Directory of U.S. Military Rockets and Missiles|
Appendix 1: Early Missiles and Drones
|Copyright © 2003 Andreas Parsch|
The XRM-90 Blue Scout II was a rocket of the U.S. Air Force's System 609A Blue Scout family (for general information on Blue Scout, see article on RM-89 Blue Scout I). The XRM-90 was a four-stage rocket, which used the same stages as the basic NASA Scout. It was nevertheless not identical to the latter, because the 4th stage was hidden in a payload fairing with the same diameter as the 3rd stage, and the first stage nozzle used a flared tail skirt between the fins. Externally, the XRM-90 was indistinguishable from the XRM-89 Blue Scout I.
The first XRM-90 launch occurred on 3 March 1961, followed by a second one on 12 April 1961. Both sub-orbital flights were successful, and measured radiation levels in the Van Allen belts. The second Blue Scout II also carried a micrometeorite sampling experiment, but the recovery of the reentry capsule failed. The third XRM-90 was used by NASA in November 1961 in an attempt to launch a communications payload for Project Mercury into orbit, but this rocket failed. The USAF subsequently abandoned the XRM-89 Blue Scout I and XRM-90 Blue Scout II vehicles, and shifted to the RM-91/SLV-1B Blue Scout Junior instead.
Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!
Data for XRM-90:
|Length||21.65 m (71 ft 0.4 in)|
|Finspan||2.84 m (9 ft 4 in)|
|Diameter||1st stage: 102 cm (40 in)|
2nd stage: 79 cm (31 in)
3rd & 4th stage: 76 cm (30 in)
|Weight||15900 kg (35000 lb)|
|Speed||> 29000 km/h (18000 mph)|
|Ceiling||> 2570 km (1600 miles)|
|Propulsion||1st stage: Aerojet General Algol 1 solid-fueled rocket; 470 kN (106000 lb) for 40 s|
2nd stage: Thiokol XM33 (TX-354-3) Castor 2 solid-fueled rocket; 259 kN (58300 lb) for 37 s
3rd stage: Allegany Ballistics Lab X-254 Antares 1A solid-fueled rocket; 60.5 kN (13600 lb) for 39 s
4th stage: Allegany Ballistics Lab X-248 Altair 1 solid-fueled rocket; 12.4 kN (2800 lb) for 38 s
 Peter Alway: "Rockets of the World, 2000 Supplement", Saturn Press, 2000
 Norman J. Bowman: "The Handbook of Rockets and Guided Missiles", Perastadion Press, 1963
 Mark Wade: Encyclopedia Astronautica
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