Black Arrow

[jimmymcgoochie]

The Black Arrow is one of my favourite rockets, so I've created a replica in KSP that sticks as closely to the original as I can while using just stock parts- Making History DLC included, but absolutely nothing else. Unfortunately that means it doesn't have the same paint scheme as the original with its spiral painted first stage and the bright orange fairing, but the vital stats are almost exactly the same as the original. I've used Cub engines from Making History because their thrust is similar to the real thing plus their single-axis gimbal actually matches the real Black Arrow Gamma 8 gimbal mechanism.

Spoiler

You want a picture? Here you go!

BLACK ARROW

Values below in brackets are for the real Black Arrow for comparison.

Height: 13.6m (13m)

Width: 1.9m (2m)

Parts: 51 including a launch clamp

Mass: 18.7 tons on the launchpad (18.1t)

Payload: 220kg replica of the Prospero satellite, launched by the real Black Arrow. (135kg)

Stage 1:

8x Cub vernier engines mounted in 4 pairs, matching the Gamma 8 configuration. Gimbal is limited to 20% of maximum to prevent oscillation. 1.875m fuel tanks are close to the 2m diameter of the Black Arrow first stage- the rest of the stages used imperial measurements but stage 1 was in metric for compatibility with the Europa rocket being developed and the Blue Streak first stage which was the UK's contribution to Europa. Stage 1 is quite loud as the Cub is a noisy engine; you have been warned...

Thrust: 231kN at sea level (256kN).

ISP: 280 at sea level. (265).

Burn time: 132s (131s).

TWR: 1.26 at launch.

Delta-V: 2479m/s (2600m/s).

Interstage:

T-12 structural tube with 4x sepratrons, mimics the interstage with 4 Siskin solid rockets for separation and ullage. 6 second burn time (6s).

Stage 2:

2x Cub vernier engines in a pair, matching the Gamma 2 configuration. Gimbal limited to 20%. 1.25m fuel tanks used, the real thing used 4.5 foot (4ft 6in, 1.37m) tanks.

Thrust: 58kN at sea level (68kN).

ISP: 280 at sea level (265).

TWR: 1.43 at sea level.

Burn time: 116s (116s).

Stage 3:

1x Spark engine. The Black Arrow used a solid third stage engine, however this is impractical in KSP so a more conventional third stage was used. The spin table and spin motors used by Black Arrow to spin-stabilise the third stage are also not included. No comparisons provided here due to those differences.

Thrust: 16.5kN at sea level.

ISP: 265 at sea level.

TWR: 2.39 at sea level.

Burn time: 42s.

Total delta-V: 6217m/s at sea level/7009m/s in vacuum.

Total cost: 16,852.

During flight testing for this rocket, I managed to land on the Mun and then return to Kerbin (though I had no parachutes and ran out of fuel 100m above Kerbin while trying to do a powered landing). If there is enough interest I can share craft files for this rocket; just remember you'll need Making History.

Link to gallery:

https://imgur.com/a/ro9TeSp

Please note- failure to launch this rocket from the Woomerang launch site will void your warranty. Black Arrow was launched from Woomera in Australia, and Woomerang is named after Woomera (and boomerangs, also from Australia ), so you must launch Black Arrow from Woomerang; it's the most appropriate combination you can get in stock KSP!

[jimmymcgoochie]

Apparently there were plans to create the 'Black Prince' rocket by using the 'Blue Streak' as a first stage and sticking an entire Black Arrow on top: Blue Streak was used as the first stage of the ill-fated Europa rocket and Black Arrow's first stage was deliberately designed to be the same size as the Europa's second stage for this very reason, and it would have given the combined rocket substantially greater payload capacity and range. It didn't happen in reality, but here's my KSP version of the Black Prince. The Blue Streak was about 3 metres wide and 18 metres high; that wasn't possible to replicate in KSP so I went with 2.5m diameter and around 15 metres high, with two Vector engines with a 75% thrust limiter to match the real thing's first stage thrust of ~1500kN.

Since this isn't actually a real rocket, merely hypothetical, and since it has a lot of extra oomph than Black Arrow (which can do Mun and return), I decided to test this one out by going a bit further afield. Gilly, to be precise, and it made it all the way there and all the way back using a fairly simple little lander as a reference payload (HECS2, FL200, FL100, terrier, 3x landing legs, 3x solar panels, 3x parachutes(!)). I could have done it properly and used the ~900m/s of fuel I had left to deorbit and re-enter Kerbin the right way, but instead I turned on ignore max temperatures and bombed into the atmosphere because it was already 11pm and I had no heat shield (and it's not a career game so it doesn't matter if I cheat a bit )

 

Spoiler

Here it is on the launch pad; the second stage up is a whole Black Arrow as seen above.

https://imgur.com/a/rfZ4TL2 for all the images. Blue Streak first stage adds about 2600m/s of Delta-V in the VAB to the Black Arrow above.

[jimmymcgoochie]

A year late, but here are some craft files:

https://kerbalx.com/jimmymcgoochie/Black-Arrow

https://kerbalx.com/jimmymcgoochie/Black-Prince

 

I also made an RO/RP-1/RSS version which matches the real thing almost exactly in every way, but this has some real stability issues if staged according to the original staging pattern; the one time I tried to launch it, it flipped as soon as I decoupled the first stage.

Looks nice though, doesn't it?

Edited April 21, 2021 by jimmymcgoochie