle was Convair-Astronautics Division of General Dynamics Corporation. ARPA would review and approve the design, development, and financial plan; provide policy and technical guidance; arrange technical direction; prescribe management and technical reports; and receive credit for technical and scientific information released on the project.19

 

In essence, ARPA bought Krafft Ehricke's modified Centaur proposal, and the wording of its order suggests that a fast decision was made before final proposals and designs were determined. The commander, ARDC, designated the special projects office, then headed by Lt. Col. John D. Seaberg, as responsible for implementing the order. This was the office formerly headed by Col. Norman Appold, who managed the Suntan project. Seaberg and others in the office, including Majors Alfred J. Gardner, Jay R. Brill, and Alfred J. Diehl, had all been a part of Suntan. Two days after the ARPA order, Pratt & Whitney conducted the tenth and final series of tests with the hydrogen-fueled 304 turbojet engine. Suntan became a thing of the past and Centaur, a hydrogen-oxygen rocket stage on top of Atlas, rose as its replacement. All the plant, equipment, and technology of Suntan could now be brought to bear in assuring that Centaur would succeed.

 

The impact of ARPA's order for Centaur was not immediately apparent to NASA, and Tischler's working group continued its study of high-energy upper stages, as a coordinated government effort. At the fourth meeting of the Silverstein committee on 11 September 1958, the working group on high-energy propellants had not heard from all pertinent contractors or assimilated all the data, but Tischler reported to the parent committee on the tentative results. He compared three propellant combinations-hydrogen-oxygen, hydrazine-fluorine, and hydrogen-fluorine-and systems using pressurized tanks versus systems using turbopumps. With payload capability as the criteria, conclusions were: (1) for pressurized systems, hydrogen-oxygen and hydrazine-fluorine were about equivalent; hydrogen-fluorine was 10-15 percent better in payload capacity; (2) systems with turbopumps were 5-15 percent better than pressurized systems; (3) hydrogen and oxygen had both been pumped successfully but pumping of fluorine needed further research; this reduced the comparison to pumped hydrogen-oxygen versus pressurized hydrazine-fluorine where the former has a 10-20 percent greater payload capability, and (4) a 53-62 kilonewton (12 000-14 000 lb thrust) rocket engine appeared best for a Thor first stage and two such engines would be suitable for an upper stage of the Atlas.20

 

At the fifth meeting of Silverstein's committee (25 September 1958) the agenda concerned liquid hydrogen pumping and storable propellants. Richard Coar and Walter Doll of Pratt & Whitney Aircraft discussed their experience with liquid [197] hydrogen pumps. One pump developed for "another purpose" (i.e., Suntan) had a flow rate of 2.2 kilograms per second with 17 hours of operation; a second pump had a flow rate of 45 kilograms per second with a delivery pressure of 54 atmospheres. They offered to deliver the latter pump in 18 months at a cost of $4.5 million. Stanley Gunn and Merle Huppert discussed Rocketdyne work on liquid-hydrogen pumps. They envisioned a six-stage, axial-flow pump. Tests of single stages of such a pump were scheduled for November, as part of the firm's work on the nuclear rocket. These presentations gave further evidence to the working group that pumping liquid hydrogen was not a major obstacle to the development of a pump-fed, hydrogen-oxygen rocket engine.21

 

Other than information exchange, the Silverstein committee took no action to initiate development of a high-energy upper stage. Tischler drafted plans for two sizes of hydrogen-oxygen engines but they were tabled. Alfred Nelson summarized high-energy propellants, engines, and stage designs. Thrust levels varied from 31 to 600 kilonewtons (7000 to 135 000 lb). In NASA's first ten-year plan (November 1958), mention was made that hydrogen-oxygen upper stages in the 45 to 445 kilonewtons (10 000 to 100 000 lb thrust) range would be available.22

 

One of the eight organizations whose high-energy propellant data Tischler's working group had studied for the Silverstein committee**** was the NASA Lewis laboratory, where both men still had close ties. Since the Lewis research continued to influence the former Lewis men in NASA headquarters, a summary of it during 1958-1959 is pertinent.

 


* Attendees at the initial meeting were: for ARPA, Dr. Arthur Stosick and Richard Cesaro; for the Air Force, Col. Donald Heaton, ARDC, and C. W. Schnare and William Rogers, WADC; for NASA, William Woodward and A. o. Tischler.

** Other members: R. B. Canright and R. S. Cesaro of ARPA; Joseph Rogers and Alfred Nelson, WADC; Alfred Garner, ARDC; and M.L. Moseson, NACA-Lewis. Nelson was a propulsion analyst at Wright Field; Schnare was the chief rocket engine expert at Wright Field and Joseph Rogers worked for him. Moseson was a design specialist at NACA-Lewis.

*** Attendees: Dr. Jack Irvine, Richard Cesaro for ARPA; Col. Donald Heaton, C. W. Schnare, Joseph Rogers, Richard Shaw, and B. Chasman for ARDC: Lt. Col. Nils Nengtson for AOMC; Dr. Abe Silverstein, William Woodward, and A. O. Tischler for NASA.

**** Bell Aircraft North American Aviation, Aerojet-General, General Dynamics-Astronautics, Marting, Space Technology Laboratories, Wright Air Development Center, and the NASA Lewis laboratory.


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