NOTSNIK: The First Air-Launched Satellite Attempts

At the dawn of the Space Age, the United State space program looked very different from today’s and was dominated by the Department of Defense. And like the other branches of the US military during this time, the Navy’s “space program” actually consisted of several, largely independent space projects run by different internal bureaus and laboratories. While the Naval Research Laboratory (NRL) ran the Vanguard program under the watchful gaze of the public (see “Vanguard 1: The Little Satellite that Could”), the Naval Ordnance Test Station (NOTS) at China Lake, California (today known as Naval Air Weapons Station China Lake) was secretly conducting an independent military satellite program whose existence was not acknowledged until 1994.

NOTS , under the direction of the Navy’s Bureau of Ordnance (BuOrd), had been responsible for the development rocket-based weapons for the Navy since its inception in 1943. During the years leading up to the Space Age, engineers and scientists at NOTS were already busy performing research on suborbital and satellite ocean surveillance systems. With the launch of Sputnik (see “Sputnik: The Launch of the Space Age”), a NOTS team proposed an all-solid-fuel launch vehicle based on the motors in the Army’s Sergeant missile. However, the Army turned down their request for the rocket motors.

Undeterred, NOTS engineers went back to the drawing board and by February 1958 came up with a remarkably innovative proposal for orbiting a payload with available hardware. The new NOTS satellite proposal, called “Project Pilot”, used a six-stage air-launched system capable of orbiting a one-kilogram payload. This system would serve as a technological pathfinder for the Navy’s future rapid response reconnaissance systems. The technical director of BuOrd’s new space program office, John Nicolaides, approved the project and development immediately proceeded with $300,000 in initial seed money (about $3.2 million in today’s money). Subsequently Project Pilot received the nickname “NOTSNIK” based on a combination of NOTS and Nicolaides’ name but also partly as a play on the “Sputnik” moniker.

The NOTSNIK Hardware

The first “stage” of the Project Pilot launch vehicle, designated NOTS-EV1 in later years, was a specially modified Douglas F4D-1 Skyray jet fighter supplied by BuAer. When the F4D-1 entered service in 1956, it was the US Navy’s first carrier-based delta-winged jet fighter. The 13.9 meter long F4D-1 to be used for NOTSNIK, serial number 130747, was a specially modified, stripped down version used for high speed trial flights. With its Pratt & Whitney J57 P-2 turbojet on full afterburner, this plane was capable of attaining speeds of Mach 1.05.

Line drawing of the Douglas F4D-1 Skyray delta wing fighter used as the “first stage” of the NOTS-EV1 satellite launch vehicle. Click on image to enlarge. (USN)

The tight clearances and limited payload capability of the Skyray set the limits on the size and mass of the subsequent five stages of the NOTSNIK launch vehicle. This rocket had a total length of 4.38 meters, a fin span of 1.65 meters and had a launch mass of only 950 kilograms. Even with the mass of the Skyray included, Project Pilot’s NOTS-EV1 rocket is the smallest known system ever built to launch satellites until recently. The rocket was mounted on a standard Aero 7A bomb rack under Skyray’s port wing. A fuel tank of like mass was carried under the starboard wing to balance the load.

Diagram showing the configuration of the NOTS-EV1 launch vehicle. Dimensions are in inches. Click on image to enlarge. (NOTS/USN)

During a launch, the Skyray would proceed at an altitude of 10,700 meters to the air-drop zone located in the Navy’s test range over the Santa Barbara Channel in the Pacific Ocean just west of Los Angeles. Before release, the pilot would start a 2-g pullup at Mach 0.9 to start a “bomb toss” maneuver. At an altitude of 12,500 meters, the rocket would be released at a speed of 742 kilometers per hour and an angle of 50° to the horizon. Three seconds later the first of the solid rocket stages would ignite.

This map shows the tracking coverage of a NOTS-EV1 ascent from the NOTS facility at China Lake. Click on image to enlarge.

The second and third stages of NOTS-EV1 actually made use of a common airframe. Each stage consisted of a pair of modified HOTROC motors like those used by the Navy’s ASROC anti-submarine weapon and produced 126 kilonewtons of thrust for 4.9 seconds. During ascent the burn of the second stage would be followed by a 12-second coast before the third stage ignited. After third stage burnout, the vehicle would coast for another 100 seconds. At an altitude of 79.4 kilometers the second/third stage structure was jettisoned and the fourth stage was ignited.

