Introducing SKYLARK

The SKYLARK rocket dominates our newly-revamped foyer in the School of Physics and Astronomy. This blog post provides some of the history of Leicester’s involvement in the SKYLARK project.

The involvement of the School of Physics and Astronomy in major space missions began with work developing instruments for Sounding Rocket flights. Starting in 1961, the Department has flown instruments on almost 70 sounding rockets, in programmes conducted by NASA and ESA, as well as in the British Skylark programme which was at its peak during the 1960’s and 70’s.

The majority of these instruments have been concerned with observations of astronomical objects at Extreme Ultraviolet and X-ray wavelengths.

SKYLARK originated in 1955 when the Royal Society embarked on a programme of upper atmosphere research associated with the International Geophysical Year of 1957/58. Initially the project called for an unguided, fin-stabilized vehicle capable of lifting a 45kg scientific payload to an altitude of around 100km. By collaboration with the royal aircraft establishment (RAE) at Farnborough this requirement progressed quickly to the design and construction of the first SKYLARK in 1956. At the same time, production of a suitable solid propellant motor was undertaken by the Rocket propulsion establishment (RPE) at Westcott and the Banwell division of Bristol aircraft Ltd. Given the name Raven – in keeping with RPE’s ornithological naming system- it was the biggest solid fuel rocket motor then in use, with a specific impulse of 1780 N s kg -1 (sea level) and a burning time of 30 seconds.

A 30 metre gimbal mounted launch tower made from bailey bridge panels was also designed by the RAE team and was constructed by the Royal Ordnance factory at Woolwich. The complete launcher was erected at the Woomera (South Australia) rocket range by May 1956 and the first SKYLARK – a technological vehicle – was launched on 13th February 1957. After a further vehicle proving flight, the first scientific experiments were flown in SL 03 in July 1957; these were followed by a series of launches associated with the 1957/58 international geophysical year.

SKYLARK’s performance was greatly enhanced in 1960 by the addition of a booster stage (Cuckoo) burning for 4 seconds, giving 80 kN thrust and adding about 40% to the peak height for a given payload mass. Later additions to the SKYLARK motor family were the Goldfinch booster and Raven XI, which when used together gave an apogee of over 500 km for a payload of 100 kg mass.

Another important SKYLARK development was the introduction of a 3-axis stabilized attitude control unit (ACU) developed jointly by RAE and Elliot Automation Ltd., Frimley. The ACU was initially designed as a sun-pointing unit but later versions were available with sun, moon or star pointing sensors. After August 1964, many attitude controlled SkylarK s were launched, gathering much new information about the nature of the solar disk and other Galactic phenomena. Over 300 SKYLARKs were launched for scientific research purposes, yielding a very noteworthy success record.

While SKYLARKs are still in use, their application to astronomical research in the UK came to an end in 1978. Leicester scientists continued their rocket work through collaboration in the NASA sounding rocket programme. These flights made use of the Astrobee-F, of similar capability to the SKYLARK, and the Canadian Black Brant Vc. By 1985, diminishing scientific returns from the short observation times available with sounding rockets no longer justified the costs and involvement in these missions ceased.

However, most recently, we have developed new, much more efficient instruments that allow us to obtain significant scientific results within the time allowed by a sounding rocket flight. After a gap of 15 years, we have twice flown the Joint Plasmadynamic Experiment (J-PEX), a high-resolution extreme ultraviolet spectrometer, on a Black Brant IX rocket. The Black Brant IX is a two-stage system comprising a Terrier booster and Vc upper stage, which allows our heavy telescope to reach an altitude of 280km.

Shown below is a summary of SKYLARKs and other rockets used by the University of Leicester X-ray and Observational Astronomy group in their research programme since 1961.

