RM-90 Blue Scout II

RM-90 Blue Scout II

Mercury-Scout 1
Function	Expendable launch system Sounding rocket
Manufacturer	Vought
Country of origin	United States
Size
Height	24 metres (79 ft)
Diameter	1.02 metres (3 ft 4 in)
Mass	16,874 kilograms (37,201 lb)
Stages	Four
Capacity
Payload to LEO	30 kilograms (66 lb)
Associated rockets
Family	Scout
Launch history
Status	Retired
Launch sites	Canaveral LC-18B
Total launches	3
Successes	2
Failures	1
First flight	1961-03-03
Last flight	1961-11-01
First stage - Algol 1B
Engines	1 solid
Thrust	471 kilonewtons (106,000 lbf)
Specific impulse	236 sec
Burn time	40 seconds
Fuel	Solid
Second stage - Castor 1A
Engines	1 solid
Thrust	286 kilonewtons (64,000 lbf)
Specific impulse	247 sec
Burn time	27 seconds
Fuel	Solid
Third stage - Antares 1A
Engines	1 X-254
Thrust	60 kilonewtons (13,000 lbf)
Specific impulse	256 sec
Burn time	39 seconds
Fuel	Solid
Fourth stage - Altair 1A
Engines	1 X-248A
Thrust	14 kilonewtons (3,100 lbf)
Specific impulse	255 sec
Burn time	40 seconds
Fuel	Solid

The RM-90 Blue Scout II was an American sounding rocket and expendable launch system which was flown three times during 1961. It was used for two HETS test flights, and the launch of the Mercury-Scout 1 satellite for NASA. It was a member of the Scout family of rockets.

The Blue Scout II was a military version of the NASA-operated Scout X-1. All three launches occurred from 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. They both carried HETS A2 plasma research experiments on suborbital trajectories. The third launch was conducted on 1 November, 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.