The X-241 motor used as the fourth stage of the NOTS-EV1 was based on the X-248 motor shown here originally developed for the Vanguard program. Click on image to enlarge. (Martin)

The fourth stage of the NOT-EV1 launch vehicle consisted of an X-241 rocket motor manufactured by the Allegany Ballistic Laboratory – a federal laboratory operated under contract for the US Navy by the Hercules Powder Company. Based on the X-248 motor developed for the NRL Vanguard rocket (see “Vanguard TV-3: America’s First Satellite Launch Attempt”), the X-241 produced 12.1 kilonewtons of thrust for 36 seconds. After another coast of three seconds, the fifth stage would come to life. This 14.9-kilogram motor was designed at NOTS and produced 5.1 kilonewtons of thrust for 5.7 seconds. After this stage burned out, NOTSNIK was travelling at 8.44 kilometers per second in a near-polar orbit with an apogee of about 2,400 kilometers. But with a perigee of about 60 kilometers, this orbit would be very short-lived. A small 568 gram solid rocket sixth stage integrated with the satellite payload would be fired 53 minutes and 20 seconds after release. Also developed at NOTS, this tiny motor produced 765 newtons of thrust for one second and would raise the NOTSNIK satellite’s perigee to a safe 2,250 kilometers allowing the mission to begin.

This diagram shows the the later stage of the ascent profile for the NOTS-EV1. Click on image to enlarge. (NOTS/USN)

With a mass of 1.05 kilograms and a diameter of 20 centimeters, the doughnut-shaped NOTSNIK satellite is among the smallest orbital payloads ever launched and straddles the border between today’s definitions for picosats and nanosats. This battery-powered, spin-stabilized satellite was constructed in-house at NOTS’ China Lake facility and was originally envisioned to carry a single instrument – an infrared “television” scanner. Similar to the units supplied by the Navy for the USAF lunar orbiters (see “Pioneer 1: NASA’s First Space Mission”), this simple imager was hardly a “television” in the usual sense. A small mirror focused light onto an lead sulfide infrared detector which would use the rotation of the satellite to scan a line in the scene. The forward motion of the satellite itself would then allow a picture to be built one line at a time with a resolution of about two kilometers. While the crude images produced by this system would have little intelligence value save for weather reconnaissance, the experience gained would be valuable in developing more capable follow-on systems.

Diagram showing the internal arrangement of systems inside of the NOTSNIK satellite. Click on image to enlarge. (NOTS/USN)

The images produced by the satellite would be transmitted to a network of about a half dozen portable tracking stations scattered around the globe. Because of the small size of the satellite, the system would only operate for about three orbits before the batteries were depleted, long enough to verify that orbit had been achieved and attempt to secure some images. Since orbital reconnaissance was a touchy subject at the time, NOTSNIK and its mission were kept top secret. The satellite’s small size and short lifetime made it unlikely that it would be detected by anyone outside the program.

The 1.05-kilogram satellite to be launched using the NOTS-EV1. Note the sixth stage motor nozzle in the middle and the opening for the primitive imager on the side. (NOTS/USN)

In May of 1958, NOTS officials went to Washington, DC to gain support for their satellite project based on its potential quick-response capabilities and low cost. In the end, $4 million ($42 million in today’s money) were directed towards Project Pilot which was authorized to attempt a half dozen launches through the end of August. While the first NOTSNIK satellites would carry a simple diagnostic package instead of a camera, the last three flights would now carry a radiation detector and be flown in support of Project Argus – an eleven-day series of high altitude nuclear weapons tests scheduled for late August and early September of 1958. This support mission also provided Project Pilot with a convenient cover story to hide the nature of its mission.

A ground-launched variant of the NOTS-EV1 shown mounted to its launch rail before testing. (NOTS/USN)

Hardware development proceeded at a rapid pace during the spring of 1958. But before actual flights of the system, a pair of ground-launched test flights were to be performed to assess the modifications made to the HOTROC motors. A ground-launched NOTS-EV1 test vehicle with two live HOTROC motors and inert upper stages was prepared for launch from the G-2 test range at China Lake on July 4, 1958. In an unintended Independence Day fireworks display, the rocket exploded one second after launch. An investigation of the failure indicated that a crack in the solid rocket motor’s grain was at fault. A second ground test firing two weeks later was even less successful. With eight seconds left in the countdown, a glitch in the electrical system caused the rocket to blow up on the test stand. Despite the two failures, project managers proceeded with an orbital attempt based on their engineers’ past experience and their faith in this simple launch system.