Leicester SKYLARK Experiments

SKYLARK	Experiment	Stabilisation	Year
SL 37	X-ray Camera	Unstabilised	1961
SL 40	X-ray Camera	Unstabilised	1961
SL 42	X-ray Camera	Unstabilised	1961
SL 45	X-ray Camera	Unstabilised	1962
SL 46	X-ray Camera	Unstabilised	1963
SL 47	X-ray Telescope	Unstabilised	1964
SL 83	X-ray Camera	Unstabilised	1961
SL 84	X-ray Spectrometer	Unstabilised	1963
SL 85	X-ray Spectrometer	Unstabilised	1963
SL 103	X-ray Spectrometer	Unstabilised	1963
SL 104	X-ray Spectrometer	Unstabilised	1963
SL 105	X-ray Camera	Unstabilised	1965
SL 106	X-ray Camera	Unstabilised	1965
SL 114	X-ray Spectrometer	Unstabilised	1962
SL 115	X-ray Spectrometer	Unstabilised	1963
SL 118	First X-ray Sky Survey	Unstabilised	1967
SL 119	First X-ray Sky Survey	Unstabilised	1967
SL 126	X-ray Camera	Unstabilised	1963
SL 127	X-ray Camera	Unstabilised	1963
SL 128	X-ray Camera	Unstabilised	1964
SL 129	X-ray Camera	Unstabilised	1964
SL 132	X-ray Camera	Unstabilised	1964
SL 133	X-ray Camera	Unstabilised	1964
SL 138	X-ray Camera	Unstabilised	1964
SL 301	X-ray Spectograph	Sun Pointing	1964
SL 302	X-ray Spectograph	Sun Pointing	1964
SL 303	X-ray Spectograph	Sun Pointing	1965
SL 304	X-ray Bragg Crystal Spectrometer	Sun Pointing	1966
SL 305	X-ray Bragg Crystal Spectrometer	Sun Pointing	1967
SL 306	X-ray Pinhole Camera	Sun Pointing	1965
SL 307	X-ray Pinhole Camera	Sun Pointing	1966
SL 403	Extra Galactic Survey of M87	Moon Pointing	1968
SL 404	X-ray Pinhole Camera	Sun Pointing	1969
SL 405	X-ray Pinhole Camera	Sun Pointing	1966
SL 406	X-ray Pinhole Camera	Sun Pointing	1966
SL 407	X-ray Pinhole Camera	Sun Pointing	1967
SL 408	X-ray Pinhole Camera	Sun Pointing	1968
SL 605	Bragg Crystal Spectrometer	Sun Pointing	1969
SL 723	Large Area Sky Survey	Unstabilised	1968
SL 724	Large Area Sky Survey	Unstabilised	1968
SL 802	Modulation Collimator Detector	Sun Pointing	1970
SL 804	Bragg Crystal Spectrometer	Sun Pointing	1970
SL 812	Survey of Norma X-1 & Cen X-3	Star Pointing	1971
SL 901	Bragg Crystal Spectrometer	Sun & Sco X-1 Pointing	1970
SL 904	Background Survey	Sun Pointing	1970
SL 972	Large Area Sky Survey	Spin Stabilised	1970
SL 1002	Lunar occultation of GX3+1	Sun & Sco X-1 Pointing	1971
SL 1010	Low energy survey	Sun Pointing	1973
SL 1011	Modulation Collimator Cir X-1 & Cen X-3	Star Pointing	1973
SL 1101	Bragg Crystal Spectrometer	Sun Pointing	1971
SL 1105	Low energy mapping of Vela	Magnetic & Moon Pointing	1975
SL 1112	Low energy interstellar gas abundance	Star pointing	1975
SL 1202	Lunar occultation of GX5-1	Sun pointing	1972
SL 1206	Bragg Crystal Spectrometer	Sun pointing	1973
SL 1304	Lunar occultation of Crab Nebula	Sun pointing	1974
SL 1306	Very large area mapping of Cyg X-1	Sun pointing	1976
SL 1611	Dust Halo 2-D imaging (cancelled)	Inertial Platform	1978

ESA Payloads:

SKYLARK	Experiment	Stabilisation	Year
S26	X-ray Spectroscopy	Unstabilised	1967
S41	Bragg Crystal Spectrometer	Sun pointing	1967
S55	Bragg Crystal Spectrometer	Sun & Sco X-1 pointing	1971
S69	Bragg Crystal Spectrometer	Sun pointing	1970
S89	Bragg Crystal Spectrometer	Sun pointing	1972

NASA Payloads

SKYLARK	Experiment	Stabilisation	Year
Astrobee-F	Imaging X-ray Telescope (Cygnus Loop)	3 axis stabilised	1977
Astrobee-F	Imaging X-ray Telescope (Puppis A + Crab + IC433)	3 axis stabilised	1978
25.040 A’bee-F	Wide Field Ultrasoft X-ray Camera	3 axis stabilised	1981
21.069 BB Vc	Wide Field Ultrasoft X-ray Camera	3 axis stabilised	1982
21.070 BB Vc	Wide Field Ultrasoft X-ray Camera	3 axis stabilised	1985
36.162 BB IX	J-PEX High Resolution EUV Spectrometer	3 axis stabilised	2000
36.195 BB IX	J-PEX High Resolution EUV Spectrometer	3 axis stabilised	2001