Tuesday, 5 September 2017

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.
  • 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 mad 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:
  • 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
  • Launched 4th March 1970
  • No payload
  • Successful flight
    • Suborbital test of first and second staging
  • Launched 2nd September 1970
  • Carried the Orba X-2 satellite
  • Failed flight
    • The second stage failed to pressurise
Orba X-2 Satellite
  • 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.

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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...