Northrop N-25B Boojum (MX-775B)

[Stargazer]

The obscure Boojum project is closely linked to the famous Snark, as both programs came to existence at the same time and resulted from the same development contract.

In October 1945 the U.S. Army Air Force began an ambitious long-term program to study and develop a large family of guided missiles, and in January 1946, Northrop submitted designs for turbojet-powered long-range cruise missiles. In March 1946, the USAAF awarded Northrop a development contract for project MX-775, covering the subsonic Snark (MX-775A) and the supersonic Boojum (MX-775B). In late 1947, the missile designator SSM-A-3 was assigned to the Snark (Northrop N-25), while Boojum became the SSM-A-5.

The Boojum supersonic intercontinental cruise missile (Northrop N-25B) was to compete head-to-head with North American Aviation's MX-771B Navaho II long-range missile. Although the initial Boojum design bore a lot of similarities to the Snark, the final XSSM-A-5 design was of a much different layout, featuring highly-swept delta-wings with turbojet engines near the wingtips. The studies envisioned a horizontal launch of the Boojum from a rocket-propelled sled, although air-launching off the back of a B-60 bomber (which at the time was expected to be a swept-wing, turboprop-equipped version of the B-36) or from a B-36 was apparently also considered as a secondary option.

After a subsonic climb to high altitude, the missile was to accelerate to supersonic speed and reach a final altitude of 21000 m (70000 ft). Two drop tanks were envisioned for the Boojum: one being a large subsonic wing, allowing for long-range subsonic cruise (see fifth attachment below), the other being a “slipper” tank that conformed to the Boojum's fuselage, allowing supersonic cruise. A celestial navigation system as developed for the SSM-A-3/SM-62 Snark was to guide the Boojum to the target at a maximum range of 8040 km (4340 nm).

Budget cuts in 1946 resulted in the cancellation of the subsonic Snark from the Army Air Force's missile program, while the Boojum was kept alive. Undeterred by this decision, Jack Northrop contacted Carl Spaatz and other Air Force officials to give the Snark a chance. He promised a two-year-and-a-half development phase with an $80,000 cost per missile for a 5000-unit production. Northrop's lobbying managed to get the Snark back on the tracks in 1947. Although both Snark and Boojum were redefined that year from the original 1945 specifications, the demise of the Boojum program soon came about. No XSSM-A-5 was ever built, and even to this day many details of the effort are still unclear. North American's Navaho II didn't fare any better.

After some protacted development, the XSSM-A-3 Snark finally flew successfully in April 1951. The SSM-A-3 Snark (later B-62,then SM-62) was launched off rails on a sled and remotely controlled by radio. Powered by an Allison J33 turbojet, it had swept wings mounted forward, and had a tailfin but no tailplane, using elevons on the wings for flight control. The air intake was under the belly. IT was also known as the WS-103A SAC Missile System.

As an aside, it is noteworthy that both the Snark and Boojum drew their names from the line of a Lewis Carroll' poem, "The Hunting of the Snark": "...for the Snark was a Boojum, you see..."


All that there is to know on the web about the Boojum (including the pics below) comes from two sources:
- www.designation-systems.net
- Scott Lowther's (Orionblamblam's) Unwanted Blog

Notes:
- Second attachment shows an early concept for the Boojum from about November 1947.
- All other images show the final configuration of the the XSSM-A-5.

 

[Arjen]

I found a link on the french wikipedia-page for the SM-62. http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA162646 It leads to this document: http://handle.dtic.mil/100.2/ADA162646

It is a 296-page document: The Evolution of the Cruise Missile, by Kenneth Werrell.

(page93)
In August 1945, the AAF established a requirement for a 600 mph. 5,000-mile-range missile with a 2,000-pound warhead. In response to an Air Force solicitationfor such a device, Northrop presented a proposal in January 1946 for a subsonic, turbojet-powered, 3,000-mile range missile. That March, the company received one-year research and study contracts for a subsonic and a supersonic missile with a range of 1,500 to 5,000 statute miles, and a 5,000-pound payload. Jack Northrop, the company president, nicknamed the former (MX-775A) Snark, and the latter (MX-775B) Boojum, both names from the pages of Lewis Carroll.20
The 1946 Christmas budget reduction deleted the subsonic Snark from the AAFmissile program, but retained the supersonic Boojum. But the matter did not end there. Jack Northrop personally contacted Carl Spaatz, Chief of the Air Arm, and others, to save the Snark. He promised development in two and one-half years, at an average cost of $90,000 for each of the 5,000-mile missiles in a 5,000-unit production run. The noted aircraft designer and manufacturer contended that it would take several years to develop the turbojet-powered missile, with 60 percent of the effort going into the guidance system. Before 1947 passed into history, USAF reconstituted the Snark program, slightly modified from the August 1945 specifications, at the same time relegating the Boojum to a follow-on status 21

