Black Arrow - Britain’s First Satellite Carrier

Hi to all! 

I have recently been having some time off which is why there haven’t been any posts for a couple of weeks but I am now back and raring to start talking about one of my favourites of the British space exploration era, the Black Arrow.

While I was planning to write this I decided it would be fun to visit the London Science Museum to take some of my own photos for this piece. They have a superb example hanging right above you as you enter the space room, as well as a Scout too!

With that in mind I booked my tickets and, long story short, it turned into a huge family day out which was a lot of fun!

Anyway, getting to the rocket. Firstly I’d like to get the stats out of the way, as well as some photos.

The Black Arrow design was a 3 stage rocket. A larger/wider first stage and a narrower second stage, followed by a much smaller third stage which carried the payload.

The first stage was 2 meters in diameter and housed a single Gamma 8 rocket engine.

The second stage was 1.37 meters in diameter housed another Gamma 2 engine.

The third stage used a spherical solid rocket motor called waxwing and it was this stage which was used to place satellites into low earth orbit.

THRUST

• Stage One     -    50,000lbf at sea level.
• Stage Two     -    15,340lbf

At take off, Black Arrow weighed 40,000lb (18,144kg).and was 13 metres tall

Cut away diagram of a Black Arrow rocket

Black Arrow originated in the 1960s and was initially conceived from studies conducted on our old friend, Black Knight. Given the green light in 1964 and developed throughout the 60s, Black Knight was launched 4 times between 1969 and 1971. Its final launch was the first and only time that Britain successfully launched a rocket into orbit.

Stages 1 and 2 were fuelled by RP-1 Paraffin and high test peroxide, (a concentrated form of hydrogen peroxide), and stage 3 utilised a solid fuel stage.

The reason it was only launched four times is that it was preferred to use the American Scout rocket as it would be cheaper than maintaining the Black Arrow programme.

In stage 1 of the rocket, the combustion chambers are arranged in 4 pairs which, in turn, were able to gimbal along a single axis. The way these were arranged meant that the rocket had full Roll, Pitch and Yaw control.

Stage 1 was 6.9 metres (23ft) long/tall and would burn for 127 seconds.

Black Arrow R4 Stage 1 at the London Science Museum

Stage 2 only had 2 combustion chambers but their configuration meant that this stage also had the same range of control. After would cut out stage 2 would continue on a coast period where it was then controlled by a reaction control system or RCS.

The second stage, which was 2.9 metres (9 ft 6 in) long burned for a further 123 seconds.

Stages 1 and 2 were connected by an interstage which housed four Siskin IB separation and ullage motors. These separated and ignited 7 seconds after stage 1 cut off and in turn separated from stage 2 just 6 seconds later.

During the second stage burn itself, at 3 minutes after lift off, the payload housing would separate and fall away from the vehicle.

Black Arrow R4 Stage 2 at the London Science Museum

Stage 3 didn’t have any attitude control at all and utilised spin stabilisation only.

As mentioned, stage 2 would coast, maintaining attitude until stage 3 would spin up to 180 rpm courtesy of 6 imp rockets. After 5 more seconds, the third stage would separate, coasting for 10 seconds until the Waxwing solid rocket motor would ignite and burn for 55 seconds.

Black Arrow R4 Stage 3 at the London Science Museum

Finally, just after a minute the payload would be released by way of gas generators pushing the stage and payload apart.

As touched on earlier, Black Arrow was launched 4 times:

R0

• Launched 28th June 1969
• No Payload
• Failed flight
• Flight was to be a suborbital test of the first and second stages but thrust vectoring failed

R1

• Launched 4th March 1970
• No payload
• Successful flight
• Suborbital test of first and second staging

R2

• Launched 2nd September 1970
• Carried the Orba X-2 satellite
• Failed flight
• The second stage failed to pressurise

Orba X-2 Satellite

R3

• Launched 28th October 1971
• Carried the Prospero satellite
• Successful flight
• Reached Earth orbit and placed Prospero in orbit

Prospero Satellite at the London Science Museum

There was a fifth Black Arrow which was designated R4 and was never launched. This is the Black Arrow rocket that you can see on display in the London Science Museum.

All of the Black Arrow launches were made in Australia at Woomera in South Australia, at Launch Area 5B. This is actually also the same launch site used for the Black Knight rocket.

Stage 1 of R3 fell back to Australia where it is still on display at William Creek.

Black Arrow R3 Stage 1 at William Creek in Australia

To date, the United Kingdom is the only country to hold the sad honour to have successfully developed and then abandoned a satellite launch capability.

The Perseid Meteor Shower - 2017

This week I’m going to be talking about something a little different from my usual topic.
As you might be aware; usually I’ll write about things to do with the history of British space exploration or research.

If any of you looked up into the sky this weekend, particularly in the early hours of Sunday morning, you would have been greeted with the incredible sight of multiple shooting stars. Sometimes as often as every few minutes.

Perseids - 2017 by Rachel Sykes

This wonderful image is made by combining 2 separate images and was made by Rachel Sykes of Edmonton, Canada.

