RM-90 Blue Scout II
The RM-90 Blue Scout II was an American sounding rocket and expendable launch system which was flown three times during 1961. It was a member of the Scout family of rockets. Blue Scout II was a military version of the NASA-operated Scout X-1, with adjustments to the payload fairings, engine nozzles and fins.
Blue Scout II had a total length of 21.65 m and a finspan of 2.84 m.
It was capable of sending a 30 kg payload to a 300 km orbit at 28.00 degrees. It was a four stage vehicle, with the following engines:
- Stage 1: Algol 1B, solid propellant;
- Stage 2: Castor 2, solid propellant;
- Stage 3: Antares 1A, solid propellant;
- Stage 4: Altair 1A, solid propellant.
Launches
All three Blue Scout II launches occurred from Cape Canaveral [Air Force Station Launch Complex 18|Launch Complex 18B] at the Cape Canaveral Air Force Station, the same launch pad used for the Blue Scout I.The first two launches were successfully conducted on 3 March and 12 April 1961 respectively, using vehicles D-4 and D-5.
They both carried HETS A2 plasma research experiments on suborbital trajectories.
The third launch was conducted on 1 November, using vehicle D-8, with the Mercury-Scout 1 satellite for NASA, which was intended to reach low Earth orbit. The launch failed after the rocket went out of control, and was destroyed by the range safety officer 43 seconds after liftoff.
| Date | Serial | Agency | Orbit | Mission Description |
| 1961 March 3 | D-4 | USAF | Suborbital, 2540 km apogee | HETS A2-1 plasma mission |
| 1961 April 12 | D-5 | USAF | Suborbital, 1931 km apogee | HETS A2-2 plasma mission |
| 1961 November 1 | D-8 | USAF | 373 km × 643 km, 32.5° | Mercury-Scout 1 |