(page 141)
20. Del Pappa and Goldberg; Rosenberg, Air Force, 76; Robert L. Perry, "System Development Strategies: A Comparative Study of Doctrine, Technology, and Organization in the USAF Ballistic and Cruise Missile Programs, 1950-1960," Rand RM-4853 PR, 1966, 30. Hereafter cited as Perry, RM4853. Fred Anderson, Norhrop (Los Angeles, Calif.: Northrop, 1976), 132; History and Development of SM-62 (WS-103-A) Weapon System, Northrop Report NOR 61-103, 1961, 1 [N].
21. Northrop designed the supersonic MX-775B Boojum to have a maximum gross weight of 112,131 pounds, fly 4,410 nm into the target at Mach 1.8 (or 4,325 nm at Mach 2). Powered by two J47 turbojets with afterburners almost at the wing tips, the vehicle was to be a two-stage affair. After about 1,300 nm, a slipper shaped fuel tank would be dropped from the tailless delta-winged aircraft measuring 35.3 feet in length (104.8 feet with the tank) and 50.9 feet in span. Other proposed versions ofthe Snark included the N-112 (QB-62) target drone, the N-124 (RSM-62) reconnaissance version, and the N.134 high altitude model. Neither the Boojum nor these other versions were built. "The Northrop MX-775B Supersonic Missile," June 1950 [NJ; NORAIR Project Designations, 16 February 1956, 11-13 [N]

 

[fightingirish]

Tony Chong - “For the Snark was a Boojum, you see.” B)

 

[Stargazer]

Excellent! Thank you so much for sharing.

 

[Stargazer]

An old illustration of the Boojum:

 

[overscan (PaulMM)]

Please don't post all the images from Tony Chong's articles here - go read them online here :


http://ghostmodeler.blogspot.com

 

[Triton]

What happens if, heaven forbid, Tony Chong's blog disappears? Not trying to steal Tony's thunder here, but this is another way to back up the images.

 

[Triton]

Did Northrop also create a Jabberwocky?

 

[Stargazer]

Did Northrop also create a Jabberwocky?

None that I know of, but it sure would be a nice idea for some what-if material...

 

[overscan (PaulMM)]

What happens if, heaven forbid, Tony Chong's blog disappears? Not trying to steal Tony's thunder here, but this is another way to back up the images.

Courtesy to Mr Chong who has kindly made these images available overrides this concern. He deserves to see the visitors to his blog. Put one or two example images, possibly at lower resolution as a teaser.


If you downloaded them, you could post them online if that ever happened.

 

[Stargazer]

From a declassified NACA report, the 1/14-scale model of the Boojum:

 

[Orionblamblam]

Courtesy to Mr Chong who has kindly made these images available overrides this concern. He deserves to see the visitors to his blog. Put one or two example images, possibly at lower resolution as a teaser.


If you downloaded them, you could post them online if that ever happened.

A thought occurs. The forum system allows for sections visible only to certain members. Does it allow for an even tighter-controlled section, visible only to, say, moderators? if so, a suggestion... set up a "vault" of images copied off of blogs and such, carefully named and categorized, for which publicly visible mini-images are available. If the blog in question does eventually go belly-up, the "teaser" images can then be hauled out of vault storage and posted publicly.

 

[Retrofit]

From a declassified NACA report, the 1/14-scale model of the Boojum:

Wallops Island Fight Test Range's Report NACA RM-L50K28a:

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930086473_1993086473.pdf

Also:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090026523_2009026764.pdf

 

[hesham]

From Ailes 11/1950,

they mentioned that,there was a piloted version as interceptor aircraft Project,of course
the drawing was not right,but I discuss only this Info ?.