The Perseid Meteor shower happens at around the same time every year and gives us an incredible chance to see numerous meteors simply be relaxing in our own back yards. Even this year, with a very bright moon, I was able to sit in the garden, stare up and see three or four within 10 minutes and I live near the centre of a very bright city!

But where do these meteors come from?
And why do they happen at the same time year in, year out?

Meteors are essentially the dusty and particulate remains of comets or asteroids. As these objects orbit our sun they leave this trail behind them as we leave footprints in snow.
In turn, as the Earth orbits the Sun, once a year it passes through these clouds, allowing the dust and particles to burn through our atmosphere and treating us to meteor showers. The bright streaks tearing across the sky are often caused by particles no larger than a single grain of sand.

In particular, the meteor shower that we witness every August is caused by the Earth passing through the dust trail of of the Swift-Tuttle comet (109P).

Swift-Tuttle is still in orbit around our sun and takes 133 years to complete its orbit. It was discovered in 1862 by Lewis Swift and Horace Tuttle. In comet terms, it’s big! Very big! It’s nucleus is 16 miles across which is nearly twice the size of the comet that some scientists believe to have lep to the extinction of the dinosaurs.

Comet Swift-Tuttle

 
A giant ball of dirty ice, Swift Tuttle last passed by the inner solar system in 1992 and the closest it gets to the Sun is 0.96 AU. (1 AU, or Astronomical Unit, is the approximate average distance between the Sun and the Earth) and the next time it’s due to pass closely with Earth is in 2126 causing some people to speculate that it will collide with the Earth. This, it must be said, is highly unlikely!

Orbit of Comet Swift-Tuttle

The only thing I haven’t mentioned is why the meteor shower we observe is called the Perseid Shower. This one is nice and easy to answer.

If you look up towards the constellation of Perseus during the peak of the shower, the ‘shooting stars’ will look as if they are coming from within that constellation. Perseid comes from the Greek ‘Perseidai’ which means Sons of Perseus.



I hope you found this short post interesting and I will be back to rockets and satellites very soon.

The Ariel Satellite Programme - (Part 2)

As the end of 1971 drew near, the second half of the Ariel Satellite programme was to kick off. Having now launched satellites from three different locations, the Ariel team were to return to a familiar launch site in Vandenberg Air Force Base to launch Ariel 4.

It had been four and a half years since Ariel 3 and on the surface the satellites and missions appeared to be very similar. Like it’s predecessor, and all further Ariel missions, Ariel 4 was launched atop a Scout launch vehicle. This was on Dec 11th 1971.

Nearly 3 years later Ariel 5 was preparing for launch. Sat at the pointy end of it’s scout rocket, Ariel 5 was the only of it’s programme to be launched from the Broglio Space Centre; an Italian owned facility near Maklindi in Kenya. It was launched from the San Marco launch platform at sea on Oct 15th 1974.

A Scout Rocket on San Marco

Ariel 5 was a joint British and American venture and was an all sky monitor (or ASM) which was dedicated to observing the sky in the X-Ray band. Ariel 5 decayed from orbit on Mar 13th 1980.

The sixth and final Ariel satellite was launched on Jun 2nd 1979. Returning to Virgina; the Scout rocket launched from Wallops Island at launch area 3A. Loaded with high energy astrophysics experiments, Ariel 6 was operated until February 1982 where it then spent a solitary 8 years until finally decaying from Earth orbit on Sep 23rd 1990.

Ariel 4

Also known as UK-4 and 05675, Ariel 4 was designed to have a mission duration/operational lifespan of just one year. With mission specific experiments and a lower budget, all effort was made to make this as efficient and economic as possible.

Ariel 4 under construction

Similar in design to previous iterations of the Ariel satellites, Ariel 4 was equipped with four wide legs that extended outward and down from the base of the main cylinder. These were equipped with solar panels and experiments. The main cylindrical body was covered with solar cells and topped with a conical structure housing particle experiment equipment. The apex of the cone was thus oriented towards the northern geomagnetic pole. Although the tape recorded data was of low resolution, realtime reading of experimental data was high res.

The Satellite:

• 99.5kg
• Tape Recorder
• 6 Experiments
• Observations of radio noise
• Electron density and temperature
• Very low frequency (VLF) and extremely low frequency (ELF) propagation
• VLF impulses
• Characteristics of low-energy charged particles

Ariel 5

An All-Sky Monitor (ASM), Ariel 5 examined the sky in the X-Ray band. Fitted with two one-dimensional pinhole cameras, the satellite rotated 10 times a minute while orbiting the Earth between 400 and 500 km. Heavier than it’s predecessor, it weighed 139kg.

Ariel 5 Under Construction

Ariel 5

All of the data was stored as it was collected and then relayed to ground teams once every orbit. Each orbit was 1hr 36min. The main purpose of the experiments on Ariel 5 were to improve the accuracy of position measurement of X-ray stars and to measure their energy spectra.

