Directory of U.S. Military Rockets and Missiles
Appendix 4: Undesignated Vehicles
Trailblazer 2
Copyright © 2005 Andreas Parsch

NASA Trailblazer 2

In the early 1960s, NASA flew the Trailblazer 1 sounding rocket to study reentry phenomena. The rocket consisted of three stages lifting the payload above the atmosphere, and three downward-pointing stages, which accelerated the payload towards the ground for a high-speed reentry. The Trailblazer 1 had only a very limited payload capacity of about 1 kg (2 lb), and therefore the Trailblazer 2 was designed to conduct such experiments with payloads weighing up to 18 kg (40 lb).

Photo: NASA, via Peter Alway
Trailblazer 2

The Trailblazer 2 was an all-solid-fueled rocket with two lift stages. The first stage was a Thiokol XM33E5 Castor assisted by two XM19 Recruit boosters, while the second stage was a Thiokol TX-55 Lance. The standard configuration used two downward-firing stages in a single payload fairing, an ABL X-248 Altair and a Cygnus 15. The two latter stages were mounted upside-down, so that the rocket didn't need to be turned around at apogee. This arrangment could propel an 18 kg (40 lb) payload to a reentry speed of about 6100 m/s (20000 fps). There was also a modified version, which replaced the Lance stage with an XM45 Skat and added a small Cygnus 5 fifth stage.

The first Trailblazer 2 launch was a NASA mission on 14 December 1961. A total of 11 rockets of this type was fired, and this included seven U.S. Air Force launches between May 1962 and December 1973. The missions included experiments to determine the radar return of the plasma generated by a high-speed reentry. One of the USAF launches used the 5-stage version of the rocket.


Note: Data given by several sources show slight variations. Figures given below may therefore be inaccurate!

Data for Trailblazer 2:

Length15.90 m (52 ft 2 in)
Diameter1st stage: 79 cm (31 in)
2ns stage: 38.3 cm (15.1 in)
3rd/4th stage fairing: 61 cm (24 in)
Finspan1st stage: 3.37 m (11 ft 0.8 in)
2nd stage: 1.73 m (5 ft 8.1 in)
Weight6100 kg (13450 lb)
Speed6100 m/s (20000 fps)
Altitude300 km (185 miles)
PropulsionBooster: 2x Thiokol XM19 Recruit solid-fueled rocket; 156 kN (35000 lb) each for 1.5 s
1st stage: Thiokol XM33E5 Castor solid-fueled rocket; 235 kN (52800 lb) for 38 s
2nd stage: Thiokol TX-55 Lance solid-fueled rocket; 227 kN (51000 lb) for 8.7 s
3rd stage: ABL X-248 Altair solid-fueled rocket; 13.4 kN (3000 lb) for 38.6 s
4th stage: Thiokol Cygnus 15 solid-fueled rocket; 22.0 kN (4950 lb) for 4.8 s

Main Sources

[1] Peter Alway: "Rockets of the World", Saturn Press, 1999
[2] Jonathan McDowell: Launch Vehicles Database

Back to Directory of U.S. Military Rockets and Missiles, Appendix 4

Last Updated: 16 February 2005