NOTSNIK Launch Attempts

On July 25, 1958, only a week after the last unsuccessful ground test, Navy pilot Commander William W. West climbed into the cockpit of the BuAer Skyray carrying a NOTS-EV1 rocket in the first all-up test flight. Once Commander West reached the drop zone, he performed the required pullup maneuver and released the rocket. Because of the sudden loss of weight from his port wing, West’s Skyray banked sharply to the right making further observations of the rocket difficult. With the sudden burst of smoke and flame from the ignition of the second stage, West and the pilot of the chase plane lost sight of the rocket. At this point it had been assumed that the launch had failed and the tracking network was shutdown. Although the recollections of project participants decades later varied, there is a report that the station in Christchurch, New Zealand had picked up a signal at the right time which some took as evidence the launch had succeeded. But without additional supporting evidence, there is no way to verify this claim.

The second live NOTS-EV1 rocket shown being fitted to the starboard wing of its Skyray carrier aircraft on August 8, 1958. (NOTS/USN)

With their first launch attempt under their belt, a second orbital attempt was made on August 8, 1958. This time the HOTROC motors blew up on ignition ending the mission. Another pair of ground tests were conducted on August 16 and 17 using test versions of the NOTS-EV1 to verify the design once again. Both flights failed about three seconds after ignition when the rockets’ stabilizing fins broke free. Obviously the structure had difficulties with the stresses of launch and required changes.

With little time left before the end of the program, the remaining four NOTSNIK rockets were prepared for launch in rapid succession. The third orbital attempt on August 22, 1958 started well with the accelerating rocket observed disappearing over the horizon. Later signals were reportedly received by a tracking station in Christchurch, New Zealand during the scheduled first and third orbital passes suggesting that orbit had been achieved. Unfortunately, the signals were too weak to obtain usable data and there were no other detections to independently verify that the NOTS satellite had actually achieved orbit.

The third NOTS-EV1 shown just after second stage ignition on August 22, 1958. (NOTS/USN)

The next mission flown on August 25 was the first to carry a radiation detector in support of Project Argus. The attempt ended 3.75 seconds after release when one of the HOTROC motors exploded. The following day the fifth attempt ended when the rocket failed to ignite and fell into the Pacific. The final NOTSNIK orbital attempt on August 28 ended when the rocket broke up after a second stage HOTROC motor failed to ignite. With this last flight, Project Pilot drew to a close.

Diagram showing the configuration of the improved NOTS-EV2. Click on image to enlarge. (NOTS/USN)

Because of the problems encountered during the launch attempts, plans for additional flights of the NOTS-EV1 were not approved and development efforts instead shifted towards upgrading the existing rocket design. One project, called Caleb, sought to build an improved NOTS-EV2 air-launch system but was eventually cancelled because of political pressure from the USAF who wanted to monopolize military space launches. While it would not launch payloads into orbit, Caleb did fly three times as part of the Navy’s secret high altitude “Hi-Hoe” program with the last flight on July 26, 1962 reaching an altitude of 1,167 kilometers. Another follow-on program, called the Satellite Interceptor Program, sought to develop an anti-satellite capability. The still largely secret program flew two ground-launched NOTS-EV2 rockets successfully in October 1961 and May 1962 from San Nicolas Island off the California coast. Although further development of these rockets ended by the mid-1960s, the program did pioneer concepts employed by future Defense Department projects.

The launch of a NOTS-EV2 on October 1, 1961 from San Nicolas Island off the coast of California for the Satellite Interceptor Project. (USN)

Follow Drew Ex Machina on Facebook.

Related Reading

“Vanguard TV-3: America’s First Satellite Launch Attempt”, Drew Ex Machina, December 7, 2017 [Post]

“Vanguard 1: The Little Satellite that Could”, Drew Ex Machina, March 17, 2018 [Post]

General References

Matt Bille and Erika Lishock, The First Space Race: Launching the World’s First Satellite, Texas A&M University Press, 2004

Peter Pesavento, “US Navy’s Untold Story of Space-Related Firsts”, Spaceflight, Vol. 38, No. 7, pp. 239-243, July 1996

Peter Pesavento, “Secret Revealed About the Early US Navy Space Programme”, Spaceflight, Vol. 38, No. 7, pp. 243-245, July 1996

Joel W. Powell, “Rockets Red Glare”, Quest, Vol. 3, No. 1, pp. 58-61, Spring 1994

Joel W. Powell, “The Nots Air-Launched Satellite Programme”, Journal of the British Interplanetary Society, Vol. 50, No. 11, pp. 433-440, November 1997

Keith J. Scala, “A History of Air-Launched Space Vehicles”, Quest, Vol. 3, No. 1, pp. 34-41, Spring 1994

History of Project Pilot (a.k.a NOTSNIK), US Naval Weapons Center, declassified and compiled 1976