The Satellite:

• 38in Diameter
• 34in Height
• 6 Experiments
• Rotation Modulation Collimator (RMC)
• 2- to 10-KeV Sky Survey Instrument (SSI)
• High-Resolution Source Spectra
• Bragg Crystal Spectrometer (BCS)
• High-Energy Cosmic X-Ray Spectra
• All-Sky Monitor

Ariel 6

The final satellite of the programme. Ariel 6 was launched in 1979 and finally decayed in 1990. Designed to carry out a range of high energy astrophysics studies, it was manufactured by the Marconi company.

Ariel 6 under construction by Marconi Company

It carried six experiments, two X-Ray and one cosmic ray. Unfortunately radar signals interfered with the satellite and affected the data it returned from the remaining three tech experiments.

The Satellite:

• 155kg
• 6 Experiments
• Cosmic Ray
• X-Ray proportional counter spectrometer
• X-Ray grazing incidence system
• Three technology experiments (data not returned)

The Ariel Satellite Programme - (Part 1)

As the 1960s dawned Russia and the USA had already launched satellites in 1957 and 1958 respectively, and still being in the predicament of ‘rockets or satelliltes’ Great Britain were determined to not be left behind and opted for the latter.

The Ariel programme was born. A scientific research programme that eventually gave birth to six satellites between 1962 and 1979. Making good use of the positive relationship between Britain and the USA, the Ariel satellites were placed into orbit by NASA rockets, the first two of which were American built rockets and the third to sixth being produced in Britain.

Ariel 1 to 4 covered a wide range of scientific study, from thunderstorms on Earth, Solar activity to radio waves picked up from deep inside the Galaxy.

Ariel 5 and 6 were primarily concerned with X-Rays, Ariel 5 focussing on position measurements of X-Ray stars and analysis of the received energy spectra. Some of the science studies conducted included:

• Long-term monitoring of a multiple X-ray sources
• The discovery of several long-period X-ray pulsars (with periods of minutes rather than seconds)
• Establishing Seyfert 1 galaxies (a type of active galactic nucleus) as a class of X-ray emitters
• Discovery of iron line emission from extragalactic sources

Ariel 6 was to carry and conduct a trio of experiments but due to ground based interference from radar sources, the data returned was very limited. The studies carried out by Ariel 6 included the following:

• 1 x Cosmic Ray experiment
• 2 x X-Ray experiments

Ariel 1

Ariel 1, also known as UK-1 and S-55, was launched in 1962 atop a Thor-Delta Rocket from Cape Canaveral as Britain's first satellite.

Ariel 1 at launch in 1962

Although late to the game, the 39th satellite launched, Britain were still only the third country to launch a satellite into orbit.

Sadly Ariel 1 was doomed to have a very short life. Launched on April 26th 1962, it was subsequently, accidentally, damaged on July 9th of that year by the Starfish Prime, High Altitude Nuclear test conducted by the United States. Limping on, it was utilised again from August 25th 1964 until November 9th 1964 to retrieve data alongside Nasa’s Explorer 20 and finally decayed from orbit on April 24h 1976, nearly 14 years to the day after it’s launch.

The satellite:

• 62-kg cylinder
• 58-cm diameter
• 22-cm height
• Tape recorder
• Instrumentation for
• One cosmic-ray experiment
• Two solar emissions experiments
• Three ionospheric experiments

Ariel 1 Satellite

Ariel 2

It wasn’t until 1964 that Britain launched their next satellite. This time utilised for the purpose of radio astronomy (making it the first radio astronomy satellite), Ariel 2 was launched on March 27th 1964 from Wallops Island aboard a Scout X-3 Rocket

Ariel 2 at launch in 1964

Specifically the satellite studied long wavelength radio noise from the Earth's Ionosphere and the Milky Way galaxy among other data gathering.

Having succeeded in its mission, Ariel 2 subsequently decayed from its low Earth orbit on November 18th 1967 after ceasing its operations in November 1964 after only 8 months.

Ariel 2 Satellite

Ariel 3

Following the first (mostly) successful launches of Ariel 1 and 2, Ariel 3 became the first artificial satellite to be completely designed and constructed in Great Britain in the town of stevenage. Launched on May 5th 1967 from Vandenburg Air Force Base, CA, Ariel 3 rode a Scout A rocket to a final orbit of up to 608km.

Scout A rocket of the type to carry Ariel 3 to orbit

• The Satellite:
• 57-cm-high
• 12-sided prism with 69.6 cm between any pair of parallel sides
• 24.2-cm-high conical structure bearing various antennas attached to the top of the prism
• Tape recorder
• Instrumentation for 5 experiments
• Mapping of noise forces within the milky way
• Measuring electronic entity
• Study of low frequency radio signals
• Distribution of oxygen and light
• Anomalous propagation from radio beacons

Ariel 3 Satellite

Sketch of Ariel 3 Satellite

On 24 October 1967 the tape recorder aboard Ariel 3 began to malfunction but data collection from real-time operation remained possible. Ariel 3 went on to suffer a major power failure in December 1968. This meant that operation of the satellite could only be conducted during daylight hours. The satellite being finally shut down in September 1969 its went on to decay from its orbit December 14th 1970.