RM-89 Blue Scout I

File:Blue Scout.jpg Blue Scout D6 ahead of the second HETS launch
Function	Sounding rocket
	Vought
	United States
Size
	21.65 metres (71.0 ft)
	1.02 metres (3 ft 4 in)
	16,738 kilograms (36,901 lb)
Stages	Three
Associated rockets
Family	Scout
	RM-90 Blue Scout II
Launch history
Status	Retired
Launch sites	Canaveral LC-18B
Total launches	4
Success(es)	2
Failure	2
First flight	1961-01-07
Last flight	1962-04-12
First stage – Algol 1B
	1 solid
	471 kilonewtons (106,000 lbf)
Specific impulse	236 sec
Burn time	40 seconds
Propellant	Solid
Second stage – Castor 1A
	1 solid
	286 kilonewtons (64,000 lbf)
Specific impulse	247 sec
Burn time	27 seconds
Propellant	Solid
Third stage – Antares 1A
	1 X-254
	60 kilonewtons (13,000 lbf)
Specific impulse	256 sec
Burn time	39 seconds
Propellant	Solid
Fourth stage – Castor 1A
	1 X-254
	65 kilonewtons (15,000 lbf)
Specific impulse	249 sec
Burn time	29 seconds
Propellant	Solid

The RM-89 Blue Scout I was an American sounding rocket which was flown four times between January 1961 and April 1962. It was used for two HETS test flights, and a flight to investigate atmospheric re-entry. It was a member of the Scout family of rockets.

The Blue Scout I was a four-stage rocket derived from the Scout X-1. All four launches occurred from Launch Complex 18B at the Cape Canaveral Air Force Station. The first two launches were conducted on 7 January and 9 May 1961 respectively. They both carried HETS A1 plasma research experiments on suborbital trajectories. The second two launches were conducted on 12 April 1962, with a payload that was intended to investigate atmospheric reentry.

The first two launches was successful, however recovery of the payload failed. The second two launches failed due to problems with the Blue Scout.

The Blue Scout II was a four-stage derivative of the Blue Scout I. It was flown four times in 1961, twice with HETS payloads, and twice with the Mercury-Scout 1 satellite.